private IEnumerator <int> ReadResidualData(FlacBitStreamReader bitReader, int blockSize, int predictorOrder)
{
const byte RiceCodingWith4BitParameter = 0;
const byte RiceCodingWith5BitParameter = 1;
uint residualRiceParamSizeType = bitReader.ReadBits(2);
int residualRiceParamSize;
if (residualRiceParamSizeType == RiceCodingWith4BitParameter)
{
residualRiceParamSize = 4;
}
else if (residualRiceParamSizeType == RiceCodingWith5BitParameter)
{
residualRiceParamSize = 5;
}
else
{
throw new FlacException("Reserved residual coding method");
}
// rice and rice2 almost the same
// read rice partitined method
int partitionOrder = (int)bitReader.ReadBits(4);
int partitionCount = 1 << partitionOrder;
int sampleCount = blockSize >> partitionOrder;
if (sampleCount < predictorOrder || sampleCount < 1 ||
(sampleCount << partitionOrder) != blockSize)
{
throw new FlacException("Invalid partition order");
}
for (int i = 0; i < partitionCount; i++)
{
int skipSamples = i == 0 ? predictorOrder : 0;
int riceParameter = (int)bitReader.ReadBits(residualRiceParamSize);
if (riceParameter + 1 == 1 << residualRiceParamSize)
{
// escape mode
int bitsPerSample = (int)bitReader.ReadBits(5);
for (int j = skipSamples; j < sampleCount; j++)
{
yield return(bitReader.ReadSignedBits(bitsPerSample));
}
}
else
{
int maxRiceK = int.MaxValue >> riceParameter;
for (int j = skipSamples; j < sampleCount; j++)
{
yield return(bitReader.ReadRice(riceParameter));
}
}
}
}
private IEnumerable <int> ReadValuesVerbatim(FlacBitStreamReader bitReader, int blockSize, int bitsPerSample)
{
for (int i = 0; i < blockSize; i++)
{
int value = bitReader.ReadSignedBits(bitsPerSample);
yield return(value);
}
}
public byte[] ReadFrameRawData()
{
if (recordType != FlacRecordType.Frame)
{
throw new FlacException("Cannot read non-frame data");
}
MemoryStream ms = new MemoryStream();
ms.Write(lastFrameHeaderData, 0, lastFrameHeaderData.Length);
// replace bitReader
ushort currentCrc16 = bitReader.Complete();
bitReader = new FlacBitStreamReader(
new SinkedStream(BaseStream, ms), currentCrc16);
// read subframes
for (int i = 0; i < FrameChannelCount; i++)
{
ReadSubframe();
SkipSampleValues();
}
bitReader.Complete();
bitReader = null;
// read footer
byte[] crc16 = ReadExactly(2);
recordType = FlacRecordType.FrameFooter;
int frameDataLength = checked ((int)ms.Length);
ms.Write(crc16, 0, crc16.Length);
byte[] frameData = ms.ToArray();
// check CRC16
ushort dataCrc16 = CrcUtils.Crc16(0, frameData, 0, frameDataLength);
int footerCrc = (crc16[0] << 8) | crc16[1];
if (dataCrc16 != footerCrc)
{
throw new FlacException("Invalid frame footer CRC16");
}
return(frameData);
}
private void ReadFrameFooter()
{
ushort crc16 = bitReader.Complete();
bitReader = null;
byte[] data = ReadExactly(2);
int footerCrc16 = data[0] << 8 | data[1];
if (crc16 != footerCrc16)
{
throw new FlacException("Invalid frame footer CRC16");
}
subframeIndex = 0;
this.recordType = FlacRecordType.FrameFooter;
}
private void ReadFrame()
{
const int FrameHeaderLength = 2 + 1 + 1;
const int FrameSync = 0xFFF8;
const int FrameSyncMask = 0xFFFC;
const int ReservedBlockSizeSamplesType = 0;
const int InvalidSampleRateType = 15;
int read;
byte[] data = new byte[FrameHeaderLength];
if (recordType != FlacRecordType.Sync)
{
read = BaseStream.Read(data, 0, FrameHeaderLength);
if (read < FrameHeaderLength)
{
if (read <= 0)
{
recordType = FlacRecordType.Eof;
return;
}
throw new FlacException("Unexpected eof of stream: invalid frame header length");
}
if (((data[0] << 8 | data[1]) & FrameSyncMask) != FrameSync)
{
throw new FlacException("Frame sync is expected");
}
}
else
{
const int SyncReadLength = 2;
read = BaseStream.Read(data, SyncReadLength, FrameHeaderLength - SyncReadLength);
if (read + SyncReadLength < FrameHeaderLength)
{
throw new FlacException("Unexpected eof of stream: invalid frame header length");
}
data[0] = (byte)(FrameSync >> 8); data[1] = secondSyncByte;
}
if ((data[1] & 0x02) != 0)
{
throw new FlacException("Frame header reserved bit (15) shall not be 1");
