Warn on ignored audio options

For raw audio codec, some audio options are ignored.

PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>

BUILD.md

@@ -15,7 +15,7 @@ First, you need to install the required packages:
 sudo apt install ffmpeg libsdl2-2.0-0 adb wget \
                  gcc git pkg-config meson ninja-build libsdl2-dev \
                  libavcodec-dev libavdevice-dev libavformat-dev libavutil-dev \
-                 libusb-1.0-0 libusb-1.0-0-dev
+                 libswresample-dev libusb-1.0-0 libusb-1.0-0-dev
 ```
 
 Then clone the repo and execute the installation script
@@ -94,7 +94,7 @@ sudo apt install ffmpeg libsdl2-2.0-0 adb libusb-1.0-0
 # client build dependencies
 sudo apt install gcc git pkg-config meson ninja-build libsdl2-dev \
                  libavcodec-dev libavdevice-dev libavformat-dev libavutil-dev \
-                 libusb-1.0-0-dev
+                 libswresample-dev libusb-1.0-0-dev
 
 # server build dependencies
 sudo apt install openjdk-11-jdk

README.md

@@ -273,12 +273,10 @@ may cause issues or crash. It is possible to select a different encoder:
 scrcpy --video-encoder=OMX.qcom.video.encoder.avc
 ```
 
-To list the available encoders, you can pass an invalid encoder name; the
-error will give the available encoders:
+To list the available encoders:
 
 ```bash
-scrcpy --video-encoder=_                     # for the default codec
-scrcpy --video-codec=h265 --video-encoder=_  # for a specific codec
+scrcpy --list-encoders
 ```
 
 ### Capture
@@ -720,7 +718,7 @@ scrcpy --display=1
 The list of display ids can be retrieved by:
 
 ```bash
-adb shell dumpsys display   # search "mDisplayId=" in the output
+scrcpy --list-displays
 ```
 
 The secondary display may only be controlled if the device runs at least Android

app/data/bash-completion/scrcpy

@@ -4,6 +4,8 @@ _scrcpy() {
         --always-on-top
         --audio-bit-rate=
         --audio-codec=
+        --audio-codec-options=
+        --audio-encoder=
         -b --video-bit-rate=
         --crop=
         -d --select-usb
@@ -17,6 +19,8 @@ _scrcpy() {
         -K --hid-keyboard
         -h --help
         --legacy-paste
+        --list-displays
+        --list-encoders
         --lock-video-orientation
         --lock-video-orientation=
         --max-fps=
@@ -41,6 +45,7 @@ _scrcpy() {
         -r --record=
         --record-format=
         --render-driver=
+        --require-audio
         --rotation=
         -s --serial=
         --shortcut-mod=
@@ -73,7 +78,7 @@ _scrcpy() {
             return
             ;;
         --audio-codec)
-            COMPREPLY=($(compgen -W 'opus aac' -- "$cur"))
+            COMPREPLY=($(compgen -W 'raw opus aac' -- "$cur"))
             return
             ;;
         --lock-video-orientation)

app/data/zsh-completion/_scrcpy

@@ -10,7 +10,9 @@ local arguments
 arguments=(
     '--always-on-top[Make scrcpy window always on top \(above other windows\)]'
     '--audio-bit-rate=[Encode the audio at the given bit-rate]'
-    '--audio-codec=[Select the audio codec]:codec:(opus aac)'
+    '--audio-codec=[Select the audio codec]:codec:(raw opus aac)'
+    '--audio-codec-options=[Set a list of comma-separated key\:type=value options for the device audio encoder]'
+    '--audio-encoder=[Use a specific MediaCodec audio encoder]'
     {-b,--video-bit-rate=}'[Encode the video at the given bit-rate]'
     '--crop=[\[width\:height\:x\:y\] Crop the device screen on the server]'
     {-d,--select-usb}'[Use USB device]'
@@ -24,6 +26,8 @@ arguments=(
     {-K,--hid-keyboard}'[Simulate a physical keyboard by using HID over AOAv2]'
     {-h,--help}'[Print the help]'
     '--legacy-paste[Inject computer clipboard text as a sequence of key events on Ctrl+v]'
+    '--list-displays[List displays available on the device]'
+    '--list-encoders[List video and audio encoders available on the device]'
     '--lock-video-orientation=[Lock video orientation]:orientation:(unlocked initial 0 1 2 3)'
     '--max-fps=[Limit the frame rate of screen capture]'
     {-M,--hid-mouse}'[Simulate a physical mouse by using HID over AOAv2]'
@@ -47,6 +51,7 @@ arguments=(
     {-r,--record=}'[Record screen to file]:record file:_files'
     '--record-format=[Force recording format]:format:(mp4 mkv)'
     '--render-driver=[Request SDL to use the given render driver]:driver name:(direct3d opengl opengles2 opengles metal software)'
+    '--require-audio=[Make scrcpy fail if audio is enabled but does not work]'
     '--rotation=[Set the initial display rotation]:rotation values:(0 1 2 3)'
     {-s,--serial=}'[The device serial number \(mandatory for multiple devices only\)]:serial:($("${ADB-adb}" devices | awk '\''$2 == "device" {print $1}'\''))'
     '--shortcut-mod=[\[key1,key2+key3,...\] Specify the modifiers to use for scrcpy shortcuts]:shortcut mod:(lctrl rctrl lalt ralt lsuper rsuper)'

app/meson.build

@@ -4,12 +4,14 @@ src = [
     'src/adb/adb_device.c',
     'src/adb/adb_parser.c',
     'src/adb/adb_tunnel.c',
+    'src/audio_player.c',
     'src/cli.c',
     'src/clock.c',
     'src/compat.c',
     'src/control_msg.c',
     'src/controller.c',
     'src/decoder.c',
+    'src/delay_buffer.c',
     'src/demuxer.c',
     'src/device_msg.c',
     'src/icon.c',
@@ -28,12 +30,16 @@ src = [
     'src/screen.c',
     'src/server.c',
     'src/version.c',
-    'src/video_buffer.c',
+    'src/trait/frame_source.c',
+    'src/trait/packet_source.c',
     'src/util/acksync.c',
+    'src/util/average.c',
+    'src/util/bytebuf.c',
     'src/util/file.c',
     'src/util/intmap.c',
     'src/util/intr.c',
     'src/util/log.c',
+    'src/util/memory.c',
     'src/util/net.c',
     'src/util/net_intr.c',
     'src/util/process.c',
@@ -99,6 +105,7 @@ if not crossbuild_windows
         dependency('libavformat', version: '>= 57.33'),
         dependency('libavcodec', version: '>= 57.37'),
         dependency('libavutil'),
+        dependency('libswresample'),
         dependency('sdl2', version: '>= 2.0.5'),
     ]
 
@@ -134,6 +141,7 @@ else
             cc.find_library('avcodec-60', dirs: ffmpeg_bin_dir),
             cc.find_library('avformat-60', dirs: ffmpeg_bin_dir),
             cc.find_library('avutil-58', dirs: ffmpeg_bin_dir),
+            cc.find_library('swresample-4', dirs: ffmpeg_bin_dir),
         ],
         include_directories: include_directories(ffmpeg_include_dir)
     )
@@ -168,6 +176,7 @@ check_functions = [
     'vasprintf',
     'nrand48',
     'jrand48',
+    'reallocarray',
 ]
 
 foreach f : check_functions
@@ -254,8 +263,9 @@ if get_option('buildtype') == 'debug'
         ['test_binary', [
             'tests/test_binary.c',
         ]],
-        ['test_cbuf', [
-            'tests/test_cbuf.c',
+        ['test_bytebuf', [
+            'tests/test_bytebuf.c',
+            'src/util/bytebuf.c',
         ]],
         ['test_cli', [
             'tests/test_cli.c',
@@ -281,9 +291,6 @@ if get_option('buildtype') == 'debug'
             'tests/test_device_msg_deserialize.c',
             'src/device_msg.c',
         ]],
-        ['test_queue', [
-            'tests/test_queue.c',
-        ]],
         ['test_strbuf', [
             'tests/test_strbuf.c',
             'src/util/strbuf.c',
@@ -293,6 +300,10 @@ if get_option('buildtype') == 'debug'
             'src/util/str.c',
             'src/util/strbuf.c',
         ]],
+        ['test_vecdeque', [
+            'tests/test_vecdeque.c',
+            'src/util/memory.c',
+        ]],
         ['test_vector', [
             'tests/test_vector.c',
         ]],

app/scrcpy.1

@@ -25,12 +25,34 @@ Encode the audio at the given bit\-rate, expressed in bits/s. Unit suffixes are
 
 Default is 196K (196000).
 
+.TP
+.BI "\-\-audio\-buffer ms
+Add a buffering delay (in milliseconds) before playing audio. This increases latency to compensate for jitter.
+
+Default is 0 (no buffering).
+
 .TP
 .BI "\-\-audio\-codec " name
-Select an audio codec (opus or aac).
+Select an audio codec (raw, opus or aac).
 
 Default is opus.
 
+.TP
+.BI "\-\-audio\-codec\-options " key\fR[:\fItype\fR]=\fIvalue\fR[,...]
+Set a list of comma-separated key:type=value options for the device audio encoder.
+
+The possible values for 'type' are 'int' (default), 'long', 'float' and 'string'.
+
+The list of possible codec options is available in the Android documentation
+.UR https://d.android.com/reference/android/media/MediaFormat
+.UE .
+
+.TP
+.BI "\-\-audio\-encoder " name
+Use a specific MediaCodec audio encoder (depending on the codec provided by \fB\-\-audio\-codec\fR).
+
+The available encoders can be listed by \-\-list\-encoders.
+
 .TP
 .BI "\-b, \-\-video\-bit\-rate " value
 Encode the video at the given bit\-rate, expressed in bits/s. Unit suffixes are supported: '\fBK\fR' (x1000) and '\fBM\fR' (x1000000).
@@ -57,10 +79,9 @@ Disable screensaver while scrcpy is running.
 
 .TP
 .BI "\-\-display " id
-Specify the display id to mirror.
+Specify the device display id to mirror.
 
-The list of possible display ids can be listed by "adb shell dumpsys display"
-(search "mDisplayId=" in the output).
+The available display ids can be listed by \-\-list\-displays.
 
 Default is 0.
 
@@ -114,6 +135,14 @@ Inject computer clipboard text as a sequence of key events on Ctrl+v (like MOD+S
 
 This is a workaround for some devices not behaving as expected when setting the device clipboard programmatically.
 
+.TP
+.B \-\-list\-encoders
+List video and audio encoders available on the device.
+
+.TP
+.B \-\-list\-displays
+List displays available on the device.
+
 .TP
 \fB\-\-lock\-video\-orientation\fR[=\fIvalue\fR]
 Lock video orientation to \fIvalue\fR. Possible values are "unlocked", "initial" (locked to the initial orientation), 0, 1, 2 and 3. Natural device orientation is 0, and each increment adds a 90 degrees rotation counterclockwise.
@@ -249,6 +278,10 @@ Supported names are currently "direct3d", "opengl", "opengles2", "opengles", "me
 .UR https://wiki.libsdl.org/SDL_HINT_RENDER_DRIVER
 .UE
 
+.TP
+.B \-\-require\-audio
+By default, scrcpy mirrors only the video if audio capture fails on the device. This flag makes scrcpy fail if audio is enabled but does not work.
+
 .TP
 .BI "\-\-rotation " value
 Set the initial display rotation. Possibles values are 0, 1, 2 and 3. Each increment adds a 90 degrees rotation counterclockwise.
@@ -341,6 +374,8 @@ The list of possible codec options is available in the Android documentation
 .BI "\-\-video\-encoder " name
 Use a specific MediaCodec video encoder (depending on the codec provided by \fB\-\-video\-codec\fR).
 
+The available encoders can be listed by \-\-list\-encoders.
+
 .TP
 .B \-w, \-\-stay-awake
 Keep the device on while scrcpy is running, when the device is plugged in.

app/src/audio_player.c

@@ -0,0 +1,378 @@
+#include "audio_player.h"
+
+#include <libavutil/opt.h>
+
+#include "util/log.h"
+
+//#define SC_AUDIO_PLAYER_NDEBUG // comment to debug
+
+/** Downcast frame_sink to sc_audio_player */
+#define DOWNCAST(SINK) container_of(SINK, struct sc_audio_player, frame_sink)
+
+#define SC_AV_SAMPLE_FMT AV_SAMPLE_FMT_FLT
+#define SC_SDL_SAMPLE_FMT AUDIO_F32
+
+#define SC_AUDIO_OUTPUT_BUFFER_SAMPLES 480 // 10ms at 48000Hz
+
+// The target number of buffered samples between the producer and the consumer.
+// This value is directly use for compensation.
+#define SC_TARGET_BUFFERED_SAMPLES (3 * SC_AUDIO_OUTPUT_BUFFER_SAMPLES)
+
+// Use a ring-buffer of 1 second (at 48000Hz) between the producer and the
+// consumer. It too big, but it guarantees that the producer and the consumer
+// will be able to access it in parallel without locking.
+#define SC_BYTEBUF_SIZE_IN_SAMPLES 48000
+
+static inline size_t
+bytes_to_samples(struct sc_audio_player *ap, size_t bytes) {
+    assert(bytes % (ap->nb_channels * ap->out_bytes_per_sample) == 0);
+    return bytes / (ap->nb_channels * ap->out_bytes_per_sample);
+}
+
+static inline size_t
+samples_to_bytes(struct sc_audio_player *ap, size_t samples) {
+    return samples * ap->nb_channels * ap->out_bytes_per_sample;
+}
+
+void
+sc_audio_player_sdl_callback(void *userdata, uint8_t *stream, int len_int) {
+    struct sc_audio_player *ap = userdata;
+
+    // This callback is called with the lock used by SDL_AudioDeviceLock(), so
+    // the bytebuf is protected
+
+    assert(len_int > 0);
+    size_t len = len_int;
+
+#ifndef SC_AUDIO_PLAYER_NDEBUG
+    LOGD("[Audio] SDL callback requests %" SC_PRIsizet " samples",
+         bytes_to_samples(ap, len));
+#endif
+
+    size_t read_avail = sc_bytebuf_read_available(&ap->buf);
+    size_t read = MIN(read_avail, len);
+    if (read) {
+        sc_bytebuf_read(&ap->buf, stream, read);
+    }
+
+    if (read < len) {
+        // Insert silence
+#ifndef SC_AUDIO_PLAYER_NDEBUG
+        LOGD("[Audio] Buffer underflow, inserting silence: %" SC_PRIsizet
+             " samples", bytes_to_samples(ap, len - read));
+#endif
+        memset(stream + read, 0, len - read);
+        // If the first frame has not been received yet, it's not an underflow
+        if (ap->received) {
+            ap->underflow += bytes_to_samples(ap, len - read);
+        }
+    }
+
+    ap->last_consumed = sc_tick_now();
+}
+
+static uint8_t *
+sc_audio_player_get_swr_buf(struct sc_audio_player *ap, size_t min_samples) {
+    size_t min_buf_size = samples_to_bytes(ap, min_samples);
+    if (min_buf_size > ap->swr_buf_alloc_size) {
+        size_t new_size = min_buf_size + 4096;
+        uint8_t *buf = realloc(ap->swr_buf, new_size);
+        if (!buf) {
+            LOG_OOM();
+            // Could not realloc to the requested size
+            return NULL;
+        }
+        ap->swr_buf = buf;
+        ap->swr_buf_alloc_size = new_size;
+    }
+
+    return ap->swr_buf;
+}
+
+static bool
+sc_audio_player_frame_sink_open(struct sc_frame_sink *sink,
+                                const AVCodecContext *ctx) {
+    struct sc_audio_player *ap = DOWNCAST(sink);
+#ifdef SCRCPY_LAVU_HAS_CHLAYOUT
+    assert(ctx->ch_layout.nb_channels > 0);
+    unsigned nb_channels = ctx->ch_layout.nb_channels;
+#else
+    int tmp = av_get_channel_layout_nb_channels(ctx->channel_layout);
+    assert(tmp > 0);
+    unsigned nb_channels = tmp;
+#endif
+
+    SDL_AudioSpec desired = {
+        .freq = ctx->sample_rate,
+        .format = SC_SDL_SAMPLE_FMT,
+        .channels = nb_channels,
+        .samples = SC_AUDIO_OUTPUT_BUFFER_SAMPLES,
+        .callback = sc_audio_player_sdl_callback,
+        .userdata = ap,
+    };
+    SDL_AudioSpec obtained;
+
+    ap->device = SDL_OpenAudioDevice(NULL, 0, &desired, &obtained, 0);
+    if (!ap->device) {
+        LOGE("Could not open audio device: %s", SDL_GetError());
+        return false;
+    }
+
+    SwrContext *swr_ctx = swr_alloc();
+    if (!swr_ctx) {
+        LOG_OOM();
+        goto error_close_audio_device;
+    }
+    ap->swr_ctx = swr_ctx;
+
+    assert(ctx->sample_rate > 0);
+    assert(!av_sample_fmt_is_planar(SC_AV_SAMPLE_FMT));
+
+    int out_bytes_per_sample = av_get_bytes_per_sample(SC_AV_SAMPLE_FMT);
+    assert(out_bytes_per_sample > 0);
+
+#ifdef SCRCPY_LAVU_HAS_CHLAYOUT
+    av_opt_set_chlayout(swr_ctx, "in_chlayout", &ctx->ch_layout, 0);
+    av_opt_set_chlayout(swr_ctx, "out_chlayout", &ctx->ch_layout, 0);
+#else
+    av_opt_set_channel_layout(swr_ctx, "in_channel_layout",
+                              ctx->channel_layout, 0);
+    av_opt_set_channel_layout(swr_ctx, "out_channel_layout",
+                              ctx->channel_layout, 0);
+#endif
+
+    av_opt_set_int(swr_ctx, "in_sample_rate", ctx->sample_rate, 0);
+    av_opt_set_int(swr_ctx, "out_sample_rate", ctx->sample_rate, 0);
+
+    av_opt_set_sample_fmt(swr_ctx, "in_sample_fmt", ctx->sample_fmt, 0);
+    av_opt_set_sample_fmt(swr_ctx, "out_sample_fmt", SC_AV_SAMPLE_FMT, 0);
+
+    int ret = swr_init(swr_ctx);
+    if (ret) {
+        LOGE("Failed to initialize the resampling context");
+        goto error_free_swr_ctx;
+    }
+
+    ap->sample_rate = ctx->sample_rate;
+    ap->nb_channels = nb_channels;
+    ap->out_bytes_per_sample = out_bytes_per_sample;
+
+    size_t bytebuf_size = samples_to_bytes(ap, SC_BYTEBUF_SIZE_IN_SAMPLES);
+
+    bool ok = sc_bytebuf_init(&ap->buf, bytebuf_size);
+    if (!ok) {
+        goto error_free_swr_ctx;
+    }
+
+    size_t initial_swr_buf_size = samples_to_bytes(ap, 4096);
+    ap->swr_buf = malloc(initial_swr_buf_size);
+    if (!ap->swr_buf) {
+        LOG_OOM();
+        goto error_destroy_bytebuf;
+    }
+    ap->swr_buf_alloc_size = initial_swr_buf_size;
+
+    ap->previous_write_avail = sc_bytebuf_write_available(&ap->buf);
+
+    sc_average_init(&ap->avg_buffering, 8);
+    ap->samples_since_resync = 0;
+
+    ap->last_consumed = 0;
+    ap->underflow = 0;
+    ap->received = 0;
+
+    SDL_PauseAudioDevice(ap->device, 0);
+
+    return true;
+
+error_destroy_bytebuf:
+    sc_bytebuf_destroy(&ap->buf);
+error_free_swr_ctx:
+    swr_free(&ap->swr_ctx);
+error_close_audio_device:
+    SDL_CloseAudioDevice(ap->device);
+
+    return false;
+}
+
+static void
+sc_audio_player_frame_sink_close(struct sc_frame_sink *sink) {
+    struct sc_audio_player *ap = DOWNCAST(sink);
+
+    assert(ap->device);
+    SDL_PauseAudioDevice(ap->device, 1);
+    SDL_CloseAudioDevice(ap->device);
+
+    free(ap->swr_buf);
+    sc_bytebuf_destroy(&ap->buf);
+    swr_free(&ap->swr_ctx);
+}
+
+static bool
+sc_audio_player_frame_sink_push(struct sc_frame_sink *sink,
+                                const AVFrame *frame) {
+    struct sc_audio_player *ap = DOWNCAST(sink);
+
+    SwrContext *swr_ctx = ap->swr_ctx;
+
+    int64_t delay = swr_get_delay(swr_ctx, ap->sample_rate);
+    // No need to av_rescale_rnd(), input and output sample rates are the same
+    // Add more space (256) for clock compensation
+    int dst_nb_samples = delay + frame->nb_samples + 256;
+
+    uint8_t *swr_buf = sc_audio_player_get_swr_buf(ap, dst_nb_samples);
+    if (!swr_buf) {
+        return false;
+    }
+
+    int ret = swr_convert(swr_ctx, &swr_buf, dst_nb_samples,
+                          (const uint8_t **) frame->data, frame->nb_samples);
+    if (ret < 0) {
+        LOGE("Resampling failed: %d", ret);
+        return false;
+    }
+
+    // swr_convert() returns the number of samples which would have been
+    // written if the buffer was big enough.
+    size_t samples_written = MIN(ret, dst_nb_samples);
+    size_t swr_buf_size = samples_to_bytes(ap, samples_written);
+#ifndef SC_AUDIO_PLAYER_NDEBUG
+    LOGD("[Audio] %" SC_PRIsizet " samples written to buffer", samples_written);
+#endif
+
+    // Since this function is the only writer, the current available space is
+    // at least the previous available space. In practice, it should almost
+    // always be possible to write without lock.
+    bool lockless_write = swr_buf_size <= ap->previous_write_avail;
+    if (lockless_write) {
+        sc_bytebuf_prepare_write(&ap->buf, swr_buf, swr_buf_size);
+    }
+
+    SDL_LockAudioDevice(ap->device);
+
+    // The consumer requests audio samples blocks (e.g. 480 samples).
+    // Convert the duration since the last consumption into samples.
+    size_t extrapolated = 0;
+    if (ap->last_consumed) {
+        sc_tick now = sc_tick_now();
+        assert(now >= ap->last_consumed);
+        extrapolated = (now - ap->last_consumed) * ap->sample_rate
+                                                 / SC_TICK_FREQ;
+    }
+
+    size_t read_avail = sc_bytebuf_read_available(&ap->buf);
+
+    // The consumer may not increase underflow value if there are still samples
+    // available
+    assert(read_avail == 0 || ap->underflow == 0);
+
+    size_t buffered_samples = bytes_to_samples(ap, read_avail);
+    // Underflow caused silence samples in excess (so it adds buffering).
+    // Extrapolated samples must be considered consumed for smoothing (so it
+    // removes buffering).
+    float buffering = (float) buffered_samples + ap->underflow - extrapolated;
+    sc_average_push(&ap->avg_buffering, buffering);
+
+#ifndef SC_AUDIO_PLAYER_NDEBUG
+    LOGD("[Audio] buffered_samples=%" SC_PRIsizet
+                " underflow=%" SC_PRIsizet
+                " extrapolated=%" SC_PRIsizet
+                " buffering=%f avg_buffering=%f",
+         buffered_samples, ap->underflow, extrapolated, buffering,
+         sc_average_get(&ap->avg_buffering));
+#endif
+
+    if (lockless_write) {
+        sc_bytebuf_commit_write(&ap->buf, swr_buf_size);
+    } else {
+        // Take care to keep full samples
+        size_t align = ap->nb_channels * ap->out_bytes_per_sample;
+        size_t write_avail =
+            sc_bytebuf_write_available(&ap->buf) / align * align;
+        if (swr_buf_size > write_avail) {
+            // Skip old samples
+            size_t cap = sc_bytebuf_capacity(&ap->buf) / align * align;
+            if (swr_buf_size > cap) {
+                // Ignore the first bytes in swr_buf
+                swr_buf += swr_buf_size - cap;
+                swr_buf_size = cap;
+            }
+            assert(swr_buf_size > write_avail);
+            if (swr_buf_size - write_avail > 0) {
+                sc_bytebuf_skip(&ap->buf, swr_buf_size - write_avail);
+            }
+        }
+        sc_bytebuf_write(&ap->buf, swr_buf, swr_buf_size);
+    }
+
+    // On buffer underflow, typically because a packet is late, silence is
+    // inserted. In that case, the late samples must be ignored when they
+    // arrive, otherwise they will delay playback.
+    //
+    // As an improvement, instead of naively skipping the silence duration, we
+    // can absorb it if it helps clock compensation.
+    if (ap->underflow) {
+        size_t avg = sc_average_get(&ap->avg_buffering);
+        if (avg > SC_TARGET_BUFFERED_SAMPLES) {
+            size_t diff = SC_TARGET_BUFFERED_SAMPLES - avg;
+            if (ap->underflow > diff) {
+                // Partially absorb underflow for clock compensation (only keep
+                // the diff with the target buffering level).
+                ap->underflow -= diff;
+            } else {
+                // Totally absorb underflow for clock compensation
+                ap->underflow = 0;
+            }
+
+            size_t skip_samples = MIN(ap->underflow, buffered_samples);
+            if (skip_samples) {
+                size_t skip_bytes = samples_to_bytes(ap, skip_samples);
+                sc_bytebuf_skip(&ap->buf, skip_bytes);
+                read_avail -= skip_bytes;
+#ifndef SC_AUDIO_PLAYER_NDEBUG
+                LOGD("[Audio] Skipping %" SC_PRIsizet " samples", skip_samples);
+#endif
+            }
+        } else {
+            // Totally absorb underflow for clock compensation
+            ap->underflow = 0;
+        }
+    }
+
+    ap->previous_write_avail = sc_bytebuf_write_available(&ap->buf);
+    ap->received = true;
+
+    SDL_UnlockAudioDevice(ap->device);
+
+    ap->samples_since_resync += samples_written;
+    if (ap->samples_since_resync >= ap->sample_rate) {
+        // Resync every second
+        ap->samples_since_resync = 0;
+
+        float avg = sc_average_get(&ap->avg_buffering);
+        int diff = SC_TARGET_BUFFERED_SAMPLES - avg;
+#ifndef SC_AUDIO_PLAYER_NDEBUG
+        LOGD("[Audio] Average buffering=%f, compensation %d", avg, diff);
+#endif
+        // Compensate the diff over 3 seconds (but will be recomputed after
+        // 1 second)
+        int ret = swr_set_compensation(swr_ctx, diff, 3 * ap->sample_rate);
+        if (ret < 0) {
+            LOGW("Resampling compensation failed: %d", ret);
+            // not fatal
+        }
+    }
+
+    return true;
+}
+
+void
+sc_audio_player_init(struct sc_audio_player *ap) {
+    static const struct sc_frame_sink_ops ops = {
+        .open = sc_audio_player_frame_sink_open,
+        .close = sc_audio_player_frame_sink_close,
+        .push = sc_audio_player_frame_sink_push,
+    };
+
+    ap->frame_sink.ops = &ops;
+}

