MediaCodecBridge: reconfigure AudioTrack when sample rate changes.

media/base/android/java/src/org/chromium/media/MediaCodecBridge.java

Index: media/base/android/java/src/org/chromium/media/MediaCodecBridge.java
diff --git a/media/base/android/java/src/org/chromium/media/MediaCodecBridge.java b/media/base/android/java/src/org/chromium/media/MediaCodecBridge.java
index 6834ed806c4b1dc44de79124f4f67e4e5921e9d4..e2e58d02cf0010320b2c6279a6ddcb5d2e6044aa 100644
--- a/media/base/android/java/src/org/chromium/media/MediaCodecBridge.java
+++ b/media/base/android/java/src/org/chromium/media/MediaCodecBridge.java
@@ -77,6 +77,7 @@ class MediaCodecBridge {
     private long mLastPresentationTimeUs;
     private String mMime;
     private boolean mAdaptivePlaybackSupported;
+    private int mSampleRate;
 
     private static class DequeueInputResult {
         private final int mStatus;
@@ -565,6 +566,15 @@ class MediaCodecBridge {
                 status = MEDIA_CODEC_OUTPUT_BUFFERS_CHANGED;
             } else if (indexOrStatus == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                 status = MEDIA_CODEC_OUTPUT_FORMAT_CHANGED;
+                MediaFormat newFormat = mMediaCodec.getOutputFormat();
+                if (newFormat.containsKey(MediaFormat.KEY_SAMPLE_RATE)) {
+                    int newSampleRate = newFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE);
+                    if (newSampleRate != mSampleRate) {
+                        if (!reconfigureAudioTrack(newFormat)) {

[qinmin, 2014/12/17 18:12:54]

nit: simply combine this if statement with the above one to reduce the
indentations below.

[gunsch, 2014/12/17 19:48:12]

Done.

+                            status = MEDIA_CODEC_ERROR;
+                        }
+                    }
+                }
             } else if (indexOrStatus == MediaCodec.INFO_TRY_AGAIN_LATER) {
                 status = MEDIA_CODEC_DEQUEUE_OUTPUT_AGAIN_LATER;
             } else {
@@ -664,20 +674,8 @@ class MediaCodecBridge {
             boolean playAudio) {
         try {
             mMediaCodec.configure(format, null, crypto, flags);
-            if (playAudio) {
-                int sampleRate = format.getInteger(MediaFormat.KEY_SAMPLE_RATE);
-                int channelCount = format.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
-                int channelConfig = getAudioFormat(channelCount);
-                // Using 16bit PCM for output. Keep this value in sync with
-                // kBytesPerAudioOutputSample in media_codec_bridge.cc.
-                int minBufferSize = AudioTrack.getMinBufferSize(sampleRate, channelConfig,
-                        AudioFormat.ENCODING_PCM_16BIT);
-                mAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, sampleRate, channelConfig,
-                        AudioFormat.ENCODING_PCM_16BIT, minBufferSize, AudioTrack.MODE_STREAM);
-                if (mAudioTrack.getState() == AudioTrack.STATE_UNINITIALIZED) {
-                    mAudioTrack = null;
-                    return false;
-                }
+            if (playAudio && !reconfigureAudioTrack(format)) {
+                return false;
             }
             return true;
         } catch (IllegalStateException e) {
@@ -687,6 +685,35 @@ class MediaCodecBridge {
     }
 
     /**
+     * Resets the AudioTrack instance, configured according to the given format.
+     * If a previous AudioTrack instance already exists, release it.
+     *
+     * @param format The format from which to get sample rate and channel count.
+     * @return Whether or not creating the AudioTrack succeeded.
+     */
+    private boolean reconfigureAudioTrack(MediaFormat format) {
+        if (mAudioTrack != null) {
+            mAudioTrack.release();
+        }
+
+        mSampleRate = format.getInteger(MediaFormat.KEY_SAMPLE_RATE);
+        int channelCount = format.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
+        int channelConfig = getAudioFormat(channelCount);
+        // Using 16bit PCM for output. Keep this value in sync with
+        // kBytesPerAudioOutputSample in media_codec_bridge.cc.
+        int minBufferSize = AudioTrack.getMinBufferSize(mSampleRate, channelConfig,
+                AudioFormat.ENCODING_PCM_16BIT);
+        mAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, mSampleRate, channelConfig,
+                AudioFormat.ENCODING_PCM_16BIT, minBufferSize, AudioTrack.MODE_STREAM);
+        if (mAudioTrack.getState() == AudioTrack.STATE_UNINITIALIZED) {
+            mAudioTrack = null;
+            Log.e(TAG, "Failed to initialize AudioTrack");
+            return false;
+        }
+        return true;
+    }
+
+    /**
      *  Play the audio buffer that is passed in.
      *
      *  @param buf Audio buffer to be rendered.