Java MimeTypes.AUDIO_AAC属性代码示例

private static String fourCCToMimeType(String fourCC) {
  if (fourCC.equalsIgnoreCase("H264") || fourCC.equalsIgnoreCase("X264")
      || fourCC.equalsIgnoreCase("AVC1") || fourCC.equalsIgnoreCase("DAVC")) {
    return MimeTypes.VIDEO_H264;
  } else if (fourCC.equalsIgnoreCase("AAC") || fourCC.equalsIgnoreCase("AACL")
      || fourCC.equalsIgnoreCase("AACH") || fourCC.equalsIgnoreCase("AACP")) {
    return MimeTypes.AUDIO_AAC;
  } else if (fourCC.equalsIgnoreCase("TTML")) {
    return MimeTypes.APPLICATION_TTML;
  } else if (fourCC.equalsIgnoreCase("ac-3") || fourCC.equalsIgnoreCase("dac3")) {
    return MimeTypes.AUDIO_AC3;
  } else if (fourCC.equalsIgnoreCase("ec-3") || fourCC.equalsIgnoreCase("dec3")) {
    return MimeTypes.AUDIO_E_AC3;
  } else if (fourCC.equalsIgnoreCase("dtsc")) {
    return MimeTypes.AUDIO_DTS;
  } else if (fourCC.equalsIgnoreCase("dtsh") || fourCC.equalsIgnoreCase("dtsl")) {
    return MimeTypes.AUDIO_DTS_HD;
  } else if (fourCC.equalsIgnoreCase("dtse")) {
    return MimeTypes.AUDIO_DTS_EXPRESS;
  } else if (fourCC.equalsIgnoreCase("opus")) {
    return MimeTypes.AUDIO_OPUS;
  }
  return null;
}
 

/**
 * Returns FFmpeg-compatible codec-specific initialization data ("extra data"), or {@code null} if
 * not required.
 */
private static byte[] getExtraData(String mimeType, List<byte[]> initializationData) {
  switch (mimeType) {
    case MimeTypes.AUDIO_AAC:
    case MimeTypes.AUDIO_OPUS:
      return initializationData.get(0);
    case MimeTypes.AUDIO_VORBIS:
      byte[] header0 = initializationData.get(0);
      byte[] header1 = initializationData.get(1);
      byte[] extraData = new byte[header0.length + header1.length + 6];
      extraData[0] = (byte) (header0.length >> 8);
      extraData[1] = (byte) (header0.length & 0xFF);
      System.arraycopy(header0, 0, extraData, 2, header0.length);
      extraData[header0.length + 2] = 0;
      extraData[header0.length + 3] = 0;
      extraData[header0.length + 4] =  (byte) (header1.length >> 8);
      extraData[header0.length + 5] = (byte) (header1.length & 0xFF);
      System.arraycopy(header1, 0, extraData, header0.length + 6, header1.length);
      return extraData;
    default:
      // Other codecs do not require extra data.
      return null;
  }
}
 

/**
 * Returns the name of the FFmpeg decoder that could be used to decode {@code mimeType}.
 */
/* package */ static String getCodecName(String mimeType) {
  switch (mimeType) {
    case MimeTypes.AUDIO_AAC:
      return "aac";
    case MimeTypes.AUDIO_MPEG:
    case MimeTypes.AUDIO_MPEG_L1:
    case MimeTypes.AUDIO_MPEG_L2:
      return "mp3";
    case MimeTypes.AUDIO_AC3:
      return "ac3";
    case MimeTypes.AUDIO_E_AC3:
      return "eac3";
    case MimeTypes.AUDIO_TRUEHD:
      return "truehd";
    case MimeTypes.AUDIO_DTS:
    case MimeTypes.AUDIO_DTS_HD:
      return "dca";
    case MimeTypes.AUDIO_VORBIS:
      return "vorbis";
    case MimeTypes.AUDIO_OPUS:
      return "opus";
    case MimeTypes.AUDIO_AMR_NB:
      return "amrnb";
    case MimeTypes.AUDIO_AMR_WB:
      return "amrwb";
    case MimeTypes.AUDIO_FLAC:
      return "flac";
    default:
      return null;
  }
}
 

/**
 * Returns codec-specific initialization data contained in an esds box.
 */
private static Pair<String, byte[]> parseEsdsFromParent(ParsableByteArray parent, int position) {
  parent.setPosition(position + Atom.HEADER_SIZE + 4);
  // Start of the ES_Descriptor (defined in 14496-1)
  parent.skipBytes(1); // ES_Descriptor tag
  parseExpandableClassSize(parent);
  parent.skipBytes(2); // ES_ID

  int flags = parent.readUnsignedByte();
  if ((flags & 0x80 /* streamDependenceFlag */) != 0) {
    parent.skipBytes(2);
  }
  if ((flags & 0x40 /* URL_Flag */) != 0) {
    parent.skipBytes(parent.readUnsignedShort());
  }
  if ((flags & 0x20 /* OCRstreamFlag */) != 0) {
    parent.skipBytes(2);
  }

  // Start of the DecoderConfigDescriptor (defined in 14496-1)
  parent.skipBytes(1); // DecoderConfigDescriptor tag
  parseExpandableClassSize(parent);

  // Set the MIME type based on the object type indication (14496-1 table 5).
  int objectTypeIndication = parent.readUnsignedByte();
  String mimeType;
  switch (objectTypeIndication) {
    case 0x6B:
      mimeType = MimeTypes.AUDIO_MPEG;
      return Pair.create(mimeType, null);
    case 0x20:
      mimeType = MimeTypes.VIDEO_MP4V;
      break;
    case 0x21:
      mimeType = MimeTypes.VIDEO_H264;
      break;
    case 0x23:
      mimeType = MimeTypes.VIDEO_H265;
      break;
    case 0x40:
    case 0x66:
    case 0x67:
    case 0x68:
      mimeType = MimeTypes.AUDIO_AAC;
      break;
    case 0xA5:
      mimeType = MimeTypes.AUDIO_AC3;
      break;
    case 0xA6:
      mimeType = MimeTypes.AUDIO_E_AC3;
      break;
    case 0xA9:
    case 0xAC:
      mimeType = MimeTypes.AUDIO_DTS;
      return Pair.create(mimeType, null);
    case 0xAA:
    case 0xAB:
      mimeType = MimeTypes.AUDIO_DTS_HD;
      return Pair.create(mimeType, null);
    default:
      mimeType = null;
      break;
  }

  parent.skipBytes(12);

  // Start of the AudioSpecificConfig.
  parent.skipBytes(1); // AudioSpecificConfig tag
  int initializationDataSize = parseExpandableClassSize(parent);
  byte[] initializationData = new byte[initializationDataSize];
  parent.readBytes(initializationData, 0, initializationDataSize);
  return Pair.create(mimeType, initializationData);
}