Add --require-audio

By default, scrcpy mirrors only the video when audio capture fails on
the device. Add a flag to force scrcpy to fail if audio is enabled but
does not work.

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

app/src/cli.c

@@ -69,6 +69,7 @@ enum {
     OPT_AUDIO_ENCODER,
     OPT_LIST_ENCODERS,
     OPT_LIST_DISPLAYS,
+    OPT_REQUIRE_AUDIO,
 };
 
 struct sc_option {
@@ -458,6 +459,13 @@ 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",
@@ -1801,6 +1809,9 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             case OPT_LIST_DISPLAYS:
                 opts->list_displays = true;
                 break;
+            case OPT_REQUIRE_AUDIO:
+                opts->require_audio = true;
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;

app/src/demuxer.c

@@ -176,14 +176,13 @@ 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;
     }
 
@@ -191,7 +190,7 @@ run_demuxer(void *data) {
         LOGW("Demuxer '%s': stream explicitly disabled by the device",
              demuxer->name);
         sc_demuxer_disable_sinks(demuxer);
-        eos = true;
+        status = SC_DEMUXER_STATUS_DISABLED;
         goto end;
     }
 
@@ -241,7 +240,7 @@ 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;
         }
 
@@ -272,7 +271,7 @@ run_demuxer(void *data) {
 finally_close_sinks:
     sc_demuxer_close_sinks(demuxer);
 end:
-    demuxer->cbs->on_ended(demuxer, eos, demuxer->cbs_userdata);
+    demuxer->cbs->on_ended(demuxer, status, demuxer->cbs_userdata);
 
     return 0;
 }

app/src/demuxer.h

@@ -27,8 +27,15 @@ struct sc_demuxer {
     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)

app/src/options.c

@@ -72,6 +72,7 @@ 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

@@ -154,6 +154,7 @@ struct scrcpy_options {
     bool start_fps_counter;
     bool power_on;
     bool audio;
+    bool require_audio;
     bool list_encoders;
     bool list_displays;
 };

app/src/scrcpy.c

@@ -218,12 +218,15 @@ 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);
@@ -231,12 +234,14 @@ 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) userdata;
 
-    // Contrary to the video demuxer, keep mirroring if only the audio fails.
+    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).
@@ -244,7 +249,9 @@ sc_audio_demuxer_on_ended(struct sc_demuxer *demuxer, bool eos,
     // explicitly selected an unknown audio encoder), 'eos' is false and scrcpy
     // must exit.
 
-    if (!eos) {
+    if (status == SC_DEMUXER_STATUS_ERROR
+            || (status == SC_DEMUXER_STATUS_DISABLED
+                && options->require_audio)) {
         PUSH_EVENT(SC_EVENT_DEMUXER_ERROR);
     }
 }
@@ -443,7 +450,7 @@ 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_video_decoder = options->display;