Move hardcoded audio configuration to AudioConfig

This will allow to use these constants from different classes not
directly related to AudioCapture.

PR Genymobile#5102 <Genymobile#5102>

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

@@ -20,17 +20,14 @@
 
 public final class AudioCapture {
 
-    public static final int SAMPLE_RATE = 48000;
-    public static final int CHANNEL_CONFIG = AudioFormat.CHANNEL_IN_STEREO;
-    public static final int CHANNELS = 2;
-    public static final int CHANNEL_MASK = AudioFormat.CHANNEL_IN_LEFT | AudioFormat.CHANNEL_IN_RIGHT;
-    public static final int ENCODING = AudioFormat.ENCODING_PCM_16BIT;
-    public static final int BYTES_PER_SAMPLE = 2;
-
-    // Never read more than 1024 samples, even if the buffer is bigger (that would increase latency).
-    // A lower value is useless, since the system captures audio samples by blocks of 1024 (so for example if we read by blocks of 256 samples, we
-    // receive 4 successive blocks without waiting, then we wait for the 4 next ones).
-    public static final int MAX_READ_SIZE = 1024 * CHANNELS * BYTES_PER_SAMPLE;
+    private static final int SAMPLE_RATE = AudioConfig.SAMPLE_RATE;
+    private static final int CHANNEL_CONFIG = AudioConfig.CHANNEL_CONFIG;
+    private static final int CHANNELS = AudioConfig.CHANNELS;
+    private static final int CHANNEL_MASK = AudioConfig.CHANNEL_MASK;
+    private static final int ENCODING = AudioConfig.ENCODING;
+    private static final int BYTES_PER_SAMPLE = AudioConfig.BYTES_PER_SAMPLE;
+
+    private static final int MAX_READ_SIZE = AudioConfig.MAX_READ_SIZE;
 
     private static final long ONE_SAMPLE_US = (1000000 + SAMPLE_RATE - 1) / SAMPLE_RATE; // 1 sample in microseconds (used for fixing PTS)
 

server/src/main/java/com/genymobile/scrcpy/audio/AudioConfig.java

@@ -0,0 +1,21 @@
+package com.genymobile.scrcpy.audio;
+
+import android.media.AudioFormat;
+
+public final class AudioConfig {
+    public static final int SAMPLE_RATE = 48000;
+    public static final int CHANNEL_CONFIG = AudioFormat.CHANNEL_IN_STEREO;
+    public static final int CHANNELS = 2;
+    public static final int CHANNEL_MASK = AudioFormat.CHANNEL_IN_LEFT | AudioFormat.CHANNEL_IN_RIGHT;
+    public static final int ENCODING = AudioFormat.ENCODING_PCM_16BIT;
+    public static final int BYTES_PER_SAMPLE = 2;
+
+    // Never read more than 1024 samples, even if the buffer is bigger (that would increase latency).
+    // A lower value is useless, since the system captures audio samples by blocks of 1024 (so for example if we read by blocks of 256 samples, we
+    // receive 4 successive blocks without waiting, then we wait for the 4 next ones).
+    public static final int MAX_READ_SIZE = 1024 * CHANNELS * BYTES_PER_SAMPLE;
+
+    private AudioConfig() {
+        // Not instantiable
+    }
+}

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

@@ -44,8 +44,8 @@ private static class OutputTask {
         }
     }
 
-    private static final int SAMPLE_RATE = AudioCapture.SAMPLE_RATE;
-    private static final int CHANNELS = AudioCapture.CHANNELS;
+    private static final int SAMPLE_RATE = AudioConfig.SAMPLE_RATE;
+    private static final int CHANNELS = AudioConfig.CHANNELS;
 
     private final AudioCapture capture;
     private final Streamer streamer;

server/src/main/java/com/genymobile/scrcpy/audio/AudioRawRecorder.java

@@ -30,7 +30,7 @@ private void record() throws IOException, AudioCaptureException {
             return;
         }
 
-        final ByteBuffer buffer = ByteBuffer.allocateDirect(AudioCapture.MAX_READ_SIZE);
+        final ByteBuffer buffer = ByteBuffer.allocateDirect(AudioConfig.MAX_READ_SIZE);
         final MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
 
         try {