Add --audio-encoder option

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

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

@@ -46,6 +46,7 @@ public final class AudioEncoder {
 
     private final Streamer streamer;
     private final int bitRate;
+    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.
@@ -60,9 +61,10 @@ public final class AudioEncoder {
 
     private boolean ended;
 
-    public AudioEncoder(Streamer streamer, int bitRate) {
+    public AudioEncoder(Streamer streamer, int bitRate, String encoderName) {
         this.streamer = streamer;
         this.bitRate = bitRate;
+        this.encoderName = encoderName;
     }
 
     private static AudioFormat createAudioFormat() {
@@ -210,14 +212,14 @@ public final class AudioEncoder {
         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);
             recorder = createAudioRecord();
 
             mediaCodecThread = new HandlerThread("AudioEncoder");
             mediaCodecThread.start();
 
-            MediaFormat format = createFormat(mimeType, bitRate);
+            MediaFormat format = createFormat(codec.getMimeType(), bitRate);
             mediaCodec.setCallback(new EncoderCallback(), new Handler(mediaCodecThread.getLooper()));
             mediaCodec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
 
@@ -257,6 +259,8 @@ public final class AudioEncoder {
             outputThread.start();
 
             waitEnded();
+        } catch (ConfigurationException e) {
+            // Do not print stack trace, a user-friendly error-message has already been logged
         } finally {
             if (!recorderStarted) {
                 // Notify the client that the audio could not be captured
@@ -307,6 +311,21 @@ 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

@@ -24,6 +24,7 @@ public class Options {
     private boolean stayAwake;
     private List<CodecOption> codecOptions;
     private String encoderName;
+    private String audioEncoderName;
     private boolean powerOffScreenOnClose;
     private boolean clipboardAutosync = true;
     private boolean downsizeOnError = true;
@@ -180,6 +181,14 @@ public class Options {
         this.encoderName = encoderName;
     }
 
+    public String getAudioEncoderName() {
+        return audioEncoderName;
+    }
+
+    public void setAudioEncoderName(String audioEncoderName) {
+        this.audioEncoderName = audioEncoderName;
+    }
+
     public void setPowerOffScreenOnClose(boolean powerOffScreenOnClose) {
         this.powerOffScreenOnClose = powerOffScreenOnClose;
     }

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

@@ -112,7 +112,7 @@ public final class Server {
             if (audio) {
                 Streamer audioStreamer = new Streamer(connection.getAudioFd(), options.getAudioCodec(), options.getSendCodecId(),
                         options.getSendFrameMeta());
-                audioEncoder = new AudioEncoder(audioStreamer, options.getAudioBitRate());
+                audioEncoder = new AudioEncoder(audioStreamer, options.getAudioBitRate(), options.getAudioEncoderName());
                 audioEncoder.start();
             }
 
@@ -264,6 +264,10 @@ public final class Server {
                         options.setEncoderName(value);
                     }
                     break;
+                case "audio_encoder_name":
+                    if (!value.isEmpty()) {
+                        options.setAudioEncoderName(value);
+                    }
                 case "power_off_on_close":
                     boolean powerOffScreenOnClose = Boolean.parseBoolean(value);
                     options.setPowerOffScreenOnClose(powerOffScreenOnClose);