Java 类com.google.android.exoplayer2.audio.Ac3Util 实例源码

项目：Exoplayer2Radio 文件：Ac3Reader.java

/**
 * Parses the sample header.
 */
@SuppressWarnings("ReferenceEquality")
private void parseHeader() {
  headerScratchBits.setPosition(0);
  Ac3Util.Ac3SyncFrameInfo frameInfo = Ac3Util.parseAc3SyncframeInfo(headerScratchBits);
  if (format == null || frameInfo.channelCount != format.channelCount
      || frameInfo.sampleRate != format.sampleRate
      || frameInfo.mimeType != format.sampleMimeType) {
    format = Format.createAudioSampleFormat(trackFormatId, frameInfo.mimeType, null,
        Format.NO_VALUE, Format.NO_VALUE, frameInfo.channelCount, frameInfo.sampleRate, null,
        null, 0, language);
    output.format(format);
  }
  sampleSize = frameInfo.frameSize;
  // In this class a sample is an access unit (syncframe in AC-3), but the MediaFormat sample rate
  // specifies the number of PCM audio samples per second.
  sampleDurationUs = C.MICROS_PER_SECOND * frameInfo.sampleCount / format.sampleRate;
}

项目：K-Sonic 文件：Ac3Reader.java

/**
 * Parses the sample header.
 */
private void parseHeader() {
  if (format == null) {
    // We read ahead to distinguish between AC-3 and E-AC-3.
    headerScratchBits.skipBits(40);
    isEac3 = headerScratchBits.readBits(5) == 16;
    headerScratchBits.setPosition(headerScratchBits.getPosition() - 45);
    format = isEac3
        ? Ac3Util.parseEac3SyncframeFormat(headerScratchBits, trackFormatId, language , null)
        : Ac3Util.parseAc3SyncframeFormat(headerScratchBits, trackFormatId, language, null);
    output.format(format);
  }
  sampleSize = isEac3 ? Ac3Util.parseEAc3SyncframeSize(headerScratchBits.data)
      : Ac3Util.parseAc3SyncframeSize(headerScratchBits.data);
  int audioSamplesPerSyncframe = isEac3
      ? Ac3Util.parseEAc3SyncframeAudioSampleCount(headerScratchBits.data)
      : Ac3Util.getAc3SyncframeAudioSampleCount();
  // In this class a sample is an access unit (syncframe in AC-3), but the MediaFormat sample rate
  // specifies the number of PCM audio samples per second.
  sampleDurationUs =
      (int) (C.MICROS_PER_SECOND * audioSamplesPerSyncframe / format.sampleRate);
}

项目：videoPickPlayer 文件：Ac3Reader.java

/**
 * Parses the sample header.
 */
private void parseHeader() {
  if (format == null) {
    // We read ahead to distinguish between AC-3 and E-AC-3.
    headerScratchBits.skipBits(40);
    isEac3 = headerScratchBits.readBits(5) == 16;
    headerScratchBits.setPosition(headerScratchBits.getPosition() - 45);
    format = isEac3 ? Ac3Util.parseEac3SyncframeFormat(headerScratchBits, null, language , null)
        : Ac3Util.parseAc3SyncframeFormat(headerScratchBits, null, language, null);
    output.format(format);
  }
  sampleSize = isEac3 ? Ac3Util.parseEAc3SyncframeSize(headerScratchBits.data)
      : Ac3Util.parseAc3SyncframeSize(headerScratchBits.data);
  int audioSamplesPerSyncframe = isEac3
      ? Ac3Util.parseEAc3SyncframeAudioSampleCount(headerScratchBits.data)
      : Ac3Util.getAc3SyncframeAudioSampleCount();
  // In this class a sample is an access unit (syncframe in AC-3), but the MediaFormat sample rate
  // specifies the number of PCM audio samples per second.
  sampleDurationUs =
      (int) (C.MICROS_PER_SECOND * audioSamplesPerSyncframe / format.sampleRate);
}

项目：transistor 文件：Ac3Reader.java

/**
 * Parses the sample header.
 */
@SuppressWarnings("ReferenceEquality")
private void parseHeader() {
  headerScratchBits.setPosition(0);
  Ac3Util.Ac3SyncFrameInfo frameInfo = Ac3Util.parseAc3SyncframeInfo(headerScratchBits);
  if (format == null || frameInfo.channelCount != format.channelCount
      || frameInfo.sampleRate != format.sampleRate
      || frameInfo.mimeType != format.sampleMimeType) {
    format = Format.createAudioSampleFormat(trackFormatId, frameInfo.mimeType, null,
        Format.NO_VALUE, Format.NO_VALUE, frameInfo.channelCount, frameInfo.sampleRate, null,
        null, 0, language);
    output.format(format);
  }
  sampleSize = frameInfo.frameSize;
  // In this class a sample is an access unit (syncframe in AC-3), but the MediaFormat sample rate
  // specifies the number of PCM audio samples per second.
  sampleDurationUs = C.MICROS_PER_SECOND * frameInfo.sampleCount / format.sampleRate;
}

