Use separate audio capture code for Android 11

The code to start audio capture is more complicated for Android 11
(launch a fake popup, wait, make several attempts, close the shell
package).

Use a distinct code path specific to Android 11.

app/data/bash-completion/scrcpy

@@ -3,9 +3,11 @@ _scrcpy() {
     local opts="
         --always-on-top
         --audio-bit-rate=
+        --audio-buffer=
         --audio-codec=
         --audio-codec-options=
         --audio-encoder=
+        --audio-output-buffer=
         -b --video-bit-rate=
         --crop=
         -d --select-usb
@@ -115,20 +117,26 @@ _scrcpy() {
             COMPREPLY=($(compgen -W "$("${ADB:-adb}" devices | awk '$2 == "device" {print $1}')" -- ${cur}))
             return
             ;;
-        -b|--video-bit-rate \
-        |--codec-options \
+        --audio-bit-rate \
+        |--audio-buffer \
+        |-b|--video-bit-rate \
+        |--audio-codec-options \
+        |--audio-encoder \
+        |--audio-output-buffer \
         |--crop \
         |--display \
         |--display-buffer \
-        |--encoder \
         |--max-fps \
         |-m|--max-size \
         |-p|--port \
         |--push-target \
+        |--rotation \
         |--tunnel-host \
         |--tunnel-port \
         |--v4l2-buffer \
         |--v4l2-sink \
+        |--video-codec-options \
+        |--video-encoder \
         |--tcpip \
         |--window-*)
             # Option accepting an argument, but nothing to auto-complete

app/data/scrcpy-console.desktop

@@ -5,7 +5,7 @@ Comment=Display and control your Android device
 # For some users, the PATH or ADB environment variables are set from the shell
 # startup file, like .bashrc or .zshrc… Run an interactive shell to get
 # environment correctly initialized.
-Exec=/bin/bash --norc --noprofile -i -c '"$SHELL" -i -c scrcpy || read -p "Press any key to quit..."'
+Exec=/bin/bash --norc --noprofile -i -c "\"\\$SHELL\" -i -c scrcpy || read -p 'Press Enter to quit...'"
 Icon=scrcpy
 Terminal=true
 Type=Application

app/data/scrcpy.desktop

@@ -5,7 +5,7 @@ Comment=Display and control your Android device
 # For some users, the PATH or ADB environment variables are set from the shell
 # startup file, like .bashrc or .zshrc… Run an interactive shell to get
 # environment correctly initialized.
-Exec=/bin/sh -c '"$SHELL" -i -c scrcpy'
+Exec=/bin/sh -c "\"\\$SHELL\" -i -c scrcpy"
 Icon=scrcpy
 Terminal=false
 Type=Application

app/data/zsh-completion/_scrcpy

@@ -10,9 +10,11 @@ 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-buffer=[Configure the audio buffering delay (in milliseconds)]'
     '--audio-codec=[Select the audio codec]:codec:(opus aac raw)'
     '--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]'
+    '--audio-output-buffer=[Configure the size of the SDL audio output buffer (in milliseconds)]'
     {-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]'

app/scrcpy.1

@@ -33,6 +33,14 @@ Lower values decrease the latency, but increase the likelyhood of buffer underru
 
 Default is 50.
 
+.TP
+.BI "\-\-audio\-output\-buffer ms
+Configure the size of the SDL audio output buffer (in milliseconds).
+
+If you get "robotic" audio playback, you should test with a higher value (10). Do not change this setting otherwise.
+
+Default is 5.
+
 .TP
 .BI "\-\-audio\-codec " name
 Select an audio codec (opus, aac or raw).

app/src/audio_player.c

@@ -59,8 +59,6 @@
 #define SC_AV_SAMPLE_FMT AV_SAMPLE_FMT_FLT
 #define SC_SDL_SAMPLE_FMT AUDIO_F32
 
-#define SC_AUDIO_OUTPUT_BUFFER_MS 5
-
 #define TO_BYTES(SAMPLES) sc_audiobuf_to_bytes(&ap->buf, (SAMPLES))
 #define TO_SAMPLES(BYTES) sc_audiobuf_to_samples(&ap->buf, (BYTES))
 
