Merge pull request #226 from google/dev

Refine logic for determining AudioTrack size.

library/src/main/java/com/google/android/exoplayer/Ac3PassthroughAudioTrackRenderer.java

@@ -73,9 +73,6 @@ public final class Ac3PassthroughAudioTrackRenderer extends TrackRenderer {
   /** Default buffer size for AC-3 packets from the sample source */
   private static final int DEFAULT_BUFFER_SIZE = 16384 * 2;
 
-  /** Multiplication factor for the audio track's buffer size. */
-  private static final int MIN_BUFFER_MULTIPLICATION_FACTOR = 3;
-
   private final Handler eventHandler;
   private final EventListener eventListener;
 
@@ -103,15 +100,15 @@ public final class Ac3PassthroughAudioTrackRenderer extends TrackRenderer {
    *     null if delivery of events is not required.
    * @param eventListener A listener of events. May be null if delivery of events is not required.
    */
-  public Ac3PassthroughAudioTrackRenderer(
+  public Ac3PassthroughAudioTrackRenderer(SampleSource source, Handler eventHandler,
-      SampleSource source, Handler eventHandler, EventListener eventListener) {
+      EventListener eventListener) {
     this.source = Assertions.checkNotNull(source);
     this.eventHandler = eventHandler;
     this.eventListener = eventListener;
     sampleHolder = new SampleHolder(SampleHolder.BUFFER_REPLACEMENT_MODE_NORMAL);
     sampleHolder.data = ByteBuffer.allocateDirect(DEFAULT_BUFFER_SIZE);
     formatHolder = new MediaFormatHolder();
-    audioTrack = new AudioTrack(MIN_BUFFER_MULTIPLICATION_FACTOR);
+    audioTrack = new AudioTrack();
     shouldReadInputBuffer = true;
   }
 

library/src/main/java/com/google/android/exoplayer/MediaCodecAudioTrackRenderer.java

@@ -17,7 +17,6 @@ package com.google.android.exoplayer;
 
 import com.google.android.exoplayer.audio.AudioTrack;
 import com.google.android.exoplayer.drm.DrmSessionManager;
-import com.google.android.exoplayer.util.Assertions;
 import com.google.android.exoplayer.util.MimeTypes;
 
 import android.annotation.TargetApi;
@@ -64,10 +63,9 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer {
   public static final int MSG_SET_VOLUME = 1;
 
   private final EventListener eventListener;
-
   private final AudioTrack audioTrack;
-  private int audioSessionId;
 
+  private int audioSessionId;
   private long currentPositionUs;
 