}
this.variableBlockSize = (data[1] & 0x01) != 0;
int blockSizeSamplesType = data[2] >> 4;
if (blockSizeSamplesType == ReservedBlockSizeSamplesType)
{
throw new FlacException("Frame header block size samples shall not be set to reserved");
}
int previousBlockSize = this.blockSize;
this.blockSize = FlacCommons.StaticBlockSizeSamples[blockSizeSamplesType];
int sampleRateType = data[2] & 0x0F;
if (sampleRateType == InvalidSampleRateType)
{
throw new FlacException("Frame header sample rate type is invalid");
}
this.sampleRate = FlacCommons.StaticSampleRates[sampleRateType];
int channelAssignmentType = data[3] >> 4;
if (channelAssignmentType >= FlacCommons.StaticChannelAssignments.Length)
{
throw new FlacException("Frame header channel assignments are defined as reserved");
}
this.channelAssignmentType = (SoundChannelAssignmentType)channelAssignmentType;
this.channelAssignment = FlacCommons.StaticChannelAssignments[channelAssignmentType];
if (channelAssignment == null)
{
throw new FlacException("Frame header channel assignment are not defined");
}
this.channelCount = channelAssignment.Length;
int sampleSizeInBitsType = (data[3] >> 1) & 0x07;
if (sampleSizeInBitsType == FlacCommons.StreaminfoSizeInBitsType)
{
this.sampleSizeInBits = Streaminfo.BitsPerSample;
}
else if (FlacCommons.StaticSampleSizeInBits[sampleSizeInBitsType] > 0)
{
this.sampleSizeInBits = FlacCommons.StaticSampleSizeInBits[sampleSizeInBitsType];
}
else
{
throw new FlacException("Frame header sample size is defined as reserved");
}
if ((data[3] & 1) != 0)
{
throw new FlacException("Frame header reserved bit (31) shall not be 1");
}
MemoryStream ms = new MemoryStream(20);
ms.Write(data, 0, FrameHeaderLength);
byte[] numberData;
if (variableBlockSize)
{
ReadUtf8Number(out this.sampleNumber, out numberData);
if (numberData.Length > 7)
{
throw new FlacException("Invalid variable block size");
}
}
else
{
ReadUtf8Number(out this.frameNumber, out numberData);
if (numberData.Length > 6)
{
throw new FlacException("Invalid frame number");
}
this.sampleNumber = this.frameNumber == 0 ? 0 :
previousBlockSize *this.frameNumber;
}
ms.Write(numberData, 0, numberData.Length);
byte[] blockSizeData = null;
switch (blockSizeSamplesType)
{
case FlacCommons.Bit8BlockSizeSamplesType:
blockSizeData = ReadExactly(1);
this.blockSize = (int)blockSizeData[0] + 1;
break;
case FlacCommons.Bit16BlockSizeSamplesType:
blockSizeData = ReadExactly(2);
this.blockSize = (blockSizeData[0] << 8 | blockSizeData[1]) + 1;
break;
}
if (blockSizeData != null)
{
ms.Write(blockSizeData, 0, blockSizeData.Length);
}
byte[] sampleRateData = null;
switch (sampleRateType)
{
case FlacCommons.StreaminfoSampleRateType:
this.sampleRate = Streaminfo.SampleRate;
break;
case FlacCommons.Bit8SampleRateType:
sampleRateData = ReadExactly(1);
this.sampleRate = sampleRateData[0];
break;
case FlacCommons.Bit16SampleRateType:
sampleRateData = ReadExactly(2);
this.sampleRate = sampleRateData[0] << 8 | sampleRateData[1];
break;
case FlacCommons.Bit16Mult10SampleRateType:
sampleRateData = ReadExactly(2);
this.sampleRate = (sampleRateData[0] << 8 | sampleRateData[1]) * 10;
break;
}
if (sampleRateData != null)
{
ms.Write(sampleRateData, 0, sampleRateData.Length);
}
byte[] readData = ms.ToArray();
byte crc8 = CrcUtils.Crc8(0, readData);
int headerCrc8 = BaseStream.ReadByte();
if (headerCrc8 < 0)
{
throw new FlacException("Unexpected end of stream: frame CRC8 expected");
}
else if (crc8 != headerCrc8)
{
throw new FlacException("Invalid frame CRC");
}
ushort currentCrc16 = CrcUtils.Crc16(
CrcUtils.Crc16(0, readData), (byte)headerCrc8);
bitReader = new FlacBitStreamReader(BaseStream, currentCrc16);
lastFrameHeaderData = new byte[readData.Length + 1];
Array.Copy(readData, lastFrameHeaderData, readData.Length);
lastFrameHeaderData[readData.Length] = crc8;
recordType = FlacRecordType.Frame;
}
private IEnumerable<int> ReadValuesVerbatim(FlacBitStreamReader bitReader, int blockSize, int bitsPerSample)
{
for (int i = 0; i < blockSize; i++)
{
