Add --print-fps to enable FPS counter on start

The FPS counter could be enabled/disabled via MOD+i.

Add a command line option to enable it on start. This is consistent with
other features like --turn-screen-off or --fullscreen.

Fixes #468 <https://github.com/Genymobile/scrcpy/issues/468>
PR #3030 <https://github.com/Genymobile/scrcpy/pull/3030>

README.md

@@ -215,6 +215,15 @@ scrcpy --max-fps 15
 
 This is officially supported since Android 10, but may work on earlier versions.
 
+The actual capture framerate may be printed to the console:
+
+```
+scrcpy --print-fps
+```
+
+It may also be enabled or disabled at any time with <kbd>MOD</kbd>+<kbd>i</kbd>.
+
+
 #### Crop
 
 The device screen may be cropped to mirror only part of the screen.

app/scrcpy.1

@@ -211,6 +211,10 @@ Inject alpha characters and space as text events instead of key events.
 This avoids issues when combining multiple keys to enter special characters,
 but breaks the expected behavior of alpha keys in games (typically WASD).
 
+.TP
+.B "\-\-print\-fps
+Start FPS counter, to print framerate logs to the console. It can be started or stopped at any time with MOD+i.
+
 .TP
 .BI "\-\-push\-target " path
 Set the target directory for pushing files to the device by drag & drop. It is passed as\-is to "adb push".

app/src/cli.c

@@ -55,6 +55,7 @@
 #define OPT_NO_DOWNSIZE_ON_ERROR   1035
 #define OPT_OTG                    1036
 #define OPT_NO_CLEANUP             1037
+#define OPT_PRINT_FPS              1038
 
 struct sc_option {
     char shortopt;
@@ -336,6 +337,12 @@ static const struct sc_option options[] = {
                 "special character, but breaks the expected behavior of alpha "
                 "keys in games (typically WASD).",
     },
+    {
+        .longopt_id = OPT_PRINT_FPS,
+        .longopt = "print-fps",
+        .text = "Start FPS counter, to print framerate logs to the console. "
+                "It can be started or stopped at any time with MOD+i.",
+    },
     {
         .longopt_id = OPT_PUSH_TARGET,
         .longopt = "push-target",
@@ -1547,6 +1554,9 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             case OPT_NO_CLEANUP:
                 opts->cleanup = false;
                 break;
+            case OPT_PRINT_FPS:
+                opts->start_fps_counter = true;
+                break;
             case OPT_OTG:
 #ifdef HAVE_USB
                 opts->otg = true;

app/src/fps_counter.c

@@ -4,10 +4,10 @@
 
 #include "util/log.h"
 
-#define FPS_COUNTER_INTERVAL SC_TICK_FROM_SEC(1)
+#define SC_FPS_COUNTER_INTERVAL SC_TICK_FROM_SEC(1)
 
 bool
-fps_counter_init(struct fps_counter *counter) {
+sc_fps_counter_init(struct sc_fps_counter *counter) {
     bool ok = sc_mutex_init(&counter->mutex);
     if (!ok) {
         return false;
@@ -27,26 +27,26 @@ fps_counter_init(struct fps_counter *counter) {
 }
 
 void
-fps_counter_destroy(struct fps_counter *counter) {
+sc_fps_counter_destroy(struct sc_fps_counter *counter) {
     sc_cond_destroy(&counter->state_cond);
     sc_mutex_destroy(&counter->mutex);
 }
 
 static inline bool
-is_started(struct fps_counter *counter) {
+is_started(struct sc_fps_counter *counter) {
     return atomic_load_explicit(&counter->started, memory_order_acquire);
 }
 
 static inline void
-set_started(struct fps_counter *counter, bool started) {
+set_started(struct sc_fps_counter *counter, bool started) {
     atomic_store_explicit(&counter->started, started, memory_order_release);
 }
 
