Java 类com.google.android.exoplayer2.text.cea.Cea608Decoder 实例源码

@Override
public SubtitleDecoder createDecoder(Format format) {
  switch (format.sampleMimeType) {
    case MimeTypes.TEXT_VTT:
      return new WebvttDecoder();
    case MimeTypes.APPLICATION_MP4VTT:
      return new Mp4WebvttDecoder();
    case MimeTypes.APPLICATION_TTML:
      return new TtmlDecoder();
    case MimeTypes.APPLICATION_SUBRIP:
      return new SubripDecoder();
    case MimeTypes.APPLICATION_TX3G:
      return new Tx3gDecoder(format.initializationData);
    case MimeTypes.APPLICATION_CEA608:
    case MimeTypes.APPLICATION_MP4CEA608:
      return new Cea608Decoder(format.sampleMimeType, format.accessibilityChannel);
    case MimeTypes.APPLICATION_CEA708:
      return new Cea708Decoder(format.accessibilityChannel);
    case MimeTypes.APPLICATION_DVBSUBS:
      return new DvbDecoder(format.initializationData);
    default:
      throw new IllegalArgumentException("Attempted to create decoder for unsupported format");
  }
}

@Override
public SubtitleDecoder createDecoder(Format format) {
  switch (format.sampleMimeType) {
    case MimeTypes.TEXT_VTT:
      return new WebvttDecoder();
    case MimeTypes.TEXT_SSA:
      return new SsaDecoder(format.initializationData);
    case MimeTypes.APPLICATION_MP4VTT:
      return new Mp4WebvttDecoder();
    case MimeTypes.APPLICATION_TTML:
      return new TtmlDecoder();
    case MimeTypes.APPLICATION_SUBRIP:
      return new SubripDecoder();
    case MimeTypes.APPLICATION_TX3G:
      return new Tx3gDecoder(format.initializationData);
    case MimeTypes.APPLICATION_CEA608:
    case MimeTypes.APPLICATION_MP4CEA608:
      return new Cea608Decoder(format.sampleMimeType, format.accessibilityChannel);
    case MimeTypes.APPLICATION_CEA708:
      return new Cea708Decoder(format.accessibilityChannel);
    case MimeTypes.APPLICATION_DVBSUBS:
      return new DvbDecoder(format.initializationData);
    default:
      throw new IllegalArgumentException("Attempted to create decoder for unsupported format");
  }
}

public void consume(long pesTimeUs, ParsableByteArray seiBuffer) {
  int b;
  while (seiBuffer.bytesLeft() > 1 /* last byte will be rbsp_trailing_bits */) {
    // Parse payload type.
    int payloadType = 0;
    do {
      b = seiBuffer.readUnsignedByte();
      payloadType += b;
    } while (b == 0xFF);
    // Parse payload size.
    int payloadSize = 0;
    do {
      b = seiBuffer.readUnsignedByte();
      payloadSize += b;
    } while (b == 0xFF);
    // Process the payload.
    if (Cea608Decoder.isSeiMessageCea608(payloadType, payloadSize, seiBuffer)) {
      // Ignore country_code (1) + provider_code (2) + user_identifier (4)
      // + user_data_type_code (1).
      seiBuffer.skipBytes(8);
      // Ignore first three bits: reserved (1) + process_cc_data_flag (1) + zero_bit (1).
      int ccCount = seiBuffer.readUnsignedByte() & 0x1F;
      seiBuffer.skipBytes(1);
      int sampleBytes = 0;
      for (int i = 0; i < ccCount; i++) {
        int ccValidityAndType = seiBuffer.peekUnsignedByte() & 0x07;
        // Check that validity == 1 and type == 0 (i.e. NTSC_CC_FIELD_1).
        if (ccValidityAndType != 0x04) {
          seiBuffer.skipBytes(3);
        } else {
          sampleBytes += 3;
          output.sampleData(seiBuffer, 3);
        }
      }
      output.sampleMetadata(pesTimeUs, C.BUFFER_FLAG_KEY_FRAME, sampleBytes, 0, null);
      // Ignore trailing information in SEI, if any.
      seiBuffer.skipBytes(payloadSize - (10 + ccCount * 3));
    } else {
      seiBuffer.skipBytes(payloadSize);
    }
  }
}