Split TsExtractor into multiple files.

There's no code change here at all, except for how TsExtractor's
getLargestSampleTimestamp method works.

library/src/main/java/com/google/android/exoplayer/hls/HlsChunkSource.java

@@ -17,7 +17,8 @@ package com.google.android.exoplayer.hls;
 
 import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.MediaFormat;
-import com.google.android.exoplayer.hls.TsExtractor.SamplePool;
+import com.google.android.exoplayer.hls.parser.SamplePool;
+import com.google.android.exoplayer.hls.parser.TsExtractor;
 import com.google.android.exoplayer.upstream.Aes128DataSource;
 import com.google.android.exoplayer.upstream.BandwidthMeter;
 import com.google.android.exoplayer.upstream.DataSource;
@@ -101,7 +102,7 @@ public class HlsChunkSource {
   private static final String TAG = "HlsChunkSource";
   private static final float BANDWIDTH_FRACTION = 0.8f;
 
-  private final SamplePool samplePool = new TsExtractor.SamplePool();
+  private final SamplePool samplePool = new SamplePool();
   private final DataSource upstreamDataSource;
   private final HlsPlaylistParser playlistParser;
   private final Variant[] enabledVariants;

library/src/main/java/com/google/android/exoplayer/hls/HlsSampleSource.java

@@ -21,6 +21,7 @@ import com.google.android.exoplayer.SampleHolder;
 import com.google.android.exoplayer.SampleSource;
 import com.google.android.exoplayer.TrackInfo;
 import com.google.android.exoplayer.TrackRenderer;
+import com.google.android.exoplayer.hls.parser.TsExtractor;
 import com.google.android.exoplayer.upstream.Loader;
 import com.google.android.exoplayer.upstream.Loader.Loadable;
 import com.google.android.exoplayer.util.Assertions;

library/src/main/java/com/google/android/exoplayer/hls/TsChunk.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer.hls;
 
+import com.google.android.exoplayer.hls.parser.TsExtractor;
 import com.google.android.exoplayer.upstream.DataSource;
 import com.google.android.exoplayer.upstream.DataSpec;
 

