Merge pull request #828 from jeoliva/flv-experiment

FLV (H.264 + AAC) support

demo/src/main/java/com/google/android/exoplayer/demo/Samples.java

@@ -145,6 +145,9 @@ import java.util.Locale;
         "http://storage.googleapis.com/exoplayer-test-media-0/play.mp3", PlayerActivity.TYPE_OTHER),
     new Sample("Google Glass (WebM Video with Vorbis Audio)",
         "http://demos.webmproject.org/exoplayer/glass_vp9_vorbis.webm", PlayerActivity.TYPE_OTHER),
+    new Sample("Big Buck Bunny (FLV Video)",
+        "http://vod.leasewebcdn.com/bbb.flv?ri=1024&rs=150&start=0", PlayerActivity.TYPE_OTHER),
+
   };
 
   private Samples() {}

library/src/main/java/com/google/android/exoplayer/extractor/ExtractorSampleSource.java

@@ -58,9 +58,10 @@ import java.util.List;
  * <li>MP3 ({@link com.google.android.exoplayer.extractor.mp3.Mp3Extractor})</li>
  * <li>AAC ({@link com.google.android.exoplayer.extractor.ts.AdtsExtractor})</li>
  * <li>MPEG TS ({@link com.google.android.exoplayer.extractor.ts.TsExtractor}</li>
+ * <li>FLV ({@link com.google.android.exoplayer.extractor.flv.FlvExtractor}</li>
  * </ul>
  *
- * <p>Seeking in AAC and MPEG TS streams is not supported.
+ * <p>Seeking in AAC, MPEG TS and FLV streams is not supported.
  *
  * <p>To override the default extractors, pass one or more {@link Extractor} instances to the
  * constructor. When reading a new stream, the first {@link Extractor} that returns {@code true}
@@ -146,6 +147,13 @@ public final class ExtractorSampleSource implements SampleSource, SampleSourceRe
     } catch (ClassNotFoundException e) {
       // Extractor not found.
     }
+    try {
+      DEFAULT_EXTRACTOR_CLASSES.add(
+          Class.forName("com.google.android.exoplayer.extractor.flv.FlvExtractor")
+              .asSubclass(Extractor.class));
+    } catch (ClassNotFoundException e) {
+      // Extractor not found.
+    }
   }
 
   private final ExtractorHolder extractorHolder;

library/src/main/java/com/google/android/exoplayer/extractor/flv/AudioTagPayloadReader.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.extractor.flv;
+
+import android.util.Pair;
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.MediaFormat;
+import com.google.android.exoplayer.extractor.TrackOutput;
+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 java.util.Collections;
+
+/**
+ * Parses audio tags of from an FLV stream and extracts AAC frames.
+ */
+final class AudioTagPayloadReader extends TagPayloadReader {
+  // Sound format
+  private static final int AUDIO_FORMAT_AAC = 10;
+
+  // AAC PACKET TYPE
+  private static final int AAC_PACKET_TYPE_SEQUENCE_HEADER = 0;
+  private static final int AAC_PACKET_TYPE_AAC_RAW = 1;
+
+  // SAMPLING RATES
+  private static final int[] AUDIO_SAMPLING_RATE_TABLE = new int[] {
+      5500, 11000, 22000, 44000
+  };
+
+  // State variables
+  private boolean hasParsedAudioDataHeader;
+  private boolean hasOutputFormat;
+
+
+  public AudioTagPayloadReader(TrackOutput output) {
+    super(output);
+  }
+
+  @Override
+  public void seek() {
+
+  }
+
+  @Override
+  protected boolean parseHeader(ParsableByteArray data) throws UnsupportedTrack {
+    // Parse audio data header, if it was not done, to extract information
+    // about the audio codec and audio configuration.