app/src/audio_player.h

@@ -0,0 +1,61 @@
+#ifndef SC_AUDIO_PLAYER_H
+#define SC_AUDIO_PLAYER_H
+
+#include "common.h"
+
+#include <stdbool.h>
+#include "trait/frame_sink.h"
+#include <util/average.h>
+#include <util/bytebuf.h>
+#include <util/thread.h>
+
+#include <libavformat/avformat.h>
+#include <libswresample/swresample.h>
+#include <SDL2/SDL.h>
+
+struct sc_audio_player {
+    struct sc_frame_sink frame_sink;
+
+    SDL_AudioDeviceID device;
+
+    // protected by SDL_AudioDeviceLock()
+    struct sc_bytebuf buf;
+    size_t previous_write_avail;
+
+    struct SwrContext *swr_ctx;
+
+    // The sample rate is the same for input and output
+    unsigned sample_rate;
+    // The number of channels is the same for input and output
+    unsigned nb_channels;
+    // The number of bytes per sample for a single channel
+    unsigned out_bytes_per_sample;
+
+    // Target buffer for resampling
+    uint8_t *swr_buf;
+    size_t swr_buf_alloc_size;
+
+    // Number of buffered samples (may be negative on underflow)
+    struct sc_average avg_buffering;
+    // Count the number of samples to trigger a compensation update regularly
+    size_t samples_since_resync;
+
+    // The last date a sample has been consumed by the audio output
+    sc_tick last_consumed;
+
+    // Number of silence samples inserted to be compensated
+    size_t underflow;
+    bool received;
+
+    const struct sc_audio_player_callbacks *cbs;
+    void *cbs_userdata;
+};
+
+struct sc_audio_player_callbacks {
+    void (*on_ended)(struct sc_audio_player *ap, bool success, void *userdata);
+};
+
+void
+sc_audio_player_init(struct sc_audio_player *ap);
+
+#endif

app/src/cli.c

@@ -65,6 +65,12 @@ enum {
     OPT_NO_AUDIO,
     OPT_AUDIO_BIT_RATE,
     OPT_AUDIO_CODEC,
+    OPT_AUDIO_CODEC_OPTIONS,
+    OPT_AUDIO_ENCODER,
+    OPT_LIST_ENCODERS,
+    OPT_LIST_DISPLAYS,
+    OPT_REQUIRE_AUDIO,
+    OPT_AUDIO_BUFFER,
 };
 
 struct sc_option {
@@ -114,13 +120,41 @@ static const struct sc_option options[] = {
                 "Unit suffixes are supported: 'K' (x1000) and 'M' (x1000000).\n"
                 "Default is 196K (196000).",
     },
+    {
+        .longopt_id = OPT_AUDIO_BUFFER,
+        .longopt = "audio-buffer",
+        .argdesc = "ms",
+        .text = "Add a buffering delay (in milliseconds) before playing audio. "
+                "This increases latency to compensate for jitter.\n"
+                "Default is 0 (no buffering).",
+    },
     {
         .longopt_id = OPT_AUDIO_CODEC,
         .longopt = "audio-codec",
         .argdesc = "name",
-        .text = "Select an audio codec (opus or aac).\n"
+        .text = "Select an audio codec (raw, opus or aac).\n"
                 "Default is opus.",
     },
+    {
+        .longopt_id = OPT_AUDIO_CODEC_OPTIONS,
+        .longopt = "audio-codec-options",
+        .argdesc = "key[:type]=value[,...]",
+        .text = "Set a list of comma-separated key:type=value options for the "
+                "device audio encoder.\n"
+                "The possible values for 'type' are 'int' (default), 'long', "
+                "'float' and 'string'.\n"
+                "The list of possible codec options is available in the "
+                "Android documentation: "
+                "<https://d.android.com/reference/android/media/MediaFormat>",
+    },
+    {
+        .longopt_id = OPT_AUDIO_ENCODER,
+        .longopt = "audio-encoder",
+        .argdesc = "name",
+        .text = "Use a specific MediaCodec audio encoder (depending on the "
+                "codec provided by --audio-codec).\n"
+                "The available encoders can be listed by --list-encoders.",
+    },
     {
         .shortopt = 'b',
         .longopt = "video-bit-rate",
@@ -168,10 +202,9 @@ static const struct sc_option options[] = {
         .longopt_id = OPT_DISPLAY_ID,
         .longopt = "display",
         .argdesc = "id",
-        .text = "Specify the display id to mirror.\n"
-                "The list of possible display ids can be listed by:\n"
-                "    adb shell dumpsys display\n"
-                "(search \"mDisplayId=\" in the output)\n"
+        .text = "Specify the device display id to mirror.\n"
+                "The available display ids can be listed by:\n"
+                "    scrcpy --list-displays\n"
                 "Default is 0.",
     },
     {
@@ -242,6 +275,16 @@ static const struct sc_option options[] = {
                 "This is a workaround for some devices not behaving as "
                 "expected when setting the device clipboard programmatically.",
     },
+    {
+        .longopt_id = OPT_LIST_DISPLAYS,
+        .longopt = "list-displays",
+        .text = "List device displays.",
+    },
+    {
+        .longopt_id = OPT_LIST_ENCODERS,
+        .longopt = "list-encoders",
+        .text = "List video and audio encoders available on the device.",
+    },
     {
         .longopt_id = OPT_LOCK_VIDEO_ORIENTATION,
         .longopt = "lock-video-orientation",
@@ -425,6 +468,13 @@ static const struct sc_option options[] = {
         .longopt_id = OPT_RENDER_EXPIRED_FRAMES,
         .longopt = "render-expired-frames",
     },
+    {
+        .longopt_id = OPT_REQUIRE_AUDIO,
+        .longopt = "require-audio",
+        .text = "By default, scrcpy mirrors only the video when audio capture "
+                "fails on the device. This flag makes scrcpy fail if audio is "
+                "enabled but does not work."
+    },
     {
         .longopt_id = OPT_ROTATION,
         .longopt = "rotation",
@@ -558,7 +608,8 @@ static const struct sc_option options[] = {
         .longopt = "video-encoder",
         .argdesc = "name",
         .text = "Use a specific MediaCodec video encoder (depending on the "
-                "codec provided by --video-codec).",
+                "codec provided by --video-codec).\n"
+                "The available encoders can be listed by --list-encoders.",
     },
     {
         .shortopt = 'w',
@@ -1455,6 +1506,10 @@ parse_video_codec(const char *optarg, enum sc_codec *codec) {
 
 static bool
 parse_audio_codec(const char *optarg, enum sc_codec *codec) {
+    if (!strcmp(optarg, "raw")) {
+        *codec = SC_CODEC_RAW;
+        return true;
+    }
     if (!strcmp(optarg, "opus")) {
         *codec = SC_CODEC_OPUS;
         return true;
@@ -1463,7 +1518,7 @@ parse_audio_codec(const char *optarg, enum sc_codec *codec) {
         *codec = SC_CODEC_AAC;
         return true;
     }
-    LOGE("Unsupported audio codec: %s (expected opus or aac)", optarg);
+    LOGE("Unsupported audio codec: %s (expected raw, opus or aac)", optarg);
     return false;
 }
 
@@ -1662,12 +1717,18 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             case OPT_VIDEO_CODEC_OPTIONS:
                 opts->video_codec_options = optarg;
                 break;
+            case OPT_AUDIO_CODEC_OPTIONS:
+                opts->audio_codec_options = optarg;
+                break;
             case OPT_ENCODER:
                 LOGW("--encoder is deprecated, use --video-encoder instead.");
                 // fall through
             case OPT_VIDEO_ENCODER:
                 opts->video_encoder = optarg;
                 break;
+            case OPT_AUDIO_ENCODER:
+                opts->audio_encoder = optarg;
+                break;
             case OPT_FORCE_ADB_FORWARD:
                 opts->force_adb_forward = true;
                 break;
@@ -1755,6 +1816,20 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
                 LOGE("V4L2 (--v4l2-buffer) is only available on Linux.");
                 return false;
 #endif
+            case OPT_LIST_ENCODERS:
+                opts->list_encoders = true;
+                break;
+            case OPT_LIST_DISPLAYS:
+                opts->list_displays = true;
+                break;
+            case OPT_REQUIRE_AUDIO:
+                opts->require_audio = true;
+                break;
+            case OPT_AUDIO_BUFFER:
+                if (!parse_buffering_time(optarg, &opts->audio_buffer)) {
+                    return false;
+                }
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;
@@ -1841,6 +1916,35 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
         }
     }
 
+    if (opts->record_filename && opts->audio_codec == SC_CODEC_RAW) {
+        LOGW("Recording does not support RAW audio codec");
+        return false;
+    }
+
+    if (opts->audio_codec == SC_CODEC_RAW) {
+        if (opts->audio_bit_rate) {
+            LOGW("--audio-bit-rate is ignored for raw audio codec");
+        }
+        if (opts->audio_codec_options) {
+            LOGW("--audio-codec-options is ignored for raw audio codec");
+        }
+        if (opts->audio_encoder) {
+            LOGW("--audio-encoder is ignored for raw audio codec");
+        }
+    }
+
+    if (opts->audio_codec == SC_CODEC_RAW) {
+        if (opts->audio_bit_rate) {
+            LOGW("--audio-bit-rate is ignored for raw audio codec");
+        }
+        if (opts->audio_codec_options) {
+            LOGW("--audio-codec-options is ignored for raw audio codec");
+        }
+        if (opts->audio_encoder) {
+            LOGW("--audio-encoder is ignored for raw audio codec");
+        }
+    }
+
     if (!opts->control) {
         if (opts->turn_screen_off) {
             LOGE("Could not request to turn screen off if control is disabled");

app/src/clock.c

@@ -18,7 +18,15 @@ sc_clock_init(struct sc_clock *clock) {
 static void
 sc_clock_estimate(struct sc_clock *clock,
                   double *out_slope, sc_tick *out_offset) {
-    assert(clock->count > 1); // two points are necessary
+    assert(clock->count);
+
+    if (clock->count == 1) {
+        // If there is only 1 point, we can't compute a slope. Assume it is 1.
+        struct sc_clock_point *single_point = &clock->right_sum;
+        *out_slope = 1;
+        *out_offset = single_point->system - single_point->stream;
+        return;
+    }
 
     struct sc_clock_point left_avg = {
         .system = clock->left_sum.system / (clock->count / 2),
@@ -93,19 +101,17 @@ sc_clock_update(struct sc_clock *clock, sc_tick system, sc_tick stream) {
 
     clock->head = (clock->head + 1) % SC_CLOCK_RANGE;
 
-    if (clock->count > 1) {
-        // Update estimation
-        sc_clock_estimate(clock, &clock->slope, &clock->offset);
+    // Update estimation
+    sc_clock_estimate(clock, &clock->slope, &clock->offset);
 
 #ifndef SC_CLOCK_NDEBUG
-        LOGD("Clock estimation: %f * pts + %" PRItick,
-             clock->slope, clock->offset);
+    LOGD("Clock estimation: %f * pts + %" PRItick,
+         clock->slope, clock->offset);
 #endif
-    }
 }
 
 sc_tick
 sc_clock_to_system_time(struct sc_clock *clock, sc_tick stream) {
-    assert(clock->count > 1); // sc_clock_update() must have been called
+    assert(clock->count); // sc_clock_update() must have been called
     return (sc_tick) (stream * clock->slope) + clock->offset;
 }

app/src/compat.c

@@ -3,6 +3,9 @@
 #include "config.h"
 
 #include <assert.h>
+#ifndef HAVE_REALLOCARRAY
+# include <errno.h>
+#endif
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdarg.h>
@@ -93,5 +96,15 @@ long jrand48(unsigned short xsubi[3]) {
     return v.i;
 }
 #endif
-
+#endif
+
+#ifndef HAVE_REALLOCARRAY
+void *reallocarray(void *ptr, size_t nmemb, size_t size) {
+    size_t bytes;
+    if (__builtin_mul_overflow(nmemb, size, &bytes)) {
+      errno = ENOMEM;
+      return NULL;
+    }
+    return realloc(ptr, bytes);
+}
 #endif

app/src/compat.h

@@ -37,6 +37,13 @@
 # define SCRCPY_LAVF_HAS_AVFORMATCONTEXT_URL
 #endif
 
+// Not documented in ffmpeg/doc/APIchanges, but the channel_layout API
+// has been replaced by chlayout in FFmpeg commit
+// f423497b455da06c1337846902c770028760e094.
+#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(57, 23, 100)
+# define SCRCPY_LAVU_HAS_CHLAYOUT
+#endif
+
 #if SDL_VERSION_ATLEAST(2, 0, 6)
 // <https://github.com/libsdl-org/SDL/commit/d7a318de563125e5bb465b1000d6bc9576fbc6fc>
 # define SCRCPY_SDL_HAS_HINT_TOUCH_MOUSE_EVENTS
@@ -67,4 +74,8 @@ long nrand48(unsigned short xsubi[3]);
 long jrand48(unsigned short xsubi[3]);
 #endif
 
+#ifndef HAVE_REALLOCARRAY
+void *reallocarray(void *ptr, size_t nmemb, size_t size);
+#endif
+
 #endif

app/src/controller.c

@@ -4,19 +4,28 @@
 
 #include "util/log.h"
 
+#define SC_CONTROL_MSG_QUEUE_MAX 64
+
 bool
 sc_controller_init(struct sc_controller *controller, sc_socket control_socket,
                    struct sc_acksync *acksync) {
-    cbuf_init(&controller->queue);
+    sc_vecdeque_init(&controller->queue);
 
-    bool ok = sc_receiver_init(&controller->receiver, control_socket, acksync);
+    bool ok = sc_vecdeque_reserve(&controller->queue, SC_CONTROL_MSG_QUEUE_MAX);
     if (!ok) {
         return false;
     }
 
+    ok = sc_receiver_init(&controller->receiver, control_socket, acksync);
+    if (!ok) {
+        sc_vecdeque_destroy(&controller->queue);
+        return false;
+    }
+
     ok = sc_mutex_init(&controller->mutex);
     if (!ok) {
         sc_receiver_destroy(&controller->receiver);
+        sc_vecdeque_destroy(&controller->queue);
         return false;
     }
 
@@ -24,6 +33,7 @@ sc_controller_init(struct sc_controller *controller, sc_socket control_socket,
     if (!ok) {
         sc_receiver_destroy(&controller->receiver);
         sc_mutex_destroy(&controller->mutex);
+        sc_vecdeque_destroy(&controller->queue);
         return false;
     }
 
@@ -38,10 +48,12 @@ sc_controller_destroy(struct sc_controller *controller) {
     sc_cond_destroy(&controller->msg_cond);
     sc_mutex_destroy(&controller->mutex);
 
-    struct sc_control_msg msg;
-    while (cbuf_take(&controller->queue, &msg)) {
-        sc_control_msg_destroy(&msg);
+    while (!sc_vecdeque_is_empty(&controller->queue)) {
+        struct sc_control_msg *msg = sc_vecdeque_popref(&controller->queue);
+        assert(msg);
+        sc_control_msg_destroy(msg);
     }
+    sc_vecdeque_destroy(&controller->queue);
 
     sc_receiver_destroy(&controller->receiver);
 }
@@ -54,13 +66,19 @@ sc_controller_push_msg(struct sc_controller *controller,
     }
 
     sc_mutex_lock(&controller->mutex);
-    bool was_empty = cbuf_is_empty(&controller->queue);
-    bool res = cbuf_push(&controller->queue, *msg);
-    if (was_empty) {
-        sc_cond_signal(&controller->msg_cond);
+    bool full = sc_vecdeque_is_full(&controller->queue);
+    if (!full) {
+        bool was_empty = sc_vecdeque_is_empty(&controller->queue);
+        sc_vecdeque_push_noresize(&controller->queue, *msg);
+        if (was_empty) {
+            sc_cond_signal(&controller->msg_cond);
+        }
     }
+    // Otherwise (if the queue is full), the msg is discarded
+
     sc_mutex_unlock(&controller->mutex);
-    return res;
+
+    return !full;
 }
 
 static bool
@@ -82,7 +100,8 @@ run_controller(void *data) {
 
     for (;;) {
         sc_mutex_lock(&controller->mutex);
-        while (!controller->stopped && cbuf_is_empty(&controller->queue)) {
+        while (!controller->stopped
+                && sc_vecdeque_is_empty(&controller->queue)) {
             sc_cond_wait(&controller->msg_cond, &controller->mutex);
         }
         if (controller->stopped) {
@@ -90,10 +109,9 @@ run_controller(void *data) {
             sc_mutex_unlock(&controller->mutex);
             break;
         }
-        struct sc_control_msg msg;
-        bool non_empty = cbuf_take(&controller->queue, &msg);
-        assert(non_empty);
-        (void) non_empty;
+
+        assert(!sc_vecdeque_is_empty(&controller->queue));
+        struct sc_control_msg msg = sc_vecdeque_pop(&controller->queue);
         sc_mutex_unlock(&controller->mutex);
 
         bool ok = process_msg(controller, &msg);

app/src/controller.h

@@ -8,11 +8,11 @@
 #include "control_msg.h"
 #include "receiver.h"
 #include "util/acksync.h"
-#include "util/cbuf.h"
 #include "util/net.h"
 #include "util/thread.h"
+#include "util/vecdeque.h"
 
-struct sc_control_msg_queue CBUF(struct sc_control_msg, 64);
+struct sc_control_msg_queue SC_VECDEQUE(struct sc_control_msg);
 
 struct sc_controller {
     sc_socket control_socket;

app/src/decoder.c

@@ -2,41 +2,15 @@
 
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
+#include <libavutil/channel_layout.h>
 
 #include "events.h"
-#include "video_buffer.h"
 #include "trait/frame_sink.h"
 #include "util/log.h"
 
 /** Downcast packet_sink to decoder */
 #define DOWNCAST(SINK) container_of(SINK, struct sc_decoder, packet_sink)
 
-static void
-sc_decoder_close_first_sinks(struct sc_decoder *decoder, unsigned count) {
-    while (count) {
-        struct sc_frame_sink *sink = decoder->sinks[--count];
-        sink->ops->close(sink);
-    }
-}
-
-static inline void
-sc_decoder_close_sinks(struct sc_decoder *decoder) {
-    sc_decoder_close_first_sinks(decoder, decoder->sink_count);
-}
-
-static bool
-sc_decoder_open_sinks(struct sc_decoder *decoder) {
-    for (unsigned i = 0; i < decoder->sink_count; ++i) {
-        struct sc_frame_sink *sink = decoder->sinks[i];
-        if (!sink->ops->open(sink)) {
-            sc_decoder_close_first_sinks(decoder, i);
-            return false;
-        }
-    }
-
-    return true;
-}
-
 static bool
 sc_decoder_open(struct sc_decoder *decoder, const AVCodec *codec) {
     decoder->codec_ctx = avcodec_alloc_context3(codec);
@@ -47,8 +21,23 @@ sc_decoder_open(struct sc_decoder *decoder, const AVCodec *codec) {
 
     decoder->codec_ctx->flags |= AV_CODEC_FLAG_LOW_DELAY;
 
+    if (codec->type == AVMEDIA_TYPE_VIDEO) {
+        // Hardcoded video properties
+        decoder->codec_ctx->pix_fmt = AV_PIX_FMT_YUV420P;
+    } else {
+        // Hardcoded audio properties
+#ifdef SCRCPY_LAVU_HAS_CHLAYOUT
+        decoder->codec_ctx->ch_layout =
+            (AVChannelLayout) AV_CHANNEL_LAYOUT_STEREO;
+#else
+        decoder->codec_ctx->channel_layout = AV_CH_LAYOUT_STEREO;
+        decoder->codec_ctx->channels = 2;
+#endif
+        decoder->codec_ctx->sample_rate = 48000;
+    }
+
     if (avcodec_open2(decoder->codec_ctx, codec, NULL) < 0) {
-        LOGE("Could not open codec");
+        LOGE("Decoder '%s': could not open codec", decoder->name);
         avcodec_free_context(&decoder->codec_ctx);
         return false;
     }
@@ -61,7 +50,8 @@ sc_decoder_open(struct sc_decoder *decoder, const AVCodec *codec) {
         return false;
     }
 
-    if (!sc_decoder_open_sinks(decoder)) {
+    if (!sc_frame_source_sinks_open(&decoder->frame_source,
+                                    decoder->codec_ctx)) {
         av_frame_free(&decoder->frame);
         avcodec_close(decoder->codec_ctx);
         avcodec_free_context(&decoder->codec_ctx);
@@ -73,24 +63,12 @@ sc_decoder_open(struct sc_decoder *decoder, const AVCodec *codec) {
 
 static void
 sc_decoder_close(struct sc_decoder *decoder) {
-    sc_decoder_close_sinks(decoder);
+    sc_frame_source_sinks_close(&decoder->frame_source);
     av_frame_free(&decoder->frame);
     avcodec_close(decoder->codec_ctx);
     avcodec_free_context(&decoder->codec_ctx);
 }
 
-static bool
-push_frame_to_sinks(struct sc_decoder *decoder, const AVFrame *frame) {
-    for (unsigned i = 0; i < decoder->sink_count; ++i) {
-        struct sc_frame_sink *sink = decoder->sinks[i];
-        if (!sink->ops->push(sink, frame)) {
-            return false;
-        }
-    }
-
-    return true;
-}
-
 static bool
 sc_decoder_push(struct sc_decoder *decoder, const AVPacket *packet) {
     bool is_config = packet->pts == AV_NOPTS_VALUE;
@@ -101,22 +79,33 @@ sc_decoder_push(struct sc_decoder *decoder, const AVPacket *packet) {
 
     int ret = avcodec_send_packet(decoder->codec_ctx, packet);
     if (ret < 0 && ret != AVERROR(EAGAIN)) {
-        LOGE("Could not send video packet: %d", ret);
+        LOGE("Decoder '%s': could not send video packet: %d",
+             decoder->name, ret);
         return false;
     }
-    ret = avcodec_receive_frame(decoder->codec_ctx, decoder->frame);
-    if (!ret) {
-        // a frame was received
-        bool ok = push_frame_to_sinks(decoder, decoder->frame);
-        // A frame lost should not make the whole pipeline fail. The error, if
-        // any, is already logged.
-        (void) ok;
 
+    for (;;) {
+        ret = avcodec_receive_frame(decoder->codec_ctx, decoder->frame);
+        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
+            break;
+        }
+
+        if (ret) {
+            LOGE("Decoder '%s', could not receive video frame: %d",
+                 decoder->name, ret);
+            return false;
+        }
+
+        // a frame was received
+        bool ok = sc_frame_source_sinks_push(&decoder->frame_source,
+                                             decoder->frame);
         av_frame_unref(decoder->frame);
-    } else if (ret != AVERROR(EAGAIN)) {
-        LOGE("Could not receive video frame: %d", ret);
-        return false;
+        if (!ok) {
+            // Error already logged
+            return false;
+        }
     }
+
     return true;
 }
 
@@ -140,8 +129,9 @@ sc_decoder_packet_sink_push(struct sc_packet_sink *sink,
 }
 
 void
-sc_decoder_init(struct sc_decoder *decoder) {
-    decoder->sink_count = 0;
+sc_decoder_init(struct sc_decoder *decoder, const char *name) {
+    decoder->name = name; // statically allocated
+    sc_frame_source_init(&decoder->frame_source);
 
     static const struct sc_packet_sink_ops ops = {
         .open = sc_decoder_packet_sink_open,
@@ -151,11 +141,3 @@ sc_decoder_init(struct sc_decoder *decoder) {
 
     decoder->packet_sink.ops = &ops;
 }
-
-void
-sc_decoder_add_sink(struct sc_decoder *decoder, struct sc_frame_sink *sink) {
-    assert(decoder->sink_count < SC_DECODER_MAX_SINKS);
-    assert(sink);
-    assert(sink->ops);
-    decoder->sinks[decoder->sink_count++] = sink;
-}

app/src/decoder.h

@@ -3,28 +3,25 @@
 
 #include "common.h"
 
+#include "trait/frame_source.h"
 #include "trait/packet_sink.h"
 
 #include <stdbool.h>
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 
-#define SC_DECODER_MAX_SINKS 2
-
 struct sc_decoder {
     struct sc_packet_sink packet_sink; // packet sink trait
+    struct sc_frame_source frame_source; // frame source trait
 
-    struct sc_frame_sink *sinks[SC_DECODER_MAX_SINKS];
-    unsigned sink_count;
+    const char *name; // must be statically allocated (e.g. a string literal)
 
     AVCodecContext *codec_ctx;
     AVFrame *frame;
 };
 
+// The name must be statically allocated (e.g. a string literal)
 void
-sc_decoder_init(struct sc_decoder *decoder);
-
-void
-sc_decoder_add_sink(struct sc_decoder *decoder, struct sc_frame_sink *sink);
+sc_decoder_init(struct sc_decoder *decoder, const char *name);
 