library/src/main/java/com/google/android/exoplayer/hls/parser/AdtsReader.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.hls.parser;
+
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.MediaFormat;
+import com.google.android.exoplayer.util.CodecSpecificDataUtil;
+import com.google.android.exoplayer.util.MimeTypes;
+import com.google.android.exoplayer.util.ParsableBitArray;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+import android.util.Pair;
+
+import java.util.Collections;
+
+/**
+ * Parses a continuous ADTS byte stream and extracts individual frames.
+ */
+/* package */ class AdtsReader extends PesPayloadReader {
+
+  private static final int STATE_FINDING_SYNC = 0;
+  private static final int STATE_READING_HEADER = 1;
+  private static final int STATE_READING_SAMPLE = 2;
+
+  private static final int HEADER_SIZE = 5;
+  private static final int CRC_SIZE = 2;
+
+  private final ParsableBitArray adtsScratch;
+
+  private int state;
+  private int bytesRead;
+
+  // Used to find the header.
+  private boolean lastByteWasOxFF;
+  private boolean hasCrc;
+
+  // Parsed from the header.
+  private long frameDurationUs;
+  private int sampleSize;
+
+  // Used when reading the samples.
+  private long timeUs;
+  private Sample currentSample;
+
+  public AdtsReader(SamplePool samplePool) {
+    super(samplePool);
+    adtsScratch = new ParsableBitArray(new byte[HEADER_SIZE + CRC_SIZE]);
+    state = STATE_FINDING_SYNC;
+  }
+
+  @Override
+  public void consume(ParsableByteArray data, long pesTimeUs, boolean startOfPacket) {
+    if (startOfPacket) {
+      timeUs = pesTimeUs;
+    }
+    while (data.bytesLeft() > 0) {
+      switch (state) {
+        case STATE_FINDING_SYNC:
+          if (skipToNextSync(data)) {
+            bytesRead = 0;
+            state = STATE_READING_HEADER;
+          }
+          break;
+        case STATE_READING_HEADER:
+          int targetLength = hasCrc ? HEADER_SIZE + CRC_SIZE : HEADER_SIZE;
+          if (continueRead(data, adtsScratch.getData(), targetLength)) {
+            parseHeader();
+            currentSample = getSample(Sample.TYPE_AUDIO);
+            currentSample.timeUs = timeUs;
+            currentSample.isKeyframe = true;
+            bytesRead = 0;
+            state = STATE_READING_SAMPLE;
+          }
+          break;
+        case STATE_READING_SAMPLE:
+          int bytesToRead = Math.min(data.bytesLeft(), sampleSize - bytesRead);
+          addToSample(currentSample, data, bytesToRead);
+          bytesRead += bytesToRead;
+          if (bytesRead == sampleSize) {
+            addSample(currentSample);
+            currentSample = null;
+            timeUs += frameDurationUs;
+            bytesRead = 0;
+            state = STATE_FINDING_SYNC;
+          }
+          break;
+      }
+    }
+  }
+
+  @Override
+  public void packetFinished() {
+    // Do nothing.
+  }
+
+  @Override
+  public void release() {
+    super.release();
+    if (currentSample != null) {
+      recycle(currentSample);
+      currentSample = null;
+    }
+  }
+
+  /**
+   * Continues a read from the provided {@code source} into a given {@code target}. It's assumed
+   * that the data should be written into {@code target} starting from an offset of zero.
+   *
+   * @param source The source from which to read.
+   * @param target The target into which data is to be read.
+   * @param targetLength The target length of the read.
+   * @return Whether the target length was reached.
+   */
+  private boolean continueRead(ParsableByteArray source, byte[] target, int targetLength) {
+    int bytesToRead = Math.min(source.bytesLeft(), targetLength - bytesRead);
+    source.readBytes(target, bytesRead, bytesToRead);
+    bytesRead += bytesToRead;
+    return bytesRead == targetLength;
+  }
+
+  /**
+   * Locates the next sync word, advancing the position to the byte that immediately follows it.
+   * If a sync word was not located, the position is advanced to the limit.
+   *
+   * @param pesBuffer The buffer whose position should be advanced.
+   * @return True if a sync word position was found. False otherwise.
+   */
+  private boolean skipToNextSync(ParsableByteArray pesBuffer) {
+    byte[] adtsData = pesBuffer.data;
+    int startOffset = pesBuffer.getPosition();
+    int endOffset = pesBuffer.length();
+    for (int i = startOffset; i < endOffset; i++) {
+      boolean byteIsOxFF = (adtsData[i] & 0xFF) == 0xFF;
