/// <summary>
/// Interprets the meta data block header.
/// </summary>
/// <param name="data"></param>
protected void ParseData(byte[] data) {
// Parses the 4 byte header data:
// Bit 1: Last-metadata-block flag: '1' if this block is the last metadata block before the audio blocks, '0' otherwise.
// Bit 2-8: Block Type,
// 0 : STREAMINFO
// 1 : PADDING
// 2 : APPLICATION
// 3 : SEEKTABLE
// 4 : VORBIS_COMMENT
// 5 : CUESHEET
// 6 : PICTURE
// 7-126 : reserved
// 127 : invalid, to avoid confusion with a frame sync code
// Next 3 bytes: Length (in bytes) of metadata to follow (does not include the size of the METADATA_BLOCK_HEADER)
this.isLastMetaDataBlock = BinaryDataHelper.GetBoolean(data, 0, 0);
typeID = data[0] & 0x7F;
switch (typeID) {
case 0:
this.type = MetadataBlockType.StreamInfo;
this.metaDataBlockLength = 34;
break;
case 1:
this.type = MetadataBlockType.Padding;
break;
case 2:
this.type = MetadataBlockType.Application;
break;
case 3:
this.type = MetadataBlockType.Seektable;
break;
case 4:
this.type = MetadataBlockType.VorbisComment;
break;
case 5:
this.type = MetadataBlockType.CueSheet;
break;
case 6:
this.type = MetadataBlockType.Picture;
break;
}
if (typeID > 6 && typeID < 127) {
this.type = MetadataBlockType.None;
} else if(typeID >= 127) {
this.type = MetadataBlockType.Invalid;
}
this.metaDataBlockLength = (BinaryDataHelper.GetUInt24(data, 1));
}
/// <summary>
/// Loads a new stream info block from the provided data.
/// </summary>
/// <param name="data"></param>
public override void LoadBlockData(byte[] data)
{
// "All numbers are big-endian coded and unsigned".
// 1: Minimum Block Size (first 16-bit)
this.minimumBlockSize = BinaryDataHelper.GetUInt16(data, 0);
this.maximumBlockSize = BinaryDataHelper.GetUInt16(data, 2);
this.minimumFrameSize = BinaryDataHelper.GetUInt24(data, 4);
this.maximumFrameSize = BinaryDataHelper.GetUInt24(data, 7);
// Interpret 20 bits starting from byte 10 as a UInt
this.sampleRateHz = (UInt32)BinaryDataHelper.GetUInt64(data, 10, 20);
this.channels = (short)(BinaryDataHelper.GetUInt64(data, 12, 3, 4) + 1);
this.bitsPerSample = (short)(BinaryDataHelper.GetUInt64(data, 12, 5, 7) + 1);
this.samples = (long)BinaryDataHelper.GetUInt64(data, 13, 36, 4);
this.md5Signature = new byte[16];
Array.Copy(data, 18, this.md5Signature, 0, 16);
}