+    if (!hasParsedAudioDataHeader) {
+      int header = data.readUnsignedByte();
+      int soundFormat = (header >> 4) & 0x0F;
+      int sampleRateIndex = (header >> 2) & 0x03;
+      int bitsPerSample = (header & 0x02) == 0x02 ? 16 : 8;
+      int channels = (header & 0x01) + 1;
+
+      if (sampleRateIndex < 0 || sampleRateIndex >= AUDIO_SAMPLING_RATE_TABLE.length) {
+        throw new UnsupportedTrack("Invalid sample rate for the audio track");
+      }
+
+      if (!hasOutputFormat) {
+        // TODO: Adds support for MP3 and PCM
+        if (soundFormat != AUDIO_FORMAT_AAC) {
+          throw new UnsupportedTrack("Audio track not supported. Format: " + soundFormat +
+              ", Sample rate: " + sampleRateIndex + ", bps: " + bitsPerSample + ", channels: " +
+              channels);
+        }
+      }
+
+      hasParsedAudioDataHeader = true;
+    } else {
+      // Skip header if it was parsed previously.
+      data.skipBytes(1);
+    }
+
+    // In all the cases we will be managing AAC format (otherwise an exception would be
+    // fired so we can just always return true
+    return true;
+  }
+
+  @Override
+  protected void parsePayload(ParsableByteArray data, long timeUs) {
+    int packetType = data.readUnsignedByte();
+    // Parse sequence header just in case it was not done before.
+    if (packetType == AAC_PACKET_TYPE_SEQUENCE_HEADER && !hasOutputFormat) {
+      ParsableBitArray adtsScratch = new ParsableBitArray(new byte[data.bytesLeft()]);
+      data.readBytes(adtsScratch.data, 0, data.bytesLeft());
+
+      int audioObjectType = adtsScratch.readBits(5);
+      int sampleRateIndex = adtsScratch.readBits(4);
+      int channelConfig = adtsScratch.readBits(4);
+
+      byte[] audioSpecificConfig = CodecSpecificDataUtil.buildAacAudioSpecificConfig(
+          audioObjectType, sampleRateIndex, channelConfig);
+      Pair<Integer, Integer> audioParams = CodecSpecificDataUtil.parseAacAudioSpecificConfig(
+          audioSpecificConfig);
+
+      MediaFormat mediaFormat = MediaFormat.createAudioFormat(MimeTypes.AUDIO_AAC,
+          MediaFormat.NO_VALUE, MediaFormat.NO_VALUE, durationUs, audioParams.second,
+          audioParams.first, Collections.singletonList(audioSpecificConfig), null);
+
+      output.format(mediaFormat);
+      hasOutputFormat = true;
+    } else if (packetType == AAC_PACKET_TYPE_AAC_RAW) {
+      // Sample audio AAC frames
+      int bytesToWrite = data.bytesLeft();
+      output.sampleData(data, bytesToWrite);
+      output.sampleMetadata(timeUs, C.SAMPLE_FLAG_SYNC, bytesToWrite, 0, null);
+    }
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/extractor/flv/ScriptTagPayloadReader.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.extractor.flv;
+
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.extractor.TrackOutput;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Parses Script Data tags from an FLV stream and extracts metadata information.
+ */
+final class ScriptTagPayloadReader extends TagPayloadReader {
+
+  // AMF object types
+  private static final int AMF_TYPE_UNKNOWN = -1;
+  private static final int AMF_TYPE_NUMBER = 0;
+  private static final int AMF_TYPE_BOOLEAN = 1;
+  private static final int AMF_TYPE_STRING = 2;
+  private static final int AMF_TYPE_OBJECT = 3;
+  private static final int AMF_TYPE_ECMA_ARRAY = 8;
+  private static final int AMF_TYPE_END_MARKER = 9;
+  private static final int AMF_TYPE_STRICT_ARRAY = 10;
+  private static final int AMF_TYPE_DATE = 11;
+
+  /**
+   * @param output A {@link TrackOutput} to which samples should be written.