@@ -230,8 +228,8 @@ sc_audio_player_frame_sink_push(struct sc_frame_sink *sink,
 
     if (played) {
         uint32_t max_buffered_samples = ap->target_buffering
-                + 12 * SC_AUDIO_OUTPUT_BUFFER_MS * ap->sample_rate / 1000
-                + ap->target_buffering / 10;
+                                      + 12 * ap->output_buffer
+                                      + ap->target_buffering / 10;
         if (buffered_samples > max_buffered_samples) {
             uint32_t skip_samples = buffered_samples - max_buffered_samples;
             sc_audiobuf_skip(&ap->buf, skip_samples);
@@ -246,7 +244,7 @@ sc_audio_player_frame_sink_push(struct sc_frame_sink *sink,
         // max_initial_buffering samples, this would cause unnecessary delay
         // (and glitches to compensate) on start.
         uint32_t max_initial_buffering = ap->target_buffering
-                + 2 * SC_AUDIO_OUTPUT_BUFFER_MS * ap->sample_rate / 1000;
+                                       + 2 * ap->output_buffer;
         if (buffered_samples > max_initial_buffering) {
             uint32_t skip_samples = buffered_samples - max_initial_buffering;
             sc_audiobuf_skip(&ap->buf, skip_samples);
@@ -333,11 +331,28 @@ sc_audio_player_frame_sink_open(struct sc_frame_sink *sink,
     unsigned nb_channels = tmp;
 #endif
 
+    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);
+
+    ap->sample_rate = ctx->sample_rate;
+    ap->nb_channels = nb_channels;
+    ap->out_bytes_per_sample = out_bytes_per_sample;
+
+    ap->target_buffering = ap->target_buffering_delay * ap->sample_rate
+                                                      / SC_TICK_FREQ;
+
+    uint64_t aout_samples = ap->output_buffer_duration * ap->sample_rate
+                                                       / SC_TICK_FREQ;
+    assert(aout_samples <= 0xFFFF);
+    ap->output_buffer = (uint16_t) aout_samples;
+
     SDL_AudioSpec desired = {
         .freq = ctx->sample_rate,
         .format = SC_SDL_SAMPLE_FMT,
         .channels = nb_channels,
-        .samples = SC_AUDIO_OUTPUT_BUFFER_MS * ctx->sample_rate / 1000,
+        .samples = aout_samples,
         .callback = sc_audio_player_sdl_callback,
         .userdata = ap,
     };
@@ -356,11 +371,6 @@ sc_audio_player_frame_sink_open(struct sc_frame_sink *sink,
     }
     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);
@@ -383,13 +393,6 @@ sc_audio_player_frame_sink_open(struct sc_frame_sink *sink,
         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;
-
-    ap->target_buffering = ap->target_buffering_delay * ap->sample_rate
-                                                      / SC_TICK_FREQ;
-
     // Use a ring-buffer of the target buffering size plus 1 second between the
     // producer and the consumer. It's too big on purpose, to guarantee that
     // the producer and the consumer will be able to access it in parallel
@@ -458,8 +461,10 @@ sc_audio_player_frame_sink_close(struct sc_frame_sink *sink) {
 }
 
 void
-sc_audio_player_init(struct sc_audio_player *ap, sc_tick target_buffering) {
+sc_audio_player_init(struct sc_audio_player *ap, sc_tick target_buffering,
+                     sc_tick output_buffer_duration) {
     ap->target_buffering_delay = target_buffering;
+    ap->output_buffer_duration = output_buffer_duration;
 
     static const struct sc_frame_sink_ops ops = {
         .open = sc_audio_player_frame_sink_open,

app/src/audio_player.h

@@ -27,6 +27,10 @@ struct sc_audio_player {
     sc_tick target_buffering_delay;
     uint32_t target_buffering; // in samples
 
+    // SDL audio output buffer size.
+    sc_tick output_buffer_duration;
+    uint16_t output_buffer;
+
     // Audio buffer to communicate between the receiver and the SDL audio
     // callback (protected by SDL_AudioDeviceLock())
     struct sc_audiobuf buf;
@@ -80,6 +84,7 @@ struct sc_audio_player_callbacks {
 };
 
 void
-sc_audio_player_init(struct sc_audio_player *ap, sc_tick target_buffering);
+sc_audio_player_init(struct sc_audio_player *ap, sc_tick target_buffering,
+                     sc_tick audio_output_buffer);
 
