Apply gapless playback metadata for MP3/MP4 playback using MediaCodec.

Issue: #497
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117219944

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

@@ -126,6 +126,14 @@ public final class Format {
    * The audio sampling rate in Hz, or {@link #NO_VALUE} if unknown or not applicable.
    */
   public final int sampleRate;
+  /**
+   * The number of samples to trim from the start of the decoded audio stream.
+   */
+  public final int encoderDelay;
+  /**
+   * The number of samples to trim from the end of the decoded audio stream.
+   */
+  public final int encoderPadding;
 
   // Text specific.
 
@@ -154,8 +162,8 @@ public final class Format {
       String sampleMimeType, int bitrate, int width, int height, float frameRate,
       List<byte[]> initializationData) {
     return new Format(id, containerMimeType, sampleMimeType, bitrate, NO_VALUE, width, height,
-        frameRate, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null, OFFSET_SAMPLE_RELATIVE,
-        initializationData, false);
+        frameRate, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null,
+        OFFSET_SAMPLE_RELATIVE, initializationData, false);
   }
 
   public static Format createVideoSampleFormat(String id, String sampleMimeType, int bitrate,
@@ -168,8 +176,8 @@ public final class Format {
       int maxInputSize, int width, int height, float frameRate, List<byte[]> initializationData,
       int rotationDegrees, float pixelWidthHeightRatio) {
     return new Format(id, null, sampleMimeType, bitrate, maxInputSize, width, height, frameRate,
-        rotationDegrees, pixelWidthHeightRatio, NO_VALUE, NO_VALUE, null, OFFSET_SAMPLE_RELATIVE,
-        initializationData, false);
+        rotationDegrees, pixelWidthHeightRatio, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null,
+        OFFSET_SAMPLE_RELATIVE, initializationData, false);
   }
 
   // Audio.
@@ -178,16 +186,23 @@ public final class Format {
       String sampleMimeType, int bitrate, int channelCount, int sampleRate,
       List<byte[]> initializationData, String language) {
     return new Format(id, containerMimeType, sampleMimeType, bitrate, NO_VALUE, NO_VALUE, NO_VALUE,
-        NO_VALUE, NO_VALUE, NO_VALUE, channelCount, sampleRate, language, OFFSET_SAMPLE_RELATIVE,
-        initializationData, false);
+        NO_VALUE, NO_VALUE, NO_VALUE, channelCount, sampleRate, NO_VALUE, NO_VALUE, language,
+        OFFSET_SAMPLE_RELATIVE, initializationData, false);
   }
 
   public static Format createAudioSampleFormat(String id, String sampleMimeType, int bitrate,
       int maxInputSize, int channelCount, int sampleRate, List<byte[]> initializationData,
       String language) {
+    return createAudioSampleFormat(id, sampleMimeType, bitrate, maxInputSize, channelCount,
+        sampleRate, NO_VALUE, NO_VALUE, initializationData, language);
+  }
+
+  public static Format createAudioSampleFormat(String id, String sampleMimeType, int bitrate,
+      int maxInputSize, int channelCount, int sampleRate, int encoderDelay, int encoderPadding,
+      List<byte[]> initializationData, String language) {
     return new Format(id, null, sampleMimeType, bitrate, maxInputSize, NO_VALUE, NO_VALUE, NO_VALUE,
-        NO_VALUE, NO_VALUE, channelCount, sampleRate, language, OFFSET_SAMPLE_RELATIVE,
-        initializationData, false);
+        NO_VALUE, NO_VALUE, channelCount, sampleRate, encoderDelay, encoderPadding, language,
+        OFFSET_SAMPLE_RELATIVE, initializationData, false);
   }
 
   // Text.
@@ -195,8 +210,8 @@ public final class Format {
   public static Format createTextContainerFormat(String id, String containerMimeType,
       String sampleMimeType, int bitrate, String language) {
     return new Format(id, containerMimeType, sampleMimeType, bitrate, NO_VALUE, NO_VALUE, NO_VALUE,
-        NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, language, OFFSET_SAMPLE_RELATIVE, null,
-        false);
+        NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, language,
+        OFFSET_SAMPLE_RELATIVE, null, false);
   }
 
   public static Format createTextSampleFormat(String id, String sampleMimeType, int bitrate,
@@ -207,7 +222,8 @@ public final class Format {
   public static Format createTextSampleFormat(String id, String sampleMimeType, int bitrate,
       String language, long subsampleOffsetUs) {
     return new Format(id, null, sampleMimeType, bitrate, NO_VALUE, NO_VALUE, NO_VALUE,
-        NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, language, subsampleOffsetUs, null, false);
+        NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, language,
+        subsampleOffsetUs, null, false);
   }
 