项目：Exoplayer2Radio 文件：Ac3Extractor.java

@Override
public boolean sniff(ExtractorInput input) throws IOException, InterruptedException {
  // Skip any ID3 headers.
  ParsableByteArray scratch = new ParsableByteArray(10);
  int startPosition = 0;
  while (true) {
    input.peekFully(scratch.data, 0, 10);
    scratch.setPosition(0);
    if (scratch.readUnsignedInt24() != ID3_TAG) {
      break;
    }
    scratch.skipBytes(3);
    int length = scratch.readSynchSafeInt();
    startPosition += 10 + length;
    input.advancePeekPosition(length);
  }
  input.resetPeekPosition();
  input.advancePeekPosition(startPosition);

  int headerPosition = startPosition;
  int validFramesCount = 0;
  while (true) {
    input.peekFully(scratch.data, 0, 5);
    scratch.setPosition(0);
    int syncBytes = scratch.readUnsignedShort();
    if (syncBytes != AC3_SYNC_WORD) {
      validFramesCount = 0;
      input.resetPeekPosition();
      if (++headerPosition - startPosition >= MAX_SNIFF_BYTES) {
        return false;
      }
      input.advancePeekPosition(headerPosition);
    } else {
      if (++validFramesCount >= 4) {
        return true;
      }
      int frameSize = Ac3Util.parseAc3SyncframeSize(scratch.data);
      if (frameSize == C.LENGTH_UNSET) {
        return false;
      }
      input.advancePeekPosition(frameSize - 5);
    }
  }
}

项目：K-Sonic 文件：Ac3Extractor.java

@Override
public boolean sniff(ExtractorInput input) throws IOException, InterruptedException {
  // Skip any ID3 headers.
  ParsableByteArray scratch = new ParsableByteArray(10);
  int startPosition = 0;
  while (true) {
    input.peekFully(scratch.data, 0, 10);
    scratch.setPosition(0);
    if (scratch.readUnsignedInt24() != ID3_TAG) {
      break;
    }
    scratch.skipBytes(3);
    int length = scratch.readSynchSafeInt();
    startPosition += 10 + length;
    input.advancePeekPosition(length);
  }
  input.resetPeekPosition();
  input.advancePeekPosition(startPosition);

  int headerPosition = startPosition;
  int validFramesCount = 0;
  while (true) {
    input.peekFully(scratch.data, 0, 5);
    scratch.setPosition(0);
    int syncBytes = scratch.readUnsignedShort();
    if (syncBytes != AC3_SYNC_WORD) {
      validFramesCount = 0;
      input.resetPeekPosition();
      if (++headerPosition - startPosition >= MAX_SNIFF_BYTES) {
        return false;
      }
      input.advancePeekPosition(headerPosition);
    } else {
      if (++validFramesCount >= 4) {
        return true;
      }
      int frameSize = Ac3Util.parseAc3SyncframeSize(scratch.data);
      if (frameSize == C.LENGTH_UNSET) {
        return false;
      }
      input.advancePeekPosition(frameSize - 5);
    }
  }
}

项目：videoPickPlayer 文件：Ac3Extractor.java

@Override
public boolean sniff(ExtractorInput input) throws IOException, InterruptedException {
  // Skip any ID3 headers.
  ParsableByteArray scratch = new ParsableByteArray(10);
  int startPosition = 0;
  while (true) {
    input.peekFully(scratch.data, 0, 10);
    scratch.setPosition(0);
    if (scratch.readUnsignedInt24() != ID3_TAG) {
      break;
    }
    scratch.skipBytes(3);
    int length = scratch.readSynchSafeInt();
    startPosition += 10 + length;
    input.advancePeekPosition(length);
  }
  input.resetPeekPosition();
  input.advancePeekPosition(startPosition);

  int headerPosition = startPosition;
  int validFramesCount = 0;
  while (true) {
    input.peekFully(scratch.data, 0, 5);
    scratch.setPosition(0);
    int syncBytes = scratch.readUnsignedShort();
    if (syncBytes != AC3_SYNC_WORD) {
      validFramesCount = 0;
      input.resetPeekPosition();
      if (++headerPosition - startPosition >= MAX_SNIFF_BYTES) {
        return false;
      }
      input.advancePeekPosition(headerPosition);
    } else {
      if (++validFramesCount >= 4) {
        return true;
      }
      int frameSize = Ac3Util.parseAc3SyncframeSize(scratch.data);
      if (frameSize == C.LENGTH_UNSET) {
        return false;
      }
      input.advancePeekPosition(frameSize - 5);
    }
  }
}

项目：transistor 文件：Ac3Extractor.java

@Override
public boolean sniff(ExtractorInput input) throws IOException, InterruptedException {
  // Skip any ID3 headers.
  ParsableByteArray scratch = new ParsableByteArray(10);
  int startPosition = 0;
  while (true) {
    input.peekFully(scratch.data, 0, 10);
    scratch.setPosition(0);
    if (scratch.readUnsignedInt24() != ID3_TAG) {
      break;
    }
    scratch.skipBytes(3);
    int length = scratch.readSynchSafeInt();
    startPosition += 10 + length;
    input.advancePeekPosition(length);
  }
  input.resetPeekPosition();
  input.advancePeekPosition(startPosition);

  int headerPosition = startPosition;
  int validFramesCount = 0;
  while (true) {
    input.peekFully(scratch.data, 0, 5);
    scratch.setPosition(0);
    int syncBytes = scratch.readUnsignedShort();
    if (syncBytes != AC3_SYNC_WORD) {
      validFramesCount = 0;
      input.resetPeekPosition();
      if (++headerPosition - startPosition >= MAX_SNIFF_BYTES) {
        return false;
      }
      input.advancePeekPosition(headerPosition);
    } else {
      if (++validFramesCount >= 4) {
        return true;
      }
      int frameSize = Ac3Util.parseAc3SyncframeSize(scratch.data);
      if (frameSize == C.LENGTH_UNSET) {
        return false;
      }
      input.advancePeekPosition(frameSize - 5);
    }
  }
}