+      boolean found = lastByteWasOxFF && !byteIsOxFF && (adtsData[i] & 0xF0) == 0xF0;
+      lastByteWasOxFF = byteIsOxFF;
+      if (found) {
+        hasCrc = (adtsData[i] & 0x1) == 0;
+        pesBuffer.setPosition(i + 1);
+        return true;
+      }
+    }
+    pesBuffer.setPosition(endOffset);
+    return false;
+  }
+
+  /**
+   * Parses the sample header.
+   */
+  private void parseHeader() {
+    adtsScratch.setPosition(0);
+
+    if (!hasMediaFormat()) {
+      int audioObjectType = adtsScratch.readBits(2) + 1;
+      int sampleRateIndex = adtsScratch.readBits(4);
+      adtsScratch.skipBits(1);
+      int channelConfig = adtsScratch.readBits(3);
+
+      byte[] audioSpecificConfig = CodecSpecificDataUtil.buildAudioSpecificConfig(
+          audioObjectType, sampleRateIndex, channelConfig);
+      Pair<Integer, Integer> audioParams = CodecSpecificDataUtil.parseAudioSpecificConfig(
+          audioSpecificConfig);
+
+      MediaFormat mediaFormat = MediaFormat.createAudioFormat(MimeTypes.AUDIO_AAC,
+          MediaFormat.NO_VALUE, audioParams.second, audioParams.first,
+          Collections.singletonList(audioSpecificConfig));
+      frameDurationUs = (C.MICROS_PER_SECOND * 1024L) / mediaFormat.sampleRate;
+      setMediaFormat(mediaFormat);
+    } else {
+      adtsScratch.skipBits(10);
+    }
+
+    adtsScratch.skipBits(4);
+    sampleSize = adtsScratch.readBits(13) - 2 /* the sync word */ - HEADER_SIZE;
+    if (hasCrc) {
+      sampleSize -= CRC_SIZE;
+    }
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/hls/parser/Id3Reader.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.hls.parser;
+
+import com.google.android.exoplayer.MediaFormat;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+import android.annotation.SuppressLint;
+
+/**
+ * Parses ID3 data and extracts individual text information frames.
+ */
+/* package */ class Id3Reader extends PesPayloadReader {
+
+  private Sample currentSample;
+
+  public Id3Reader(SamplePool samplePool) {
+    super(samplePool);
+    setMediaFormat(MediaFormat.createId3Format());
+  }
+
+  @SuppressLint("InlinedApi")
+  @Override
+  public void consume(ParsableByteArray data, long pesTimeUs, boolean startOfPacket) {
+    if (startOfPacket) {
+      currentSample = getSample(Sample.TYPE_MISC);
+      currentSample.timeUs = pesTimeUs;
+      currentSample.isKeyframe = true;
+    }
+    if (currentSample != null) {
+      addToSample(currentSample, data, data.bytesLeft());
+    }
+  }
+
+  @Override
+  public void packetFinished() {
+    addSample(currentSample);
+    currentSample = null;
+  }
+
+  @Override
+  public void release() {
+    super.release();
+    if (currentSample != null) {
+      recycle(currentSample);
+      currentSample = null;
+    }
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/hls/parser/PesPayloadReader.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.hls.parser;
+
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+/**
+ * Extracts individual samples from continuous byte stream, preserving original order.
+ */
+/* package */ abstract class PesPayloadReader extends SampleQueue {
+
+  private final ConcurrentLinkedQueue<Sample> internalQueue;
+
+  protected PesPayloadReader(SamplePool samplePool) {
+    super(samplePool);
+    internalQueue = new ConcurrentLinkedQueue<Sample>();
+  }
+
+  @Override
+  protected final Sample internalPeekSample() {
+    return internalQueue.peek();
+  }
+
+  @Override
+  protected final Sample internalPollSample() {
+    return internalQueue.poll();
+  }
+
+  @Override
+  protected final void internalQueueSample(Sample sample) {
+    internalQueue.add(sample);
+  }
+
+  /**
+   * Consumes (possibly partial) payload data.
+   *
+   * @param data The payload data to consume.
+   * @param pesTimeUs The timestamp associated with the payload.
+   * @param startOfPacket True if this is the first time this method is being called for the
+   *     current packet. False otherwise.
+   */
+  public abstract void consume(ParsableByteArray data, long pesTimeUs, boolean startOfPacket);
+
+  /**
+   * Invoked once all of the payload data for a packet has been passed to
+   * {@link #consume(ParsableByteArray, long, boolean)}. The next call to
+   * {@link #consume(ParsableByteArray, long, boolean)} will have {@code startOfPacket == true}.
+   */
+  public abstract void packetFinished();
+
+}