   // Generic.
@@ -215,19 +231,21 @@ public final class Format {
   public static Format createContainerFormat(String id, String containerMimeType,
       String sampleMimeType, int bitrate) {
     return new Format(id, containerMimeType, sampleMimeType, bitrate, NO_VALUE, NO_VALUE, NO_VALUE,
-        NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null, OFFSET_SAMPLE_RELATIVE, null,
-        false);
+        NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null,
+        OFFSET_SAMPLE_RELATIVE, null, false);
   }
 
   public static Format createSampleFormat(String id, String sampleMimeType, int bitrate) {
     return new Format(id, null, sampleMimeType, bitrate, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE,
-        NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null, OFFSET_SAMPLE_RELATIVE, null, false);
+        NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null, OFFSET_SAMPLE_RELATIVE,
+        null, false);
   }
 
   /* package */ Format(String id, String containerMimeType, String sampleMimeType,
       int bitrate, int maxInputSize, int width, int height, float frameRate, int rotationDegrees,
-      float pixelWidthHeightRatio, int channelCount, int sampleRate, String language,
-      long subsampleOffsetUs, List<byte[]> initializationData, boolean requiresSecureDecryption) {
+      float pixelWidthHeightRatio, int channelCount, int sampleRate, int encoderDelay,
+      int encoderPadding, String language, long subsampleOffsetUs, List<byte[]> initializationData,
+      boolean requiresSecureDecryption) {
     this.id = id;
     this.containerMimeType = containerMimeType;
     this.sampleMimeType = sampleMimeType;
@@ -240,6 +258,8 @@ public final class Format {
     this.pixelWidthHeightRatio = pixelWidthHeightRatio;
     this.channelCount = channelCount;
     this.sampleRate = sampleRate;
+    this.encoderDelay = encoderDelay;
+    this.encoderPadding = encoderPadding;
     this.language = language;
     this.subsampleOffsetUs = subsampleOffsetUs;
     this.initializationData = initializationData == null ? Collections.<byte[]>emptyList()
@@ -250,22 +270,32 @@ public final class Format {
   public Format copyWithMaxInputSize(int maxInputSize) {
     return new Format(id, containerMimeType, sampleMimeType, bitrate, maxInputSize, width,
         height, frameRate, rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate,
-        language, subsampleOffsetUs, initializationData, requiresSecureDecryption);
+        encoderDelay, encoderPadding, language, subsampleOffsetUs, initializationData,
+        requiresSecureDecryption);
   }
 
   public Format copyWithSubsampleOffsetUs(long subsampleOffsetUs) {
     return new Format(id, containerMimeType, sampleMimeType, bitrate, maxInputSize, width,
         height, frameRate, rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate,
-        language, subsampleOffsetUs, initializationData, requiresSecureDecryption);
+        encoderDelay, encoderPadding, language, subsampleOffsetUs, initializationData,
+        requiresSecureDecryption);
   }
 
   public Format copyWithContainerInfo(String id, int bitrate, int width, int height,
       String language) {
     return new Format(id, containerMimeType, sampleMimeType, bitrate, maxInputSize, width,
         height, frameRate, rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate,
-        language, subsampleOffsetUs, initializationData, requiresSecureDecryption);
+        encoderDelay, encoderPadding, language, subsampleOffsetUs, initializationData,
+        requiresSecureDecryption);
   }
 
+  public Format copyWithGaplessInfo(int encoderDelay, int encoderPadding) {
+    return new Format(id, containerMimeType, sampleMimeType, bitrate, maxInputSize, width,
+        height, frameRate, rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate,
+        encoderDelay, encoderPadding, language, subsampleOffsetUs, initializationData,
+        requiresSecureDecryption);
+  }
+  
   /**
    * @return A {@link MediaFormat} representation of this format.
    */
@@ -283,6 +313,8 @@ public final class Format {
       maybeSetIntegerV16(format, "rotation-degrees", rotationDegrees);
       maybeSetIntegerV16(format, MediaFormat.KEY_CHANNEL_COUNT, channelCount);
       maybeSetIntegerV16(format, MediaFormat.KEY_SAMPLE_RATE, sampleRate);
+      maybeSetIntegerV16(format, "encoder-delay", encoderDelay);
+      maybeSetIntegerV16(format, "encoder-padding", encoderPadding);
       for (int i = 0; i < initializationData.size(); i++) {
         format.setByteBuffer("csd-" + i, ByteBuffer.wrap(initializationData.get(i)));
       }
@@ -322,6 +354,8 @@ public final class Format {
       result = 31 * result + height;
       result = 31 * result + channelCount;
       result = 31 * result + sampleRate;
+      result = 31 * result + encoderDelay;
+      result = 31 * result + encoderPadding;
       result = 31 * result + (language == null ? 0 : language.hashCode());
       hashCode = result;
     }
@@ -343,6 +377,7 @@ public final class Format {
         || rotationDegrees != other.rotationDegrees
         || pixelWidthHeightRatio != other.pixelWidthHeightRatio
         || channelCount != other.channelCount || sampleRate != other.sampleRate
+        || encoderDelay != other.encoderDelay || encoderPadding != other.encoderPadding
         || subsampleOffsetUs != other.subsampleOffsetUs
         || !Util.areEqual(id, other.id) || !Util.areEqual(language, other.language)
         || !Util.areEqual(containerMimeType, other.containerMimeType)