+   */
+  public ScriptTagPayloadReader(TrackOutput output) {
+    super(output);
+  }
+
+  @Override
+  public void seek() {
+
+  }
+
+  @Override
+  protected boolean parseHeader(ParsableByteArray data) throws UnsupportedTrack {
+    return true;
+  }
+
+  @SuppressWarnings("unchecked")
+  @Override
+  protected void parsePayload(ParsableByteArray data, long timeUs) {
+    // Read message name (don't storing it as we are not going to give it any use)
+    readAMFData(data, AMF_TYPE_UNKNOWN);
+    Object obj = readAMFData(data, AMF_TYPE_UNKNOWN);
+
+    if (obj instanceof Map) {
+      Map<String, Object> extractedMetadata = (Map<String, Object>) obj;
+      for (Map.Entry<String, Object> entry : extractedMetadata.entrySet()) {
+        if (entry.getValue() == null) {
+          continue;
+        }
+
+        switch (entry.getKey()) {
+          case "duration":
+            this.durationUs = (long)(C.MICROS_PER_SECOND * (Double)(entry.getValue()));
+            break;
+
+          default:
+            break;
+        }
+      }
+    }
+  }
+
+  private Object readAMFData(ParsableByteArray data, int type) {
+    if (type == AMF_TYPE_UNKNOWN) {
+      type = data.readUnsignedByte();
+    }
+    switch (type) {
+      case AMF_TYPE_NUMBER:
+        return readAMFDouble(data);
+      case AMF_TYPE_BOOLEAN:
+        return readAMFBoolean(data);
+      case AMF_TYPE_STRING:
+        return readAMFString(data);
+      case AMF_TYPE_OBJECT:
+        return readAMFObject(data);
+      case AMF_TYPE_ECMA_ARRAY:
+        return readAMFEcmaArray(data);
+      case AMF_TYPE_STRICT_ARRAY:
+        return readAMFStrictArray(data);
+      case AMF_TYPE_DATE:
+        return readAMFDate(data);
+      default:
+        return null;
+    }
+  }
+
+  /**
+   * Read a boolean from an AMF encoded buffer
+   * @param data Buffer
+   * @return Boolean value read from the buffer
+   */
+  private Boolean readAMFBoolean(ParsableByteArray data) {
+    return data.readUnsignedByte() == 1;
+  }
+
+  /**
+   * Read a double number from an AMF encoded buffer
+   * @param data Buffer
+   * @return Double number read from the buffer
+   */
+  private Double readAMFDouble(ParsableByteArray data) {
+    byte []b = new byte[8];
+    data.readBytes(b, 0, b.length);
+    return ByteBuffer.wrap(b).getDouble();
+  }
+
+  /**
+   * Read a string from an AMF encoded buffer
+   * @param data Buffer
+   * @return String read from the buffer
+   */
+  private String readAMFString(ParsableByteArray data) {
+    int size = data.readUnsignedShort();
+    byte []b = new byte[size];
+    data.readBytes(b, 0, b.length);
+    return new String(b);
+  }
+
+  /**
+   * Read an array from an AMF encoded buffer
+   * @param data Buffer
+   * @return Array read from the buffer
+   */
+  private Object readAMFStrictArray(ParsableByteArray data) {
+    long count = data.readUnsignedInt();
+    ArrayList<Object> list = new ArrayList<>();
+    for (int i = 0; i < count; i++) {
+      list.add(readAMFData(data, AMF_TYPE_UNKNOWN));
+    }
+    return list;
+  }
+
+  /**
+   * Read an object from an AMF encoded buffer
+   * @param data Buffer
+   * @return Object read from the buffer
+   */
+  private Object readAMFObject(ParsableByteArray data) {
+    HashMap<String, Object> array = new HashMap<>();
+    while (true) {
+      String key = readAMFString(data);
+      int type = data.readUnsignedByte();
+      if (type == AMF_TYPE_END_MARKER) {
+        break;
+      }
+      array.put(key, readAMFData(data, type));
+    }
+    return array;
+  }
+
+  /**
+   * Read am ecma array from an AMF encoded buffer
+   * @param data Buffer
+   * @return Ecma array read from the buffer
+   */
+  private Object readAMFEcmaArray(ParsableByteArray data) {
+    long count = data.readUnsignedInt();
+    HashMap<String, Object> array = new HashMap<>();
+    for (int i = 0; i < count; i++) {
+      String key = readAMFString(data);
+      int type = data.readUnsignedByte();
+      array.put(key, readAMFData(data, type));
+    }
+    return array;
+  }
+
+  /**
+   * Read a date from an AMF encoded buffer
+   * @param data Buffer
+   * @return Date read from the buffer
+   */
+  private Date readAMFDate(ParsableByteArray data) {
+    final Date date = new Date((long) readAMFDouble(data).doubleValue());
+    data.readUnsignedShort();
+    return date;
+  }
+}

library/src/main/java/com/google/android/exoplayer/extractor/flv/TagPayloadReader.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.extractor.flv;
+
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.extractor.TrackOutput;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+/**
+ * Extracts individual samples from FLV tags, preserving original order.