   /**
@@ -118,72 +116,10 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer {
    */
   public MediaCodecAudioTrackRenderer(SampleSource source, DrmSessionManager drmSessionManager,
       boolean playClearSamplesWithoutKeys, Handler eventHandler, EventListener eventListener) {
-    this(source, drmSessionManager, playClearSamplesWithoutKeys, eventHandler, eventListener,
-        new AudioTrack());
-  }
-
-  /**
-   * @param source The upstream source from which the renderer obtains samples.
-   * @param minBufferMultiplicationFactor When instantiating an underlying
-   *     {@link android.media.AudioTrack}, the size of the track is calculated as this value
-   *     multiplied by the minimum buffer size obtained from
-   *     {@link android.media.AudioTrack#getMinBufferSize(int, int, int)}. The multiplication
-   *     factor must be greater than or equal to 1.
-   * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
-   *     null if delivery of events is not required.
-   * @param eventListener A listener of events. May be null if delivery of events is not required.
-   */
-  public MediaCodecAudioTrackRenderer(SampleSource source, float minBufferMultiplicationFactor,
-      Handler eventHandler, EventListener eventListener) {
-    this(source, null, true, minBufferMultiplicationFactor, eventHandler, eventListener);
-  }
-
-  /**
-   * @param source The upstream source from which the renderer obtains samples.
-   * @param drmSessionManager For use with encrypted content. May be null if support for encrypted
-   *     content is not required.
-   * @param playClearSamplesWithoutKeys Encrypted media may contain clear (un-encrypted) regions.
-   *     For example a media file may start with a short clear region so as to allow playback to
-   *     begin in parallel with key acquisision. This parameter specifies whether the renderer is
-   *     permitted to play clear regions of encrypted media files before {@code drmSessionManager}
-   *     has obtained the keys necessary to decrypt encrypted regions of the media.
-   * @param minBufferMultiplicationFactor When instantiating an underlying
-   *     {@link android.media.AudioTrack}, the size of the track is calculated as this value
-   *     multiplied by the minimum buffer size obtained from
-   *     {@link android.media.AudioTrack#getMinBufferSize(int, int, int)}. The multiplication
-   *     factor must be greater than or equal to 1.
-   * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
-   *     null if delivery of events is not required.
-   * @param eventListener A listener of events. May be null if delivery of events is not required.
-   */
-  public MediaCodecAudioTrackRenderer(SampleSource source, DrmSessionManager drmSessionManager,
-      boolean playClearSamplesWithoutKeys, float minBufferMultiplicationFactor,
-      Handler eventHandler, EventListener eventListener) {
-    this(source, drmSessionManager, playClearSamplesWithoutKeys, eventHandler, eventListener,
-        new AudioTrack(minBufferMultiplicationFactor));
-  }
-
-  /**
-   * @param source The upstream source from which the renderer obtains samples.
-   * @param drmSessionManager For use with encrypted content. May be null if support for encrypted
-   *     content is not required.
-   * @param playClearSamplesWithoutKeys Encrypted media may contain clear (un-encrypted) regions.
-   *     For example a media file may start with a short clear region so as to allow playback to
-   *     begin in parallel with key acquisision. This parameter specifies whether the renderer is
-   *     permitted to play clear regions of encrypted media files before {@code drmSessionManager}
-   *     has obtained the keys necessary to decrypt encrypted regions of the media.
-   * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
-   *     null if delivery of events is not required.
-   * @param eventListener A listener of events. May be null if delivery of events is not required.
-   * @param audioTrack Used for playing back decoded audio samples.
-   */
-  public MediaCodecAudioTrackRenderer(SampleSource source, DrmSessionManager drmSessionManager,
-      boolean playClearSamplesWithoutKeys, Handler eventHandler, EventListener eventListener,
-      AudioTrack audioTrack) {
     super(source, drmSessionManager, playClearSamplesWithoutKeys, eventHandler, eventListener);
     this.eventListener = eventListener;
-    this.audioTrack = Assertions.checkNotNull(audioTrack);
     this.audioSessionId = AudioTrack.SESSION_ID_NOT_SET;
+    this.audioTrack = new AudioTrack();
   }
 
   @Override

library/src/main/java/com/google/android/exoplayer/audio/AudioTrack.java

@@ -16,7 +16,6 @@
 package com.google.android.exoplayer.audio;
 
 import com.google.android.exoplayer.C;
-import com.google.android.exoplayer.util.Assertions;
 import com.google.android.exoplayer.util.Util;
 
 import android.annotation.SuppressLint;
@@ -89,12 +88,19 @@ public final class AudioTrack {
   /** Represents an unset {@link android.media.AudioTrack} session identifier. */
   public static final int SESSION_ID_NOT_SET = 0;
 
-  /** The default multiplication factor used when determining the size of the track's buffer. */
-  public static final float DEFAULT_MIN_BUFFER_MULTIPLICATION_FACTOR = 4;
-
   /** Returned by {@link #getCurrentPositionUs} when the position is not set. */
   public static final long CURRENT_POSITION_NOT_SET = Long.MIN_VALUE;
 
+  /** A minimum length for the {@link android.media.AudioTrack} buffer, in microseconds. */
+  private static final long MIN_BUFFER_DURATION_US = 250000;
+  /** A maximum length for the {@link android.media.AudioTrack} buffer, in microseconds. */
+  private static final long MAX_BUFFER_DURATION_US = 750000;
+  /**
+   * A multiplication factor to apply to the minimum buffer size requested by the underlying
+   * {@link android.media.AudioTrack}.
+   */
+  private static final int BUFFER_MULTIPLICATION_FACTOR = 4;
+
   private static final String TAG = "AudioTrack";
 
   /**
@@ -126,7 +132,6 @@ public final class AudioTrack {
   private final ConditionVariable releasingConditionVariable;
   private final AudioTimestampCompat audioTimestampCompat;
   private final long[] playheadOffsets;
-  private final float minBufferMultiplicationFactor;
 
   private android.media.AudioTrack audioTrack;
   private int sampleRate;
@@ -162,15 +167,7 @@ public final class AudioTrack {
   /** Bitrate measured in kilobits per second, if {@link #isAc3} is true. */
   private int ac3Bitrate;
 