 #endif

app/src/delay_buffer.c

@@ -0,0 +1,244 @@
+#include "delay_buffer.h"
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include <libavutil/avutil.h>
+#include <libavformat/avformat.h>
+
+#include "util/log.h"
+
+#define SC_BUFFERING_NDEBUG // comment to debug
+
+/** Downcast frame_sink to sc_delay_buffer */
+#define DOWNCAST(SINK) container_of(SINK, struct sc_delay_buffer, frame_sink)
+
+static bool
+sc_delayed_frame_init(struct sc_delayed_frame *dframe, const AVFrame *frame) {
+    dframe->frame = av_frame_alloc();
+    if (!dframe->frame) {
+        LOG_OOM();
+        return false;
+    }
+
+    if (av_frame_ref(dframe->frame, frame)) {
+        LOG_OOM();
+        av_frame_free(&dframe->frame);
+        return false;
+    }
+
+    return true;
+}
+
+static void
+sc_delayed_frame_destroy(struct sc_delayed_frame *dframe) {
+    av_frame_unref(dframe->frame);
+    av_frame_free(&dframe->frame);
+}
+
+static int
+run_buffering(void *data) {
+    struct sc_delay_buffer *db = data;
+
+    assert(db->delay > 0);
+
+    for (;;) {
+        sc_mutex_lock(&db->mutex);
+
+        while (!db->stopped && sc_vecdeque_is_empty(&db->queue)) {
+            sc_cond_wait(&db->queue_cond, &db->mutex);
+        }
+
+        if (db->stopped) {
+            sc_mutex_unlock(&db->mutex);
+            goto stopped;
+        }
+
+        struct sc_delayed_frame dframe = sc_vecdeque_pop(&db->queue);
+
+        sc_tick max_deadline = sc_tick_now() + db->delay;
+        // PTS (written by the server) are expressed in microseconds
+        sc_tick pts = SC_TICK_TO_US(dframe.frame->pts);
+
+        bool timed_out = false;
+        while (!db->stopped && !timed_out) {
+            sc_tick deadline = sc_clock_to_system_time(&db->clock, pts)
+                             + db->delay;
+            if (deadline > max_deadline) {
+                deadline = max_deadline;
+            }
+
+            timed_out =
+                !sc_cond_timedwait(&db->wait_cond, &db->mutex, deadline);
+        }
+
+        bool stopped = db->stopped;
+        sc_mutex_unlock(&db->mutex);
+
+        if (stopped) {
+            sc_delayed_frame_destroy(&dframe);
+            goto stopped;
+        }
+
+#ifndef SC_BUFFERING_NDEBUG
+        LOGD("Buffering: %" PRItick ";%" PRItick ";%" PRItick,
+             pts, dframe.push_date, sc_tick_now());
+#endif
+
+        bool ok = sc_frame_source_sinks_push(&db->frame_source, dframe.frame);
+        sc_delayed_frame_destroy(&dframe);
+        if (!ok) {
+            LOGE("Delayed frame could not be pushed, stopping");
+            sc_mutex_lock(&db->mutex);
+            // Prevent to push any new frame
+            db->stopped = true;
+            sc_mutex_unlock(&db->mutex);
+            goto stopped;
+        }
+    }
+
+stopped:
+    assert(db->stopped);
+
+    // Flush queue
+    while (!sc_vecdeque_is_empty(&db->queue)) {
+        struct sc_delayed_frame *dframe = sc_vecdeque_popref(&db->queue);
+        sc_delayed_frame_destroy(dframe);
+    }
+
+    LOGD("Buffering thread ended");
+
+    return 0;
+}
+
+static bool
+sc_delay_buffer_frame_sink_open(struct sc_frame_sink *sink,
+                                const AVCodecContext *ctx) {
+    struct sc_delay_buffer *db = DOWNCAST(sink);
+    (void) ctx;
+
+    bool ok = sc_mutex_init(&db->mutex);
+    if (!ok) {
+        return false;
+    }
+
+    ok = sc_cond_init(&db->queue_cond);
+    if (!ok) {
+        goto error_destroy_mutex;
+    }
+
+    ok = sc_cond_init(&db->wait_cond);
+    if (!ok) {
+        goto error_destroy_queue_cond;
+    }
+
+    sc_clock_init(&db->clock);
+    sc_vecdeque_init(&db->queue);
+
+    if (!sc_frame_source_sinks_open(&db->frame_source, ctx)) {
+        goto error_destroy_wait_cond;
+    }
+
+    ok = sc_thread_create(&db->thread, run_buffering, "scrcpy-dbuf", db);
+    if (!ok) {
+        LOGE("Could not start buffering thread");
+        goto error_close_sinks;
+    }
+
+    return true;
+
+error_close_sinks:
+    sc_frame_source_sinks_close(&db->frame_source);
+error_destroy_wait_cond:
+    sc_cond_destroy(&db->wait_cond);
+error_destroy_queue_cond:
+    sc_cond_destroy(&db->queue_cond);
+error_destroy_mutex:
+    sc_mutex_destroy(&db->mutex);
+
+    return false;
+}
+
+static void
+sc_delay_buffer_frame_sink_close(struct sc_frame_sink *sink) {
+    struct sc_delay_buffer *db = DOWNCAST(sink);
+
+    sc_mutex_lock(&db->mutex);
+    db->stopped = true;
+    sc_cond_signal(&db->queue_cond);
+    sc_cond_signal(&db->wait_cond);
+    sc_mutex_unlock(&db->mutex);
+
+    sc_thread_join(&db->thread, NULL);
+
+    sc_frame_source_sinks_close(&db->frame_source);
+
+    sc_cond_destroy(&db->wait_cond);
+    sc_cond_destroy(&db->queue_cond);
+    sc_mutex_destroy(&db->mutex);
+}
+
+static bool
+sc_delay_buffer_frame_sink_push(struct sc_frame_sink *sink,
+                                const AVFrame *frame) {
+    struct sc_delay_buffer *db = DOWNCAST(sink);
+
+    sc_mutex_lock(&db->mutex);
+
+    if (db->stopped) {
+        sc_mutex_unlock(&db->mutex);
+        return false;
+    }
+
+    sc_tick pts = SC_TICK_FROM_US(frame->pts);
+    sc_clock_update(&db->clock, sc_tick_now(), pts);
+    sc_cond_signal(&db->wait_cond);
+
+    if (db->first_frame_asap && db->clock.count == 1) {
+        sc_mutex_unlock(&db->mutex);
+        return sc_frame_source_sinks_push(&db->frame_source, frame);
+    }
+
+    struct sc_delayed_frame dframe;
+    bool ok = sc_delayed_frame_init(&dframe, frame);
+    if (!ok) {
+        sc_mutex_unlock(&db->mutex);
+        return false;
+    }
+
+#ifndef SC_BUFFERING_NDEBUG
+    dframe.push_date = sc_tick_now();
+#endif
+
+    ok = sc_vecdeque_push(&db->queue, dframe);
+    if (!ok) {
+        sc_mutex_unlock(&db->mutex);
+        LOG_OOM();
+        return false;
+    }
+
+    sc_cond_signal(&db->queue_cond);
+
+    sc_mutex_unlock(&db->mutex);
+
+    return true;
+}
+
+void
+sc_delay_buffer_init(struct sc_delay_buffer *db, sc_tick delay,
+                     bool first_frame_asap) {
+    assert(delay > 0);
+
+    db->delay = delay;
+    db->first_frame_asap = first_frame_asap;
+
+    sc_frame_source_init(&db->frame_source);
+
+    static const struct sc_frame_sink_ops ops = {
+        .open = sc_delay_buffer_frame_sink_open,
+        .close = sc_delay_buffer_frame_sink_close,
+        .push = sc_delay_buffer_frame_sink_push,
+    };
+
+    db->frame_sink.ops = &ops;
+}

app/src/delay_buffer.h

@@ -0,0 +1,60 @@
+#ifndef SC_DELAY_BUFFER_H
+#define SC_DELAY_BUFFER_H
+
+#include "common.h"
+
+#include <stdbool.h>
+
+#include "clock.h"
+#include "trait/frame_source.h"
+#include "trait/frame_sink.h"
+#include "util/thread.h"
+#include "util/tick.h"
+#include "util/vecdeque.h"
+
+// forward declarations
+typedef struct AVFrame AVFrame;
+
+struct sc_delayed_frame {
+    AVFrame *frame;
+#ifndef NDEBUG
+    sc_tick push_date;
+#endif
+};
+
+struct sc_delayed_frame_queue SC_VECDEQUE(struct sc_delayed_frame);
+
+struct sc_delay_buffer {
+    struct sc_frame_source frame_source; // frame source trait
+    struct sc_frame_sink frame_sink; // frame sink trait
+
+    sc_tick delay;
+    bool first_frame_asap;
+
+    sc_thread thread;
+    sc_mutex mutex;
+    sc_cond queue_cond;
+    sc_cond wait_cond;
+
+    struct sc_clock clock;
+    struct sc_delayed_frame_queue queue;
+    bool stopped;
+};
+
+struct sc_delay_buffer_callbacks {
+    bool (*on_new_frame)(struct sc_delay_buffer *db, const AVFrame *frame,
+                         void *userdata);
+};
+
+/**
+ * Initialize a delay buffer.
+ *
+ * \param delay a (strictly) positive delay
+ * \param first_frame_asap if true, do not delay the first frame (useful for
+                           a video stream).
+ */
+void
+sc_delay_buffer_init(struct sc_delay_buffer *db, sc_tick delay,
+                     bool first_frame_asap);
+
+#endif

app/src/demuxer.c

@@ -23,6 +23,7 @@ sc_demuxer_to_avcodec_id(uint32_t codec_id) {
 #define SC_CODEC_ID_H264 UINT32_C(0x68323634) // "h264" in ASCII
 #define SC_CODEC_ID_H265 UINT32_C(0x68323635) // "h265" in ASCII
 #define SC_CODEC_ID_AV1 UINT32_C(0x00617631) // "av1" in ASCII
+#define SC_CODEC_ID_RAW UINT32_C(0x00726177) // "raw" in ASCII
 #define SC_CODEC_ID_OPUS UINT32_C(0x6f707573) // "opus" in ASCII
 #define SC_CODEC_ID_AAC UINT32_C(0x00616163) // "aac in ASCII"
     switch (codec_id) {
@@ -32,6 +33,8 @@ sc_demuxer_to_avcodec_id(uint32_t codec_id) {
             return AV_CODEC_ID_HEVC;
         case SC_CODEC_ID_AV1:
             return AV_CODEC_ID_AV1;
+        case SC_CODEC_ID_RAW:
+            return AV_CODEC_ID_PCM_S16LE;
         case SC_CODEC_ID_OPUS:
             return AV_CODEC_ID_OPUS;
         case SC_CODEC_ID_AAC:
@@ -112,86 +115,32 @@ sc_demuxer_recv_packet(struct sc_demuxer *demuxer, AVPacket *packet) {
     return true;
 }
 
-static bool
-push_packet_to_sinks(struct sc_demuxer *demuxer, const AVPacket *packet) {
-    for (unsigned i = 0; i < demuxer->sink_count; ++i) {
-        struct sc_packet_sink *sink = demuxer->sinks[i];
-        if (!sink->ops->push(sink, packet)) {
-            return false;
-        }
-    }
-
-    return true;
-}
-
-static bool
-sc_demuxer_push_packet(struct sc_demuxer *demuxer, AVPacket *packet) {
-    bool ok = push_packet_to_sinks(demuxer, packet);
-    if (!ok) {
-        LOGE("Demuxer '%s': could not process packet", demuxer->name);
-        return false;
-    }
-
-    return true;
-}
-
-static void
-sc_demuxer_close_first_sinks(struct sc_demuxer *demuxer, unsigned count) {
-    while (count) {
-        struct sc_packet_sink *sink = demuxer->sinks[--count];
-        sink->ops->close(sink);
-    }
-}
-
-static inline void
-sc_demuxer_close_sinks(struct sc_demuxer *demuxer) {
-    sc_demuxer_close_first_sinks(demuxer, demuxer->sink_count);
-}
-
-static bool
-sc_demuxer_open_sinks(struct sc_demuxer *demuxer, const AVCodec *codec) {
-    for (unsigned i = 0; i < demuxer->sink_count; ++i) {
-        struct sc_packet_sink *sink = demuxer->sinks[i];
-        if (!sink->ops->open(sink, codec)) {
-            sc_demuxer_close_first_sinks(demuxer, i);
-            return false;
-        }
-    }
-
-    return true;
-}
-
-static void
-sc_demuxer_disable_sinks(struct sc_demuxer *demuxer) {
-    for (unsigned i = 0; i < demuxer->sink_count; ++i) {
-        struct sc_packet_sink *sink = demuxer->sinks[i];
-        if (sink->ops->disable) {
-            sink->ops->disable(sink);
-        }
-    }
-}
-
 static int
 run_demuxer(void *data) {
     struct sc_demuxer *demuxer = data;
 
     // Flag to report end-of-stream (i.e. device disconnected)
-    bool eos = false;
+    enum sc_demuxer_status status = SC_DEMUXER_STATUS_ERROR;
 
     uint32_t raw_codec_id;
     bool ok = sc_demuxer_recv_codec_id(demuxer, &raw_codec_id);
     if (!ok) {
         LOGE("Demuxer '%s': stream disabled due to connection error",
              demuxer->name);
-        eos = true;
         goto end;
     }
 
     if (raw_codec_id == 0) {
         LOGW("Demuxer '%s': stream explicitly disabled by the device",
              demuxer->name);
-        sc_demuxer_disable_sinks(demuxer);
-        eos = true;
+        sc_packet_source_sinks_disable(&demuxer->packet_source);
+        status = SC_DEMUXER_STATUS_DISABLED;
+        goto end;
+    }
+
+    if (raw_codec_id == 1) {
+        LOGE("Demuxer '%s': stream configuration error on the device",
+             demuxer->name);
         goto end;
     }
 
@@ -199,7 +148,7 @@ run_demuxer(void *data) {
     if (codec_id == AV_CODEC_ID_NONE) {
         LOGE("Demuxer '%s': stream disabled due to unsupported codec",
              demuxer->name);
-        sc_demuxer_disable_sinks(demuxer);
+        sc_packet_source_sinks_disable(&demuxer->packet_source);
         goto end;
     }
 
@@ -207,11 +156,11 @@ run_demuxer(void *data) {
     if (!codec) {
         LOGE("Demuxer '%s': stream disabled due to missing decoder",
              demuxer->name);
-        sc_demuxer_disable_sinks(demuxer);
+        sc_packet_source_sinks_disable(&demuxer->packet_source);
         goto end;
     }
 
-    if (!sc_demuxer_open_sinks(demuxer, codec)) {
+    if (!sc_packet_source_sinks_open(&demuxer->packet_source, codec)) {
         goto end;
     }
 
@@ -235,7 +184,7 @@ run_demuxer(void *data) {
         bool ok = sc_demuxer_recv_packet(demuxer, packet);
         if (!ok) {
             // end of stream
-            eos = true;
+            status = SC_DEMUXER_STATUS_EOS;
             break;
         }
 
@@ -248,10 +197,10 @@ run_demuxer(void *data) {
             }
         }
 
-        ok = sc_demuxer_push_packet(demuxer, packet);
+        ok = sc_packet_source_sinks_push(&demuxer->packet_source, packet);
         av_packet_unref(packet);
         if (!ok) {
-            // cannot process packet (error already logged)
+            LOGE("Demuxer '%s': could not process packet", demuxer->name);
             break;
         }
     }
@@ -264,9 +213,9 @@ run_demuxer(void *data) {
 
     av_packet_free(&packet);
 finally_close_sinks:
-    sc_demuxer_close_sinks(demuxer);
+    sc_packet_source_sinks_close(&demuxer->packet_source);
 end:
-    demuxer->cbs->on_ended(demuxer, eos, demuxer->cbs_userdata);
+    demuxer->cbs->on_ended(demuxer, status, demuxer->cbs_userdata);
 
     return 0;
 }
@@ -278,7 +227,7 @@ sc_demuxer_init(struct sc_demuxer *demuxer, const char *name, sc_socket socket,
 
     demuxer->name = name; // statically allocated
     demuxer->socket = socket;
-    demuxer->sink_count = 0;
+    sc_packet_source_init(&demuxer->packet_source);
 
     assert(cbs && cbs->on_ended);
 
@@ -286,14 +235,6 @@ sc_demuxer_init(struct sc_demuxer *demuxer, const char *name, sc_socket socket,
     demuxer->cbs_userdata = cbs_userdata;
 }
 
-void
-sc_demuxer_add_sink(struct sc_demuxer *demuxer, struct sc_packet_sink *sink) {
-    assert(demuxer->sink_count < SC_DEMUXER_MAX_SINKS);
-    assert(sink);
-    assert(sink->ops);
-    demuxer->sinks[demuxer->sink_count++] = sink;
-}
-
 bool
 sc_demuxer_start(struct sc_demuxer *demuxer) {
     LOGD("Demuxer '%s': starting thread", demuxer->name);

app/src/demuxer.h

@@ -8,27 +8,32 @@
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 
+#include "trait/packet_source.h"
 #include "trait/packet_sink.h"
 #include "util/net.h"
 #include "util/thread.h"
 
-#define SC_DEMUXER_MAX_SINKS 2
-
 struct sc_demuxer {
+    struct sc_packet_source packet_source; // packet source trait
+
     const char *name; // must be statically allocated (e.g. a string literal)
 
     sc_socket socket;
     sc_thread thread;
 
-    struct sc_packet_sink *sinks[SC_DEMUXER_MAX_SINKS];
-    unsigned sink_count;
-
     const struct sc_demuxer_callbacks *cbs;
     void *cbs_userdata;
 };
 
+enum sc_demuxer_status {
+    SC_DEMUXER_STATUS_EOS,
+    SC_DEMUXER_STATUS_DISABLED,
+    SC_DEMUXER_STATUS_ERROR,
+};
+
 struct sc_demuxer_callbacks {
-    void (*on_ended)(struct sc_demuxer *demuxer, bool eos, void *userdata);
+    void (*on_ended)(struct sc_demuxer *demuxer, enum sc_demuxer_status,
+                     void *userdata);
 };
 
 // The name must be statically allocated (e.g. a string literal)
@@ -36,9 +41,6 @@ void
 sc_demuxer_init(struct sc_demuxer *demuxer, const char *name, sc_socket socket,
                 const struct sc_demuxer_callbacks *cbs, void *cbs_userdata);
 
-void
-sc_demuxer_add_sink(struct sc_demuxer *demuxer, struct sc_packet_sink *sink);
-
 bool
 sc_demuxer_start(struct sc_demuxer *demuxer);
 

app/src/file_pusher.c

@@ -19,7 +19,7 @@ sc_file_pusher_init(struct sc_file_pusher *fp, const char *serial,
                     const char *push_target) {
     assert(serial);
 
-    cbuf_init(&fp->queue);
+    sc_vecdeque_init(&fp->queue);
 
     bool ok = sc_mutex_init(&fp->mutex);
     if (!ok) {
@@ -65,9 +65,10 @@ sc_file_pusher_destroy(struct sc_file_pusher *fp) {
     sc_intr_destroy(&fp->intr);
     free(fp->serial);
 
-    struct sc_file_pusher_request req;
-    while (cbuf_take(&fp->queue, &req)) {
-        sc_file_pusher_request_destroy(&req);
+    while (!sc_vecdeque_is_empty(&fp->queue)) {
+        struct sc_file_pusher_request *req = sc_vecdeque_popref(&fp->queue);
+        assert(req);
+        sc_file_pusher_request_destroy(req);
     }
 }
 
@@ -91,13 +92,20 @@ sc_file_pusher_request(struct sc_file_pusher *fp,
     };
 
     sc_mutex_lock(&fp->mutex);
-    bool was_empty = cbuf_is_empty(&fp->queue);
-    bool res = cbuf_push(&fp->queue, req);
+    bool was_empty = sc_vecdeque_is_empty(&fp->queue);
+    bool res = sc_vecdeque_push(&fp->queue, req);
+    if (!res) {
+        LOG_OOM();
+        sc_mutex_unlock(&fp->mutex);
+        return false;
+    }
+
     if (was_empty) {
         sc_cond_signal(&fp->event_cond);
     }
     sc_mutex_unlock(&fp->mutex);
-    return res;
+
+    return true;
 }
 
 static int
@@ -113,7 +121,7 @@ run_file_pusher(void *data) {
 
     for (;;) {
         sc_mutex_lock(&fp->mutex);
-        while (!fp->stopped && cbuf_is_empty(&fp->queue)) {
+        while (!fp->stopped && sc_vecdeque_is_empty(&fp->queue)) {
             sc_cond_wait(&fp->event_cond, &fp->mutex);
         }
         if (fp->stopped) {
@@ -121,10 +129,9 @@ run_file_pusher(void *data) {
             sc_mutex_unlock(&fp->mutex);
             break;
         }
-        struct sc_file_pusher_request req;
-        bool non_empty = cbuf_take(&fp->queue, &req);
-        assert(non_empty);
-        (void) non_empty;
+
+        assert(!sc_vecdeque_is_empty(&fp->queue));
+        struct sc_file_pusher_request req = sc_vecdeque_pop(&fp->queue);
         sc_mutex_unlock(&fp->mutex);
 
         if (req.action == SC_FILE_PUSHER_ACTION_INSTALL_APK) {

app/src/file_pusher.h

@@ -5,9 +5,9 @@
 
 #include <stdbool.h>
 
-#include "util/cbuf.h"
-#include "util/thread.h"
 #include "util/intr.h"
+#include "util/thread.h"
+#include "util/vecdeque.h"
 
 enum sc_file_pusher_action {
     SC_FILE_PUSHER_ACTION_INSTALL_APK,
@@ -19,7 +19,7 @@ struct sc_file_pusher_request {
     char *file;
 };
 
-struct sc_file_pusher_request_queue CBUF(struct sc_file_pusher_request, 16);
+struct sc_file_pusher_request_queue SC_VECDEQUE(struct sc_file_pusher_request);
 
 struct sc_file_pusher {
     char *serial;

app/src/options.c

@@ -8,7 +8,9 @@ const struct scrcpy_options scrcpy_options_default = {
     .push_target = NULL,
     .render_driver = NULL,
     .video_codec_options = NULL,
+    .audio_codec_options = NULL,
     .video_encoder = NULL,
+    .audio_encoder = NULL,
 #ifdef HAVE_V4L2
     .v4l2_device = NULL,
 #endif
@@ -41,6 +43,7 @@ const struct scrcpy_options scrcpy_options_default = {
     .display_id = 0,
     .display_buffer = 0,
     .v4l2_buffer = 0,
+    .audio_buffer = 0,
 #ifdef HAVE_USB
     .otg = false,
 #endif
@@ -70,4 +73,7 @@ const struct scrcpy_options scrcpy_options_default = {
     .start_fps_counter = false,
     .power_on = true,
     .audio = true,
+    .require_audio = false,
+    .list_encoders = false,
+    .list_displays = false,
 };

app/src/options.h

@@ -27,6 +27,7 @@ enum sc_codec {
     SC_CODEC_H264,
     SC_CODEC_H265,
     SC_CODEC_AV1,
+    SC_CODEC_RAW,
     SC_CODEC_OPUS,
     SC_CODEC_AAC,
 };
@@ -96,7 +97,9 @@ struct scrcpy_options {
     const char *push_target;
     const char *render_driver;
     const char *video_codec_options;
+    const char *audio_codec_options;
     const char *video_encoder;
+    const char *audio_encoder;
 #ifdef HAVE_V4L2
     const char *v4l2_device;
 #endif
@@ -123,6 +126,7 @@ struct scrcpy_options {
     uint32_t display_id;
     sc_tick display_buffer;
     sc_tick v4l2_buffer;
+    sc_tick audio_buffer;
 #ifdef HAVE_USB
     bool otg;
 #endif
@@ -152,6 +156,9 @@ struct scrcpy_options {
     bool start_fps_counter;
     bool power_on;
     bool audio;
+    bool require_audio;
+    bool list_encoders;
+    bool list_displays;
 };
 
 extern const struct scrcpy_options scrcpy_options_default;

app/src/recorder.c

@@ -33,41 +33,27 @@ find_muxer(const char *name) {
     return oformat;
 }
 
-static struct sc_record_packet *
-sc_record_packet_new(const AVPacket *packet) {
-    struct sc_record_packet *rec = malloc(sizeof(*rec));
-    if (!rec) {
+static AVPacket *
+sc_recorder_packet_ref(const AVPacket *packet) {
+    AVPacket *p = av_packet_alloc();
+    if (!p) {
         LOG_OOM();
         return NULL;
     }
 
-    rec->packet = av_packet_alloc();
-    if (!rec->packet) {
-        LOG_OOM();
-        free(rec);
+    if (av_packet_ref(p, packet)) {
+        av_packet_free(&p);
         return NULL;
     }
 
-    if (av_packet_ref(rec->packet, packet)) {
-        av_packet_free(&rec->packet);
-        free(rec);
-        return NULL;
-    }
-    return rec;
-}
-
-static void
-sc_record_packet_delete(struct sc_record_packet *rec) {
-    av_packet_free(&rec->packet);
-    free(rec);
+    return p;
 }
 
 static void
 sc_recorder_queue_clear(struct sc_recorder_queue *queue) {
-    while (!sc_queue_is_empty(queue)) {
-        struct sc_record_packet *rec;
-        sc_queue_take(queue, next, &rec);
-        sc_record_packet_delete(rec);
+    while (!sc_vecdeque_is_empty(queue)) {
+        AVPacket *p = sc_vecdeque_pop(queue);
+        av_packet_free(&p);
     }
 }
 
@@ -216,7 +202,12 @@ sc_recorder_wait_audio_stream(struct sc_recorder *recorder) {
 
         stream->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
         stream->codecpar->codec_id = codec->id;
+#ifdef SCRCPY_LAVU_HAS_CHLAYOUT
         stream->codecpar->ch_layout.nb_channels = 2;
+#else
+        stream->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
+        stream->codecpar->channels = 2;
+#endif
         stream->codecpar->sample_rate = 48000;
 
         recorder->audio_stream_index = stream->index;
@@ -227,12 +218,12 @@ sc_recorder_wait_audio_stream(struct sc_recorder *recorder) {
 
 static inline bool
 sc_recorder_has_empty_queues(struct sc_recorder *recorder) {
-    if (sc_queue_is_empty(&recorder->video_queue)) {
+    if (sc_vecdeque_is_empty(&recorder->video_queue)) {
         // The video queue is empty
         return true;
     }
 
-    if (recorder->audio && sc_queue_is_empty(&recorder->audio_queue)) {
+    if (recorder->audio && sc_vecdeque_is_empty(&recorder->audio_queue)) {
         // The audio queue is empty (when audio is enabled)
         return true;
     }
@@ -249,27 +240,26 @@ sc_recorder_process_header(struct sc_recorder *recorder) {
         sc_cond_wait(&recorder->queue_cond, &recorder->mutex);
     }
 
-    if (recorder->stopped && sc_queue_is_empty(&recorder->video_queue)) {
+    if (recorder->stopped && sc_vecdeque_is_empty(&recorder->video_queue)) {
         // If the recorder is stopped, don't process anything if there are not
         // at least video packets
         sc_mutex_unlock(&recorder->mutex);
         return false;
     }
 
-    struct sc_record_packet *video_pkt;
-    sc_queue_take(&recorder->video_queue, next, &video_pkt);
+    AVPacket *video_pkt = sc_vecdeque_pop(&recorder->video_queue);
 
-    struct sc_record_packet *audio_pkt = NULL;
-    if (!sc_queue_is_empty(&recorder->audio_queue)) {
+    AVPacket *audio_pkt = NULL;
+    if (!sc_vecdeque_is_empty(&recorder->audio_queue)) {
         assert(recorder->audio);
-        sc_queue_take(&recorder->audio_queue, next, &audio_pkt);
+        audio_pkt = sc_vecdeque_pop(&recorder->audio_queue);
     }
 
     sc_mutex_unlock(&recorder->mutex);
 
     int ret = false;
 
-    if (video_pkt->packet->pts != AV_NOPTS_VALUE) {
+    if (video_pkt->pts != AV_NOPTS_VALUE) {
         LOGE("The first video packet is not a config packet");
         goto end;
     }
@@ -277,13 +267,13 @@ sc_recorder_process_header(struct sc_recorder *recorder) {
     assert(recorder->video_stream_index >= 0);
     AVStream *video_stream =
         recorder->ctx->streams[recorder->video_stream_index];
-    bool ok = sc_recorder_set_extradata(video_stream, video_pkt->packet);
+    bool ok = sc_recorder_set_extradata(video_stream, video_pkt);
     if (!ok) {
         goto end;
     }
 
     if (audio_pkt) {
-        if (audio_pkt->packet->pts != AV_NOPTS_VALUE) {
+        if (audio_pkt->pts != AV_NOPTS_VALUE) {
             LOGE("The first audio packet is not a config packet");
             goto end;
         }
@@ -291,7 +281,7 @@ sc_recorder_process_header(struct sc_recorder *recorder) {
         assert(recorder->audio_stream_index >= 0);
         AVStream *audio_stream =
             recorder->ctx->streams[recorder->audio_stream_index];
-        ok = sc_recorder_set_extradata(audio_stream, audio_pkt->packet);
+        ok = sc_recorder_set_extradata(audio_stream, audio_pkt);
         if (!ok) {
             goto end;
         }
@@ -306,9 +296,9 @@ sc_recorder_process_header(struct sc_recorder *recorder) {
     ret = true;
 
 end:
-    sc_record_packet_delete(video_pkt);
+    av_packet_free(&video_pkt);
     if (audio_pkt) {
-        sc_record_packet_delete(audio_pkt);
+        av_packet_free(&audio_pkt);
     }
 
     return ret;
@@ -323,12 +313,12 @@ sc_recorder_process_packets(struct sc_recorder *recorder) {
         return false;
     }
 
-    struct sc_record_packet *video_pkt = NULL;
-    struct sc_record_packet *audio_pkt = NULL;
+    AVPacket *video_pkt = NULL;
+    AVPacket *audio_pkt = NULL;
 
     // We can write a video packet only once we received the next one so that
     // we can set its duration (next_pts - current_pts)
-    struct sc_record_packet *video_pkt_previous = NULL;
+    AVPacket *video_pkt_previous = NULL;
 
     bool error = false;
 
@@ -336,12 +326,12 @@ sc_recorder_process_packets(struct sc_recorder *recorder) {
         sc_mutex_lock(&recorder->mutex);
 
         while (!recorder->stopped) {
-            if (!video_pkt && !sc_queue_is_empty(&recorder->video_queue)) {
+            if (!video_pkt && !sc_vecdeque_is_empty(&recorder->video_queue)) {
                 // A new packet may be assigned to video_pkt and be processed
                 break;
             }
             if (recorder->audio && !audio_pkt
-                    && !sc_queue_is_empty(&recorder->audio_queue)) {
+                    && !sc_vecdeque_is_empty(&recorder->audio_queue)) {
                 // A new packet may be assigned to audio_pkt and be processed
                 break;
             }
@@ -353,20 +343,20 @@ sc_recorder_process_packets(struct sc_recorder *recorder) {
 