library/src/main/java/com/google/android/exoplayer/hls/parser/Sample.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.hls.parser;
+
+import com.google.android.exoplayer.SampleHolder;
+
+/**
+ * An internal variant of {@link SampleHolder} for internal pooling and buffering.
+ */
+/* package */ class Sample {
+
+  public static final int TYPE_VIDEO = 0;
+  public static final int TYPE_AUDIO = 1;
+  public static final int TYPE_MISC = 2;
+  public static final int TYPE_COUNT = 3;
+
+  public final int type;
+  public Sample nextInPool;
+
+  public byte[] data;
+  public boolean isKeyframe;
+  public int size;
+  public long timeUs;
+
+  public Sample(int type, int length) {
+    this.type = type;
+    data = new byte[length];
+  }
+
+  public void expand(int length) {
+    byte[] newBuffer = new byte[data.length + length];
+    System.arraycopy(data, 0, newBuffer, 0, size);
+    data = newBuffer;
+  }
+
+  public void reset() {
+    isKeyframe = false;
+    size = 0;
+    timeUs = 0;
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/hls/parser/SamplePool.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.hls.parser;
+
+/**
+ * A pool from which the extractor can obtain sample objects for internal use.
+ *
+ * TODO: Over time the average size of a sample in the video pool will become larger, as the
+ * proportion of samples in the pool that have at some point held a keyframe grows. Currently
+ * this leads to inefficient memory usage, since samples large enough to hold keyframes end up
+ * being used to hold non-keyframes. We need to fix this.
+ */
+public class SamplePool {
+
+  private static final int[] DEFAULT_SAMPLE_SIZES;
+  static {
+    DEFAULT_SAMPLE_SIZES = new int[Sample.TYPE_COUNT];
+    DEFAULT_SAMPLE_SIZES[Sample.TYPE_VIDEO] = 10 * 1024;
+    DEFAULT_SAMPLE_SIZES[Sample.TYPE_AUDIO] = 512;
+    DEFAULT_SAMPLE_SIZES[Sample.TYPE_MISC] = 512;
+  }
+
+  private final Sample[] pools;
+
+  public SamplePool() {
+    pools = new Sample[Sample.TYPE_COUNT];
+  }
+
+  /* package */ synchronized Sample get(int type) {
+    if (pools[type] == null) {
+      return new Sample(type, DEFAULT_SAMPLE_SIZES[type]);
+    }
+    Sample sample = pools[type];
+    pools[type] = sample.nextInPool;
+    sample.nextInPool = null;
+    return sample;
+  }
+
+  /* package */ synchronized void recycle(Sample sample) {
+    sample.reset();
+    sample.nextInPool = pools[sample.type];
+    pools[sample.type] = sample;
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/hls/parser/SampleQueue.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.hls.parser;
+
+import com.google.android.exoplayer.MediaFormat;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+/* package */ abstract class SampleQueue {
+
+  private final SamplePool samplePool;
+
+  // Accessed only by the consuming thread.
+  private boolean needKeyframe;
+  private long lastReadTimeUs;
+  private long spliceOutTimeUs;
+
+  // Accessed by both the loading and consuming threads.
+  private volatile MediaFormat mediaFormat;
+  private volatile long largestParsedTimestampUs;
+
+  protected SampleQueue(SamplePool samplePool) {
+    this.samplePool = samplePool;
+    needKeyframe = true;
+    lastReadTimeUs = Long.MIN_VALUE;
+    spliceOutTimeUs = Long.MIN_VALUE;
+    largestParsedTimestampUs = Long.MIN_VALUE;
+  }
+
+  public long getLargestParsedTimestampUs() {
+    return largestParsedTimestampUs;
+  }
+
+  public boolean hasMediaFormat() {
+    return mediaFormat != null;
+  }
+
+  public MediaFormat getMediaFormat() {
+    return mediaFormat;
+  }
+
+  protected void setMediaFormat(MediaFormat mediaFormat) {
+    this.mediaFormat = mediaFormat;
+  }
+
+  /**
+   * Removes and returns the next sample from the queue.
+   * <p>
+   * The first sample returned is guaranteed to be a keyframe, since any non-keyframe samples
+   * queued prior to the first keyframe are discarded.
+   *
+   * @return The next sample from the queue, or null if a sample isn't available.
+   */
+  public Sample poll() {
+    Sample head = peek();
+    if (head != null) {
+      internalPollSample();
+      needKeyframe = false;
+      lastReadTimeUs = head.timeUs;
+    }
+    return head;
+  }
+
+  /**
+   * Like {@link #poll()}, except the returned sample is not removed from the queue.
+   *
+   * @return The next sample from the queue, or null if a sample isn't available.
+   */
+  public Sample peek() {
