1 files changed, 143 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ogg/FlacReader.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ogg/FlacReader.java
new file mode 100644
index 0000000000..449bf35f78
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ogg/FlacReader.java
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2016 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 org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ogg;
+
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorInput;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.FlacFrameReader;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.FlacMetadataReader;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.FlacSeekTableSeekMap;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.SeekMap;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.FlacConstants;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.FlacStreamMetadata;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableByteArray;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util;
+import java.io.IOException;
+import java.util.Arrays;
+
+/**
+ * {@link StreamReader} to extract Flac data out of Ogg byte stream.
+ */
+/* package */ final class FlacReader extends StreamReader {
+
+  private static final byte AUDIO_PACKET_TYPE = (byte) 0xFF;
+
+  private static final int FRAME_HEADER_SAMPLE_NUMBER_OFFSET = 4;
+
+  private FlacStreamMetadata streamMetadata;
+  private FlacOggSeeker flacOggSeeker;
+
+  public static boolean verifyBitstreamType(ParsableByteArray data) {
+    return data.bytesLeft() >= 5 && data.readUnsignedByte() == 0x7F && // packet type
+        data.readUnsignedInt() == 0x464C4143; // ASCII signature "FLAC"
+  }
+
+  @Override
+  protected void reset(boolean headerData) {
+    super.reset(headerData);
+    if (headerData) {
+      streamMetadata = null;
+      flacOggSeeker = null;
+    }
+  }
+
+  private static boolean isAudioPacket(byte[] data) {
+    return data[0] == AUDIO_PACKET_TYPE;
+  }
+
+  @Override
+  protected long preparePayload(ParsableByteArray packet) {
+    if (!isAudioPacket(packet.data)) {
+      return -1;
+    }
+    return getFlacFrameBlockSize(packet);
+  }
+
+  @Override
+  protected boolean readHeaders(ParsableByteArray packet, long position, SetupData setupData) {
+    byte[] data = packet.data;
+    if (streamMetadata == null) {
+      streamMetadata = new FlacStreamMetadata(data, 17);
+      byte[] metadata = Arrays.copyOfRange(data, 9, packet.limit());
+      setupData.format = streamMetadata.getFormat(metadata, /* id3Metadata= */ null);
+    } else if ((data[0] & 0x7F) == FlacConstants.METADATA_TYPE_SEEK_TABLE) {
+      flacOggSeeker = new FlacOggSeeker();
+      FlacStreamMetadata.SeekTable seekTable =
+          FlacMetadataReader.readSeekTableMetadataBlock(packet);
+      streamMetadata = streamMetadata.copyWithSeekTable(seekTable);
+    } else if (isAudioPacket(data)) {
+      if (flacOggSeeker != null) {
+        flacOggSeeker.setFirstFrameOffset(position);
+        setupData.oggSeeker = flacOggSeeker;
+      }
+      return false;
+    }
+    return true;
+  }
+
+  private int getFlacFrameBlockSize(ParsableByteArray packet) {
+    int blockSizeKey = (packet.data[2] & 0xFF) >> 4;
+    if (blockSizeKey == 6 || blockSizeKey == 7) {
+      // Skip the sample number.
+      packet.skipBytes(FRAME_HEADER_SAMPLE_NUMBER_OFFSET);
+      packet.readUtf8EncodedLong();
+    }
+    int result = FlacFrameReader.readFrameBlockSizeSamplesFromKey(packet, blockSizeKey);
+    packet.setPosition(0);
+    return result;
+  }
+
+  private class FlacOggSeeker implements OggSeeker {
+
+    private long firstFrameOffset;
+    private long pendingSeekGranule;
+
+    public FlacOggSeeker() {
+      firstFrameOffset = -1;
+      pendingSeekGranule = -1;
+    }
+
+    public void setFirstFrameOffset(long firstFrameOffset) {
+      this.firstFrameOffset = firstFrameOffset;
+    }
+
+    @Override
+    public long read(ExtractorInput input) throws IOException, InterruptedException {
+      if (pendingSeekGranule >= 0) {
+        long result = -(pendingSeekGranule + 2);
+        pendingSeekGranule = -1;
+        return result;
+      }
+      return -1;
+    }
+
+    @Override
+    public void startSeek(long targetGranule) {
+      Assertions.checkNotNull(streamMetadata.seekTable);
+      long[] seekPointGranules = streamMetadata.seekTable.pointSampleNumbers;
+      int index = Util.binarySearchFloor(seekPointGranules, targetGranule, true, true);
+      pendingSeekGranule = seekPointGranules[index];
+    }
+
+    @Override
+    public SeekMap createSeekMap() {
+      Assertions.checkState(firstFrameOffset != -1);
+      return new FlacSeekTableSeekMap(streamMetadata, firstFrameOffset);
+    }
+
+  }
+
+}