         // If there is no audio, then the audio_queue will remain empty forever
         // and audio_pkt will always be NULL.
-        assert(recorder->audio
-                || (!audio_pkt && sc_queue_is_empty(&recorder->audio_queue)));
+        assert(recorder->audio || (!audio_pkt
+                && sc_vecdeque_is_empty(&recorder->audio_queue)));
 
-        if (!video_pkt && !sc_queue_is_empty(&recorder->video_queue)) {
-            sc_queue_take(&recorder->video_queue, next, &video_pkt);
+        if (!video_pkt && !sc_vecdeque_is_empty(&recorder->video_queue)) {
+            video_pkt = sc_vecdeque_pop(&recorder->video_queue);
         }
 
-        if (!audio_pkt && !sc_queue_is_empty(&recorder->audio_queue)) {
-            sc_queue_take(&recorder->audio_queue, next, &audio_pkt);
+        if (!audio_pkt && !sc_vecdeque_is_empty(&recorder->audio_queue)) {
+            audio_pkt = sc_vecdeque_pop(&recorder->audio_queue);
         }
 
         if (recorder->stopped && !video_pkt && !audio_pkt) {
-            assert(sc_queue_is_empty(&recorder->video_queue));
-            assert(sc_queue_is_empty(&recorder->audio_queue));
+            assert(sc_vecdeque_is_empty(&recorder->video_queue));
+            assert(sc_vecdeque_is_empty(&recorder->audio_queue));
             sc_mutex_unlock(&recorder->mutex);
             break;
         }
@@ -378,28 +368,27 @@ sc_recorder_process_packets(struct sc_recorder *recorder) {
         // Ignore further config packets (e.g. on device orientation
         // change). The next non-config packet will have the config packet
         // data prepended.
-        if (video_pkt && video_pkt->packet->pts == AV_NOPTS_VALUE) {
-            sc_record_packet_delete(video_pkt);
+        if (video_pkt && video_pkt->pts == AV_NOPTS_VALUE) {
+            av_packet_free(&video_pkt);
             video_pkt = NULL;
         }
 
-        if (audio_pkt && audio_pkt->packet->pts == AV_NOPTS_VALUE) {
-            sc_record_packet_delete(audio_pkt);
-            audio_pkt= NULL;
+        if (audio_pkt && audio_pkt->pts == AV_NOPTS_VALUE) {
+            av_packet_free(&audio_pkt);
+            audio_pkt = NULL;
         }
 
         if (pts_origin == AV_NOPTS_VALUE) {
             if (!recorder->audio) {
                 assert(video_pkt);
-                pts_origin = video_pkt->packet->pts;
+                pts_origin = video_pkt->pts;
             } else if (video_pkt && audio_pkt) {
-                pts_origin =
-                    MIN(video_pkt->packet->pts, audio_pkt->packet->pts);
+                pts_origin = MIN(video_pkt->pts, audio_pkt->pts);
             } else if (recorder->stopped) {
                 if (video_pkt) {
                     // The recorder is stopped without audio, record the video
                     // packets
-                    pts_origin = video_pkt->packet->pts;
+                    pts_origin = video_pkt->pts;
                 } else {
                     // Fail if there is no video
                     error = true;
@@ -408,8 +397,7 @@ sc_recorder_process_packets(struct sc_recorder *recorder) {
                 // If the recorder is stopped while one of the streams has no
                 // packets, then we must avoid a live-loop and correctly record
                 // the stream having packets.
-                pts_origin = video_pkt ? video_pkt->packet->pts
-                                       : audio_pkt->packet->pts;
+                pts_origin = video_pkt ? video_pkt->pts : audio_pkt->pts;
             } else {
                 // We need both video and audio packets to initialize pts_origin
                 continue;
@@ -419,17 +407,16 @@ sc_recorder_process_packets(struct sc_recorder *recorder) {
         assert(pts_origin != AV_NOPTS_VALUE);
 
         if (video_pkt) {
-            video_pkt->packet->pts -= pts_origin;
-            video_pkt->packet->dts = video_pkt->packet->pts;
+            video_pkt->pts -= pts_origin;
+            video_pkt->dts = video_pkt->pts;
 
             if (video_pkt_previous) {
                 // we now know the duration of the previous packet
-                video_pkt_previous->packet->duration =
-                    video_pkt->packet->pts - video_pkt_previous->packet->pts;
+                video_pkt_previous->duration = video_pkt->pts
+                                             - video_pkt_previous->pts;
 
-                bool ok = sc_recorder_write_video(recorder,
-                                                  video_pkt_previous->packet);
-                sc_record_packet_delete(video_pkt_previous);
+                bool ok = sc_recorder_write_video(recorder, video_pkt_previous);
+                av_packet_free(&video_pkt_previous);
                 if (!ok) {
                     LOGE("Could not record video packet");
                     error = true;
@@ -442,34 +429,34 @@ sc_recorder_process_packets(struct sc_recorder *recorder) {
         }
 
         if (audio_pkt) {
-            audio_pkt->packet->pts -= pts_origin;
-            audio_pkt->packet->dts = audio_pkt->packet->pts;
+            audio_pkt->pts -= pts_origin;
+            audio_pkt->dts = audio_pkt->pts;
 
-            bool ok = sc_recorder_write_audio(recorder, audio_pkt->packet);
+            bool ok = sc_recorder_write_audio(recorder, audio_pkt);
             if (!ok) {
                 LOGE("Could not record audio packet");
                 error = true;
                 goto end;
             }
 
-            sc_record_packet_delete(audio_pkt);
+            av_packet_free(&audio_pkt);
             audio_pkt = NULL;
         }
     }
 
     // Write the last video packet
-    struct sc_record_packet *last = video_pkt_previous;
+    AVPacket *last = video_pkt_previous;
     if (last) {
         // assign an arbitrary duration to the last packet
-        last->packet->duration = 100000;
-        bool ok = sc_recorder_write_video(recorder, last->packet);
+        last->duration = 100000;
+        bool ok = sc_recorder_write_video(recorder, last);
         if (!ok) {
             // failing to write the last frame is not very serious, no
             // future frame may depend on it, so the resulting file
             // will still be valid
             LOGW("Could not record last packet");
         }
-        sc_record_packet_delete(last);
+        av_packet_free(&last);
     }
 
     int ret = av_write_trailer(recorder->ctx);
@@ -480,10 +467,10 @@ sc_recorder_process_packets(struct sc_recorder *recorder) {
 
 end:
     if (video_pkt) {
-        sc_record_packet_delete(video_pkt);
+        av_packet_free(&video_pkt);
     }
     if (audio_pkt) {
-        sc_record_packet_delete(audio_pkt);
+        av_packet_free(&audio_pkt);
     }
 
     return !error;
@@ -589,16 +576,22 @@ sc_recorder_video_packet_sink_push(struct sc_packet_sink *sink,
         return false;
     }
 
-    struct sc_record_packet *rec = sc_record_packet_new(packet);
+    AVPacket *rec = sc_recorder_packet_ref(packet);
     if (!rec) {
         LOG_OOM();
         sc_mutex_unlock(&recorder->mutex);
         return false;
     }
 
-    rec->packet->stream_index = 0;
+    rec->stream_index = 0;
+
+    bool ok = sc_vecdeque_push(&recorder->video_queue, rec);
+    if (!ok) {
+        LOG_OOM();
+        sc_mutex_unlock(&recorder->mutex);
+        return false;
+    }
 
-    sc_queue_push(&recorder->video_queue, next, rec);
     sc_cond_signal(&recorder->queue_cond);
 
     sc_mutex_unlock(&recorder->mutex);
@@ -652,16 +645,22 @@ sc_recorder_audio_packet_sink_push(struct sc_packet_sink *sink,
         return false;
     }
 
-    struct sc_record_packet *rec = sc_record_packet_new(packet);
+    AVPacket *rec = sc_recorder_packet_ref(packet);
     if (!rec) {
         LOG_OOM();
         sc_mutex_unlock(&recorder->mutex);
         return false;
     }
 
-    rec->packet->stream_index = 1;
+    rec->stream_index = 1;
+
+    bool ok = sc_vecdeque_push(&recorder->audio_queue, rec);
+    if (!ok) {
+        LOG_OOM();
+        sc_mutex_unlock(&recorder->mutex);
+        return false;
+    }
 
-    sc_queue_push(&recorder->audio_queue, next, rec);
     sc_cond_signal(&recorder->queue_cond);
 
     sc_mutex_unlock(&recorder->mutex);
@@ -712,8 +711,8 @@ sc_recorder_init(struct sc_recorder *recorder, const char *filename,
 
     recorder->audio = audio;
 
-    sc_queue_init(&recorder->video_queue);
-    sc_queue_init(&recorder->audio_queue);
+    sc_vecdeque_init(&recorder->video_queue);
+    sc_vecdeque_init(&recorder->audio_queue);
     recorder->stopped = false;
 
     recorder->video_codec = NULL;

app/src/recorder.h

@@ -9,15 +9,10 @@
 #include "coords.h"
 #include "options.h"
 #include "trait/packet_sink.h"
-#include "util/queue.h"
 #include "util/thread.h"
+#include "util/vecdeque.h"
 
-struct sc_record_packet {
-    AVPacket *packet;
-    struct sc_record_packet *next;
-};
-
-struct sc_recorder_queue SC_QUEUE(struct sc_record_packet);
+struct sc_recorder_queue SC_VECDEQUE(AVPacket *);
 
 struct sc_recorder {
     struct sc_packet_sink video_packet_sink;

app/src/scrcpy.c

@@ -13,8 +13,10 @@
 # include <windows.h>
 #endif
 
+#include "audio_player.h"
 #include "controller.h"
 #include "decoder.h"
+#include "delay_buffer.h"
 #include "demuxer.h"
 #include "events.h"
 #include "file_pusher.h"
@@ -40,12 +42,17 @@
 struct scrcpy {
     struct sc_server server;
     struct sc_screen screen;
+    struct sc_audio_player audio_player;
+    struct sc_delay_buffer audio_buffer;
     struct sc_demuxer video_demuxer;
     struct sc_demuxer audio_demuxer;
-    struct sc_decoder decoder;
+    struct sc_decoder video_decoder;
+    struct sc_decoder audio_decoder;
     struct sc_recorder recorder;
+    struct sc_delay_buffer display_buffer;
 #ifdef HAVE_V4L2
     struct sc_v4l2_sink v4l2_sink;
+    struct sc_delay_buffer v4l2_buffer;
 #endif
     struct sc_controller controller;
     struct sc_file_pusher file_pusher;
@@ -183,15 +190,16 @@ await_for_server(bool *connected) {
     while (SDL_WaitEvent(&event)) {
         switch (event.type) {
             case SDL_QUIT:
-                LOGD("User requested to quit");
-                *connected = false;
+                if (connected) {
+                    *connected = false;
+                }
                 return true;
             case SC_EVENT_SERVER_CONNECTION_FAILED:
-                LOGE("Server connection failed");
                 return false;
             case SC_EVENT_SERVER_CONNECTED:
-                LOGD("Server connected");
-                *connected = true;
+                if (connected) {
+                    *connected = true;
+                }
                 return true;
             default:
                 break;
@@ -214,12 +222,15 @@ sc_recorder_on_ended(struct sc_recorder *recorder, bool success,
 }
 
 static void
-sc_video_demuxer_on_ended(struct sc_demuxer *demuxer, bool eos,
-                          void *userdata) {
+sc_video_demuxer_on_ended(struct sc_demuxer *demuxer,
+                          enum sc_demuxer_status status, void *userdata) {
     (void) demuxer;
     (void) userdata;
 
-    if (eos) {
+    // The device may not decide to disable the video
+    assert(status != SC_DEMUXER_STATUS_DISABLED);
+
+    if (status == SC_DEMUXER_STATUS_EOS) {
         PUSH_EVENT(SC_EVENT_DEVICE_DISCONNECTED);
     } else {
         PUSH_EVENT(SC_EVENT_DEMUXER_ERROR);
@@ -227,13 +238,26 @@ sc_video_demuxer_on_ended(struct sc_demuxer *demuxer, bool eos,
 }
 
 static void
-sc_audio_demuxer_on_ended(struct sc_demuxer *demuxer, bool eos,
-                          void *userdata) {
+sc_audio_demuxer_on_ended(struct sc_demuxer *demuxer,
+                          enum sc_demuxer_status status, void *userdata) {
     (void) demuxer;
-    (void) eos;
-    (void) userdata;
+
+    const struct scrcpy_options *options = userdata;
 
     // Contrary to the video demuxer, keep mirroring if only the audio fails
+    // (unless --require-audio is set).
+    // 'eos' is true on end-of-stream, including when audio capture is not
+    // possible on the device (so that scrcpy continue to mirror video without
+    // failing).
+    // However, if an audio configuration failure occurs (for example the user
+    // explicitly selected an unknown audio encoder), 'eos' is false and scrcpy
+    // must exit.
+
+    if (status == SC_DEMUXER_STATUS_ERROR
+            || (status == SC_DEMUXER_STATUS_DISABLED
+                && options->require_audio)) {
+        PUSH_EVENT(SC_EVENT_DEMUXER_ERROR);
+    }
 }
 
 static void
@@ -331,7 +355,9 @@ scrcpy(struct scrcpy_options *options) {
         .show_touches = options->show_touches,
         .stay_awake = options->stay_awake,
         .video_codec_options = options->video_codec_options,
+        .audio_codec_options = options->audio_codec_options,
         .video_encoder = options->video_encoder,
+        .audio_encoder = options->audio_encoder,
         .force_adb_forward = options->force_adb_forward,
         .power_off_on_close = options->power_off_on_close,
         .clipboard_autosync = options->clipboard_autosync,
@@ -340,6 +366,8 @@ scrcpy(struct scrcpy_options *options) {
         .tcpip_dst = options->tcpip_dst,
         .cleanup = options->cleanup,
         .power_on = options->power_on,
+        .list_encoders = options->list_encoders,
+        .list_displays = options->list_displays,
     };
 
     static const struct sc_server_callbacks cbs = {
@@ -357,14 +385,27 @@ scrcpy(struct scrcpy_options *options) {
 
     server_started = true;
 
+    if (options->list_encoders || options->list_displays) {
+        bool ok = await_for_server(NULL);
+        ret = ok ? SCRCPY_EXIT_SUCCESS : SCRCPY_EXIT_FAILURE;
+        goto end;
+    }
+
     if (options->display) {
         sdl_set_hints(options->render_driver);
     }
 
     // Initialize SDL video in addition if display is enabled
-    if (options->display && SDL_Init(SDL_INIT_VIDEO)) {
-        LOGE("Could not initialize SDL: %s", SDL_GetError());
-        goto end;
+    if (options->display) {
+        if (SDL_Init(SDL_INIT_VIDEO)) {
+            LOGE("Could not initialize SDL video: %s", SDL_GetError());
+            goto end;
+        }
+
+        if (options->audio && SDL_Init(SDL_INIT_AUDIO)) {
+            LOGE("Could not initialize SDL audio: %s", SDL_GetError());
+            goto end;
+        }
     }
 
     sdl_configure(options->display, options->disable_screensaver);
@@ -372,15 +413,19 @@ scrcpy(struct scrcpy_options *options) {
     // Await for server without blocking Ctrl+C handling
     bool connected;
     if (!await_for_server(&connected)) {
+        LOGE("Server connection failed");
         goto end;
     }
 
     if (!connected) {
         // This is not an error, user requested to quit
+        LOGD("User requested to quit");
         ret = SCRCPY_EXIT_SUCCESS;
         goto end;
     }
 
+    LOGD("Server connected");
+
     // It is necessarily initialized here, since the device is connected
     struct sc_server_info *info = &s->server.info;
 
@@ -409,16 +454,23 @@ scrcpy(struct scrcpy_options *options) {
             .on_ended = sc_audio_demuxer_on_ended,
         };
         sc_demuxer_init(&s->audio_demuxer, "audio", s->server.audio_socket,
-                        &audio_demuxer_cbs, NULL);
+                        &audio_demuxer_cbs, options);
     }
 
-    bool needs_decoder = options->display;
+    bool needs_video_decoder = options->display;
+    bool needs_audio_decoder = options->audio && options->display;
 #ifdef HAVE_V4L2
-    needs_decoder |= !!options->v4l2_device;
+    needs_video_decoder |= !!options->v4l2_device;
 #endif
-    if (needs_decoder) {
-        sc_decoder_init(&s->decoder);
-        sc_demuxer_add_sink(&s->video_demuxer, &s->decoder.packet_sink);
+    if (needs_video_decoder) {
+        sc_decoder_init(&s->video_decoder, "video");
+        sc_packet_source_add_sink(&s->video_demuxer.packet_source,
+                                  &s->video_decoder.packet_sink);
+    }
+    if (needs_audio_decoder) {
+        sc_decoder_init(&s->audio_decoder, "audio");
+        sc_packet_source_add_sink(&s->audio_demuxer.packet_source,
+                                  &s->audio_decoder.packet_sink);
     }
 
     if (options->record_filename) {
@@ -437,10 +489,11 @@ scrcpy(struct scrcpy_options *options) {
         }
         recorder_started = true;
 
-        sc_demuxer_add_sink(&s->video_demuxer, &s->recorder.video_packet_sink);
+        sc_packet_source_add_sink(&s->video_demuxer.packet_source,
+                                  &s->recorder.video_packet_sink);
         if (options->audio) {
-            sc_demuxer_add_sink(&s->audio_demuxer,
-                                &s->recorder.audio_packet_sink);
+            sc_packet_source_add_sink(&s->audio_demuxer.packet_source,
+                                      &s->recorder.audio_packet_sink);
         }
     }
 
@@ -624,7 +677,6 @@ aoa_hid_end:
             .mipmaps = options->mipmaps,
             .fullscreen = options->fullscreen,
             .start_fps_counter = options->start_fps_counter,
-            .buffering_time = options->display_buffer,
         };
 
         if (!sc_screen_init(&s->screen, &screen_params)) {
@@ -632,17 +684,45 @@ aoa_hid_end:
         }
         screen_initialized = true;
 
-        sc_decoder_add_sink(&s->decoder, &s->screen.frame_sink);
+        struct sc_frame_source *src = &s->video_decoder.frame_source;
+        if (options->display_buffer) {
+            sc_delay_buffer_init(&s->display_buffer, options->display_buffer,
+                                 true);
+            sc_frame_source_add_sink(src, &s->display_buffer.frame_sink);
+            src = &s->display_buffer.frame_source;
+        }
+
+        sc_frame_source_add_sink(src, &s->screen.frame_sink);
+
+        if (options->audio) {
+            struct sc_frame_source *src = &s->audio_decoder.frame_source;
+            if (options->audio_buffer) {
+                sc_delay_buffer_init(&s->audio_buffer, options->audio_buffer,
+                                     false);
+                sc_frame_source_add_sink(src, &s->audio_buffer.frame_sink);
+                src = &s->audio_buffer.frame_source;
+            }
+
+            sc_audio_player_init(&s->audio_player);
+            sc_frame_source_add_sink(src, &s->audio_player.frame_sink);
+        }
     }
 
 #ifdef HAVE_V4L2
     if (options->v4l2_device) {
         if (!sc_v4l2_sink_init(&s->v4l2_sink, options->v4l2_device,
-                               info->frame_size, options->v4l2_buffer)) {
+                               info->frame_size)) {
             goto end;
         }
 
-        sc_decoder_add_sink(&s->decoder, &s->v4l2_sink.frame_sink);
+        struct sc_frame_source *src = &s->video_decoder.frame_source;
+        if (options->v4l2_buffer) {
+            sc_delay_buffer_init(&s->v4l2_buffer, options->v4l2_buffer, true);
+            sc_frame_source_add_sink(src, &s->v4l2_buffer.frame_sink);
+            src = &s->v4l2_buffer.frame_source;
+        }
+
+        sc_frame_source_add_sink(src, &s->v4l2_sink.frame_sink);
 
         v4l2_sink_initialized = true;
     }

app/src/screen.c

@@ -7,7 +7,6 @@
 #include "events.h"
 #include "icon.h"
 #include "options.h"
-#include "video_buffer.h"
 #include "util/log.h"
 
 #define DISPLAY_MARGINS 96
@@ -330,7 +329,11 @@ event_watcher(void *data, SDL_Event *event) {
 #endif
 
 static bool
-sc_screen_frame_sink_open(struct sc_frame_sink *sink) {
+sc_screen_frame_sink_open(struct sc_frame_sink *sink,
+                          const AVCodecContext *ctx) {
+    assert(ctx->pix_fmt == AV_PIX_FMT_YUV420P);
+    (void) ctx;
+
     struct sc_screen *screen = DOWNCAST(sink);
     (void) screen;
 #ifndef NDEBUG
@@ -355,30 +358,18 @@ sc_screen_frame_sink_close(struct sc_frame_sink *sink) {
 static bool
 sc_screen_frame_sink_push(struct sc_frame_sink *sink, const AVFrame *frame) {
     struct sc_screen *screen = DOWNCAST(sink);
-    return sc_video_buffer_push(&screen->vb, frame);
-}
 
-static void
-sc_video_buffer_on_new_frame(struct sc_video_buffer *vb, bool previous_skipped,
-                             void *userdata) {
-    (void) vb;
-    struct sc_screen *screen = userdata;
+    bool previous_skipped;
+    bool ok = sc_frame_buffer_push(&screen->fb, frame, &previous_skipped);
+    if (!ok) {
+        return false;
+    }
 
-    // event_failed implies previous_skipped (the previous frame may not have
-    // been consumed if the event was not sent)
-    assert(!screen->event_failed || previous_skipped);
-
-    bool need_new_event;
     if (previous_skipped) {
         sc_fps_counter_add_skipped_frame(&screen->fps_counter);
         // The SC_EVENT_NEW_FRAME triggered for the previous frame will consume
-        // this new frame instead, unless the previous event failed
-        need_new_event = screen->event_failed;
+        // this new frame instead
     } else {
-        need_new_event = true;
-    }
-
-    if (need_new_event) {
         static SDL_Event new_frame_event = {
             .type = SC_EVENT_NEW_FRAME,
         };
@@ -387,11 +378,11 @@ sc_video_buffer_on_new_frame(struct sc_video_buffer *vb, bool previous_skipped,
         int ret = SDL_PushEvent(&new_frame_event);
         if (ret < 0) {
             LOGW("Could not post new frame event: %s", SDL_GetError());
-            screen->event_failed = true;
-        } else {
-            screen->event_failed = false;
+            return false;
         }
     }
+
+    return true;
 }
 
 bool
@@ -401,7 +392,6 @@ sc_screen_init(struct sc_screen *screen,
     screen->has_frame = false;
     screen->fullscreen = false;
     screen->maximized = false;
-    screen->event_failed = false;
     screen->mouse_capture_key_pressed = 0;
 
     screen->req.x = params->window_x;
@@ -411,23 +401,13 @@ sc_screen_init(struct sc_screen *screen,
     screen->req.fullscreen = params->fullscreen;
     screen->req.start_fps_counter = params->start_fps_counter;
 
-    static const struct sc_video_buffer_callbacks cbs = {
-        .on_new_frame = sc_video_buffer_on_new_frame,
-    };
-
-    bool ok = sc_video_buffer_init(&screen->vb, params->buffering_time, &cbs,
-                                   screen);
+    bool ok = sc_frame_buffer_init(&screen->fb);
     if (!ok) {
         return false;
     }
 
-    ok = sc_video_buffer_start(&screen->vb);
-    if (!ok) {
-        goto error_destroy_video_buffer;
-    }
-
     if (!sc_fps_counter_init(&screen->fps_counter)) {
-        goto error_stop_and_join_video_buffer;
+        goto error_destroy_frame_buffer;
     }
 
     screen->frame_size = params->frame_size;
@@ -559,11 +539,8 @@ error_destroy_window:
     SDL_DestroyWindow(screen->window);
 error_destroy_fps_counter:
     sc_fps_counter_destroy(&screen->fps_counter);
-error_stop_and_join_video_buffer:
-    sc_video_buffer_stop(&screen->vb);
-    sc_video_buffer_join(&screen->vb);
-error_destroy_video_buffer:
-    sc_video_buffer_destroy(&screen->vb);
+error_destroy_frame_buffer:
+    sc_frame_buffer_destroy(&screen->fb);
 
     return false;
 }
@@ -600,13 +577,11 @@ sc_screen_hide_window(struct sc_screen *screen) {
 
 void
 sc_screen_interrupt(struct sc_screen *screen) {
-    sc_video_buffer_stop(&screen->vb);
     sc_fps_counter_interrupt(&screen->fps_counter);
 }
 
 void
 sc_screen_join(struct sc_screen *screen) {
-    sc_video_buffer_join(&screen->vb);
     sc_fps_counter_join(&screen->fps_counter);
 }
 
@@ -620,7 +595,7 @@ sc_screen_destroy(struct sc_screen *screen) {
     SDL_DestroyRenderer(screen->renderer);
     SDL_DestroyWindow(screen->window);
     sc_fps_counter_destroy(&screen->fps_counter);
-    sc_video_buffer_destroy(&screen->vb);
+    sc_frame_buffer_destroy(&screen->fb);
 }
 
 static void
@@ -726,7 +701,7 @@ update_texture(struct sc_screen *screen, const AVFrame *frame) {
 static bool
 sc_screen_update_frame(struct sc_screen *screen) {
     av_frame_unref(screen->frame);
-    sc_video_buffer_consume(&screen->vb, screen->frame);
+    sc_frame_buffer_consume(&screen->fb, screen->frame);
     AVFrame *frame = screen->frame;
 
     sc_fps_counter_add_rendered_frame(&screen->fps_counter);

app/src/screen.h

@@ -10,12 +10,12 @@
 #include "controller.h"
 #include "coords.h"
 #include "fps_counter.h"
+#include "frame_buffer.h"
 #include "input_manager.h"
 #include "opengl.h"
 #include "trait/key_processor.h"
 #include "trait/frame_sink.h"
 #include "trait/mouse_processor.h"
-#include "video_buffer.h"
 
 struct sc_screen {
     struct sc_frame_sink frame_sink; // frame sink trait
@@ -25,7 +25,7 @@ struct sc_screen {
 #endif
 
     struct sc_input_manager im;
-    struct sc_video_buffer vb;
+    struct sc_frame_buffer fb;
     struct sc_fps_counter fps_counter;
 
     // The initial requested window properties
@@ -59,8 +59,6 @@ struct sc_screen {
     bool maximized;
     bool mipmaps;
 
-    bool event_failed; // in case SDL_PushEvent() returned an error
-
     // To enable/disable mouse capture, a mouse capture key (LALT, LGUI or
     // RGUI) must be pressed. This variable tracks the pressed capture key.
     SDL_Keycode mouse_capture_key_pressed;
@@ -95,8 +93,6 @@ struct sc_screen_params {
 
     bool fullscreen;
     bool start_fps_counter;
-
-    sc_tick buffering_time;
 };
 
 // initialize screen, create window, renderer and texture (window is hidden)

app/src/server.c

@@ -72,7 +72,9 @@ sc_server_params_destroy(struct sc_server_params *params) {
     free((char *) params->req_serial);
     free((char *) params->crop);
     free((char *) params->video_codec_options);
+    free((char *) params->audio_codec_options);
     free((char *) params->video_encoder);
+    free((char *) params->audio_encoder);
     free((char *) params->tcpip_dst);
 }
 