 // must be called with mutex locked
 static void
-display_fps(struct fps_counter *counter) {
+display_fps(struct sc_fps_counter *counter) {
     unsigned rendered_per_second =
-        counter->nr_rendered * SC_TICK_FREQ / FPS_COUNTER_INTERVAL;
+        counter->nr_rendered * SC_TICK_FREQ / SC_FPS_COUNTER_INTERVAL;
     if (counter->nr_skipped) {
         LOGI("%u fps (+%u frames skipped)", rendered_per_second,
                                             counter->nr_skipped);
@@ -57,7 +57,7 @@ display_fps(struct fps_counter *counter) {
 
 // must be called with mutex locked
 static void
-check_interval_expired(struct fps_counter *counter, uint32_t now) {
+check_interval_expired(struct sc_fps_counter *counter, sc_tick now) {
     if (now < counter->next_timestamp) {
         return;
     }
@@ -67,13 +67,13 @@ check_interval_expired(struct fps_counter *counter, uint32_t now) {
     counter->nr_skipped = 0;
     // add a multiple of the interval
     uint32_t elapsed_slices =
-        (now - counter->next_timestamp) / FPS_COUNTER_INTERVAL + 1;
-    counter->next_timestamp += FPS_COUNTER_INTERVAL * elapsed_slices;
+        (now - counter->next_timestamp) / SC_FPS_COUNTER_INTERVAL + 1;
+    counter->next_timestamp += SC_FPS_COUNTER_INTERVAL * elapsed_slices;
 }
 
 static int
 run_fps_counter(void *data) {
-    struct fps_counter *counter = data;
+    struct sc_fps_counter *counter = data;
 
     sc_mutex_lock(&counter->mutex);
     while (!counter->interrupted) {
@@ -94,9 +94,9 @@ run_fps_counter(void *data) {
 }
 
 bool
-fps_counter_start(struct fps_counter *counter) {
+sc_fps_counter_start(struct sc_fps_counter *counter) {
     sc_mutex_lock(&counter->mutex);
-    counter->next_timestamp = sc_tick_now() + FPS_COUNTER_INTERVAL;
+    counter->next_timestamp = sc_tick_now() + SC_FPS_COUNTER_INTERVAL;
     counter->nr_rendered = 0;
     counter->nr_skipped = 0;
     sc_mutex_unlock(&counter->mutex);
@@ -117,22 +117,24 @@ fps_counter_start(struct fps_counter *counter) {
         counter->thread_started = true;
     }
 
+    LOGI("FPS counter started");
     return true;
 }
 
 void
-fps_counter_stop(struct fps_counter *counter) {
+sc_fps_counter_stop(struct sc_fps_counter *counter) {
     set_started(counter, false);
     sc_cond_signal(&counter->state_cond);
+    LOGI("FPS counter stopped");
 }
 
 bool
-fps_counter_is_started(struct fps_counter *counter) {
+sc_fps_counter_is_started(struct sc_fps_counter *counter) {
     return is_started(counter);
 }
 
 void
-fps_counter_interrupt(struct fps_counter *counter) {
+sc_fps_counter_interrupt(struct sc_fps_counter *counter) {
     if (!counter->thread_started) {
         return;
     }
@@ -145,7 +147,7 @@ fps_counter_interrupt(struct fps_counter *counter) {
 }
 
 void
-fps_counter_join(struct fps_counter *counter) {
+sc_fps_counter_join(struct sc_fps_counter *counter) {
     if (counter->thread_started) {
         // interrupted must be set by the thread calling join(), so no need to
         // lock for the assertion
@@ -156,7 +158,7 @@ fps_counter_join(struct fps_counter *counter) {
 }
 
 void
-fps_counter_add_rendered_frame(struct fps_counter *counter) {
+sc_fps_counter_add_rendered_frame(struct sc_fps_counter *counter) {
     if (!is_started(counter)) {
         return;
     }
@@ -169,7 +171,7 @@ fps_counter_add_rendered_frame(struct fps_counter *counter) {
 }
 
 void
-fps_counter_add_skipped_frame(struct fps_counter *counter) {
+sc_fps_counter_add_skipped_frame(struct sc_fps_counter *counter) {
     if (!is_started(counter)) {
         return;
     }

app/src/fps_counter.h

@@ -9,7 +9,7 @@
 
 #include "util/thread.h"
 