+ */
+/* package */ abstract class TagPayloadReader {
+
+  protected final TrackOutput output;
+
+  // Duration of the track
+  protected long durationUs;
+
+  /**
+   * @param output A {@link TrackOutput} to which samples should be written.
+   */
+  protected TagPayloadReader(TrackOutput output) {
+    this.output = output;
+    this.durationUs = C.UNKNOWN_TIME_US;
+  }
+
+  /**
+   * Notifies the reader that a seek has occurred.
+   * <p>
+   * Following a call to this method, the data passed to the next invocation of
+   * {@link #consume(ParsableByteArray, long)} will not be a continuation of the data that
+   * was previously passed. Hence the reader should reset any internal state.
+   */
+  public abstract void seek();
+
+  /**
+   * Parses tag header
+   * @param data Buffer where the tag header is stored
+   * @return True if header was parsed successfully and then payload should be read;
+   * Otherwise, false
+   * @throws UnsupportedTrack
+   */
+  protected abstract boolean parseHeader(ParsableByteArray data) throws UnsupportedTrack;
+
+  /**
+   * Parses tag payload
+   * @param data Buffer where tag payload is stored
+   * @param timeUs Time position of the frame
+   */
+  protected abstract void parsePayload(ParsableByteArray data, long timeUs);
+
+  /**
+   * Consumes payload data.
+   *
+   * @param data The payload data to consume.
+   * @param timeUs The timestamp associated with the payload.
+   */
+  public void consume(ParsableByteArray data, long timeUs) throws UnsupportedTrack {
+    if (parseHeader(data)) {
+      parsePayload(data, timeUs);
+    }
+  }
+
+  /**
+   * Sets duration in microseconds
+   * @param durationUs duration in microseconds
+   */
+  public void setDurationUs(long durationUs) {
+    this.durationUs = durationUs;
+  }
+
+  public long getDurationUs() {
+    return durationUs;
+  }
+  /**
+   * Thrown when format described in the AudioTrack is not supported
+   */
+  public static final class UnsupportedTrack extends Exception {
+
+    public UnsupportedTrack(String msg) {
+      super(msg);
+    }
+
+  }
+}

library/src/main/java/com/google/android/exoplayer/extractor/flv/VideoTagPayloadReader.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.extractor.flv;
+
+import android.util.Log;
+
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.MediaFormat;
+import com.google.android.exoplayer.ParserException;
+import com.google.android.exoplayer.extractor.TrackOutput;
+import com.google.android.exoplayer.util.Assertions;
+import com.google.android.exoplayer.util.CodecSpecificDataUtil;
+import com.google.android.exoplayer.util.MimeTypes;
+import com.google.android.exoplayer.util.NalUnitUtil;
+import com.google.android.exoplayer.util.ParsableBitArray;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Parses video tags from an FLV stream and extracts H.264 nal units.
+ */
+final class VideoTagPayloadReader extends TagPayloadReader {
+  private static final String TAG = "VideoTagPayloadReader";
+
+  // Video codec
+  private static final int VIDEO_CODEC_AVC = 7;
+
+  // FRAME TYPE
+  private static final int VIDEO_FRAME_KEYFRAME = 1;
+  private static final int VIDEO_FRAME_VIDEO_INFO = 5;
+
+  // PACKET TYPE
+  private static final int AVC_PACKET_TYPE_SEQUENCE_HEADER = 0;
+  private static final int AVC_PACKET_TYPE_AVC_NALU = 1;
+  private static final int AVC_PACKET_TYPE_AVC_END_OF_SEQUENCE = 2;
+
+  // Temporary arrays.