@@ -96,7 +98,9 @@ sc_server_params_copy(struct sc_server_params *dst,
     COPY(req_serial);
     COPY(crop);
     COPY(video_codec_options);
+    COPY(audio_codec_options);
     COPY(video_encoder);
+    COPY(audio_encoder);
     COPY(tcpip_dst);
 #undef COPY
 
@@ -165,6 +169,8 @@ sc_server_get_codec_name(enum sc_codec codec) {
             return "h265";
         case SC_CODEC_AV1:
             return "av1";
+        case SC_CODEC_RAW:
+            return "raw";
         case SC_CODEC_OPUS:
             return "opus";
         case SC_CODEC_AAC:
@@ -268,9 +274,15 @@ execute_server(struct sc_server *server,
     if (params->video_codec_options) {
         ADD_PARAM("video_codec_options=%s", params->video_codec_options);
     }
+    if (params->audio_codec_options) {
+        ADD_PARAM("audio_codec_options=%s", params->audio_codec_options);
+    }
     if (params->video_encoder) {
         ADD_PARAM("video_encoder=%s", params->video_encoder);
     }
+    if (params->audio_encoder) {
+        ADD_PARAM("audio_encoder=%s", params->audio_encoder);
+    }
     if (params->power_off_on_close) {
         ADD_PARAM("power_off_on_close=true");
     }
@@ -290,6 +302,12 @@ execute_server(struct sc_server *server,
         // By default, power_on is true
         ADD_PARAM("power_on=false");
     }
+    if (params->list_encoders) {
+        ADD_PARAM("list_encoders=true");
+    }
+    if (params->list_displays) {
+        ADD_PARAM("list_displays=true");
+    }
 
 #undef ADD_PARAM
 
@@ -838,6 +856,25 @@ run_server(void *data) {
     assert(serial);
     LOGD("Device serial: %s", serial);
 
+    ok = push_server(&server->intr, serial);
+    if (!ok) {
+        goto error_connection_failed;
+    }
+
+    // If --list-* is passed, then the server just prints the requested data
+    // then exits.
+    if (params->list_encoders || params->list_displays) {
+        sc_pid pid = execute_server(server, params);
+        if (pid == SC_PROCESS_NONE) {
+            goto error_connection_failed;
+        }
+        sc_process_wait(pid, NULL); // ignore exit code
+        sc_process_close(pid);
+        // Wake up await_for_server()
+        server->cbs->on_connected(server, server->cbs_userdata);
+        return 0;
+    }
+
     int r = asprintf(&server->device_socket_name, SC_SOCKET_NAME_PREFIX "%08x",
                      params->scid);
     if (r == -1) {
@@ -847,11 +884,6 @@ run_server(void *data) {
     assert(r == sizeof(SC_SOCKET_NAME_PREFIX) - 1 + 8);
     assert(server->device_socket_name);
 
-    ok = push_server(&server->intr, serial);
-    if (!ok) {
-        goto error_connection_failed;
-    }
-
     ok = sc_adb_tunnel_open(&server->tunnel, &server->intr, serial,
                             server->device_socket_name, params->port_range,
                             params->force_adb_forward);

app/src/server.h

@@ -29,7 +29,9 @@ struct sc_server_params {
     enum sc_codec audio_codec;
     const char *crop;
     const char *video_codec_options;
+    const char *audio_codec_options;
     const char *video_encoder;
+    const char *audio_encoder;
     struct sc_port_range port_range;
     uint32_t tunnel_host;
     uint16_t tunnel_port;
@@ -53,6 +55,8 @@ struct sc_server_params {
     bool select_tcpip;
     bool cleanup;
     bool power_on;
+    bool list_encoders;
+    bool list_displays;
 };
 
 struct sc_server {

app/src/trait/frame_sink.h

@@ -5,6 +5,7 @@
 
 #include <assert.h>
 #include <stdbool.h>
+#include <libavcodec/avcodec.h>
 
 typedef struct AVFrame AVFrame;
 
@@ -18,7 +19,7 @@ struct sc_frame_sink {
 };
 
 struct sc_frame_sink_ops {
-    bool (*open)(struct sc_frame_sink *sink);
+    bool (*open)(struct sc_frame_sink *sink, const AVCodecContext *ctx);
     void (*close)(struct sc_frame_sink *sink);
     bool (*push)(struct sc_frame_sink *sink, const AVFrame *frame);
 };

app/src/trait/frame_source.c

@@ -0,0 +1,59 @@
+#include "frame_source.h"
+
+void
+sc_frame_source_init(struct sc_frame_source *source) {
+    source->sink_count = 0;
+}
+
+void
+sc_frame_source_add_sink(struct sc_frame_source *source,
+                         struct sc_frame_sink *sink) {
+    assert(source->sink_count < SC_FRAME_SOURCE_MAX_SINKS);
+    assert(sink);
+    assert(sink->ops);
+    source->sinks[source->sink_count++] = sink;
+}
+
+static void
+sc_frame_source_sinks_close_firsts(struct sc_frame_source *source,
+                                    unsigned count) {
+    while (count) {
+        struct sc_frame_sink *sink = source->sinks[--count];
+        sink->ops->close(sink);
+    }
+}
+
+bool
+sc_frame_source_sinks_open(struct sc_frame_source *source,
+                           const AVCodecContext *ctx) {
+    assert(source->sink_count);
+    for (unsigned i = 0; i < source->sink_count; ++i) {
+        struct sc_frame_sink *sink = source->sinks[i];
+        if (!sink->ops->open(sink, ctx)) {
+            sc_frame_source_sinks_close_firsts(source, i);
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void
+sc_frame_source_sinks_close(struct sc_frame_source *source) {
+    assert(source->sink_count);
+    sc_frame_source_sinks_close_firsts(source, source->sink_count);
+}
+
+bool
+sc_frame_source_sinks_push(struct sc_frame_source *source,
+                            const AVFrame *frame) {
+    assert(source->sink_count);
+    for (unsigned i = 0; i < source->sink_count; ++i) {
+        struct sc_frame_sink *sink = source->sinks[i];
+        if (!sink->ops->push(sink, frame)) {
+            return false;
+        }
+    }
+
+    return true;
+}

app/src/trait/frame_source.h

@@ -0,0 +1,38 @@
+#ifndef SC_FRAME_SOURCE_H
+#define SC_FRAME_SOURCE_H
+
+#include "common.h"
+
+#include "frame_sink.h"
+
+#define SC_FRAME_SOURCE_MAX_SINKS 2
+
+/**
+ * Frame source trait
+ *
+ * Component able to send AVFrames should implement this trait.
+ */
+struct sc_frame_source {
+    struct sc_frame_sink *sinks[SC_FRAME_SOURCE_MAX_SINKS];
+    unsigned sink_count;
+};
+
+void
+sc_frame_source_init(struct sc_frame_source *source);
+
+void
+sc_frame_source_add_sink(struct sc_frame_source *source,
+                         struct sc_frame_sink *sink);
+
+bool
+sc_frame_source_sinks_open(struct sc_frame_source *source,
+                           const AVCodecContext *ctx);
+
+void
+sc_frame_source_sinks_close(struct sc_frame_source *source);
+
+bool
+sc_frame_source_sinks_push(struct sc_frame_source *source,
+                           const AVFrame *frame);
+
+#endif

app/src/trait/packet_source.c

@@ -0,0 +1,70 @@
+#include "packet_source.h"
+
+void
+sc_packet_source_init(struct sc_packet_source *source) {
+    source->sink_count = 0;
+}
+
+void
+sc_packet_source_add_sink(struct sc_packet_source *source,
+                          struct sc_packet_sink *sink) {
+    assert(source->sink_count < SC_PACKET_SOURCE_MAX_SINKS);
+    assert(sink);
+    assert(sink->ops);
+    source->sinks[source->sink_count++] = sink;
+}
+
+static void
+sc_packet_source_sinks_close_firsts(struct sc_packet_source *source,
+                                    unsigned count) {
+    while (count) {
+        struct sc_packet_sink *sink = source->sinks[--count];
+        sink->ops->close(sink);
+    }
+}
+
+bool
+sc_packet_source_sinks_open(struct sc_packet_source *source,
+                            const AVCodec *codec) {
+    assert(source->sink_count);
+    for (unsigned i = 0; i < source->sink_count; ++i) {
+        struct sc_packet_sink *sink = source->sinks[i];
+        if (!sink->ops->open(sink, codec)) {
+            sc_packet_source_sinks_close_firsts(source, i);
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void
+sc_packet_source_sinks_close(struct sc_packet_source *source) {
+    assert(source->sink_count);
+    sc_packet_source_sinks_close_firsts(source, source->sink_count);
+}
+
+bool
+sc_packet_source_sinks_push(struct sc_packet_source *source,
+                            const AVPacket *packet) {
+    assert(source->sink_count);
+    for (unsigned i = 0; i < source->sink_count; ++i) {
+        struct sc_packet_sink *sink = source->sinks[i];
+        if (!sink->ops->push(sink, packet)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void
+sc_packet_source_sinks_disable(struct sc_packet_source *source) {
+    assert(source->sink_count);
+    for (unsigned i = 0; i < source->sink_count; ++i) {
+        struct sc_packet_sink *sink = source->sinks[i];
+        if (sink->ops->disable) {
+            sink->ops->disable(sink);
+        }
+    }
+}

app/src/trait/packet_source.h

@@ -0,0 +1,41 @@
+#ifndef SC_PACKET_SOURCE_H
+#define SC_PACKET_SOURCE_H
+
+#include "common.h"
+
+#include "packet_sink.h"
+
+#define SC_PACKET_SOURCE_MAX_SINKS 2
+
+/**
+ * Packet source trait
+ *
+ * Component able to send AVPackets should implement this trait.
+ */
+struct sc_packet_source {
+    struct sc_packet_sink *sinks[SC_PACKET_SOURCE_MAX_SINKS];
+    unsigned sink_count;
+};
+
+void
+sc_packet_source_init(struct sc_packet_source *source);
+
+void
+sc_packet_source_add_sink(struct sc_packet_source *source,
+                          struct sc_packet_sink *sink);
+
+bool
+sc_packet_source_sinks_open(struct sc_packet_source *source,
+                            const AVCodec *codec);
+
+void
+sc_packet_source_sinks_close(struct sc_packet_source *source);
+
+bool
+sc_packet_source_sinks_push(struct sc_packet_source *source,
+                            const AVPacket *packet);
+
+void
+sc_packet_source_sinks_disable(struct sc_packet_source *source);
+
+#endif

app/src/usb/aoa_hid.c

@@ -14,6 +14,8 @@
 
 #define DEFAULT_TIMEOUT 1000
 
+#define SC_HID_EVENT_QUEUE_MAX 64
+
 static void
 sc_hid_event_log(const struct sc_hid_event *event) {
     // HID Event: [00] FF FF FF FF...
@@ -48,14 +50,20 @@ sc_hid_event_destroy(struct sc_hid_event *hid_event) {
 bool
 sc_aoa_init(struct sc_aoa *aoa, struct sc_usb *usb,
             struct sc_acksync *acksync) {
-    cbuf_init(&aoa->queue);
+    sc_vecdeque_init(&aoa->queue);
+
+    if (!sc_vecdeque_reserve(&aoa->queue, SC_HID_EVENT_QUEUE_MAX)) {
+        return false;
+    }
 
     if (!sc_mutex_init(&aoa->mutex)) {
+        sc_vecdeque_destroy(&aoa->queue);
         return false;
     }
 
     if (!sc_cond_init(&aoa->event_cond)) {
         sc_mutex_destroy(&aoa->mutex);
+        sc_vecdeque_destroy(&aoa->queue);
         return false;
     }
 
@@ -69,9 +77,10 @@ sc_aoa_init(struct sc_aoa *aoa, struct sc_usb *usb,
 void
 sc_aoa_destroy(struct sc_aoa *aoa) {
     // Destroy remaining events
-    struct sc_hid_event event;
-    while (cbuf_take(&aoa->queue, &event)) {
-        sc_hid_event_destroy(&event);
+    while (!sc_vecdeque_is_empty(&aoa->queue)) {
+        struct sc_hid_event *event = sc_vecdeque_popref(&aoa->queue);
+        assert(event);
+        sc_hid_event_destroy(event);
     }
 
     sc_cond_destroy(&aoa->event_cond);
@@ -212,13 +221,19 @@ sc_aoa_push_hid_event(struct sc_aoa *aoa, const struct sc_hid_event *event) {
     }
 
     sc_mutex_lock(&aoa->mutex);
-    bool was_empty = cbuf_is_empty(&aoa->queue);
-    bool res = cbuf_push(&aoa->queue, *event);
-    if (was_empty) {
-        sc_cond_signal(&aoa->event_cond);
+    bool full = sc_vecdeque_is_full(&aoa->queue);
+    if (!full) {
+        bool was_empty = sc_vecdeque_is_empty(&aoa->queue);
+        sc_vecdeque_push_noresize(&aoa->queue, *event);
+        if (was_empty) {
+            sc_cond_signal(&aoa->event_cond);
+        }
     }
+    // Otherwise (if the queue is full), the event is discarded
+
     sc_mutex_unlock(&aoa->mutex);
-    return res;
+
+    return !full;
 }
 
 static int
@@ -227,7 +242,7 @@ run_aoa_thread(void *data) {
 
     for (;;) {
         sc_mutex_lock(&aoa->mutex);
-        while (!aoa->stopped && cbuf_is_empty(&aoa->queue)) {
+        while (!aoa->stopped && sc_vecdeque_is_empty(&aoa->queue)) {
             sc_cond_wait(&aoa->event_cond, &aoa->mutex);
         }
         if (aoa->stopped) {
@@ -235,11 +250,9 @@ run_aoa_thread(void *data) {
             sc_mutex_unlock(&aoa->mutex);
             break;
         }
-        struct sc_hid_event event;
-        bool non_empty = cbuf_take(&aoa->queue, &event);
-        assert(non_empty);
-        (void) non_empty;
 
+        assert(!sc_vecdeque_is_empty(&aoa->queue));
+        struct sc_hid_event event = sc_vecdeque_pop(&aoa->queue);
         uint64_t ack_to_wait = event.ack_to_wait;
         sc_mutex_unlock(&aoa->mutex);
 

app/src/usb/aoa_hid.h

@@ -8,9 +8,9 @@
 
 #include "usb.h"
 #include "util/acksync.h"
-#include "util/cbuf.h"
 #include "util/thread.h"
 #include "util/tick.h"
+#include "util/vecdeque.h"
 
 struct sc_hid_event {
     uint16_t accessory_id;
@@ -27,7 +27,7 @@ sc_hid_event_init(struct sc_hid_event *hid_event, uint16_t accessory_id,
 void
 sc_hid_event_destroy(struct sc_hid_event *hid_event);
 
-struct sc_hid_event_queue CBUF(struct sc_hid_event, 64);
+struct sc_hid_event_queue SC_VECDEQUE(struct sc_hid_event);
 
 struct sc_aoa {
     struct sc_usb *usb;

app/src/util/average.c

@@ -0,0 +1,26 @@
+#include "average.h"
+
+#include <assert.h>
+
+void
+sc_average_init(struct sc_average *avg, unsigned range) {
+    avg->range = range;
+    avg->avg = 0;
+    avg->count = 0;
+}
+
+void
+sc_average_push(struct sc_average *avg, float value) {
+    if (avg->count < avg->range) {
+        ++avg->count;
+    }
+
+    assert(avg->count);
+    avg->avg = ((avg->count - 1) * avg->avg + value) / avg->count;
+}
+
+float
+sc_average_get(struct sc_average *avg) {
+    assert(avg->count);
+    return avg->avg;
+}

app/src/util/average.h

@@ -0,0 +1,40 @@
+#ifndef SC_AVERAGE
+#define SC_AVERAGE
+
+#include "common.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+
+struct sc_average {
+    // Current average value
+    float avg;
+
+    // Target range, to update the average as follow:
+    //     avg = ((range - 1) * avg + new_value) / range
+    unsigned range;
+
+    // Number of values pushed when less than range (count <= range).
+    // The purpose is to handle the first (range - 1) values properly.
+    unsigned count;
+};
+
+void
+sc_average_init(struct sc_average *avg, unsigned range);
+
+/**
+ * Push a new value to update the "rolling" average
+ */
+void
+sc_average_push(struct sc_average *avg, float value);
+
+/**
+ * Get the current average value
+ *
+ * It is an error to call this function if sc_average_push() has not been
+ * called at least once.
+ */
+float
+sc_average_get(struct sc_average *avg);
+
+#endif

app/src/util/bytebuf.c

@@ -0,0 +1,105 @@
+#include "bytebuf.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util/log.h"
+
+bool
+sc_bytebuf_init(struct sc_bytebuf *buf, size_t alloc_size) {
+    assert(alloc_size);
+    // sufficient, but use more for alignment.
+    buf->data = malloc(alloc_size);
+    if (!buf->data) {
+        LOG_OOM();
+        return false;
+    }
+
+    buf->alloc_size = alloc_size;
+    buf->head = 0;
+    buf->tail = 0;
+
+    return true;
+}
+
+void
+sc_bytebuf_destroy(struct sc_bytebuf *buf) {
+    free(buf->data);
+}
+
+void
+sc_bytebuf_read(struct sc_bytebuf *buf, uint8_t *to, size_t len) {
+    assert(len);
+    assert(len <= sc_bytebuf_read_available(buf));
+    assert(buf->tail != buf->head); // the buffer could not be empty
+
+    size_t right_limit = buf->tail < buf->head ? buf->head : buf->alloc_size;
+    size_t right_len = right_limit - buf->tail;
+    if (len < right_len) {
+        right_len = len;
+    }
+    memcpy(to, buf->data + buf->tail, right_len);
+
+    if (len > right_len) {
+        memcpy(to + right_len, buf->data, len - right_len);
+    }
+
+    buf->tail = (buf->tail + len) % buf->alloc_size;
+}
+
+void
+sc_bytebuf_skip(struct sc_bytebuf *buf, size_t len) {
+    assert(len);
+    assert(len <= sc_bytebuf_read_available(buf));
+    assert(buf->tail != buf->head); // the buffer could not be empty
+
+    buf->tail = (buf->tail + len) % buf->alloc_size;
+}
+
+static inline void
+sc_bytebuf_write_step0(struct sc_bytebuf *buf, const uint8_t *from,
+                       size_t len) {
+    size_t right_len = buf->alloc_size - buf->head;
+    if (len < right_len) {
+        right_len = len;
+    }
+
+    memcpy(buf->data + buf->head, from, right_len);
+    if (len > right_len) {
+        memcpy(buf->data, from + right_len, len - right_len);
+    }
+}
+
+static inline void
+sc_bytebuf_write_step1(struct sc_bytebuf *buf, size_t len) {
+    buf->head = (buf->head + len) % buf->alloc_size;
+}
+
+void
+sc_bytebuf_write(struct sc_bytebuf *buf, const uint8_t *from, size_t len) {
+    assert(len);
+    assert(len <= sc_bytebuf_write_available(buf));
+
+    sc_bytebuf_write_step0(buf, from, len);
+    sc_bytebuf_write_step1(buf, len);
+}
+
+void
+sc_bytebuf_prepare_write(struct sc_bytebuf *buf, const uint8_t *from,
+                         size_t len) {
+    // *This function MUST NOT access buf->tail (even in assert()).*
+    // The purpose of this function is to allow a reader and a writer to access
+    // different parts of the buffer in parallel simultaneously. It is intended
+    // to be called without lock (only sc_bytebuf_commit_write() is intended to
+    // be called with lock held).
+
+    assert(len < buf->alloc_size - 1);
+    sc_bytebuf_write_step0(buf, from, len);
+}
+
+void
+sc_bytebuf_commit_write(struct sc_bytebuf *buf, size_t len) {
+    assert(len <= sc_bytebuf_write_available(buf));
+    sc_bytebuf_write_step1(buf, len);
+}

app/src/util/bytebuf.h

@@ -0,0 +1,116 @@
+#ifndef SC_BYTEBUF_H
+#define SC_BYTEBUF_H
+
+#include "common.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+
+struct sc_bytebuf {
+    uint8_t *data;
+    // The actual capacity is (allocated - 1) so that head == tail is
+    // non-ambiguous
+    size_t alloc_size;
+    size_t head; // writter cursor
+    size_t tail; // reader cursor
+    // empty: tail == head
+    // full: (tail + 1) % allocated == head
+};
+
+bool
+sc_bytebuf_init(struct sc_bytebuf *buf, size_t alloc_size);
+
+/**
+ * Copy from the bytebuf to a user-provided array
+ *
+ * The caller must check that len <= sc_bytebuf_read_available() (it is an
+ * error to attempt to read more bytes than available).
+ *
+ * This function is guaranteed not to write to buf->head.
+ */
+void
+sc_bytebuf_read(struct sc_bytebuf *buf, uint8_t *to, size_t len);
+
+/**
+ * Drop len bytes from the buffer
+ *
+ * The caller must check that len <= sc_bytebuf_read_available() (it is an
+ * error to attempt to skip more bytes than available).
+ *
+ * This function is guaranteed not to change the head.
+ *
+ * This function is guaranteed to not change the head.
+ *
+ * It is equivalent to call sc_bytebuf_read() to some array and discard the
+ * array (but more efficient since there is no copy).
+ */
+void
+sc_bytebuf_skip(struct sc_bytebuf *buf, size_t len);
+
+/**
+ * Copy the user-provided array to the bytebuf
+ *
+ * The caller must check that len <= sc_bytebuf_write_available() (it is an
+ * error to write more bytes than the remaining available space).
+ *
+ * This function is guaranteed not to write to buf->tail.
+ */
+void
+sc_bytebuf_write(struct sc_bytebuf *buf, const uint8_t *from, size_t len);
+
+/**
+ * Copy the user-provided array to the bytebuf, but do not advance the cursor
+ *
+ * The caller must check that len <= sc_bytebuf_write_available() (it is an
+ * error to write more bytes than the remaining available space).
+ *
+ * After this function is called, the write must be committed with
+ * sc_bytebuf_commit_write().
+ *
+ * The purpose of this mechanism is to acquire a lock only to commit the write,
+ * but not to perform the actual copy.
+ *
+ * This function is guaranteed not to access buf->tail.
+ */
+void
+sc_bytebuf_prepare_write(struct sc_bytebuf *buf, const uint8_t *from,
+                         size_t len);
+
+/**
+ * Commit a prepared write
+ */
+void
+sc_bytebuf_commit_write(struct sc_bytebuf *buf, size_t len);
+
+/**
+ * Return the number of bytes which can be read
+ *
+ * It is an error to read more bytes than available.
+ */
+static inline size_t
+sc_bytebuf_read_available(struct sc_bytebuf *buf) {
+    return (buf->alloc_size + buf->head - buf->tail) % buf->alloc_size;
+}
+
+/**
+ * Return the number of bytes which can be written
+ *
+ * It is an error to write more bytes than available.
+ */
+static inline size_t
+sc_bytebuf_write_available(struct sc_bytebuf *buf) {
+    return (buf->alloc_size + buf->tail - buf->head - 1) % buf->alloc_size;
+}
+
+/**
+ * Return the actual capacity of the buffer (read available + write available)
+ */
+static inline size_t
+sc_bytebuf_capacity(struct sc_bytebuf *buf) {
+    return buf->alloc_size - 1;
+}
+
+void
+sc_bytebuf_destroy(struct sc_bytebuf *buf);
+
+#endif

app/src/util/cbuf.h

@@ -1,52 +0,0 @@
-// generic circular buffer (bounded queue) implementation
-#ifndef SC_CBUF_H
-#define SC_CBUF_H
-
-#include "common.h"
-
-#include <stdbool.h>
-#include <unistd.h>
-
-// To define a circular buffer type of 20 ints:
-//     struct cbuf_int CBUF(int, 20);
-//
-// data has length CAP + 1 to distinguish empty vs full.
-#define CBUF(TYPE, CAP) { \
-    TYPE data[(CAP) + 1]; \
-    size_t head; \
-    size_t tail; \
-}
-
-#define cbuf_size_(PCBUF) \
-    (sizeof((PCBUF)->data) / sizeof(*(PCBUF)->data))
-
-#define cbuf_is_empty(PCBUF) \
-    ((PCBUF)->head == (PCBUF)->tail)
-
-#define cbuf_is_full(PCBUF) \
-    (((PCBUF)->head + 1) % cbuf_size_(PCBUF) == (PCBUF)->tail)
-
-#define cbuf_init(PCBUF) \
-    (void) ((PCBUF)->head = (PCBUF)->tail = 0)
-
-#define cbuf_push(PCBUF, ITEM) \
-    ({ \
-        bool ok = !cbuf_is_full(PCBUF); \
-        if (ok) { \
-            (PCBUF)->data[(PCBUF)->head] = (ITEM); \
-            (PCBUF)->head = ((PCBUF)->head + 1) % cbuf_size_(PCBUF); \
-        } \
-        ok; \
-    })
-
-#define cbuf_take(PCBUF, PITEM) \
-    ({ \
-        bool ok = !cbuf_is_empty(PCBUF); \
-        if (ok) { \
-            *(PITEM) = (PCBUF)->data[(PCBUF)->tail]; \
-            (PCBUF)->tail = ((PCBUF)->tail + 1) % cbuf_size_(PCBUF); \
-        } \
-        ok; \
-    })
-
-#endif

app/src/util/memory.c

@@ -0,0 +1,14 @@
+#include "memory.h"
+
+#include <stdlib.h>
+#include <errno.h>
+
+void *
+sc_allocarray(size_t nmemb, size_t size) {
+    size_t bytes;
+    if (__builtin_mul_overflow(nmemb, size, &bytes)) {
+      errno = ENOMEM;
+      return NULL;
+    }
+    return malloc(bytes);
+}

app/src/util/memory.h

@@ -0,0 +1,12 @@
+#ifndef SC_MEMORY_H
+#define SC_MEMORY_H
+
+#include <stddef.h>
+
+/* Like calloc(), but without initialization.
+ * Like reallocarray(), but without reallocation.
+ */
+void *
+sc_allocarray(size_t nmemb, size_t size);
+
+#endif

app/src/util/queue.h

@@ -1,77 +0,0 @@
-// generic intrusive FIFO queue
-#ifndef SC_QUEUE_H
-#define SC_QUEUE_H
-
-#include "common.h"
-
-#include <assert.h>
-#include <stdbool.h>
-#include <stddef.h>
-
-// To define a queue type of "struct foo":
-//    struct queue_foo QUEUE(struct foo);
-#define SC_QUEUE(TYPE) { \
-    TYPE *first; \
-    TYPE *last; \
-}
-
-#define sc_queue_init(PQ) \
-    (void) ((PQ)->first = (PQ)->last = NULL)
-
-#define sc_queue_is_empty(PQ) \
-    !(PQ)->first
-
-// NEXTFIELD is the field in the ITEM type used for intrusive linked-list
-//
-// For example:
-//    struct foo {
-//        int value;
-//        struct foo *next;
-//    };
-//
-//    // define the type "struct my_queue"
-//    struct my_queue SC_QUEUE(struct foo);
-//
-//    struct my_queue queue;
-//    sc_queue_init(&queue);
-//
-//    struct foo v1 = { .value = 42 };
-//    struct foo v2 = { .value = 27 };
-//
-//    sc_queue_push(&queue, next, v1);
-//    sc_queue_push(&queue, next, v2);
-//
-//    struct foo *foo;
-//    sc_queue_take(&queue, next, &foo);
-//    assert(foo->value == 42);
-//    sc_queue_take(&queue, next, &foo);
-//    assert(foo->value == 27);
-//    assert(sc_queue_is_empty(&queue));
-//
-
-// push a new item into the queue
-#define sc_queue_push(PQ, NEXTFIELD, ITEM) \
-    (void) ({ \
-        (ITEM)->NEXTFIELD = NULL; \
-        if (sc_queue_is_empty(PQ)) { \
-            (PQ)->first = (PQ)->last = (ITEM); \
-        } else { \
-            (PQ)->last->NEXTFIELD = (ITEM); \
-            (PQ)->last = (ITEM); \
-        } \
-    })
-
-// take the next item and remove it from the queue (the queue must not be empty)
-// the result is stored in *(PITEM)
-// (without typeof(), we could not store a local variable having the correct
-// type so that we can "return" it)
-#define sc_queue_take(PQ, NEXTFIELD, PITEM) \
-    (void) ({ \
-        assert(!sc_queue_is_empty(PQ)); \
-        *(PITEM) = (PQ)->first; \
-        (PQ)->first = (PQ)->first->NEXTFIELD; \
-    })
-    // no need to update (PQ)->last if the queue is left empty:
-    // (PQ)->last is undefined if !(PQ)->first anyway
-
-#endif