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

@@ -312,6 +312,8 @@ public final class FrameworkSampleSource implements SampleSource {
     int rotationDegrees = getOptionalIntegerV16(mediaFormat, "rotation-degrees");
     int channelCount = getOptionalIntegerV16(mediaFormat, MediaFormat.KEY_CHANNEL_COUNT);
     int sampleRate = getOptionalIntegerV16(mediaFormat, MediaFormat.KEY_SAMPLE_RATE);
+    int encoderDelay = getOptionalIntegerV16(mediaFormat, "encoder-delay");
+    int encoderPadding = getOptionalIntegerV16(mediaFormat, "encoder-padding");
     ArrayList<byte[]> initializationData = new ArrayList<>();
     for (int i = 0; mediaFormat.containsKey("csd-" + i); i++) {
       ByteBuffer buffer = mediaFormat.getByteBuffer("csd-" + i);
@@ -322,7 +324,8 @@ public final class FrameworkSampleSource implements SampleSource {
     }
     Format format = new Format(Integer.toString(index), null, mimeType, Format.NO_VALUE,
         maxInputSize, width, height, frameRate, rotationDegrees, Format.NO_VALUE, channelCount,
-        sampleRate, language, Format.OFFSET_SAMPLE_RELATIVE, initializationData, false);
+        sampleRate, encoderDelay, encoderPadding, language, Format.OFFSET_SAMPLE_RELATIVE,
+        initializationData, false);
     format.setFrameworkMediaFormatV16(mediaFormat);
     return format;
   }

library/src/main/java/com/google/android/exoplayer/extractor/mp3/Mp3Extractor.java

@@ -119,9 +119,11 @@ public final class Mp3Extractor implements Extractor {
     if (seeker == null) {
       setupSeeker(input);
       extractorOutput.seekMap(seeker);
+      int encoderDelay = gaplessInfo != null ? gaplessInfo.encoderDelay : Format.NO_VALUE;
+      int encoderPadding = gaplessInfo != null ? gaplessInfo.encoderPadding : Format.NO_VALUE;
       trackOutput.format(Format.createAudioSampleFormat(null, synchronizedHeader.mimeType,
           Format.NO_VALUE, MpegAudioHeader.MAX_FRAME_SIZE_BYTES, synchronizedHeader.channels,
-          synchronizedHeader.sampleRate, null, null));
+          synchronizedHeader.sampleRate, encoderDelay, encoderPadding, null, null));
     }
     return readSample(input);
   }

library/src/main/java/com/google/android/exoplayer/extractor/mp4/Mp4Extractor.java

@@ -16,9 +16,11 @@
 package com.google.android.exoplayer.extractor.mp4;
 
 import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.Format;
 import com.google.android.exoplayer.extractor.Extractor;
 import com.google.android.exoplayer.extractor.ExtractorInput;
 import com.google.android.exoplayer.extractor.ExtractorOutput;
+import com.google.android.exoplayer.extractor.GaplessInfo;
 import com.google.android.exoplayer.extractor.PositionHolder;
 import com.google.android.exoplayer.extractor.SeekMap;
 import com.google.android.exoplayer.extractor.TrackOutput;
@@ -282,12 +284,12 @@ public final class Mp4Extractor implements Extractor, SeekMap {
     long durationUs = C.UNKNOWN_TIME_US;
     List<Mp4Track> tracks = new ArrayList<>();
     long earliestSampleOffset = Long.MAX_VALUE;
-    // TODO: Apply gapless information.
-    // GaplessInfo gaplessInfo = null;
-    // Atom.ContainerAtom udta = moov.getContainerAtomOfType(Atom.TYPE_udta);
-    // if (udta != null) {
-    //   gaplessInfo = AtomParsers.parseUdta(udta);
-    // }
+    GaplessInfo gaplessInfo = null;
+    Atom.ContainerAtom udta = moov.getContainerAtomOfType(Atom.TYPE_udta);
+    if (udta != null) {
+      gaplessInfo = AtomParsers.parseUdta(udta);
+    }
+
     for (int i = 0; i < moov.containerChildren.size(); i++) {
       Atom.ContainerAtom atom = moov.containerChildren.get(i);
       if (atom.type != Atom.TYPE_trak) {
@@ -311,7 +313,11 @@ public final class Mp4Extractor implements Extractor, SeekMap {
       // Each sample has up to three bytes of overhead for the start code that replaces its length.
       // Allow ten source samples per output sample, like the platform extractor.
       int maxInputSize = trackSampleTable.maximumSize + 3 * 10;
-      mp4Track.trackOutput.format(track.format.copyWithMaxInputSize(maxInputSize));
+      Format format = track.format.copyWithMaxInputSize(maxInputSize);
+      if (gaplessInfo != null) {
+        format = format.copyWithGaplessInfo(gaplessInfo.encoderDelay, gaplessInfo.encoderPadding);
+      }
+      mp4Track.trackOutput.format(format);
 
       durationUs = Math.max(durationUs, track.durationUs);
       tracks.add(mp4Track);