 #endif

app/src/cli.c

@@ -71,6 +71,7 @@ enum {
     OPT_LIST_DISPLAYS,
     OPT_REQUIRE_AUDIO,
     OPT_AUDIO_BUFFER,
+    OPT_AUDIO_OUTPUT_BUFFER,
 };
 
 struct sc_option {
@@ -129,6 +130,16 @@ static const struct sc_option options[] = {
                 "likelyhood of buffer underrun (causing audio glitches).\n"
                 "Default is 50.",
     },
+    {
+        .longopt_id = OPT_AUDIO_OUTPUT_BUFFER,
+        .longopt = "audio-output-buffer",
+        .argdesc = "ms",
+        .text = "Configure the size of the SDL audio output buffer (in "
+                "milliseconds).\n"
+                "If you get \"robotic\" audio playback, you should test with "
+                "a higher value (10). Do not change this setting otherwise.\n"
+                "Default is 5.",
+    },
     {
         .longopt_id = OPT_AUDIO_CODEC,
         .longopt = "audio-codec",
@@ -1204,6 +1215,19 @@ parse_buffering_time(const char *s, sc_tick *tick) {
     return true;
 }
 
+static bool
+parse_audio_output_buffer(const char *s, sc_tick *tick) {
+    long value;
+    bool ok = parse_integer_arg(s, &value, false, 0, 1000,
+                                "audio output buffer");
+    if (!ok) {
+        return false;
+    }
+
+    *tick = SC_TICK_FROM_MS(value);
+    return true;
+}
+
 static bool
 parse_lock_video_orientation(const char *s,
                              enum sc_lock_video_orientation *lock_mode) {
@@ -1831,6 +1855,12 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
                     return false;
                 }
                 break;
+            case OPT_AUDIO_OUTPUT_BUFFER:
+                if (!parse_audio_output_buffer(optarg,
+                                               &opts->audio_output_buffer)) {
+                    return false;
+                }
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;

app/src/options.c

@@ -44,6 +44,7 @@ const struct scrcpy_options scrcpy_options_default = {
     .display_buffer = 0,
     .v4l2_buffer = 0,
     .audio_buffer = SC_TICK_FROM_MS(50),
+    .audio_output_buffer = SC_TICK_FROM_MS(5),
 #ifdef HAVE_USB
     .otg = false,
 #endif

app/src/options.h

@@ -127,6 +127,7 @@ struct scrcpy_options {
     sc_tick display_buffer;
     sc_tick v4l2_buffer;
     sc_tick audio_buffer;
+    sc_tick audio_output_buffer;
 #ifdef HAVE_USB
     bool otg;
 #endif

app/src/scrcpy.c

@@ -688,7 +688,8 @@ aoa_hid_end:
         sc_frame_source_add_sink(src, &s->screen.frame_sink);
 
         if (options->audio) {
-            sc_audio_player_init(&s->audio_player, options->audio_buffer);
+            sc_audio_player_init(&s->audio_player, options->audio_buffer,
+                                 options->audio_output_buffer);
             sc_frame_source_add_sink(&s->audio_decoder.frame_source,
                                      &s->audio_player.frame_sink);
         }

doc/audio.md

@@ -88,3 +88,14 @@ avoid glitches and smooth the playback:
 ```
 scrcpy --display-buffer=200 --audio-buffer=200
 ```
+
+It is also possible to configure another audio buffer (the audio output buffer),
+by default set to 5ms. Don't change it, unless you get some [robotic and glitchy
+sound][#3793]:
+
+```bash
+# Only if absolutely necessary
+scrcpy --audio-output-buffer=10
+```
+
+[#3793]: https://github.com/Genymobile/scrcpy/issues/3793

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

@@ -59,45 +59,58 @@ public final class AudioCapture {
     }
 
     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);
-            }
-        }
+        // 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.
+        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);
     }
 
     private static void stopWorkaroundAndroid11() {
-        if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {
-            ServiceManager.getActivityManager().forceStopPackage(FakeContext.PACKAGE_NAME);
+        ServiceManager.getActivityManager().forceStopPackage(FakeContext.PACKAGE_NAME);
+    }
+
+    private void tryStartRecording(int attempts, int delayMs) throws AudioCaptureForegroundException {
+        while (attempts-- > 0) {
+            // Wait for activity to start
+            SystemClock.sleep(delayMs);
+            try {
+                startRecording();
+                return; // it worked
+            } catch (UnsupportedOperationException e) {
+                if (attempts == 0) {
+                    Ln.e("Failed to start audio capture");
+                    Ln.e("On Android 11, audio capture must be started in the foreground, make sure that the device is unlocked when starting " +
+                            "scrcpy.");
+                    throw new AudioCaptureForegroundException();
+                } else {
+                    Ln.d("Failed to start audio capture, retrying...");
+                }
+            }
         }
     }
 