app/src/util/vecdeque.h

@@ -0,0 +1,379 @@
+#ifndef SC_VECDEQUE_H
+#define SC_VECDEQUE_H
+
+#include "common.h"
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util/memory.h"
+
+/**
+ * A double-ended queue implemented with a growable ring buffer.
+ *
+ * Inspired from the Rust VecDeque type:
+ * <https://doc.rust-lang.org/std/collections/struct.VecDeque.html>
+ */
+
+/**
+ * VecDeque struct body
+ *
+ * A VecDeque is a dynamic ring-buffer, managed by the sc_vecdeque_* helpers.
+ *
+ * It is generic over the type of its items, so it is implemented via macros.
+ *
+ * To use a VecDeque, a new type must be defined:
+ *
+ *     struct vecdeque_int SC_VECDEQUE(int);
+ *
+ * The struct may be anonymous:
+ *
+ *     struct SC_VECDEQUE(const char *) names;
+ *
+ * Functions and macros having name ending with '_' are private.
+ */
+#define SC_VECDEQUE(type) { \
+    size_t cap; \
+    size_t origin; \
+    size_t size; \
+    type *data; \
+}
+
+/**
+ * Static initializer for a VecDeque
+ */
+#define SC_VECDEQUE_INITIALIZER { 0, 0, 0, NULL }
+
+/**
+ * Initialize an empty VecDeque
+ */
+#define sc_vecdeque_init(pv) \
+({ \
+    (pv)->data = NULL; \
+    (pv)->cap = 0; \
+    (pv)->origin = 0; \
+    (pv)->size = 0; \
+})
+
+/**
+ * Destroy a VecDeque
+ */
+#define sc_vecdeque_destroy(pv) \
+    free((pv)->data)
+
+/**
+ * Clear a VecDeque
+ *
+ * Remove all items.
+ */
+#define sc_vecdeque_clear(pv) \
+(void) ({ \
+    sc_vecdeque_destroy(pv); \
+    sc_vecdeque_init(pv); \
+})
+
+/**
+ * Returns the content size
+ */
+#define sc_vecdeque_size(pv) \
+    (pv)->size
+
+/**
+ * Return whether the VecDeque is empty (i.e. its size is 0)
+ */
+#define sc_vecdeque_is_empty(pv) \
+    ((pv)->size == 0)
+
+/**
+ * Return whether the VecDeque is full
+ *
+ * A VecDeque is full when its size equals its current capacity. However, it
+ * does not prevent to push a new item (with sc_vecdeque_push()), since this
+ * will increase its capacity.
+ */
+#define sc_vecdeque_is_full(pv) \
+    ((pv)->size == (pv)->cap)
+
+/**
+ * The minimal allocation size, in number of items
+ *
+ * Private.
+ */
+#define SC_VECDEQUE_MINCAP_ ((size_t) 10)
+
+/**
+ * The maximal allocation size, in number of items
+ *
+ * Use SIZE_MAX/2 to fit in ssize_t, and so that cap*1.5 does not overflow.
+ *
+ * Private.
+ */
+#define sc_vecdeque_max_cap_(pv) (SIZE_MAX / 2 / sizeof(*(pv)->data))
+
+/**
+ * Realloc the internal array to a specific capacity
+ *
+ * On reallocation success, update the VecDeque capacity (`*pcap`) and origin
+ * (`*porigin`), and return the reallocated data.
+ *
+ * On reallocation failure, return NULL without any change.
+ *
+ * Private.
+ *
+ * \param ptr the current `data` field of the SC_VECDEQUE to realloc
+ * \param newcap the requested capacity, in number of items
+ * \param item_size the size of one item (the generic type is unknown from this
+ *                  function)
+ * \param pcap a pointer to the `cap` field of the SC_VECDEQUE [IN/OUT]
+ * \param porigin a pointer to pv->origin (will be read and updated)
+ * \param size the `size` field of the SC_VECDEQUE
+ * \return the new array to assign to the `data` field of the SC_VECDEQUE (if
+ *         not NULL)
+ */
+static inline void *
+sc_vecdeque_reallocdata_(void *ptr, size_t newcap, size_t item_size,
+                         size_t *pcap, size_t *porigin, size_t size) {
+
+    size_t oldcap = *pcap;
+    size_t oldorigin = *porigin;
+
+    assert(newcap > oldcap); // Could only grow
+
+    if (oldorigin + size <= oldcap) {
+        // The current content will stay in place, just realloc
+        //
+        // As an example, here is the content of a ring-buffer (oldcap=10)
+        // before the realloc:
+        //
+        //     _ _ 2 3 4 5 6 7 _ _
+        //         ^
+        //         origin
+        //
+        // It is resized (newcap=15), e.g. with sc_vecdeque_reserve():
+        //
+        //     _ _ 2 3 4 5 6 7 _ _ _ _ _ _ _
+        //         ^
+        //         origin
+
+        void *newptr = reallocarray(ptr, newcap, item_size);
+        if (!newptr) {
+            return NULL;
+        }
+
+        *pcap = newcap;
+        return newptr;
+    }
+
+    // Copy the current content to the new array
+    //
+    // As an example, here is the content of a ring-buffer (oldcap=10) before
+    // the realloc:
+    //
+    //     5 6 7 _ _ 0 1 2 3 4
+    //               ^
+    //               origin
+    //
+    // It is resized (newcap=15), e.g. with sc_vecdeque_reserve():
+    //
+    //     0 1 2 3 4 5 6 7 _ _ _ _ _ _ _
+    //     ^
+    //     origin
+
+    assert(size);
+    void *newptr = sc_allocarray(newcap, item_size);
+    if (!newptr) {
+        return NULL;
+    }
+
+    size_t right_len = MIN(size, oldcap - oldorigin);
+    assert(right_len);
+    memcpy(newptr, ptr + (oldorigin * item_size), right_len * item_size);
+
+    if (size > right_len) {
+        memcpy(newptr + (right_len * item_size), ptr,
+               (size - right_len) * item_size);
+    }
+
+    free(ptr);
+
+    *pcap = newcap;
+    *porigin = 0;
+    return newptr;
+}
+
+/**
+ * Macro to realloc the internal data to a new capacity
+ *
+ * Private.
+ *
+ * \retval true on success
+ * \retval false on allocation failure (the VecDeque is left untouched)
+ */
+#define sc_vecdeque_realloc_(pv, newcap) \
+({ \
+    void *p = sc_vecdeque_reallocdata_((pv)->data, newcap, \
+                                       sizeof(*(pv)->data), &(pv)->cap, \
+                                       &(pv)->origin, (pv)->size); \
+    if (p) { \
+        (pv)->data = p; \
+    } \
+    (bool) p; \
+});
+
+static inline size_t
+sc_vecdeque_growsize_(size_t value)
+{
+    /* integer multiplication by 1.5 */
+    return value + (value >> 1);
+}
+
+/**
+ * Increase the capacity of the VecDeque to at least `mincap`
+ *
+ * \param pv a pointer to the VecDeque
+ * \param mincap (`size_t`) the requested capacity
+ * \retval true on success
+ * \retval false on allocation failure (the VecDeque is left untouched)
+ */
+#define sc_vecdeque_reserve(pv, mincap) \
+({ \
+    assert(mincap <= sc_vecdeque_max_cap_(pv)); \
+    bool ok; \
+    /* avoid to allocate tiny arrays (< SC_VECDEQUE_MINCAP_) */ \
+    size_t mincap_ = MAX(mincap, SC_VECDEQUE_MINCAP_); \
+    if (mincap_ <= (pv)->cap) { \
+        /* nothing to do */ \
+        ok = true; \
+    } else if (mincap_ <= sc_vecdeque_max_cap_(pv)) { \
+        /* not too big */ \
+        size_t newsize = sc_vecdeque_growsize_((pv)->cap); \
+        newsize = CLAMP(newsize, mincap_, sc_vecdeque_max_cap_(pv)); \
+        ok = sc_vecdeque_realloc_(pv, newsize); \
+    } else { \
+        ok = false; \
+    } \
+    ok; \
+})
+
+/**
+ * Automatically grow the VecDeque capacity
+ *
+ * Private.
+ *
+ * \retval true on success
+ * \retval false on allocation failure (the VecDeque is left untouched)
+ */
+#define sc_vecdeque_grow_(pv) \
+({ \
+    bool ok; \
+    if ((pv)->cap < sc_vecdeque_max_cap_(pv)) { \
+        size_t newsize = sc_vecdeque_growsize_((pv)->cap); \
+        newsize = CLAMP(newsize, SC_VECDEQUE_MINCAP_, \
+                        sc_vecdeque_max_cap_(pv)); \
+        ok = sc_vecdeque_realloc_(pv, newsize); \
+    } else { \
+        ok = false; \
+    } \
+    ok; \
+})
+
+/**
+ * Grow the VecDeque capacity if it is full
+ *
+ * Private.
+ *
+ * \retval true on success
+ * \retval false on allocation failure (the VecDeque is left untouched)
+ */
+#define sc_vecdeque_grow_if_needed_(pv) \
+    (!sc_vecdeque_is_full(pv) || sc_vecdeque_grow_(pv))
+
+/**
+ * Push an uninitialized item, and return a pointer to it
+ *
+ * It does not attempt to resize the VecDeque. It is an error to this function
+ * if the VecDeque is full.
+ *
+ * This function may not fail. It returns a valid non-NULL pointer to the
+ * uninitialized item just pushed.
+ */
+#define sc_vecdeque_push_hole_noresize(pv) \
+({ \
+    assert(!sc_vecdeque_is_full(pv)); \
+    ++(pv)->size; \
+    &(pv)->data[((pv)->origin + (pv)->size - 1) % (pv)->cap]; \
+})
+
+/**
+ * Push an uninitialized item, and return a pointer to it
+ *
+ * If the VecDeque is full, it is resized.
+ *
+ * This function returns either a valid non-nULL pointer to the uninitialized
+ * item just pushed, or NULL on reallocation failure.
+ */
+#define sc_vecdeque_push_hole(pv) \
+    (sc_vecdeque_grow_if_needed_(pv) ? \
+            sc_vecdeque_push_hole_noresize(pv) : NULL)
+
+/**
+ * Push an item
+ *
+ * It does not attempt to resize the VecDeque. It is an error to this function
+ * if the VecDeque is full.
+ *
+ * This function may not fail.
+ */
+#define sc_vecdeque_push_noresize(pv, item) \
+(void) ({ \
+    assert(!sc_vecdeque_is_full(pv)); \
+    ++(pv)->size; \
+    (pv)->data[((pv)->origin + (pv)->size - 1) % (pv)->cap] = item; \
+})
+
+/**
+ * Push an item
+ *
+ * If the VecDeque is full, it is resized.
+ *
+ * \retval true on success
+ * \retval false on allocation failure (the VecDeque is left untouched)
+ */
+#define sc_vecdeque_push(pv, item) \
+({ \
+    bool ok = sc_vecdeque_grow_if_needed_(pv); \
+    if (ok) { \
+        sc_vecdeque_push_noresize(pv, item); \
+    } \
+    ok; \
+})
+
+/**
+ * Pop an item and return a pointer to it (still in the VecDeque)
+ *
+ * Returning a pointer allows the caller to destroy it in place without copy
+ * (especially if the item type is big).
+ *
+ * It is an error to call this function if the VecDeque is empty.
+ */
+#define sc_vecdeque_popref(pv) \
+({ \
+    assert(!sc_vecdeque_is_empty(pv)); \
+    size_t pos = (pv)->origin; \
+    (pv)->origin = ((pv)->origin + 1) % (pv)->cap; \
+    --(pv)->size; \
+    &(pv)->data[pos]; \
+})
+
+/**
+ * Pop an item and returns it
+ *
+ * It is an error to call this function if the VecDeque is empty.
+ */
+#define sc_vecdeque_pop(pv) \
+    (*sc_vecdeque_popref(pv))
+
+#endif

app/src/util/vector.h

@@ -118,7 +118,7 @@ static inline void *
 sc_vector_reallocdata_(void *ptr, size_t count, size_t size,
                         size_t *restrict pcap, size_t *restrict psize)
 {
-    void *p = realloc(ptr, count * size);
+    void *p = reallocarray(ptr, count, size);
     if (!p) {
         return NULL;
     }

app/src/v4l2_sink.c

@@ -126,7 +126,7 @@ run_v4l2_sink(void *data) {
         vs->has_frame = false;
         sc_mutex_unlock(&vs->mutex);
 
-        sc_video_buffer_consume(&vs->vb, vs->frame);
+        sc_frame_buffer_consume(&vs->fb, vs->frame);
 
         bool ok = encode_and_write_frame(vs, vs->frame);
         av_frame_unref(vs->frame);
@@ -141,39 +141,19 @@ run_v4l2_sink(void *data) {
     return 0;
 }
 
-static void
-sc_video_buffer_on_new_frame(struct sc_video_buffer *vb, bool previous_skipped,
-                             void *userdata) {
-    (void) vb;
-    struct sc_v4l2_sink *vs = userdata;
-
-    if (!previous_skipped) {
-        sc_mutex_lock(&vs->mutex);
-        vs->has_frame = true;
-        sc_cond_signal(&vs->cond);
-        sc_mutex_unlock(&vs->mutex);
-    }
-}
-
 static bool
-sc_v4l2_sink_open(struct sc_v4l2_sink *vs) {
-    static const struct sc_video_buffer_callbacks cbs = {
-        .on_new_frame = sc_video_buffer_on_new_frame,
-    };
+sc_v4l2_sink_open(struct sc_v4l2_sink *vs, const AVCodecContext *ctx) {
+    assert(ctx->pix_fmt == AV_PIX_FMT_YUV420P);
+    (void) ctx;
 
-    bool ok = sc_video_buffer_init(&vs->vb, vs->buffering_time, &cbs, vs);
+    bool ok = sc_frame_buffer_init(&vs->fb);
     if (!ok) {
         return false;
     }
 
-    ok = sc_video_buffer_start(&vs->vb);
-    if (!ok) {
-        goto error_video_buffer_destroy;
-    }
-
     ok = sc_mutex_init(&vs->mutex);
     if (!ok) {
-        goto error_video_buffer_stop_and_join;
+        goto error_frame_buffer_destroy;
     }
 
     ok = sc_cond_init(&vs->cond);
@@ -298,11 +278,8 @@ error_cond_destroy:
     sc_cond_destroy(&vs->cond);
 error_mutex_destroy:
     sc_mutex_destroy(&vs->mutex);
-error_video_buffer_stop_and_join:
-    sc_video_buffer_stop(&vs->vb);
-    sc_video_buffer_join(&vs->vb);
-error_video_buffer_destroy:
-    sc_video_buffer_destroy(&vs->vb);
+error_frame_buffer_destroy:
+    sc_frame_buffer_destroy(&vs->fb);
 
     return false;
 }
@@ -314,10 +291,7 @@ sc_v4l2_sink_close(struct sc_v4l2_sink *vs) {
     sc_cond_signal(&vs->cond);
     sc_mutex_unlock(&vs->mutex);
 
-    sc_video_buffer_stop(&vs->vb);
-
     sc_thread_join(&vs->thread, NULL);
-    sc_video_buffer_join(&vs->vb);
 
     av_packet_free(&vs->packet);
     av_frame_free(&vs->frame);
@@ -327,18 +301,31 @@ sc_v4l2_sink_close(struct sc_v4l2_sink *vs) {
     avformat_free_context(vs->format_ctx);
     sc_cond_destroy(&vs->cond);
     sc_mutex_destroy(&vs->mutex);
-    sc_video_buffer_destroy(&vs->vb);
+    sc_frame_buffer_destroy(&vs->fb);
 }
 
 static bool
 sc_v4l2_sink_push(struct sc_v4l2_sink *vs, const AVFrame *frame) {
-    return sc_video_buffer_push(&vs->vb, frame);
+    bool previous_skipped;
+    bool ok = sc_frame_buffer_push(&vs->fb, frame, &previous_skipped);
+    if (!ok) {
+        return false;
+    }
+
+    if (!previous_skipped) {
+        sc_mutex_lock(&vs->mutex);
+        vs->has_frame = true;
+        sc_cond_signal(&vs->cond);
+        sc_mutex_unlock(&vs->mutex);
+    }
+
+    return true;
 }
 
 static bool
-sc_v4l2_frame_sink_open(struct sc_frame_sink *sink) {
+sc_v4l2_frame_sink_open(struct sc_frame_sink *sink, const AVCodecContext *ctx) {
     struct sc_v4l2_sink *vs = DOWNCAST(sink);
-    return sc_v4l2_sink_open(vs);
+    return sc_v4l2_sink_open(vs, ctx);
 }
 
 static void
@@ -355,7 +342,7 @@ sc_v4l2_frame_sink_push(struct sc_frame_sink *sink, const AVFrame *frame) {
 
 bool
 sc_v4l2_sink_init(struct sc_v4l2_sink *vs, const char *device_name,
-                  struct sc_size frame_size, sc_tick buffering_time) {
+                  struct sc_size frame_size) {
     vs->device_name = strdup(device_name);
     if (!vs->device_name) {
         LOGE("Could not strdup v4l2 device name");
@@ -363,7 +350,6 @@ sc_v4l2_sink_init(struct sc_v4l2_sink *vs, const char *device_name,
     }
 
     vs->frame_size = frame_size;
-    vs->buffering_time = buffering_time;
 
     static const struct sc_frame_sink_ops ops = {
         .open = sc_v4l2_frame_sink_open,

app/src/v4l2_sink.h

@@ -8,19 +8,18 @@
 
 #include "coords.h"
 #include "trait/frame_sink.h"
-#include "video_buffer.h"
+#include "frame_buffer.h"
 #include "util/tick.h"
 
 struct sc_v4l2_sink {
     struct sc_frame_sink frame_sink; // frame sink trait
 
-    struct sc_video_buffer vb;
+    struct sc_frame_buffer fb;
     AVFormatContext *format_ctx;
     AVCodecContext *encoder_ctx;
 
     char *device_name;
     struct sc_size frame_size;
-    sc_tick buffering_time;
 
     sc_thread thread;
     sc_mutex mutex;
@@ -35,7 +34,7 @@ struct sc_v4l2_sink {
 
 bool
 sc_v4l2_sink_init(struct sc_v4l2_sink *vs, const char *device_name,
-                  struct sc_size frame_size, sc_tick buffering_time);
+                  struct sc_size frame_size);
 
 void
 sc_v4l2_sink_destroy(struct sc_v4l2_sink *vs);

app/src/video_buffer.c

@@ -1,254 +0,0 @@
-#include "video_buffer.h"
-
-#include <assert.h>
-#include <stdlib.h>
-
-#include <libavutil/avutil.h>
-#include <libavformat/avformat.h>
-
-#include "util/log.h"
-
-#define SC_BUFFERING_NDEBUG // comment to debug
-
-static struct sc_video_buffer_frame *
-sc_video_buffer_frame_new(const AVFrame *frame) {
-    struct sc_video_buffer_frame *vb_frame = malloc(sizeof(*vb_frame));
-    if (!vb_frame) {
-        LOG_OOM();
-        return NULL;
-    }
-
-    vb_frame->frame = av_frame_alloc();
-    if (!vb_frame->frame) {
-        LOG_OOM();
-        free(vb_frame);
-        return NULL;
-    }
-
-    if (av_frame_ref(vb_frame->frame, frame)) {
-        av_frame_free(&vb_frame->frame);
-        free(vb_frame);
-        return NULL;
-    }
-
-    return vb_frame;
-}
-
-static void
-sc_video_buffer_frame_delete(struct sc_video_buffer_frame *vb_frame) {
-    av_frame_unref(vb_frame->frame);
-    av_frame_free(&vb_frame->frame);
-    free(vb_frame);
-}
-
-static bool
-sc_video_buffer_offer(struct sc_video_buffer *vb, const AVFrame *frame) {
-    bool previous_skipped;
-    bool ok = sc_frame_buffer_push(&vb->fb, frame, &previous_skipped);
-    if (!ok) {
-        return false;
-    }
-
-    vb->cbs->on_new_frame(vb, previous_skipped, vb->cbs_userdata);
-    return true;
-}
-
-static int
-run_buffering(void *data) {
-    struct sc_video_buffer *vb = data;
-
-    assert(vb->buffering_time > 0);
-
-    for (;;) {
-        sc_mutex_lock(&vb->b.mutex);
-
-        while (!vb->b.stopped && sc_queue_is_empty(&vb->b.queue)) {
-            sc_cond_wait(&vb->b.queue_cond, &vb->b.mutex);
-        }
-
-        if (vb->b.stopped) {
-            sc_mutex_unlock(&vb->b.mutex);
-            goto stopped;
-        }
-
-        struct sc_video_buffer_frame *vb_frame;
-        sc_queue_take(&vb->b.queue, next, &vb_frame);
-
-        sc_tick max_deadline = sc_tick_now() + vb->buffering_time;
-        // PTS (written by the server) are expressed in microseconds
-        sc_tick pts = SC_TICK_TO_US(vb_frame->frame->pts);
-
-        bool timed_out = false;
-        while (!vb->b.stopped && !timed_out) {
-            sc_tick deadline = sc_clock_to_system_time(&vb->b.clock, pts)
-                             + vb->buffering_time;
-            if (deadline > max_deadline) {
-                deadline = max_deadline;
-            }
-
-            timed_out =
-                !sc_cond_timedwait(&vb->b.wait_cond, &vb->b.mutex, deadline);
-        }
-
-        if (vb->b.stopped) {
-            sc_video_buffer_frame_delete(vb_frame);
-            sc_mutex_unlock(&vb->b.mutex);
-            goto stopped;
-        }
-
-        sc_mutex_unlock(&vb->b.mutex);
-
-#ifndef SC_BUFFERING_NDEBUG
-        LOGD("Buffering: %" PRItick ";%" PRItick ";%" PRItick,
-             pts, vb_frame->push_date, sc_tick_now());
-#endif
-
-        sc_video_buffer_offer(vb, vb_frame->frame);
-
-        sc_video_buffer_frame_delete(vb_frame);
-    }
-
-stopped:
-    // Flush queue
-    while (!sc_queue_is_empty(&vb->b.queue)) {
-        struct sc_video_buffer_frame *vb_frame;
-        sc_queue_take(&vb->b.queue, next, &vb_frame);
-        sc_video_buffer_frame_delete(vb_frame);
-    }
-
-    LOGD("Buffering thread ended");
-
-    return 0;
-}
-
-bool
-sc_video_buffer_init(struct sc_video_buffer *vb, sc_tick buffering_time,
-                     const struct sc_video_buffer_callbacks *cbs,
-                     void *cbs_userdata) {
-    bool ok = sc_frame_buffer_init(&vb->fb);
-    if (!ok) {
-        return false;
-    }
-
-    assert(buffering_time >= 0);
-    if (buffering_time) {
-        ok = sc_mutex_init(&vb->b.mutex);
-        if (!ok) {
-            sc_frame_buffer_destroy(&vb->fb);
-            return false;
-        }
-
-        ok = sc_cond_init(&vb->b.queue_cond);
-        if (!ok) {
-            sc_mutex_destroy(&vb->b.mutex);
-            sc_frame_buffer_destroy(&vb->fb);
-            return false;
-        }
-
-        ok = sc_cond_init(&vb->b.wait_cond);
-        if (!ok) {
-            sc_cond_destroy(&vb->b.queue_cond);
-            sc_mutex_destroy(&vb->b.mutex);
-            sc_frame_buffer_destroy(&vb->fb);
-            return false;
-        }
-
-        sc_clock_init(&vb->b.clock);
-        sc_queue_init(&vb->b.queue);
-    }
-
-    assert(cbs);
-    assert(cbs->on_new_frame);
-
-    vb->buffering_time = buffering_time;
-    vb->cbs = cbs;
-    vb->cbs_userdata = cbs_userdata;
-    return true;
-}
-
-bool
-sc_video_buffer_start(struct sc_video_buffer *vb) {
-    if (vb->buffering_time) {
-        bool ok =
-            sc_thread_create(&vb->b.thread, run_buffering, "scrcpy-vbuf", vb);
-        if (!ok) {
-            LOGE("Could not start buffering thread");
-            return false;
-        }
-    }
-
-    return true;
-}
-
-void
-sc_video_buffer_stop(struct sc_video_buffer *vb) {
-    if (vb->buffering_time) {
-        sc_mutex_lock(&vb->b.mutex);
-        vb->b.stopped = true;
-        sc_cond_signal(&vb->b.queue_cond);
-        sc_cond_signal(&vb->b.wait_cond);
-        sc_mutex_unlock(&vb->b.mutex);
-    }
-}
-
-void
-sc_video_buffer_join(struct sc_video_buffer *vb) {
-    if (vb->buffering_time) {
-        sc_thread_join(&vb->b.thread, NULL);
-    }
-}
-
-void
-sc_video_buffer_destroy(struct sc_video_buffer *vb) {
-    sc_frame_buffer_destroy(&vb->fb);
-    if (vb->buffering_time) {
-        sc_cond_destroy(&vb->b.wait_cond);
-        sc_cond_destroy(&vb->b.queue_cond);
-        sc_mutex_destroy(&vb->b.mutex);
-    }
-}
-
-bool
-sc_video_buffer_push(struct sc_video_buffer *vb, const AVFrame *frame) {
-    if (!vb->buffering_time) {
-        // No buffering
-        return sc_video_buffer_offer(vb, frame);
-    }
-
-    sc_mutex_lock(&vb->b.mutex);
-
-    sc_tick pts = SC_TICK_FROM_US(frame->pts);
-    sc_clock_update(&vb->b.clock, sc_tick_now(), pts);
-    sc_cond_signal(&vb->b.wait_cond);
-
-    if (vb->b.clock.count == 1) {
-        sc_mutex_unlock(&vb->b.mutex);
-        // First frame, offer it immediately, for two reasons:
-        //  - not to delay the opening of the scrcpy window
-        //  - the buffering estimation needs at least two clock points, so it
-        //  could not handle the first frame
-        return sc_video_buffer_offer(vb, frame);
-    }
-
-    struct sc_video_buffer_frame *vb_frame = sc_video_buffer_frame_new(frame);
-    if (!vb_frame) {
-        sc_mutex_unlock(&vb->b.mutex);
-        LOG_OOM();
-        return false;
-    }
-
-#ifndef SC_BUFFERING_NDEBUG
-    vb_frame->push_date = sc_tick_now();
-#endif
-    sc_queue_push(&vb->b.queue, next, vb_frame);
-    sc_cond_signal(&vb->b.queue_cond);
-
-    sc_mutex_unlock(&vb->b.mutex);
-
-    return true;
-}
-
-void
-sc_video_buffer_consume(struct sc_video_buffer *vb, AVFrame *dst) {
-    sc_frame_buffer_consume(&vb->fb, dst);
-}

