private int ReadByte()
{
int i = BaseStream.ReadByte();
if (i < 0)
{
throw new FlacException("Unexpected end of stream: bit reader needs data");
}
crc16 = CrcUtils.Crc16(crc16, (byte)i);
return(i);
}
private void WriteFullFrame(byte[] buffer, int offset, int count, bool lastFrame, bool overflow)
{
// TODO add logic for "overflow" pages
int segments = (count + 254) / 255;
byte[] frameHeader = new byte[27 + segments];
Array.Copy(OggHeader, frameHeader, OggHeader.Length);
frameHeader[4] = 0x00;
int frameType = 0;
if (!isFirstFrameWitten)
{
frameType |= FirstPageFlag;
isFirstFrameWitten = true;
}
if (lastFrame)
{
frameType |= LastPageFlag;
isLastFrameWritten = true;
}
frameHeader[5] = (byte)frameType;
Array.Copy(BitConverter.GetBytes(position), 0, frameHeader, 6, 8);
Array.Copy(BitConverter.GetBytes(streamId), 0, frameHeader, 14, 4);
Array.Copy(BitConverter.GetBytes(pageNumber), 0, frameHeader, 18, 4);
// 22 - 26 crc32
frameHeader[26] = (byte)segments;
for (int i = 0; i < segments - 1; i++)
{
frameHeader[27 + i] = 255;
}
frameHeader[27 + segments - 1] = (byte)(count - (segments - 1) * 255);
uint crc32 = CrcUtils.Crc32(0, frameHeader);
crc32 = CrcUtils.Crc32(crc32, buffer, offset, count);
Array.Copy(BitConverter.GetBytes(crc32), 0, frameHeader, 22, 4);
baseStream.Write(frameHeader, 0, frameHeader.Length);
baseStream.Write(buffer, offset, count);
pageNumber++;
position += (ulong)count;
}
private void WriteByte(byte b)
{
baseStream.WriteByte(b);
crc16 = CrcUtils.Crc16(crc16, b);
++count;
}
public void WriteFrame(FlacMethodAndDataPair[] methods, SoundChannelAssignmentType channelAssignment)
{
EnsureFramesMode();
sink.StartFrame(streamPosition, currentSample);
if (methods == null)
{
throw new ArgumentNullException("methods");
}
if (methods.Length != Streaminfo.ChannelsCount)
{
throw new ArgumentNullException("Methods items does not correspond to amount of channels");
}
int samplesCount = methods[0].Data.Length;
const byte Blocking = 0x00; // fixed
MemoryStream frameHeader = new MemoryStream();
// sync code + reserved = 0 + blocking
frameHeader.WriteByte(0xFF); frameHeader.WriteByte(0xF8 | Blocking);
int interChannelSamplesTypeIndex = Array.IndexOf(FlacCommons.StaticBlockSizeSamples, samplesCount);
int interChannelSamplesType;
if (interChannelSamplesTypeIndex > 0)
{
interChannelSamplesType = interChannelSamplesTypeIndex;
}
else if (samplesCount > 256)
{
interChannelSamplesType = FlacCommons.Bit16BlockSizeSamplesType;
}
else
{
interChannelSamplesType = FlacCommons.Bit8BlockSizeSamplesType;
}
int sampleRateTypeIndex = Array.IndexOf(FlacCommons.StaticSampleRates, Streaminfo.SampleRate);
int sampleRateType = sampleRateTypeIndex > 0
? sampleRateTypeIndex : FlacCommons.StreaminfoSampleRateType;
frameHeader.WriteByte((byte)(interChannelSamplesType << 4 | sampleRateType));
int channelAssignmetType = (int)channelAssignment;
int sampleSizeInBitsTypeIndex = Array.IndexOf(FlacCommons.StaticSampleSizeInBits, Streaminfo.BitsPerSample);
int sampleSizeInBitsType = sampleSizeInBitsTypeIndex > 0
? sampleSizeInBitsTypeIndex : FlacCommons.StreaminfoSizeInBitsType;
frameHeader.WriteByte((byte)(channelAssignmetType << 4 | sampleSizeInBitsType << 1));
WriteUtf8Number(frameHeader, frameNumber);
switch (interChannelSamplesType)
{
case FlacCommons.Bit8BlockSizeSamplesType:
frameHeader.WriteByte((byte)(samplesCount - 1)); break;
case FlacCommons.Bit16BlockSizeSamplesType:
frameHeader.WriteByte((byte)((samplesCount - 1) >> 8));
frameHeader.WriteByte((byte)(samplesCount - 1));
break;
}
frameHeader.Dispose();
byte[] frameHeaderData = frameHeader.ToArray();
byte crc8 = CrcUtils.Crc8(0, frameHeaderData);
BaseStream.Write(frameHeaderData, 0, frameHeaderData.Length);
BaseStream.WriteByte(crc8);
++frameNumber;
ushort crc16Seed = CrcUtils.Crc16(CrcUtils.Crc16(0, frameHeaderData), crc8);
// write channels
FlacBitStreamWriter bitWriter = new FlacBitStreamWriter(BaseStream, crc16Seed);
for (int i = 0; i < methods.Length; i++)
{
WriteSubframe(bitWriter, methods[i]);
}
int subframesLength;
ushort crc16;
bitWriter.Complete(out crc16, out subframesLength);
// write footer
BaseStream.WriteByte((byte)(crc16 >> 8)); BaseStream.WriteByte((byte)crc16);
int frameSize = frameHeaderData.Length + 1 + subframesLength + 2;
streamPosition += frameSize;
currentSample += samplesCount;
sink.EndFrame(streamPosition, currentSample);
}
private static uint Crc32(uint seed, byte[] data)
{
return(CrcUtils.Crc32(seed, data));
}