-struct fps_counter {
+struct sc_fps_counter {
     sc_thread thread;
     sc_mutex mutex;
     sc_cond state_cond;
@@ -28,32 +28,32 @@ struct fps_counter {
 };
 
 bool
-fps_counter_init(struct fps_counter *counter);
+sc_fps_counter_init(struct sc_fps_counter *counter);
 
 void
-fps_counter_destroy(struct fps_counter *counter);
+sc_fps_counter_destroy(struct sc_fps_counter *counter);
 
 bool
-fps_counter_start(struct fps_counter *counter);
+sc_fps_counter_start(struct sc_fps_counter *counter);
 
 void
-fps_counter_stop(struct fps_counter *counter);
+sc_fps_counter_stop(struct sc_fps_counter *counter);
 
 bool
-fps_counter_is_started(struct fps_counter *counter);
+sc_fps_counter_is_started(struct sc_fps_counter *counter);
 
 // request to stop the thread (on quit)
-// must be called before fps_counter_join()
+// must be called before sc_fps_counter_join()
 void
-fps_counter_interrupt(struct fps_counter *counter);
+sc_fps_counter_interrupt(struct sc_fps_counter *counter);
 
 void
-fps_counter_join(struct fps_counter *counter);
+sc_fps_counter_join(struct sc_fps_counter *counter);
 
 void
-fps_counter_add_rendered_frame(struct fps_counter *counter);
+sc_fps_counter_add_rendered_frame(struct sc_fps_counter *counter);
 
 void
-fps_counter_add_skipped_frame(struct fps_counter *counter);
+sc_fps_counter_add_skipped_frame(struct sc_fps_counter *counter);
 
 #endif

app/src/input_manager.c

@@ -242,18 +242,14 @@ set_screen_power_mode(struct sc_controller *controller,
 }
 
 static void
-switch_fps_counter_state(struct fps_counter *fps_counter) {
+switch_fps_counter_state(struct sc_fps_counter *fps_counter) {
     // the started state can only be written from the current thread, so there
     // is no ToCToU issue
-    if (fps_counter_is_started(fps_counter)) {
-        fps_counter_stop(fps_counter);
-        LOGI("FPS counter stopped");
+    if (sc_fps_counter_is_started(fps_counter)) {
+        sc_fps_counter_stop(fps_counter);
     } else {
-        if (fps_counter_start(fps_counter)) {
-            LOGI("FPS counter started");
-        } else {
-            LOGE("FPS counter starting failed");
-        }
+        sc_fps_counter_start(fps_counter);
+        // Any error is already logged
     }
 }
 

app/src/options.c

@@ -63,4 +63,5 @@ const struct scrcpy_options scrcpy_options_default = {
     .select_tcpip = false,
     .select_usb = false,
     .cleanup = true,
+    .start_fps_counter = false,
 };

app/src/options.h

@@ -138,6 +138,7 @@ struct scrcpy_options {
     bool select_usb;
     bool select_tcpip;
     bool cleanup;
+    bool start_fps_counter;
 };
 
 extern const struct scrcpy_options scrcpy_options_default;

app/src/scrcpy.c

@@ -588,6 +588,7 @@ aoa_hid_end:
             .rotation = options->rotation,
             .mipmaps = options->mipmaps,
             .fullscreen = options->fullscreen,
+            .start_fps_counter = options->start_fps_counter,
             .buffering_time = options->display_buffer,
         };
 

app/src/screen.c

@@ -347,7 +347,7 @@ sc_video_buffer_on_new_frame(struct sc_video_buffer *vb, bool previous_skipped,
 
     bool need_new_event;
     if (previous_skipped) {
-        fps_counter_add_skipped_frame(&screen->fps_counter);
+        sc_fps_counter_add_skipped_frame(&screen->fps_counter);
         // The 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;
@@ -386,6 +386,7 @@ sc_screen_init(struct sc_screen *screen,
     screen->req.width = params->window_width;
     screen->req.height = params->window_height;
     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,
@@ -402,7 +403,7 @@ sc_screen_init(struct sc_screen *screen,
         goto error_destroy_video_buffer;
     }
 