app/src/video_buffer.h

@@ -1,76 +0,0 @@
-#ifndef SC_VIDEO_BUFFER_H
-#define SC_VIDEO_BUFFER_H
-
-#include "common.h"
-
-#include <stdbool.h>
-
-#include "clock.h"
-#include "frame_buffer.h"
-#include "util/queue.h"
-#include "util/thread.h"
-#include "util/tick.h"
-
-// forward declarations
-typedef struct AVFrame AVFrame;
-
-struct sc_video_buffer_frame {
-    AVFrame *frame;
-    struct sc_video_buffer_frame *next;
-#ifndef NDEBUG
-    sc_tick push_date;
-#endif
-};
-
-struct sc_video_buffer_frame_queue SC_QUEUE(struct sc_video_buffer_frame);
-
-struct sc_video_buffer {
-    struct sc_frame_buffer fb;
-
-    sc_tick buffering_time;
-
-    // only if buffering_time > 0
-    struct {
-        sc_thread thread;
-        sc_mutex mutex;
-        sc_cond queue_cond;
-        sc_cond wait_cond;
-
-        struct sc_clock clock;
-        struct sc_video_buffer_frame_queue queue;
-        bool stopped;
-    } b; // buffering
-
-    const struct sc_video_buffer_callbacks *cbs;
-    void *cbs_userdata;
-};
-
-struct sc_video_buffer_callbacks {
-    void (*on_new_frame)(struct sc_video_buffer *vb, bool previous_skipped,
-                         void *userdata);
-};
-
-bool
-sc_video_buffer_init(struct sc_video_buffer *vb, sc_tick buffering_time,
-                     const struct sc_video_buffer_callbacks *cbs,
-                     void *cbs_userdata);
-
-bool
-sc_video_buffer_start(struct sc_video_buffer *vb);
-
-void
-sc_video_buffer_stop(struct sc_video_buffer *vb);
-
-void
-sc_video_buffer_join(struct sc_video_buffer *vb);
-
-void
-sc_video_buffer_destroy(struct sc_video_buffer *vb);
-
-bool
-sc_video_buffer_push(struct sc_video_buffer *vb, const AVFrame *frame);
-
-void
-sc_video_buffer_consume(struct sc_video_buffer *vb, AVFrame *dst);
-
-#endif

app/tests/test_bytebuf.c

@@ -0,0 +1,126 @@
+#include "common.h"
+
+#include <assert.h>
+#include <string.h>
+
+#include "util/bytebuf.h"
+
+void test_bytebuf_simple(void) {
+    struct sc_bytebuf buf;
+    uint8_t data[20];
+
+    bool ok = sc_bytebuf_init(&buf, 20);
+    assert(ok);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "hello", sizeof("hello") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 5);
+
+    sc_bytebuf_read(&buf, data, 4);
+    assert(!strncmp((char *) data, "hell", 4));
+
+    sc_bytebuf_write(&buf, (uint8_t *) " world", sizeof(" world") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 7);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "!", 1);
+    assert(sc_bytebuf_read_available(&buf) == 8);
+
+    sc_bytebuf_read(&buf, &data[4], 8);
+    assert(sc_bytebuf_read_available(&buf) == 0);
+
+    data[12] = '\0';
+    assert(!strcmp((char *) data, "hello world!"));
+    assert(sc_bytebuf_read_available(&buf) == 0);
+
+    sc_bytebuf_destroy(&buf);
+}
+
+void test_bytebuf_boundaries(void) {
+    struct sc_bytebuf buf;
+    uint8_t data[20];
+
+    bool ok = sc_bytebuf_init(&buf, 20);
+    assert(ok);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "hello ", sizeof("hello ") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 6);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "hello ", sizeof("hello ") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 12);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "hello ", sizeof("hello ") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 18);
+
+    sc_bytebuf_read(&buf, data, 9);
+    assert(!strncmp((char *) data, "hello hel", 9));
+    assert(sc_bytebuf_read_available(&buf) == 9);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "world", sizeof("world") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 14);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "!", 1);
+    assert(sc_bytebuf_read_available(&buf) == 15);
+
+    sc_bytebuf_skip(&buf, 3);
+    assert(sc_bytebuf_read_available(&buf) == 12);
+
+    sc_bytebuf_read(&buf, data, 12);
+    data[12] = '\0';
+    assert(!strcmp((char *) data, "hello world!"));
+    assert(sc_bytebuf_read_available(&buf) == 0);
+
+    sc_bytebuf_destroy(&buf);
+}
+
+void test_bytebuf_two_steps_write(void) {
+    struct sc_bytebuf buf;
+    uint8_t data[20];
+
+    bool ok = sc_bytebuf_init(&buf, 20);
+    assert(ok);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "hello ", sizeof("hello ") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 6);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "hello ", sizeof("hello ") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 12);
+
+    sc_bytebuf_prepare_write(&buf, (uint8_t *) "hello ", sizeof("hello ") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 12); // write not committed yet
+
+    sc_bytebuf_read(&buf, data, 9);
+    assert(!strncmp((char *) data, "hello hel", 3));
+    assert(sc_bytebuf_read_available(&buf) == 3);
+
+    sc_bytebuf_commit_write(&buf, sizeof("hello ") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 9);
+
+    sc_bytebuf_prepare_write(&buf, (uint8_t *) "world", sizeof("world") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 9); // write not committed yet
+
+    sc_bytebuf_commit_write(&buf, sizeof("world") - 1);
+    assert(sc_bytebuf_read_available(&buf) == 14);
+
+    sc_bytebuf_write(&buf, (uint8_t *) "!", 1);
+    assert(sc_bytebuf_read_available(&buf) == 15);
+
+    sc_bytebuf_skip(&buf, 3);
+    assert(sc_bytebuf_read_available(&buf) == 12);
+
+    sc_bytebuf_read(&buf, data, 12);
+    data[12] = '\0';
+    assert(!strcmp((char *) data, "hello world!"));
+    assert(sc_bytebuf_read_available(&buf) == 0);
+
+    sc_bytebuf_destroy(&buf);
+}
+
+int main(int argc, char *argv[]) {
+    (void) argc;
+    (void) argv;
+
+    test_bytebuf_simple();
+    test_bytebuf_boundaries();
+    test_bytebuf_two_steps_write();
+
+    return 0;
+}

app/tests/test_cbuf.c

@@ -1,78 +0,0 @@
-#include "common.h"
-
-#include <assert.h>
-#include <string.h>
-
-#include "util/cbuf.h"
-
-struct int_queue CBUF(int, 32);
-
-static void test_cbuf_empty(void) {
-    struct int_queue queue;
-    cbuf_init(&queue);
-
-    assert(cbuf_is_empty(&queue));
-
-    bool push_ok = cbuf_push(&queue, 42);
-    assert(push_ok);
-    assert(!cbuf_is_empty(&queue));
-
-    int item;
-    bool take_ok = cbuf_take(&queue, &item);
-    assert(take_ok);
-    assert(cbuf_is_empty(&queue));
-
-    bool take_empty_ok = cbuf_take(&queue, &item);
-    assert(!take_empty_ok); // the queue is empty
-}
-
-static void test_cbuf_full(void) {
-    struct int_queue queue;
-    cbuf_init(&queue);
-
-    assert(!cbuf_is_full(&queue));
-
-    // fill the queue
-    for (int i = 0; i < 32; ++i) {
-        bool ok = cbuf_push(&queue, i);
-        assert(ok);
-    }
-    bool ok = cbuf_push(&queue, 42);
-    assert(!ok); // the queue if full
-
-    int item;
-    bool take_ok = cbuf_take(&queue, &item);
-    assert(take_ok);
-    assert(!cbuf_is_full(&queue));
-}
-
-static void test_cbuf_push_take(void) {
-    struct int_queue queue;
-    cbuf_init(&queue);
-
-    bool push1_ok = cbuf_push(&queue, 42);
-    assert(push1_ok);
-
-    bool push2_ok = cbuf_push(&queue, 35);
-    assert(push2_ok);
-
-    int item;
-
-    bool take1_ok = cbuf_take(&queue, &item);
-    assert(take1_ok);
-    assert(item == 42);
-
-    bool take2_ok = cbuf_take(&queue, &item);
-    assert(take2_ok);
-    assert(item == 35);
-}
-
-int main(int argc, char *argv[]) {
-    (void) argc;
-    (void) argv;
-
-    test_cbuf_empty();
-    test_cbuf_full();
-    test_cbuf_push_take();
-    return 0;
-}

app/tests/test_queue.c

@@ -1,43 +0,0 @@
-#include "common.h"
-
-#include <assert.h>
-
-#include "util/queue.h"
-
-struct foo {
-    int value;
-    struct foo *next;
-};
-
-static void test_queue(void) {
-    struct my_queue SC_QUEUE(struct foo) queue;
-    sc_queue_init(&queue);
-
-    assert(sc_queue_is_empty(&queue));
-
-    struct foo v1 = { .value = 42 };
-    struct foo v2 = { .value = 27 };
-
-    sc_queue_push(&queue, next, &v1);
-    sc_queue_push(&queue, next, &v2);
-
-    struct foo *foo;
-
-    assert(!sc_queue_is_empty(&queue));
-    sc_queue_take(&queue, next, &foo);
-    assert(foo->value == 42);
-
-    assert(!sc_queue_is_empty(&queue));
-    sc_queue_take(&queue, next, &foo);
-    assert(foo->value == 27);
-
-    assert(sc_queue_is_empty(&queue));
-}
-
-int main(int argc, char *argv[]) {
-    (void) argc;
-    (void) argv;
-
-    test_queue();
-    return 0;
-}

app/tests/test_vecdeque.c

@@ -0,0 +1,197 @@
+#include "common.h"
+
+#include <assert.h>
+
+#include "util/vecdeque.h"
+
+#define pr(pv) \
+({ \
+    fprintf(stderr, "cap=%lu origin=%lu size=%lu\n", (pv)->cap, (pv)->origin, (pv)->size); \
+    for (size_t i = 0; i < (pv)->cap; ++i) \
+        fprintf(stderr, "%d ", (pv)->data[i]); \
+    fprintf(stderr, "\n"); \
+})
+
+static void test_vecdeque_push_pop(void) {
+    struct SC_VECDEQUE(int) vdq = SC_VECDEQUE_INITIALIZER;
+
+    assert(sc_vecdeque_is_empty(&vdq));
+    assert(sc_vecdeque_size(&vdq) == 0);
+
+    bool ok = sc_vecdeque_push(&vdq, 5);
+    assert(ok);
+    assert(sc_vecdeque_size(&vdq) == 1);
+
+    ok = sc_vecdeque_push(&vdq, 12);
+    assert(ok);
+    assert(sc_vecdeque_size(&vdq) == 2);
+
+    int v = sc_vecdeque_pop(&vdq);
+    assert(v == 5);
+    assert(sc_vecdeque_size(&vdq) == 1);
+
+    ok = sc_vecdeque_push(&vdq, 7);
+    assert(ok);
+    assert(sc_vecdeque_size(&vdq) == 2);
+
+    int *p = sc_vecdeque_popref(&vdq);
+    assert(p);
+    assert(*p == 12);
+    assert(sc_vecdeque_size(&vdq) == 1);
+
+    v = sc_vecdeque_pop(&vdq);
+    assert(v == 7);
+    assert(sc_vecdeque_size(&vdq) == 0);
+    assert(sc_vecdeque_is_empty(&vdq));
+
+    sc_vecdeque_destroy(&vdq);
+}
+
+static void test_vecdeque_reserve(void) {
+    struct SC_VECDEQUE(int) vdq = SC_VECDEQUE_INITIALIZER;
+
+    bool ok = sc_vecdeque_reserve(&vdq, 20);
+    assert(ok);
+    assert(vdq.cap == 20);
+
+    assert(sc_vecdeque_size(&vdq) == 0);
+
+    for (size_t i = 0; i < 20; ++i) {
+        ok = sc_vecdeque_push(&vdq, i);
+        assert(ok);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 20);
+
+    // It is now full
+
+    for (int i = 0; i < 5; ++i) {
+        int v = sc_vecdeque_pop(&vdq);
+        assert(v == i);
+    }
+    assert(sc_vecdeque_size(&vdq) == 15);
+
+    for (int i = 20; i < 25; ++i) {
+        ok = sc_vecdeque_push(&vdq, i);
+        assert(ok);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 20);
+    assert(vdq.cap == 20);
+
+    // Now, the content wraps around the ring buffer:
+    // 20 21 22 23 24  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19
+    //                 ^
+    //                 origin
+
+    // It is now full, let's reserve some space
+    ok = sc_vecdeque_reserve(&vdq, 30);
+    assert(ok);
+    assert(vdq.cap == 30);
+
+    assert(sc_vecdeque_size(&vdq) == 20);
+
+    for (int i = 0; i < 20; ++i) {
+        // We should retrieve the items we inserted in order
+        int v = sc_vecdeque_pop(&vdq);
+        assert(v == i + 5);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 0);
+
+    sc_vecdeque_destroy(&vdq);
+}
+
+static void test_vecdeque_grow() {
+    struct SC_VECDEQUE(int) vdq = SC_VECDEQUE_INITIALIZER;
+
+    bool ok = sc_vecdeque_reserve(&vdq, 20);
+    assert(ok);
+    assert(vdq.cap == 20);
+
+    assert(sc_vecdeque_size(&vdq) == 0);
+
+    for (int i = 0; i < 500; ++i) {
+        ok = sc_vecdeque_push(&vdq, i);
+        assert(ok);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 500);
+
+    for (int i = 0; i < 100; ++i) {
+        int v = sc_vecdeque_pop(&vdq);
+        assert(v == i);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 400);
+
+    for (int i = 500; i < 1000; ++i) {
+        ok = sc_vecdeque_push(&vdq, i);
+        assert(ok);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 900);
+
+    for (int i = 100; i < 1000; ++i) {
+        int v = sc_vecdeque_pop(&vdq);
+        assert(v == i);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 0);
+
+    sc_vecdeque_destroy(&vdq);
+}
+
+static void test_vecdeque_push_hole() {
+    struct SC_VECDEQUE(int) vdq = SC_VECDEQUE_INITIALIZER;
+
+    bool ok = sc_vecdeque_reserve(&vdq, 20);
+    assert(ok);
+    assert(vdq.cap == 20);
+
+    assert(sc_vecdeque_size(&vdq) == 0);
+
+    for (int i = 0; i < 20; ++i) {
+        int *p = sc_vecdeque_push_hole(&vdq);
+        assert(p);
+        *p = i * 10;
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 20);
+
+    for (int i = 0; i < 10; ++i) {
+        int v = sc_vecdeque_pop(&vdq);
+        assert(v == i * 10);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 10);
+
+    for (int i = 20; i < 30; ++i) {
+        int *p = sc_vecdeque_push_hole(&vdq);
+        assert(p);
+        *p = i * 10;
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 20);
+
+    for (int i = 10; i < 30; ++i) {
+        int v = sc_vecdeque_pop(&vdq);
+        assert(v == i * 10);
+    }
+
+    assert(sc_vecdeque_size(&vdq) == 0);
+
+    sc_vecdeque_destroy(&vdq);
+}
+
+int main(int argc, char *argv[]) {
+    (void) argc;
+    (void) argv;
+
+    test_vecdeque_push_pop();
+    test_vecdeque_reserve();
+    test_vecdeque_grow();
+    test_vecdeque_push_hole();
+
+    return 0;
+}

server/src/main/java/com/genymobile/scrcpy/AudioCapture.java

@@ -0,0 +1,148 @@
+package com.genymobile.scrcpy;
+
+import com.genymobile.scrcpy.wrappers.ServiceManager;
+
+import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
+import android.content.ComponentName;
+import android.content.Intent;
+import android.media.AudioFormat;
+import android.media.AudioRecord;
+import android.media.AudioTimestamp;
+import android.media.MediaCodec;
+import android.media.MediaRecorder;
+import android.os.Build;
+import android.os.SystemClock;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+public final class AudioCapture {
+
+    public static final int SAMPLE_RATE = 48000;
+    public static final int CHANNEL_CONFIG = AudioFormat.CHANNEL_IN_STEREO;
+    public static final int CHANNELS = 2;
+    public static final int FORMAT = AudioFormat.ENCODING_PCM_16BIT;
+    public static final int BYTES_PER_SAMPLE = 2;
+
+    private AudioRecord recorder;
+
+    private final AudioTimestamp timestamp = new AudioTimestamp();
+    private long previousPts = 0;
+    private long nextPts = 0;
+
+    public static int millisToBytes(int millis) {
+        return SAMPLE_RATE * CHANNELS * BYTES_PER_SAMPLE * millis / 1000;
+    }
+
+    private static AudioFormat createAudioFormat() {
+        AudioFormat.Builder builder = new AudioFormat.Builder();
+        builder.setEncoding(FORMAT);
+        builder.setSampleRate(SAMPLE_RATE);
+        builder.setChannelMask(CHANNEL_CONFIG);
+        return builder.build();
+    }
+
+    @TargetApi(Build.VERSION_CODES.M)
+    @SuppressLint({"WrongConstant", "MissingPermission"})
+    private static AudioRecord createAudioRecord() {
+        AudioRecord.Builder builder = new AudioRecord.Builder();
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            // On older APIs, Workarounds.fillAppInfo() must be called beforehand
+            builder.setContext(FakeContext.get());
+        }
+        builder.setAudioSource(MediaRecorder.AudioSource.REMOTE_SUBMIX);
+        builder.setAudioFormat(createAudioFormat());
+        int minBufferSize = AudioRecord.getMinBufferSize(SAMPLE_RATE, CHANNEL_CONFIG, FORMAT);
+        // This buffer size does not impact latency
+        builder.setBufferSizeInBytes(8 * minBufferSize);
+        return builder.build();
+    }
+
+    private static void startWorkaroundAndroid11() {
+        if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {
+            // Android 11 requires Apps to be at foreground to record audio.
+            // Normally, each App has its own user ID, so Android checks whether the requesting App has the user ID that's at the foreground.
+            // But scrcpy server is NOT an App, it's a Java application started from Android shell, so it has the same user ID (2000) with Android
+            // shell ("com.android.shell").
+            // If there is an Activity from Android shell running at foreground, then the permission system will believe scrcpy is also in the
+            // foreground.
+            if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {
+                Intent intent = new Intent(Intent.ACTION_MAIN);
+                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+                intent.addCategory(Intent.CATEGORY_LAUNCHER);
+                intent.setComponent(new ComponentName(FakeContext.PACKAGE_NAME, "com.android.shell.HeapDumpActivity"));
+                ServiceManager.getActivityManager().startActivityAsUserWithFeature(intent);
+                // Wait for activity to start
+                SystemClock.sleep(150);
+            }
+        }
+    }
+
+    private static void stopWorkaroundAndroid11() {
+        if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {
+            ServiceManager.getActivityManager().forceStopPackage(FakeContext.PACKAGE_NAME);
+        }
+    }
+
+    public void start() throws AudioCaptureForegroundException {
+        startWorkaroundAndroid11();
+        try {
+            recorder = createAudioRecord();
+            recorder.startRecording();
+        } catch (UnsupportedOperationException e) {
+            if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {
+                Ln.e("Failed to start audio capture");
+                Ln.e("On Android 11, it is only possible to capture in foreground, make sure that the device is unlocked when starting scrcpy.");
+                throw new AudioCaptureForegroundException();
+            }
+            throw e;
+        } finally {
+            stopWorkaroundAndroid11();
+        }
+    }
+
+    public void stop() {
+        if (recorder != null) {
+            // Will call .stop() if necessary, without throwing an IllegalStateException
+            recorder.release();
+        }
+    }
+
+    @TargetApi(Build.VERSION_CODES.N)
+    public int read(ByteBuffer directBuffer, int size, MediaCodec.BufferInfo outBufferInfo) throws IOException {
+        int r = recorder.read(directBuffer, size);
+        if (r < 0) {
+            return r;
+        }
+
+        long pts;
+
+        int ret = recorder.getTimestamp(timestamp, AudioTimestamp.TIMEBASE_MONOTONIC);
+        if (ret == AudioRecord.SUCCESS) {
+            pts = timestamp.nanoTime / 1000;
+        } else {
+            if (nextPts == 0) {
+                Ln.w("Could not get any audio timestamp");
+            }
+            // compute from previous timestamp and packet size
+            pts = nextPts;
+        }
+
+        long durationMs = r * 1000 / CHANNELS / SAMPLE_RATE;
+        nextPts = pts + durationMs;
+
+        if (previousPts != 0 && pts < previousPts) {
+            // Audio PTS may come from two sources:
+            //  - recorder.getTimestamp() if the call works;
+            //  - an estimation from the previous PTS and the packet size as a fallback.
+            //
+            // Therefore, the property that PTS are monotonically increasing is no guaranteed in corner cases, so enforce it.
+            pts = previousPts + 1;
+        }
+        previousPts = pts;
+
+        outBufferInfo.set(0, r, pts, 0);
+        return r;
+    }
+}

server/src/main/java/com/genymobile/scrcpy/AudioCaptureForegroundException.java

@@ -0,0 +1,7 @@
+package com.genymobile.scrcpy;
+
+/**
+ * Exception thrown if audio capture failed on Android 11 specifically because the running App (shell) was not in foreground.
+ */
+public class AudioCaptureForegroundException extends Exception {
+}

server/src/main/java/com/genymobile/scrcpy/AudioCodec.java

@@ -3,6 +3,7 @@ package com.genymobile.scrcpy;
 import android.media.MediaFormat;
 
 public enum AudioCodec implements Codec {
+    RAW(0x00_72_61_77, "raw", MediaFormat.MIMETYPE_AUDIO_RAW),
     OPUS(0x6f_70_75_73, "opus", MediaFormat.MIMETYPE_AUDIO_OPUS),
     AAC(0x00_61_61_63, "aac", MediaFormat.MIMETYPE_AUDIO_AAC);
 

server/src/main/java/com/genymobile/scrcpy/AudioEncoder.java

@@ -1,13 +1,8 @@
 package com.genymobile.scrcpy;
 
-import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
-import android.media.AudioFormat;
-import android.media.AudioRecord;
-import android.media.AudioTimestamp;
 import android.media.MediaCodec;
 import android.media.MediaFormat;
-import android.media.MediaRecorder;
 import android.os.Build;
 import android.os.Handler;
 import android.os.HandlerThread;
@@ -15,10 +10,11 @@ import android.os.Looper;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.util.List;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
 
-public final class AudioEncoder {
+public final class AudioEncoder implements AudioRecorder {
 
     private static class InputTask {
         private final int index;
@@ -38,17 +34,16 @@ public final class AudioEncoder {
         }
     }
 
-    private static final int SAMPLE_RATE = 48000;
-    private static final int CHANNEL_CONFIG = AudioFormat.CHANNEL_IN_STEREO;
-    private static final int CHANNELS = 2;
-    private static final int FORMAT = AudioFormat.ENCODING_PCM_16BIT;
-    private static final int BYTES_PER_SAMPLE = 2;
+    private static final int SAMPLE_RATE = AudioCapture.SAMPLE_RATE;
+    private static final int CHANNELS = AudioCapture.CHANNELS;
 
     private static final int READ_MS = 5; // milliseconds
-    private static final int READ_SIZE = SAMPLE_RATE * CHANNELS * BYTES_PER_SAMPLE * READ_MS / 1000;
+    private static final int READ_SIZE = AudioCapture.millisToBytes(READ_MS);
 
     private final Streamer streamer;
     private final int bitRate;
+    private final List<CodecOption> codecOptions;
+    private final String encoderName;
 
     // Capacity of 64 is in practice "infinite" (it is limited by the number of available MediaCodec buffers, typically 4).
     // So many pending tasks would lead to an unacceptable delay anyway.
@@ -63,86 +58,45 @@ public final class AudioEncoder {
 
     private boolean ended;
 
-    public AudioEncoder(Streamer streamer, int bitRate) {
+    public AudioEncoder(Streamer streamer, int bitRate, List<CodecOption> codecOptions, String encoderName) {
         this.streamer = streamer;
         this.bitRate = bitRate;
+        this.codecOptions = codecOptions;
+        this.encoderName = encoderName;
     }
 
-    private static AudioFormat createAudioFormat() {
-        AudioFormat.Builder builder = new AudioFormat.Builder();
-        builder.setEncoding(FORMAT);
-        builder.setSampleRate(SAMPLE_RATE);
-        builder.setChannelMask(CHANNEL_CONFIG);
-        return builder.build();
-    }
-
-    @TargetApi(Build.VERSION_CODES.M)
-    @SuppressLint({"WrongConstant", "MissingPermission"})
-    private static AudioRecord createAudioRecord() {
-        AudioRecord.Builder builder = new AudioRecord.Builder();
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-            // On older APIs, Workarounds.fillAppInfo() must be called beforehand
-            builder.setContext(FakeContext.get());
-        }
-        builder.setAudioSource(MediaRecorder.AudioSource.REMOTE_SUBMIX);
-        builder.setAudioFormat(createAudioFormat());
-        int minBufferSize = AudioRecord.getMinBufferSize(SAMPLE_RATE, CHANNEL_CONFIG, FORMAT);
-        // This buffer size does not impact latency
-        builder.setBufferSizeInBytes(8 * minBufferSize);
-        return builder.build();
-    }
-
-    private static MediaFormat createFormat(String mimeType, int bitRate) {
+    private static MediaFormat createFormat(String mimeType, int bitRate, List<CodecOption> codecOptions) {
         MediaFormat format = new MediaFormat();
         format.setString(MediaFormat.KEY_MIME, mimeType);
         format.setInteger(MediaFormat.KEY_BIT_RATE, bitRate);
         format.setInteger(MediaFormat.KEY_CHANNEL_COUNT, CHANNELS);
         format.setInteger(MediaFormat.KEY_SAMPLE_RATE, SAMPLE_RATE);
+
+        if (codecOptions != null) {
+            for (CodecOption option : codecOptions) {
+                String key = option.getKey();
+                Object value = option.getValue();
+                CodecUtils.setCodecOption(format, key, value);
+                Ln.d("Audio codec option set: " + key + " (" + value.getClass().getSimpleName() + ") = " + value);
+            }
+        }
+
         return format;
     }
 
     @TargetApi(Build.VERSION_CODES.N)
-    private void inputThread(MediaCodec mediaCodec, AudioRecord recorder) throws IOException, InterruptedException {
-        final AudioTimestamp timestamp = new AudioTimestamp();
-        long previousPts = 0;
-        long nextPts = 0;
+    private void inputThread(MediaCodec mediaCodec, AudioCapture capture) throws IOException, InterruptedException {
+        final MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
 
         while (!Thread.currentThread().isInterrupted()) {
             InputTask task = inputTasks.take();
             ByteBuffer buffer = mediaCodec.getInputBuffer(task.index);
-            int r = recorder.read(buffer, READ_SIZE);
+            int r = capture.read(buffer, READ_SIZE, bufferInfo);
             if (r < 0) {
                 throw new IOException("Could not read audio: " + r);
             }
 
