Add --audio-encoder

Similar to --video-encoder, but for audio.

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

app/data/bash-completion/scrcpy

@@ -5,6 +5,7 @@ _scrcpy() {
         --audio-bit-rate=
         --audio-codec=
         --audio-codec-options=
+        --audio-encoder=
         -b --video-bit-rate=
         --crop=
         -d --select-usb

app/data/zsh-completion/_scrcpy

@@ -12,6 +12,7 @@ arguments=(
     '--audio-bit-rate=[Encode the audio at the given bit-rate]'
     '--audio-codec=[Select the audio codec]:codec:(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]'

app/scrcpy.1

@@ -41,6 +41,10 @@ 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).
+
 .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).

app/src/cli.c

@@ -67,6 +67,7 @@ enum {
     OPT_AUDIO_BIT_RATE,
     OPT_AUDIO_CODEC,
     OPT_AUDIO_CODEC_OPTIONS,
+    OPT_AUDIO_ENCODER,
 };
 
 struct sc_option {
@@ -135,6 +136,13 @@ static const struct sc_option options[] = {
                 "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).",
+    },
     {
         .shortopt = 'b',
         .longopt = "video-bit-rate",
@@ -1694,6 +1702,9 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             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;

app/src/options.c

@@ -10,6 +10,7 @@ const struct scrcpy_options scrcpy_options_default = {
     .video_codec_options = NULL,
     .audio_codec_options = NULL,
     .video_encoder = NULL,
+    .audio_encoder = NULL,
 #ifdef HAVE_V4L2
     .v4l2_device = NULL,
 #endif

app/src/options.h

@@ -98,6 +98,7 @@ struct scrcpy_options {
     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

app/src/scrcpy.c

@@ -333,6 +333,7 @@ scrcpy(struct scrcpy_options *options) {
         .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,

app/src/server.c

@@ -74,6 +74,7 @@ sc_server_params_destroy(struct sc_server_params *params) {
     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);
 }
 
@@ -99,6 +100,7 @@ sc_server_params_copy(struct sc_server_params *dst,
     COPY(video_codec_options);
     COPY(audio_codec_options);
     COPY(video_encoder);
+    COPY(audio_encoder);
     COPY(tcpip_dst);
 #undef COPY
 
@@ -276,6 +278,9 @@ execute_server(struct sc_server *server,
     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");
     }

app/src/server.h

@@ -31,6 +31,7 @@ struct sc_server_params {
     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;

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

@@ -51,6 +51,7 @@ public final class AudioEncoder {
     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.
@@ -65,10 +66,11 @@ public final class AudioEncoder {
 
     private boolean ended;
 
-    public AudioEncoder(Streamer streamer, int bitRate, List<CodecOption> codecOptions) {
+    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() {
@@ -177,6 +179,8 @@ public final class AudioEncoder {
         thread = new Thread(() -> {
             try {
                 encode();
+            } catch (ConfigurationException 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 {
@@ -215,7 +219,7 @@ public final class AudioEncoder {
     }
 
     @TargetApi(Build.VERSION_CODES.M)
-    public void encode() throws IOException {
+    public void encode() throws IOException, ConfigurationException {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
             Ln.w("Audio disabled: it is not supported before Android 11");
             streamer.writeDisableStream();
@@ -228,13 +232,13 @@ public final class AudioEncoder {
         boolean mediaCodecStarted = false;
         boolean recorderStarted = false;
         try {
-            String mimeType = streamer.getCodec().getMimeType();
+            Codec codec = streamer.getCodec();
-            mediaCodec = MediaCodec.createEncoderByType(mimeType); // may throw IOException
+            mediaCodec = createMediaCodec(codec, encoderName);
 
             mediaCodecThread = new HandlerThread("AudioEncoder");
             mediaCodecThread.start();
 
-            MediaFormat format = createFormat(mimeType, bitRate, codecOptions);
+            MediaFormat format = createFormat(codec.getMimeType(), bitRate, codecOptions);
             mediaCodec.setCallback(new EncoderCallback(), new Handler(mediaCodecThread.getLooper()));
             mediaCodec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
 
@@ -324,6 +328,21 @@ public final class AudioEncoder {
         }
     }
 
+    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(CodecUtils.buildUnknownEncoderMessage(codec, encoderName));
+                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/Options.java

@@ -26,6 +26,7 @@ public class Options {
     private List<CodecOption> audioCodecOptions;
 
     private String videoEncoder;
+    private String audioEncoder;
     private boolean powerOffScreenOnClose;
     private boolean clipboardAutosync = true;
     private boolean downsizeOnError = true;
@@ -190,6 +191,14 @@ 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;
     }

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

@@ -111,7 +111,7 @@ public final class Server {
             if (audio) {
                 Streamer audioStreamer = new Streamer(connection.getAudioFd(), options.getAudioCodec(), options.getSendCodecId(),
                         options.getSendFrameMeta());
-                audioEncoder = new AudioEncoder(audioStreamer, options.getAudioBitRate(), options.getAudioCodecOptions());
+                audioEncoder = new AudioEncoder(audioStreamer, options.getAudioBitRate(), options.getAudioCodecOptions(), options.getAudioEncoder());
                 audioEncoder.start();
             }
 
@@ -267,6 +267,10 @@ public final class Server {
                         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);