+  private final ParsableByteArray nalStartCode;
+  private final ParsableByteArray nalLength;
+  private int nalUnitsLength;
+
+  // State variables.
+  private boolean hasOutputFormat;
+  private int frameType;
+
+  /**
+   * @param output A {@link TrackOutput} to which samples should be written.
+   */
+  public VideoTagPayloadReader(TrackOutput output) {
+    super(output);
+
+    nalStartCode = new ParsableByteArray(NalUnitUtil.NAL_START_CODE);
+    nalLength = new ParsableByteArray(4);
+  }
+
+  @Override
+  public void seek() {
+
+  }
+
+  @Override
+  protected boolean parseHeader(ParsableByteArray data) throws UnsupportedTrack {
+    int header = data.readUnsignedByte();
+    int frameType = (header >> 4) & 0x0F;
+    int videoCodec = (header & 0x0F);
+
+    // Support just H.264 encoded content.
+    if (videoCodec != VIDEO_CODEC_AVC) {
+      throw new UnsupportedTrack("Video codec not supported. Codec: " + videoCodec);
+    }
+    this.frameType = frameType;
+    return (frameType != VIDEO_FRAME_VIDEO_INFO);
+  }
+
+  @Override
+  protected void parsePayload(ParsableByteArray data, long timeUs) {
+    int packetType = data.readUnsignedByte();
+    int compositionTime = data.readUnsignedInt24();
+    // If there is a composition time, adjust timeUs accordingly
+    // Note: compositionTime within AVCVIDEOPACKET is provided in milliseconds
+    // and timeUs is in microseconds.
+    if (compositionTime > 0) {
+      timeUs += compositionTime * 1000;
+    }
+    // Parse avc sequence header in case this was not done before.
+    if (packetType == AVC_PACKET_TYPE_SEQUENCE_HEADER && !hasOutputFormat) {
+      ParsableByteArray videoSequence = new ParsableByteArray(new byte[data.bytesLeft()]);
+      data.readBytes(videoSequence.data, 0, data.bytesLeft());
+
+      AvcSequenceHeaderData avcData;
+      try {
+        avcData = parseAvcCodecPrivate(videoSequence);
+        nalUnitsLength = avcData.nalUnitLengthFieldLength;
+      } catch (ParserException e) {
+        e.printStackTrace();
+        return;
+      }
+
+      // Construct and output the format.
+      MediaFormat mediaFormat = MediaFormat.createVideoFormat(MimeTypes.VIDEO_H264,
+          MediaFormat.NO_VALUE, MediaFormat.NO_VALUE, durationUs, avcData.width, avcData.height,
+          avcData.initializationData, MediaFormat.NO_VALUE, avcData.pixelWidthAspectRatio);
+      output.format(mediaFormat);
+      hasOutputFormat = true;
+    } else if (packetType == AVC_PACKET_TYPE_AVC_NALU) {
+      // TODO: Deduplicate with Mp4Extractor.
+      // Zero the top three bytes of the array that we'll use to parse nal unit lengths, in case
+      // they're only 1 or 2 bytes long.
+      byte[] nalLengthData = nalLength.data;
+      nalLengthData[0] = 0;
+      nalLengthData[1] = 0;
+      nalLengthData[2] = 0;
+      int nalUnitLengthFieldLength = nalUnitsLength;
+      int nalUnitLengthFieldLengthDiff = 4 - nalUnitsLength;
+      // NAL units are length delimited, but the decoder requires start code delimited units.
+      // Loop until we've written the sample to the track output, replacing length delimiters with
+      // start codes as we encounter them.
+      int bytesWritten = 0;
+      int bytesToWrite;
+      while (data.bytesLeft() > 0) {
+        // Read the NAL length so that we know where we find the next one.