-    if (!fps_counter_init(&screen->fps_counter)) {
+    if (!sc_fps_counter_init(&screen->fps_counter)) {
         goto error_stop_and_join_video_buffer;
     }
 
@@ -534,7 +535,7 @@ error_destroy_renderer:
 error_destroy_window:
     SDL_DestroyWindow(screen->window);
 error_destroy_fps_counter:
-    fps_counter_destroy(&screen->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);
@@ -562,6 +563,10 @@ sc_screen_show_initial_window(struct sc_screen *screen) {
         sc_screen_switch_fullscreen(screen);
     }
 
+    if (screen->req.start_fps_counter) {
+        sc_fps_counter_start(&screen->fps_counter);
+    }
+
     SDL_ShowWindow(screen->window);
 }
 
@@ -573,13 +578,13 @@ sc_screen_hide_window(struct sc_screen *screen) {
 void
 sc_screen_interrupt(struct sc_screen *screen) {
     sc_video_buffer_stop(&screen->vb);
-    fps_counter_interrupt(&screen->fps_counter);
+    sc_fps_counter_interrupt(&screen->fps_counter);
 }
 
 void
 sc_screen_join(struct sc_screen *screen) {
     sc_video_buffer_join(&screen->vb);
-    fps_counter_join(&screen->fps_counter);
+    sc_fps_counter_join(&screen->fps_counter);
 }
 
 void
@@ -591,7 +596,7 @@ sc_screen_destroy(struct sc_screen *screen) {
     SDL_DestroyTexture(screen->texture);
     SDL_DestroyRenderer(screen->renderer);
     SDL_DestroyWindow(screen->window);
-    fps_counter_destroy(&screen->fps_counter);
+    sc_fps_counter_destroy(&screen->fps_counter);
     sc_video_buffer_destroy(&screen->vb);
 }
 
@@ -701,7 +706,7 @@ sc_screen_update_frame(struct sc_screen *screen) {
     sc_video_buffer_consume(&screen->vb, screen->frame);
     AVFrame *frame = screen->frame;
 
-    fps_counter_add_rendered_frame(&screen->fps_counter);
+    sc_fps_counter_add_rendered_frame(&screen->fps_counter);
 
     struct sc_size new_frame_size = {frame->width, frame->height};
     if (!prepare_for_frame(screen, new_frame_size)) {

app/src/screen.h

@@ -26,7 +26,7 @@ struct sc_screen {
 
     struct sc_input_manager im;
     struct sc_video_buffer vb;
-    struct fps_counter fps_counter;
+    struct sc_fps_counter fps_counter;
 
     // The initial requested window properties
     struct {
@@ -35,6 +35,7 @@ struct sc_screen {
         uint16_t width;
         uint16_t height;
         bool fullscreen;
+        bool start_fps_counter;
     } req;
 
     SDL_Window *window;
@@ -93,6 +94,7 @@ struct sc_screen_params {
     bool mipmaps;
 
     bool fullscreen;
+    bool start_fps_counter;
 
     sc_tick buffering_time;
 };

app/src/util/thread.c

@@ -136,7 +136,9 @@ sc_cond_timedwait(sc_cond *cond, sc_mutex *mutex, sc_tick deadline) {
         return false; // timeout
     }
 
-    uint32_t ms = SC_TICK_TO_MS(deadline - now);
+    // Round up to the next millisecond to guarantee that the deadline is
+    // reached when returning due to timeout
+    uint32_t ms = SC_TICK_TO_MS(deadline - now + SC_TICK_FROM_MS(1) - 1);
     int r = SDL_CondWaitTimeout(cond->cond, mutex->mutex, ms);
 #ifndef NDEBUG
     if (r < 0) {
@@ -148,6 +150,8 @@ sc_cond_timedwait(sc_cond *cond, sc_mutex *mutex, sc_tick deadline) {
                           memory_order_relaxed);
 #endif
     assert(r == 0 || r == SDL_MUTEX_TIMEDOUT);
+    // The deadline is reached on timeout
+    assert(r != SDL_MUTEX_TIMEDOUT || sc_tick_now() >= deadline);
     return r == 0;
 }