+    private void startRecording() {
+        recorder = createAudioRecord();
+        recorder.startRecording();
+    }
+
     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();
+        if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {
+            startWorkaroundAndroid11();
+            try {
+                tryStartRecording(3, 100);
+            } finally {
+                stopWorkaroundAndroid11();
             }
-            throw e;
-        } finally {
-            stopWorkaroundAndroid11();
+        } else {
+            startRecording();
         }
     }
 

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

@@ -271,13 +271,22 @@ public final class AudioEncoder implements AsyncProcessor {
             try {
                 return MediaCodec.createByCodecName(encoderName);
             } catch (IllegalArgumentException e) {
-                Ln.e("Encoder '" + encoderName + "' for " + codec.getName() + " not found\n" + LogUtils.buildAudioEncoderListMessage());
+                Ln.e("Audio encoder '" + encoderName + "' for " + codec.getName() + " not found\n" + LogUtils.buildAudioEncoderListMessage());
                 throw new ConfigurationException("Unknown encoder: " + encoderName);
+            } catch (IOException e) {
+                Ln.e("Could not create video encoder '" + encoderName + "' for " + codec.getName() + "\n" + LogUtils.buildAudioEncoderListMessage());
+                throw e;
             }
         }
-        MediaCodec mediaCodec = MediaCodec.createEncoderByType(codec.getMimeType());
-        Ln.d("Using audio encoder: '" + mediaCodec.getName() + "'");
-        return mediaCodec;
+
+        try {
+            MediaCodec mediaCodec = MediaCodec.createEncoderByType(codec.getMimeType());
+            Ln.d("Using audio encoder: '" + mediaCodec.getName() + "'");
+            return mediaCodec;
+        } catch (IOException | IllegalArgumentException e) {
+            Ln.e("Could not create default audio encoder for " + codec.getName() + "\n" + LogUtils.buildAudioEncoderListMessage());
+            throw e;
+        }
     }
 
     private class EncoderCallback extends MediaCodec.Callback {

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

@@ -288,10 +288,7 @@ public final class Device {
             boolean allOk = true;
             for (long physicalDisplayId : physicalDisplayIds) {
                 IBinder binder = SurfaceControl.getPhysicalDisplayToken(physicalDisplayId);
-                boolean ok = SurfaceControl.setDisplayPowerMode(binder, mode);
-                if (!ok) {
-                    allOk = false;
-                }
+                allOk &= SurfaceControl.setDisplayPowerMode(binder, mode);
             }
             return allOk;
         }

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

@@ -202,13 +202,22 @@ public class ScreenEncoder implements Device.RotationListener {
             try {
                 return MediaCodec.createByCodecName(encoderName);
             } catch (IllegalArgumentException e) {
-                Ln.e("Encoder '" + encoderName + "' for " + codec.getName() + " not found\n" + LogUtils.buildVideoEncoderListMessage());
+                Ln.e("Video encoder '" + encoderName + "' for " + codec.getName() + " not found\n" + LogUtils.buildVideoEncoderListMessage());
                 throw new ConfigurationException("Unknown encoder: " + encoderName);
+            } catch (IOException e) {
+                Ln.e("Could not create video encoder '" + encoderName + "' for " + codec.getName() + "\n" + LogUtils.buildVideoEncoderListMessage());
+                throw e;
             }
         }
-        MediaCodec mediaCodec = MediaCodec.createEncoderByType(codec.getMimeType());
-        Ln.d("Using encoder: '" + mediaCodec.getName() + "'");
-        return mediaCodec;
+
+        try {
+            MediaCodec mediaCodec = MediaCodec.createEncoderByType(codec.getMimeType());
+            Ln.d("Using video encoder: '" + mediaCodec.getName() + "'");
+            return mediaCodec;
+        } catch (IOException | IllegalArgumentException e) {
+            Ln.e("Could not create default video encoder for " + codec.getName() + "\n" + LogUtils.buildVideoEncoderListMessage());
+            throw e;
+        }
     }
 
     private static MediaFormat createFormat(String videoMimeType, int bitRate, int maxFps, List<CodecOption> codecOptions) {