+        data.readBytes(nalLength.data, nalUnitLengthFieldLengthDiff, nalUnitLengthFieldLength);
+        nalLength.setPosition(0);
+        bytesToWrite = nalLength.readUnsignedIntToInt();
+
+        // First, write nal start code (replacing length field by nal delimiter codes)
+        nalStartCode.setPosition(0);
+        output.sampleData(nalStartCode, 4);
+        bytesWritten += 4;
+
+        // Then write nal unit itsef
+        output.sampleData(data, bytesToWrite);
+        bytesWritten += bytesToWrite;
+      }
+      output.sampleMetadata(timeUs, frameType == VIDEO_FRAME_KEYFRAME ? C.SAMPLE_FLAG_SYNC : 0,
+          bytesWritten, 0, null);
+    } else if (packetType == AVC_PACKET_TYPE_AVC_END_OF_SEQUENCE) {
+      Log.d(TAG, "End of seq!!!");
+    }
+  }
+
+  /**
+   * Builds initialization data for a {@link MediaFormat} from H.264 (AVC) codec private data.
+   *
+   * @return The AvcSequenceHeader data with all the information needed to initialize
+   * the video codec.
+   * @throws ParserException If the initialization data could not be built.
+   */
+  private AvcSequenceHeaderData parseAvcCodecPrivate(ParsableByteArray buffer)
+      throws ParserException {
+    try {
+      // TODO: Deduplicate with AtomParsers.parseAvcCFromParent.
+      buffer.setPosition(4);
+      int nalUnitLengthFieldLength = (buffer.readUnsignedByte() & 0x03) + 1;
+      Assertions.checkState(nalUnitLengthFieldLength != 3);
+      List<byte[]> initializationData = new ArrayList<>();
+      int numSequenceParameterSets = buffer.readUnsignedByte() & 0x1F;
+      for (int i = 0; i < numSequenceParameterSets; i++) {
+        initializationData.add(NalUnitUtil.parseChildNalUnit(buffer));
+      }
+      int numPictureParameterSets = buffer.readUnsignedByte();
+      for (int j = 0; j < numPictureParameterSets; j++) {
+        initializationData.add(NalUnitUtil.parseChildNalUnit(buffer));
+      }
+
+      float pixelWidthAspectRatio = 1;
+      int width = MediaFormat.NO_VALUE;
+      int height = MediaFormat.NO_VALUE;
+      if (numSequenceParameterSets > 0) {
+        // Parse the first sequence parameter set to obtain pixelWidthAspectRatio.
+        ParsableBitArray spsDataBitArray = new ParsableBitArray(initializationData.get(0));
+        // Skip the NAL header consisting of the nalUnitLengthField and the type (1 byte).
+        spsDataBitArray.setPosition(8 * (nalUnitLengthFieldLength + 1));
+        CodecSpecificDataUtil.SpsData sps = CodecSpecificDataUtil.parseSpsNalUnit(spsDataBitArray);
+        width = sps.width;
+        height = sps.height;
+        pixelWidthAspectRatio = sps.pixelWidthAspectRatio;
+      }
+
+      return new AvcSequenceHeaderData(initializationData, nalUnitLengthFieldLength,
+          width, height, pixelWidthAspectRatio);
+    } catch (ArrayIndexOutOfBoundsException e) {
+      throw new ParserException("Error parsing AVC codec private");
+    }
+  }
+
+  /**
+   * Holds data parsed from an Sequence Header video tag atom.
+   */
+  private static final class AvcSequenceHeaderData {
+
+    public final List<byte[]> initializationData;
+    public final int nalUnitLengthFieldLength;
+    public final float pixelWidthAspectRatio;
+    public final int width;
+    public final int height;
+
+    public AvcSequenceHeaderData(List<byte[]> initializationData, int nalUnitLengthFieldLength,
+        int width, int height, float pixelWidthAspectRatio) {
+      this.initializationData = initializationData;
+      this.nalUnitLengthFieldLength = nalUnitLengthFieldLength;
+      this.pixelWidthAspectRatio = pixelWidthAspectRatio;
+      this.width = width;
+      this.height = height;
+    }
+
+  }
+
+}