-            long pts;
-
-            int ret = recorder.getTimestamp(timestamp, AudioTimestamp.TIMEBASE_MONOTONIC);
-            if (ret == AudioRecord.SUCCESS) {
-                pts = timestamp.nanoTime / 1000;
-            } else {
-                if (nextPts == 0) {
-                    Ln.w("Could not get any audio timestamp");
-                }
-                // compute from previous timestamp and packet size
-                pts = nextPts;
-            }
-
-            long durationMs = r * 1000 / CHANNELS / SAMPLE_RATE;
-            nextPts = pts + durationMs;
-
-            if (previousPts != 0 && pts < previousPts) {
-                // Audio PTS may come from two sources:
-                //  - recorder.getTimestamp() if the call works;
-                //  - an estimation from the previous PTS and the packet size as a fallback.
-                //
-                // Therefore, the property that PTS are monotonically increasing is no guaranteed in corner cases, so enforce it.
-                pts = previousPts + 1;
-            }
-
-            previousPts = pts;
-
-            mediaCodec.queueInputBuffer(task.index, 0, r, pts, 0);
+            mediaCodec.queueInputBuffer(task.index, bufferInfo.offset, bufferInfo.size, bufferInfo.presentationTimeUs, bufferInfo.flags);
         }
     }
 
@@ -164,6 +118,8 @@ public final class AudioEncoder {
         thread = new Thread(() -> {
             try {
                 encode();
+            } catch (ConfigurationException | AudioCaptureForegroundException e) {
+                // Do not print stack trace, a user-friendly error-message has already been logged
             } catch (IOException e) {
                 Ln.e("Audio encoding error", e);
             } finally {
@@ -202,38 +158,35 @@ public final class AudioEncoder {
     }
 
     @TargetApi(Build.VERSION_CODES.M)
-    public void encode() throws IOException {
+    public void encode() throws IOException, ConfigurationException, AudioCaptureForegroundException {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
             Ln.w("Audio disabled: it is not supported before Android 11");
-            streamer.writeDisableStream();
+            streamer.writeDisableStream(false);
             return;
         }
 
         MediaCodec mediaCodec = null;
-        AudioRecord recorder = null;
+        AudioCapture capture = new AudioCapture();
 
         boolean mediaCodecStarted = false;
-        boolean recorderStarted = false;
         try {
-            String mimeType = streamer.getCodec().getMimeType();
-            mediaCodec = MediaCodec.createEncoderByType(mimeType); // may throw IOException
+            Codec codec = streamer.getCodec();
+            mediaCodec = createMediaCodec(codec, encoderName);
 
             mediaCodecThread = new HandlerThread("AudioEncoder");
             mediaCodecThread.start();
 
-            MediaFormat format = createFormat(mimeType, bitRate);
+            MediaFormat format = createFormat(codec.getMimeType(), bitRate, codecOptions);
             mediaCodec.setCallback(new EncoderCallback(), new Handler(mediaCodecThread.getLooper()));
             mediaCodec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
 
-            recorder = createAudioRecord();
-            recorder.startRecording();
-            recorderStarted = true;
+            capture.start();
 
             final MediaCodec mediaCodecRef = mediaCodec;
-            final AudioRecord recorderRef = recorder;
+            final AudioCapture captureRef = capture;
             inputThread = new Thread(() -> {
                 try {
-                    inputThread(mediaCodecRef, recorderRef);
+                    inputThread(mediaCodecRef, captureRef);
                 } catch (IOException | InterruptedException e) {
                     Ln.e("Audio capture error", e);
                 } finally {
@@ -262,9 +215,13 @@ public final class AudioEncoder {
             outputThread.start();
 
             waitEnded();
+        } catch (ConfigurationException e) {
+            // Notify the error to make scrcpy exit
+            streamer.writeDisableStream(true);
+            throw e;
         } catch (Throwable e) {
             // Notify the client that the audio could not be captured
-            streamer.writeDisableStream();
+            streamer.writeDisableStream(false);
             throw e;
         } finally {
             // Cleanup everything (either at the end or on error at any step of the initialization)
@@ -302,15 +259,27 @@ public final class AudioEncoder {
                 }
                 mediaCodec.release();
             }
-            if (recorder != null) {
-                if (recorderStarted) {
-                    recorder.stop();
-                }
-                recorder.release();
+            if (capture != null) {
+                capture.stop();
             }
         }
     }
 
+    private static MediaCodec createMediaCodec(Codec codec, String encoderName) throws IOException, ConfigurationException {
+        if (encoderName != null) {
+            Ln.d("Creating audio encoder by name: '" + encoderName + "'");
+            try {
+                return MediaCodec.createByCodecName(encoderName);
+            } catch (IllegalArgumentException e) {
+                Ln.e("Encoder '" + encoderName + "' for " + codec.getName() + " not found\n" + LogUtils.buildAudioEncoderListMessage());
+                throw new ConfigurationException("Unknown encoder: " + encoderName);
+            }
+        }
+        MediaCodec mediaCodec = MediaCodec.createEncoderByType(codec.getMimeType());
+        Ln.d("Using audio encoder: '" + mediaCodec.getName() + "'");
+        return mediaCodec;
+    }
+
     private class EncoderCallback extends MediaCodec.Callback {
         @TargetApi(Build.VERSION_CODES.N)
         @Override

server/src/main/java/com/genymobile/scrcpy/AudioRawRecorder.java

@@ -0,0 +1,75 @@
+package com.genymobile.scrcpy;
+
+import android.media.MediaCodec;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+public final class AudioRawRecorder implements AudioRecorder {
+
+    private final Streamer streamer;
+
+    private Thread thread;
+
+    private static final int READ_MS = 5; // milliseconds
+    private static final int READ_SIZE = AudioCapture.millisToBytes(READ_MS);
+
+    public AudioRawRecorder(Streamer streamer) {
+        this.streamer = streamer;
+    }
+
+    private void record() throws IOException, AudioCaptureForegroundException {
+        final ByteBuffer buffer = ByteBuffer.allocateDirect(READ_SIZE);
+        final MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
+
+        AudioCapture capture = new AudioCapture();
+        try {
+            capture.start();
+
+            streamer.writeHeader();
+            while (!Thread.currentThread().isInterrupted()) {
+                buffer.position(0);
+                int r = capture.read(buffer, READ_SIZE, bufferInfo);
+                if (r < 0) {
+                    throw new IOException("Could not read audio: " + r);
+                }
+                buffer.limit(r);
+
+                streamer.writePacket(buffer, bufferInfo);
+            }
+        } catch (Throwable e) {
+            // Notify the client that the audio could not be captured
+            streamer.writeDisableStream(false);
+            throw e;
+        } finally {
+            capture.stop();
+        }
+    }
+
+    public void start() {
+        thread = new Thread(() -> {
+            try {
+                record();
+            } catch (AudioCaptureForegroundException e) {
+                // Do not print stack trace, a user-friendly error-message has already been logged
+            } catch (IOException e) {
+                Ln.e("Audio recording error", e);
+            } finally {
+                Ln.d("Audio recorder stopped");
+            }
+        });
+        thread.start();
+    }
+
+    public void stop() {
+        if (thread != null) {
+            thread.interrupt();
+        }
+    }
+
+    public void join() throws InterruptedException {
+        if (thread != null) {
+            thread.join();
+        }
+    }
+}

server/src/main/java/com/genymobile/scrcpy/AudioRecorder.java

@@ -0,0 +1,12 @@
+package com.genymobile.scrcpy;
+
+/**
+ * A component able to record audio asynchronously
+ *
+ * The implementation is responsible to send packets.
+ */
+public interface AudioRecorder {
+    void start();
+    void stop();
+    void join() throws InterruptedException;
+}

server/src/main/java/com/genymobile/scrcpy/CleanUp.java

@@ -139,7 +139,7 @@ public final class CleanUp {
         builder.start();
     }
 
-    private static void unlinkSelf() {
+    public static void unlinkSelf() {
         try {
             new File(SERVER_PATH).delete();
         } catch (Exception e) {

server/src/main/java/com/genymobile/scrcpy/CodecUtils.java

@@ -10,6 +10,24 @@ import java.util.List;
 
 public final class CodecUtils {
 
+    public static final class DeviceEncoder {
+        private final Codec codec;
+        private final MediaCodecInfo info;
+
+        DeviceEncoder(Codec codec, MediaCodecInfo info) {
+            this.codec = codec;
+            this.info = info;
+        }
+
+        public Codec getCodec() {
+            return codec;
+        }
+
+        public MediaCodecInfo getInfo() {
+            return info;
+        }
+    }
+
     private CodecUtils() {
         // not instantiable
     }
@@ -25,4 +43,36 @@ public final class CodecUtils {
             format.setString(key, (String) value);
         }
     }
+
+    private static MediaCodecInfo[] getEncoders(MediaCodecList codecs, String mimeType) {
+        List<MediaCodecInfo> result = new ArrayList<>();
+        for (MediaCodecInfo codecInfo : codecs.getCodecInfos()) {
+            if (codecInfo.isEncoder() && Arrays.asList(codecInfo.getSupportedTypes()).contains(mimeType)) {
+                result.add(codecInfo);
+            }
+        }
+        return result.toArray(new MediaCodecInfo[result.size()]);
+    }
+
+    public static List<DeviceEncoder> listVideoEncoders() {
+        List<DeviceEncoder> encoders = new ArrayList<>();
+        MediaCodecList codecs = new MediaCodecList(MediaCodecList.REGULAR_CODECS);
+        for (VideoCodec codec : VideoCodec.values()) {
+            for (MediaCodecInfo info : getEncoders(codecs, codec.getMimeType())) {
+                encoders.add(new DeviceEncoder(codec, info));
+            }
+        }
+        return encoders;
+    }
+
+    public static List<DeviceEncoder> listAudioEncoders() {
+        List<DeviceEncoder> encoders = new ArrayList<>();
+        MediaCodecList codecs = new MediaCodecList(MediaCodecList.REGULAR_CODECS);
+        for (AudioCodec codec : AudioCodec.values()) {
+            for (MediaCodecInfo info : getEncoders(codecs, codec.getMimeType())) {
+                encoders.add(new DeviceEncoder(codec, info));
+            }
+        }
+        return encoders;
+    }
 }

server/src/main/java/com/genymobile/scrcpy/Device.java

@@ -65,7 +65,7 @@ public final class Device {
         displayId = options.getDisplayId();
         DisplayInfo displayInfo = ServiceManager.getDisplayManager().getDisplayInfo(displayId);
         if (displayInfo == null) {
-            Ln.e(buildUnknownDisplayIdMessage(displayId));
+            Ln.e("Display " + displayId + " not found\n" + LogUtils.buildDisplayListMessage());
             throw new ConfigurationException("Unknown display id: " + displayId);
         }
 
@@ -130,18 +130,6 @@ public final class Device {
         }
     }
 
-    private static String buildUnknownDisplayIdMessage(int displayId) {
-        StringBuilder msg = new StringBuilder("Display ").append(displayId).append(" not found");
-        int[] displayIds = ServiceManager.getDisplayManager().getDisplayIds();
-        if (displayIds != null && displayIds.length > 0) {
-            msg.append("\nTry to use one of the available display ids:");
-            for (int id : displayIds) {
-                msg.append("\n    scrcpy --display=").append(id);
-            }
-        }
-        return msg.toString();
-    }
-
     public synchronized void setMaxSize(int newMaxSize) {
         maxSize = newMaxSize;
         screenInfo = ScreenInfo.computeScreenInfo(screenInfo.getReverseVideoRotation(), deviceSize, crop, newMaxSize, lockVideoOrientation);

server/src/main/java/com/genymobile/scrcpy/LogUtils.java

@@ -0,0 +1,63 @@
+package com.genymobile.scrcpy;
+
+import com.genymobile.scrcpy.wrappers.DisplayManager;
+import com.genymobile.scrcpy.wrappers.ServiceManager;
+
+import java.util.List;
+
+public final class LogUtils {
+
+    private LogUtils() {
+        // not instantiable
+    }
+
+    public static String buildVideoEncoderListMessage() {
+        StringBuilder builder = new StringBuilder("List of video encoders:");
+        List<CodecUtils.DeviceEncoder> videoEncoders = CodecUtils.listVideoEncoders();
+        if (videoEncoders.isEmpty()) {
+            builder.append("\n    (none)");
+        } else {
+            for (CodecUtils.DeviceEncoder encoder : videoEncoders) {
+                builder.append("\n    --video-codec=").append(encoder.getCodec().getName());
+                builder.append(" --video-encoder='").append(encoder.getInfo().getName()).append("'");
+            }
+        }
+        return builder.toString();
+    }
+
+    public static String buildAudioEncoderListMessage() {
+        StringBuilder builder = new StringBuilder("List of audio encoders:");
+        List<CodecUtils.DeviceEncoder> audioEncoders = CodecUtils.listAudioEncoders();
+        if (audioEncoders.isEmpty()) {
+            builder.append("\n    (none)");
+        } else {
+            for (CodecUtils.DeviceEncoder encoder : audioEncoders) {
+                builder.append("\n    --audio-codec=").append(encoder.getCodec().getName());
+                builder.append(" --audio-encoder='").append(encoder.getInfo().getName()).append("'");
+            }
+        }
+        return builder.toString();
+    }
+
+    public static String buildDisplayListMessage() {
+        StringBuilder builder = new StringBuilder("List of displays:");
+        DisplayManager displayManager = ServiceManager.getDisplayManager();
+        int[] displayIds = displayManager.getDisplayIds();
+        if (displayIds == null || displayIds.length == 0) {
+            builder.append("\n    (none)");
+        } else {
+            for (int id : displayIds) {
+                builder.append("\n    --display=").append(id).append("    (");
+                DisplayInfo displayInfo = displayManager.getDisplayInfo(id);
+                if (displayInfo != null) {
+                    Size size = displayInfo.getSize();
+                    builder.append(size.getWidth()).append("x").append(size.getHeight());
+                } else {
+                    builder.append("size unknown");
+                }
+                builder.append(")");
+            }
+        }
+        return builder.toString();
+    }
+}

server/src/main/java/com/genymobile/scrcpy/Options.java

@@ -23,13 +23,19 @@ public class Options {
     private boolean showTouches;
     private boolean stayAwake;
     private List<CodecOption> videoCodecOptions;
+    private List<CodecOption> audioCodecOptions;
+
     private String videoEncoder;
+    private String audioEncoder;
     private boolean powerOffScreenOnClose;
     private boolean clipboardAutosync = true;
     private boolean downsizeOnError = true;
     private boolean cleanup = true;
     private boolean powerOn = true;
 
+    private boolean listEncoders;
+    private boolean listDisplays;
+
     // Options not used by the scrcpy client, but useful to use scrcpy-server directly
     private boolean sendDeviceMeta = true; // send device name and size
     private boolean sendFrameMeta = true; // send PTS so that the client may record properly
@@ -172,6 +178,14 @@ public class Options {
         this.videoCodecOptions = videoCodecOptions;
     }
 
+    public List<CodecOption> getAudioCodecOptions() {
+        return audioCodecOptions;
+    }
+
+    public void setAudioCodecOptions(List<CodecOption> audioCodecOptions) {
+        this.audioCodecOptions = audioCodecOptions;
+    }
+
     public String getVideoEncoder() {
         return videoEncoder;
     }
@@ -180,6 +194,14 @@ public class Options {
         this.videoEncoder = videoEncoder;
     }
 
+    public String getAudioEncoder() {
+        return audioEncoder;
+    }
+
+    public void setAudioEncoder(String audioEncoder) {
+        this.audioEncoder = audioEncoder;
+    }
+
     public void setPowerOffScreenOnClose(boolean powerOffScreenOnClose) {
         this.powerOffScreenOnClose = powerOffScreenOnClose;
     }
@@ -220,6 +242,22 @@ public class Options {
         this.powerOn = powerOn;
     }
 
+    public boolean getListEncoders() {
+        return listEncoders;
+    }
+
+    public void setListEncoders(boolean listEncoders) {
+        this.listEncoders = listEncoders;
+    }
+
+    public boolean getListDisplays() {
+        return listDisplays;
+    }
+
+    public void setListDisplays(boolean listDisplays) {
+        this.listDisplays = listDisplays;
+    }
+
     public boolean getSendDeviceMeta() {
         return sendDeviceMeta;
     }

server/src/main/java/com/genymobile/scrcpy/ScreenEncoder.java

@@ -5,7 +5,6 @@ import com.genymobile.scrcpy.wrappers.SurfaceControl;
 import android.graphics.Rect;
 import android.media.MediaCodec;
 import android.media.MediaCodecInfo;
-import android.media.MediaCodecList;
 import android.media.MediaFormat;
 import android.os.Build;
 import android.os.IBinder;
@@ -14,8 +13,6 @@ import android.view.Surface;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -199,24 +196,13 @@ public class ScreenEncoder implements Device.RotationListener {
         return !eof;
     }
 
-    private static MediaCodecInfo[] listEncoders(String videoMimeType) {
-        List<MediaCodecInfo> result = new ArrayList<>();
-        MediaCodecList list = new MediaCodecList(MediaCodecList.REGULAR_CODECS);
-        for (MediaCodecInfo codecInfo : list.getCodecInfos()) {
-            if (codecInfo.isEncoder() && Arrays.asList(codecInfo.getSupportedTypes()).contains(videoMimeType)) {
-                result.add(codecInfo);
-            }
-        }
-        return result.toArray(new MediaCodecInfo[result.size()]);
-    }
-
     private static MediaCodec createMediaCodec(Codec codec, String encoderName) throws IOException, ConfigurationException {
         if (encoderName != null) {
             Ln.d("Creating encoder by name: '" + encoderName + "'");
             try {
                 return MediaCodec.createByCodecName(encoderName);
             } catch (IllegalArgumentException e) {
-                Ln.e(buildUnknownEncoderMessage(codec, encoderName));
+                Ln.e("Encoder '" + encoderName + "' for " + codec.getName() + " not found\n" + LogUtils.buildVideoEncoderListMessage());
                 throw new ConfigurationException("Unknown encoder: " + encoderName);
             }
         }
@@ -225,18 +211,6 @@ public class ScreenEncoder implements Device.RotationListener {
         return mediaCodec;
     }
 
-    private static String buildUnknownEncoderMessage(Codec codec, String encoderName) {
-        StringBuilder msg = new StringBuilder("Encoder '").append(encoderName).append("' for ").append(codec.getName()).append(" not found");
-        MediaCodecInfo[] encoders = listEncoders(codec.getMimeType());
-        if (encoders != null && encoders.length > 0) {
-            msg.append("\nTry to use one of the available encoders:");
-            for (MediaCodecInfo encoder : encoders) {
-                msg.append("\n    scrcpy --video-codec=").append(codec.getName()).append(" --encoder='").append(encoder.getName()).append("'");
-            }
-        }
-        return msg.toString();
-    }
-
     private static MediaFormat createFormat(String videoMimeType, int bitRate, int maxFps, List<CodecOption> codecOptions) {
         MediaFormat format = new MediaFormat();
         format.setString(MediaFormat.KEY_MIME, videoMimeType);

server/src/main/java/com/genymobile/scrcpy/Server.java

@@ -92,7 +92,7 @@ public final class Server {
         }
 
         Controller controller = null;
-        AudioEncoder audioEncoder = null;
+        AudioRecorder audioRecorder = null;
 
         try (DesktopConnection connection = DesktopConnection.open(scid, tunnelForward, audio, control, sendDummyByte)) {
             if (options.getSendDeviceMeta()) {
@@ -109,10 +109,15 @@ public final class Server {
             }
 
             if (audio) {
-                Streamer audioStreamer = new Streamer(connection.getAudioFd(), options.getAudioCodec(), options.getSendCodecId(),
-                        options.getSendFrameMeta());
-                audioEncoder = new AudioEncoder(audioStreamer, options.getAudioBitRate());
-                audioEncoder.start();
+                AudioCodec audioCodec = options.getAudioCodec();
+                Streamer audioStreamer = new Streamer(connection.getAudioFd(), audioCodec, options.getSendCodecId(), options.getSendFrameMeta());
+                if (audioCodec == AudioCodec.RAW) {
+                    audioRecorder = new AudioRawRecorder(audioStreamer);
+                } else {
+                    audioRecorder = new AudioEncoder(audioStreamer, options.getAudioBitRate(), options.getAudioCodecOptions(),
+                            options.getAudioEncoder());
+                }
+                audioRecorder.start();
             }
 
             Streamer videoStreamer = new Streamer(connection.getVideoFd(), options.getVideoCodec(), options.getSendCodecId(),
@@ -131,8 +136,8 @@ public final class Server {
         } finally {
             Ln.d("Screen streaming stopped");
             initThread.interrupt();
-            if (audioEncoder != null) {
-                audioEncoder.stop();
+            if (audioRecorder != null) {
+                audioRecorder.stop();
             }
             if (controller != null) {
                 controller.stop();
@@ -140,8 +145,8 @@ public final class Server {
 
             try {
                 initThread.join();
-                if (audioEncoder != null) {
-                    audioEncoder.join();
+                if (audioRecorder != null) {
+                    audioRecorder.join();
                 }
                 if (controller != null) {
                     controller.join();
@@ -258,11 +263,19 @@ public final class Server {
                     List<CodecOption> videoCodecOptions = CodecOption.parse(value);
                     options.setVideoCodecOptions(videoCodecOptions);
                     break;
+                case "audio_codec_options":
+                    List<CodecOption> audioCodecOptions = CodecOption.parse(value);
+                    options.setAudioCodecOptions(audioCodecOptions);
+                    break;
                 case "video_encoder":
                     if (!value.isEmpty()) {
                         options.setVideoEncoder(value);
                     }
                     break;
+                case "audio_encoder":
+                    if (!value.isEmpty()) {
+                        options.setAudioEncoder(value);
+                    }
                 case "power_off_on_close":
                     boolean powerOffScreenOnClose = Boolean.parseBoolean(value);
                     options.setPowerOffScreenOnClose(powerOffScreenOnClose);
@@ -283,6 +296,14 @@ public final class Server {
                     boolean powerOn = Boolean.parseBoolean(value);
                     options.setPowerOn(powerOn);
                     break;
+                case "list_encoders":
+                    boolean listEncoders = Boolean.parseBoolean(value);
+                    options.setListEncoders(listEncoders);
+                    break;
+                case "list_displays":
+                    boolean listDisplays = Boolean.parseBoolean(value);
+                    options.setListDisplays(listDisplays);
+                    break;
                 case "send_device_meta":
                     boolean sendDeviceMeta = Boolean.parseBoolean(value);
                     options.setSendDeviceMeta(sendDeviceMeta);
@@ -342,6 +363,22 @@ public final class Server {
 
         Ln.initLogLevel(options.getLogLevel());
 
+        if (options.getListEncoders() || options.getListDisplays()) {
+            if (options.getCleanup()) {
+                CleanUp.unlinkSelf();
+            }
+
+            if (options.getListEncoders()) {
+                Ln.i(LogUtils.buildVideoEncoderListMessage());
+                Ln.i(LogUtils.buildAudioEncoderListMessage());
+            }
+            if (options.getListDisplays()) {
+                Ln.i(LogUtils.buildDisplayListMessage());
+            }
+            // Just print the requested data, do not mirror
+            return;
+        }
+
         try {
             scrcpy(options);
         } catch (ConfigurationException e) {

server/src/main/java/com/genymobile/scrcpy/Streamer.java

@@ -40,10 +40,15 @@ public final class Streamer {
         }
     }
 
-    public void writeDisableStream() throws IOException {
-        // Writing 0 (32-bit) as codec-id means that the device disables the stream (because it could not capture)
-        byte[] zeros = new byte[4];
-        IO.writeFully(fd, zeros, 0, zeros.length);
+    public void writeDisableStream(boolean error) throws IOException {
+        // Writing a specific code as codec-id means that the device disables the stream
+        //   code 0: it explicitly disables the stream (because it could not capture audio), scrcpy should continue mirroring video only
+        //   code 1: a configuration error occurred, scrcpy must be stopped
+        byte[] code = new byte[4];
+        if (error) {
+            code[3] = 1;
+        }
+        IO.writeFully(fd, code, 0, code.length);
     }
 
     public void writePacket(ByteBuffer buffer, long pts, boolean config, boolean keyFrame) throws IOException {

server/src/main/java/com/genymobile/scrcpy/wrappers/ActivityManager.java

@@ -3,7 +3,12 @@ package com.genymobile.scrcpy.wrappers;
 import com.genymobile.scrcpy.FakeContext;
 import com.genymobile.scrcpy.Ln;
 
+import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
+import android.content.Intent;
 import android.os.Binder;
+import android.os.Build;
+import android.os.Bundle;
 import android.os.IBinder;
 import android.os.IInterface;
 
@@ -11,12 +16,15 @@ import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 
+@SuppressLint("PrivateApi,DiscouragedPrivateApi")
 public class ActivityManager {
 
     private final IInterface manager;
     private Method getContentProviderExternalMethod;
     private boolean getContentProviderExternalMethodNewVersion = true;
     private Method removeContentProviderExternalMethod;
+    private Method startActivityAsUserWithFeatureMethod;
+    private Method forceStopPackageMethod;
 
     public ActivityManager(IInterface manager) {
         this.manager = manager;
@@ -43,6 +51,7 @@ public class ActivityManager {
         return removeContentProviderExternalMethod;
     }
 
+    @TargetApi(Build.VERSION_CODES.Q)
     private ContentProvider getContentProviderExternal(String name, IBinder token) {
         try {
             Method method = getGetContentProviderExternalMethod();
@@ -85,4 +94,55 @@ public class ActivityManager {
     public ContentProvider createSettingsProvider() {
         return getContentProviderExternal("settings", new Binder());
     }
+
+    private Method getStartActivityAsUserWithFeatureMethod() throws NoSuchMethodException, ClassNotFoundException {
+        if (startActivityAsUserWithFeatureMethod == null) {
+            Class<?> iApplicationThreadClass = Class.forName("android.app.IApplicationThread");
+            Class<?> profilerInfo = Class.forName("android.app.ProfilerInfo");
+            startActivityAsUserWithFeatureMethod = manager.getClass()
+                    .getMethod("startActivityAsUserWithFeature", iApplicationThreadClass, String.class, String.class, Intent.class, String.class,
+                            IBinder.class, String.class, int.class, int.class, profilerInfo, Bundle.class, int.class);
+        }
+        return startActivityAsUserWithFeatureMethod;
+    }
+
+    @SuppressWarnings("ConstantConditions")
+    public int startActivityAsUserWithFeature(Intent intent) {
+        try {
+            Method method = getStartActivityAsUserWithFeatureMethod();
+            return (int) method.invoke(
+                    /* this */ manager,
+                    /* caller */ null,
+                    /* callingPackage */ FakeContext.PACKAGE_NAME,
+                    /* callingFeatureId */ null,
+                    /* intent */ intent,
+                    /* resolvedType */ null,
+                    /* resultTo */ null,
+                    /* resultWho */ null,
+                    /* requestCode */ 0,
+                    /* startFlags */ 0,
+                    /* profilerInfo */ null,
+                    /* bOptions */ null,
+                    /* userId */ /* UserHandle.USER_CURRENT */ -2);
+        } catch (Throwable e) {
+            Ln.e("Could not invoke method", e);
+            return 0;
+        }
+    }
+
+    private Method getForceStopPackageMethod() throws NoSuchMethodException {
+        if (forceStopPackageMethod == null) {
+            forceStopPackageMethod = manager.getClass().getMethod("forceStopPackage", String.class, int.class);
+        }
+        return forceStopPackageMethod;
+    }
+
+    public void forceStopPackage(String packageName) {
+        try {
+            Method method = getForceStopPackageMethod();
+            method.invoke(manager, packageName, /* userId */ /* UserHandle.USER_CURRENT */ -2);
+        } catch (Throwable e) {
+            Ln.e("Could not invoke method", e);
+        }
+    }
 }