public void Index()
{
var buffer = new BlockBuffer <byte>(100);
var bytes = new byte[100];
buffer.Write(bytes);
buffer.Read(50);
buffer.ResetIndex();
Assert.AreEqual(buffer.WritePosition, 50);
Assert.AreEqual(buffer.ReadPosition, 0);
}
public void Read()
{
var buffer = new BlockBuffer <byte>();
var buffer2 = new BlockBuffer <int>();
var bytes = new byte[100];
buffer.Write(bytes);
buffer.Read(50);
Assert.AreEqual(buffer.WritePosition, 100);
Assert.AreEqual(buffer.ReadPosition, 50);
}
protected override void Unpack(BlockBuffer <byte> bytes, Action <byte[]> onUnpacked)
{
//Because header is int and cost 4 byte
while (bytes.WritePosition > 4)
{
int length = BitConverter.ToInt32(bytes.Buffer, 0);
//If receive body
if (bytes.WritePosition >= 4 + length)
{
bytes.MoveReadPostion(4);
var data = bytes.Read(length);
//Notice unpack finished
onUnpacked(data);
bytes.ResetIndex();
}
}
}
/// <summary>
/// Reads an E-AC-3 header from a bitstream.
/// </summary>
/// <remarks>Has to read a calculated number of bytes from the source stream.</remarks>
/// <returns>A <see cref="BitExtractor"/> that continues at the beginning of the audio frame.</returns>
public BitExtractor Decode(BlockBuffer <byte> reader)
{
BitExtractor extractor = new BitExtractor(reader.Read(mustDecode));
if (!extractor.Readable)
{
return(extractor);
}
if (extractor.Read(16) != syncWord)
{
throw new SyncException();
}
StreamType = (StreamTypes)extractor.Read(2);
SubstreamID = extractor.Read(3);
WordsPerSyncframe = extractor.Read(11) + 1;
SampleRateCode = extractor.Read(2);
Blocks = numberOfBlocks[extractor.Read(2)];
ChannelMode = extractor.Read(3);
LFE = extractor.ReadBit();
Decoder = ParseDecoder(extractor.Read(5));
if (Decoder != EnhancedAC3.Decoders.EAC3)
{
StreamType = StreamTypes.Repackaged;
SubstreamID = 0;
Blocks = 6;
SampleRateCode = extractor[4] >> 6;
frmsizecod = extractor[4] & 63;
WordsPerSyncframe = frameSizes[frmsizecod >> 1];
if (SampleRateCode == 1) // 44.1 kHz
{
WordsPerSyncframe = WordsPerSyncframe * 1393 / 1280;
if ((frmsizecod & 1) == 1)
{
++WordsPerSyncframe;
}
}
else if (SampleRateCode == 2)
{
WordsPerSyncframe = WordsPerSyncframe * 3 / 2;
}
bsmod = extractor.Read(3);
ChannelMode = extractor.Read(3);
}
extractor.Expand(reader.Read(WordsPerSyncframe * 2 - mustDecode));
if (StreamType == StreamTypes.Dependent)
{
SubstreamID += 8; // There can be 8 dependent and independent substreams, both start at 0
}
if (StreamType == StreamTypes.Reserved)
{
throw new ReservedValueException("strmtyp");
}
if (SampleRateCode == 3)
{
throw new ReservedValueException("fscod");
}
SampleRate = sampleRates[SampleRateCode];
channelMapping = null;
switch (Decoder)
{
case EnhancedAC3.Decoders.AlternateAC3:
case EnhancedAC3.Decoders.AC3:
BitStreamInformation(extractor);
break;
case EnhancedAC3.Decoders.EAC3:
BitStreamInformationEAC3(extractor);
break;
}
return(extractor);
}