+    Sample head = internalPeekSample();
+    if (needKeyframe) {
+      // Peeking discard of samples until we find a keyframe or run out of available samples.
+      while (head != null && !head.isKeyframe) {
+        recycle(head);
+        internalPollSample();
+        head = internalPeekSample();
+      }
+    }
+    if (head == null) {
+      return null;
+    }
+    if (spliceOutTimeUs != Long.MIN_VALUE && head.timeUs >= spliceOutTimeUs) {
+      // The sample is later than the time this queue is spliced out.
+      recycle(head);
+      internalPollSample();
+      return null;
+    }
+    return head;
+  }
+
+  /**
+   * Discards samples from the queue up to the specified time.
+   *
+   * @param timeUs The time up to which samples should be discarded, in microseconds.
+   */
+  public void discardUntil(long timeUs) {
+    Sample head = peek();
+    while (head != null && head.timeUs < timeUs) {
+      recycle(head);
+      internalPollSample();
+      head = internalPeekSample();
+      // We're discarding at least one sample, so any subsequent read will need to start at
+      // a keyframe.
+      needKeyframe = true;
+    }
+    lastReadTimeUs = Long.MIN_VALUE;
+  }
+
+  /**
+   * Clears the queue.
+   */
+  public void release() {
+    Sample toRecycle = internalPollSample();
+    while (toRecycle != null) {
+      recycle(toRecycle);
+      toRecycle = internalPollSample();
+    }
+  }
+
+  /**
+   * Recycles a sample.
+   *
+   * @param sample The sample to recycle.
+   */
+  public void recycle(Sample sample) {
+    samplePool.recycle(sample);
+  }
+
+  /**
+   * Attempts to configure a splice from this queue to the next.
+   *
+   * @param nextQueue The queue being spliced to.
+   * @return Whether the splice was configured successfully.
+   */
+  public boolean configureSpliceTo(SampleQueue nextQueue) {
+    if (spliceOutTimeUs != Long.MIN_VALUE) {
+      // We've already configured the splice.
+      return true;
+    }
+    long firstPossibleSpliceTime;
+    Sample nextSample = internalPeekSample();
+    if (nextSample != null) {
+      firstPossibleSpliceTime = nextSample.timeUs;
+    } else {
+      firstPossibleSpliceTime = lastReadTimeUs + 1;
+    }
+    Sample nextQueueSample = nextQueue.internalPeekSample();
+    while (nextQueueSample != null
+        && (nextQueueSample.timeUs < firstPossibleSpliceTime || !nextQueueSample.isKeyframe)) {
+      // Discard samples from the next queue for as long as they are before the earliest possible
+      // splice time, or not keyframes.
+      nextQueue.internalPollSample();
+      nextQueueSample = nextQueue.internalPeekSample();
+    }
+    if (nextQueueSample != null) {
+      // We've found a keyframe in the next queue that can serve as the splice point. Set the
+      // splice point now.
+      spliceOutTimeUs = nextQueueSample.timeUs;
+      return true;
+    }
+    return false;
+  }
+
+  /**
+   * Obtains a Sample object to use.
+   *
+   * @param type The type of the sample.
+   * @return The sample.
+   */
+  protected Sample getSample(int type) {
+    return samplePool.get(type);
+  }
+
+  /**
+   * Creates a new Sample and adds it to the queue.
+   *
+   * @param type The type of the sample.
+   * @param buffer The buffer to read sample data.
+   * @param sampleSize The size of the sample data.
+   * @param sampleTimeUs The sample time stamp.
+   * @param isKeyframe True if the sample is a keyframe. False otherwise.
+   */
+  protected void addSample(int type, ParsableByteArray buffer, int sampleSize, long sampleTimeUs,
+      boolean isKeyframe) {
+    Sample sample = getSample(type);
+    addToSample(sample, buffer, sampleSize);
+    sample.isKeyframe = isKeyframe;
+    sample.timeUs = sampleTimeUs;
+    addSample(sample);
+  }
+
+  protected void addSample(Sample sample) {
+    largestParsedTimestampUs = Math.max(largestParsedTimestampUs, sample.timeUs);
+    internalQueueSample(sample);
+  }
+
+  protected void addToSample(Sample sample, ParsableByteArray buffer, int size) {
+    if (sample.data.length - sample.size < size) {
+      sample.expand(size - sample.data.length + sample.size);
+    }
+    buffer.readBytes(sample.data, sample.size, size);
+    sample.size += size;
+  }
+
+  protected abstract Sample internalPeekSample();
+  protected abstract Sample internalPollSample();
+  protected abstract void internalQueueSample(Sample sample);
+
+}

