1 files changed, 181 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/DtsReader.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/DtsReader.java
new file mode 100644
index 0000000000..a4205add7b
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/DtsReader.java
@@ -0,0 +1,181 @@
+/*
+ * 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.ts;
+
+import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.Format;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.audio.DtsUtil;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorOutput;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.TrackOutput;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableByteArray;
+
+/**
+ * Parses a continuous DTS byte stream and extracts individual samples.
+ */
+public final class DtsReader implements ElementaryStreamReader {
+
+  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 = 18;
+
+  private final ParsableByteArray headerScratchBytes;
+  private final String language;
+
+  private String formatId;
+  private TrackOutput output;
+
+  private int state;
+  private int bytesRead;
+
+  // Used to find the header.
+  private int syncBytes;
+
+  // Used when parsing the header.
+  private long sampleDurationUs;
+  private Format format;
+  private int sampleSize;
+
+  // Used when reading the samples.
+  private long timeUs;
+
+  /**
+   * Constructs a new reader for DTS elementary streams.
+   *
+   * @param language Track language.
+   */
+  public DtsReader(String language) {
+    headerScratchBytes = new ParsableByteArray(new byte[HEADER_SIZE]);
+    state = STATE_FINDING_SYNC;
+    this.language = language;
+  }
+
+  @Override
+  public void seek() {
+    state = STATE_FINDING_SYNC;
+    bytesRead = 0;
+    syncBytes = 0;
+  }
+
+  @Override
+  public void createTracks(ExtractorOutput extractorOutput, TrackIdGenerator idGenerator) {
+    idGenerator.generateNewId();
+    formatId = idGenerator.getFormatId();
+    output = extractorOutput.track(idGenerator.getTrackId(), C.TRACK_TYPE_AUDIO);
+  }
+
+  @Override
+  public void packetStarted(long pesTimeUs, @TsPayloadReader.Flags int flags) {
+    timeUs = pesTimeUs;
+  }
+
+  @Override
+  public void consume(ParsableByteArray data) {
+    while (data.bytesLeft() > 0) {
+      switch (state) {
+        case STATE_FINDING_SYNC:
+          if (skipToNextSync(data)) {
+            state = STATE_READING_HEADER;
+          }
+          break;
+        case STATE_READING_HEADER:
+          if (continueRead(data, headerScratchBytes.data, HEADER_SIZE)) {
+            parseHeader();
+            headerScratchBytes.setPosition(0);
+            output.sampleData(headerScratchBytes, HEADER_SIZE);
+            state = STATE_READING_SAMPLE;
+          }
+          break;
+        case STATE_READING_SAMPLE:
+          int bytesToRead = Math.min(data.bytesLeft(), sampleSize - bytesRead);
+          output.sampleData(data, bytesToRead);
+          bytesRead += bytesToRead;
+          if (bytesRead == sampleSize) {
+            output.sampleMetadata(timeUs, C.BUFFER_FLAG_KEY_FRAME, sampleSize, 0, null);
+            timeUs += sampleDurationUs;
+            state = STATE_FINDING_SYNC;
+          }
+          break;
+        default:
+          throw new IllegalStateException();
+      }
+    }
+  }
+
+  @Override
+  public void packetFinished() {
+    // Do nothing.
+  }
+
+  /**
+   * 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 value in the buffer, advancing the position to the byte that immediately
+   * follows it. If SYNC was not located, the position is advanced to the limit.
+   *
+   * @param pesBuffer The buffer whose position should be advanced.
+   * @return Whether SYNC was found.
+   */
+  private boolean skipToNextSync(ParsableByteArray pesBuffer) {
+    while (pesBuffer.bytesLeft() > 0) {
+      syncBytes <<= 8;
+      syncBytes |= pesBuffer.readUnsignedByte();
+      if (DtsUtil.isSyncWord(syncBytes)) {
+        headerScratchBytes.data[0] = (byte) ((syncBytes >> 24) & 0xFF);
+        headerScratchBytes.data[1] = (byte) ((syncBytes >> 16) & 0xFF);
+        headerScratchBytes.data[2] = (byte) ((syncBytes >> 8) & 0xFF);
+        headerScratchBytes.data[3] = (byte) (syncBytes & 0xFF);
+        bytesRead = 4;
+        syncBytes = 0;
+        return true;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Parses the sample header.
+   */
+  private void parseHeader() {
+    byte[] frameData = headerScratchBytes.data;
+    if (format == null) {
+      format = DtsUtil.parseDtsFormat(frameData, formatId, language, null);
+      output.format(format);
+    }
+    sampleSize = DtsUtil.getDtsFrameSize(frameData);
+    // In this class a sample is an access unit (frame in DTS), but the format's sample rate
+    // specifies the number of PCM audio samples per second.
+    sampleDurationUs = (int) (C.MICROS_PER_SECOND
+        * DtsUtil.parseDtsAudioSampleCount(frameData) / format.sampleRate);
+  }
+
+}