-  /** Constructs an audio track using the default minimum buffer size multiplier. */
   public AudioTrack() {
-    this(DEFAULT_MIN_BUFFER_MULTIPLICATION_FACTOR);
-  }
-
-  /** Constructs an audio track using the specified minimum buffer size multiplier. */
-  public AudioTrack(float minBufferMultiplicationFactor) {
-    Assertions.checkArgument(minBufferMultiplicationFactor >= 1);
-    this.minBufferMultiplicationFactor = minBufferMultiplicationFactor;
     releasingConditionVariable = new ConditionVariable(true);
     if (Util.SDK_INT >= 19) {
       audioTimestampCompat = new AudioTimestampCompatV19();
@@ -297,11 +294,11 @@ public final class AudioTrack {
    *
    * @param format Specifies the channel count and sample rate to play back.
    * @param encoding The format in which audio is represented.
-   * @param bufferSize The total size of the playback buffer in bytes. Specify 0 to use a buffer
+   * @param specifiedBufferSize A specific size for the playback buffer in bytes, or 0 to use a
-   *     size based on the minimum for format.
+   *     size inferred from the format.
    */
   @SuppressLint("InlinedApi")
-  public void reconfigure(MediaFormat format, int encoding, int bufferSize) {
+  public void reconfigure(MediaFormat format, int encoding, int specifiedBufferSize) {
     int channelCount = format.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
     int channelConfig;
     switch (channelCount) {
@@ -333,16 +330,25 @@ public final class AudioTrack {
 
     reset();
 
-    minBufferSize = android.media.AudioTrack.getMinBufferSize(sampleRate, channelConfig, encoding);
-
     this.encoding = encoding;
-    this.bufferSize =
-        bufferSize == 0 ? (int) (minBufferMultiplicationFactor * minBufferSize) : bufferSize;
     this.sampleRate = sampleRate;
     this.channelConfig = channelConfig;
     this.isAc3 = isAc3;
     ac3Bitrate = UNKNOWN_AC3_BITRATE; // Calculated on receiving the first buffer if isAc3 is true.
     frameSize = 2 * channelCount; // 2 bytes per 16 bit sample * number of channels.
+    minBufferSize = android.media.AudioTrack.getMinBufferSize(sampleRate, channelConfig, encoding);
+
+    if (specifiedBufferSize != 0) {
+      bufferSize = specifiedBufferSize;
+    } else {
+      int multipliedBufferSize = minBufferSize * BUFFER_MULTIPLICATION_FACTOR;
+      int minAppBufferSize = (int) durationUsToFrames(MIN_BUFFER_DURATION_US) * frameSize;
+      int maxAppBufferSize = (int) Math.max(minBufferSize,
+          durationUsToFrames(MAX_BUFFER_DURATION_US) * frameSize);
+      bufferSize = multipliedBufferSize < minAppBufferSize ? minAppBufferSize
+          : multipliedBufferSize > maxAppBufferSize ? maxAppBufferSize
+          : multipliedBufferSize;
+    }
   }
 
   /** Starts/resumes playing audio if the audio track has been initialized. */
@@ -434,7 +440,7 @@ public final class AudioTrack {
     int bytesWritten = 0;
     if (Util.SDK_INT < 21) {
       // Work out how many bytes we can write without the risk of blocking.
-      int bytesPending = (int) (submittedBytes - framesToBytes(getPlaybackPositionFrames()));
+      int bytesPending = (int) (submittedBytes - (getPlaybackPositionFrames() * frameSize));
       int bytesToWrite = bufferSize - bytesPending;
       if (bytesToWrite > 0) {
         bytesToWrite = Math.min(temporaryBufferSize, bytesToWrite);
@@ -651,11 +657,6 @@ public final class AudioTrack {
     return framesToDurationUs(getPlaybackPositionFrames());
   }
 
-  private long framesToBytes(long frameCount) {
-    // This method is unused on SDK >= 21.
-    return frameCount * frameSize;
-  }
-
   private long bytesToFrames(long byteCount) {
     if (isAc3) {
       return