library/src/main/java/com/google/android/exoplayer/hls/parser/SeiReader.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer.hls.parser;
+
+import com.google.android.exoplayer.MediaFormat;
+import com.google.android.exoplayer.mp4.Mp4Util;
+import com.google.android.exoplayer.text.eia608.Eia608Parser;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+import android.annotation.SuppressLint;
+
+import java.util.Comparator;
+import java.util.TreeSet;
+
+/**
+ * Parses a SEI data from H.264 frames and extracts samples with closed captions data.
+ *
+ * TODO: Technically, we shouldn't allow a sample to be read from the queue until we're sure that
+ * a sample with an earlier timestamp won't be added to it.
+ */
+/* package */ class SeiReader extends SampleQueue implements Comparator<Sample> {
+
+  // SEI data, used for Closed Captions.
+  private static final int NAL_UNIT_TYPE_SEI = 6;
+
+  private final ParsableByteArray seiBuffer;
+  private final TreeSet<Sample> internalQueue;
+
+  public SeiReader(SamplePool samplePool) {
+    super(samplePool);
+    setMediaFormat(MediaFormat.createEia608Format());
+    seiBuffer = new ParsableByteArray();
+    internalQueue = new TreeSet<Sample>(this);
+  }
+
+  @SuppressLint("InlinedApi")
+  public void read(byte[] data, int length, long pesTimeUs) {
+    seiBuffer.reset(data, length);
+    while (seiBuffer.bytesLeft() > 0) {
+      int currentOffset = seiBuffer.getPosition();
+      int seiOffset = Mp4Util.findNalUnit(data, currentOffset, length, NAL_UNIT_TYPE_SEI);
+      if (seiOffset == length) {
+        return;
+      }
+      seiBuffer.skip(seiOffset + 4 - currentOffset);
+      int ccDataSize = Eia608Parser.parseHeader(seiBuffer);
+      if (ccDataSize > 0) {
+        addSample(Sample.TYPE_MISC, seiBuffer, ccDataSize, pesTimeUs, true);
+      }
+    }
+  }
+
+  @Override
+  public int compare(Sample first, Sample second) {
+    // Note - We don't expect samples to have identical timestamps.
+    return first.timeUs <= second.timeUs ? -1 : 1;
+  }
+
+  @Override
+  protected synchronized Sample internalPeekSample() {
+    return internalQueue.isEmpty() ? null : internalQueue.first();
+  }
+
+  @Override
+  protected synchronized Sample internalPollSample() {
+    return internalQueue.pollFirst();
+  }
+
+  @Override
+  protected synchronized void internalQueueSample(Sample sample) {
+    internalQueue.add(sample);
+  }
+
+}