int value = bitReader.ReadSignedBits(bitsPerSample);
yield return value;
}
}
private IEnumerator<int> ReadResidualData(FlacBitStreamReader bitReader, int blockSize, int predictorOrder)
{
const byte RiceCodingWith4BitParameter = 0;
const byte RiceCodingWith5BitParameter = 1;
uint residualRiceParamSizeType = bitReader.ReadBits(2);
int residualRiceParamSize;
if (residualRiceParamSizeType == RiceCodingWith4BitParameter)
residualRiceParamSize = 4;
else if (residualRiceParamSizeType == RiceCodingWith5BitParameter)
residualRiceParamSize = 5;
else
throw new FlacException("Reserved residual coding method");
// rice and rice2 almost the same
// read rice partitined method
int partitionOrder = (int)bitReader.ReadBits(4);
int partitionCount = 1 << partitionOrder;
int sampleCount = blockSize >> partitionOrder;
if (sampleCount < predictorOrder || sampleCount < 1 ||
(sampleCount << partitionOrder) != blockSize )
throw new FlacException("Invalid partition order");
for (int i = 0; i < partitionCount; i++)
{
int skipSamples = i == 0 ? predictorOrder : 0;
int riceParameter = (int)bitReader.ReadBits(residualRiceParamSize);
if (riceParameter + 1 == 1 << residualRiceParamSize)
{
// escape mode
int bitsPerSample = (int)bitReader.ReadBits(5);
for (int j = skipSamples; j < sampleCount; j++)
{
yield return bitReader.ReadSignedBits(bitsPerSample);
}
}
else
{
int maxRiceK = int.MaxValue >> riceParameter;
for (int j = skipSamples; j < sampleCount; j++)
{
yield return bitReader.ReadRice(riceParameter);
}
}
}
}
private void ReadFrameFooter()
{
ushort crc16 = bitReader.Complete();
bitReader = null;
byte[] data = ReadExactly(2);
int footerCrc16 = data[0] << 8 | data[1];
if (crc16 != footerCrc16)
throw new FlacException("Invalid frame footer CRC16");
subframeIndex = 0;
this.recordType = FlacRecordType.FrameFooter;
}
private void ReadFrame()
{
const int FrameHeaderLength = 2 + 1 + 1;
const int FrameSync = 0xFFF8;
const int FrameSyncMask = 0xFFFC;
const int ReservedBlockSizeSamplesType = 0;
const int InvalidSampleRateType = 15;
int read;
byte[] data = new byte[FrameHeaderLength];
if (recordType != FlacRecordType.Sync)
{
read = BaseStream.Read(data, 0, FrameHeaderLength);
if (read < FrameHeaderLength)
{
if (read <= 0)
{
recordType = FlacRecordType.Eof;
return;
}
throw new FlacException("Unexpected eof of stream: invalid frame header length");
}
if (((data[0] << 8 | data[1]) & FrameSyncMask) != FrameSync)
throw new FlacException("Frame sync is expected");
}
else
{
const int SyncReadLength = 2;
read = BaseStream.Read(data, SyncReadLength, FrameHeaderLength - SyncReadLength);
if(read + SyncReadLength < FrameHeaderLength)
throw new FlacException("Unexpected eof of stream: invalid frame header length");
data[0] = (byte)(FrameSync >> 8); data[1] = secondSyncByte;
}
if((data[1] & 0x02) != 0)
throw new FlacException("Frame header reserved bit (15) shall not be 1");
this.variableBlockSize = (data[1] & 0x01) != 0;
int blockSizeSamplesType = data[2] >> 4;
if(blockSizeSamplesType == ReservedBlockSizeSamplesType)
throw new FlacException("Frame header block size samples shall not be set to reserved");
int previousBlockSize = this.blockSize;
this.blockSize = FlacCommons.StaticBlockSizeSamples[blockSizeSamplesType];
int sampleRateType = data[2] & 0x0F;
if(sampleRateType == InvalidSampleRateType)
throw new FlacException("Frame header sample rate type is invalid");
this.sampleRate = FlacCommons.StaticSampleRates[sampleRateType];
int channelAssignmentType = data[3] >> 4;
if (channelAssignmentType >= FlacCommons.StaticChannelAssignments.Length)
throw new FlacException("Frame header channel assignments are defined as reserved");
this.channelAssignmentType = (SoundChannelAssignmentType)channelAssignmentType;
this.channelAssignment = FlacCommons.StaticChannelAssignments[channelAssignmentType];
if (channelAssignment == null)
throw new FlacException("Frame header channel assignment are not defined");
this.channelCount = channelAssignment.Length;
int sampleSizeInBitsType = (data[3] >> 1) & 0x07;
if (sampleSizeInBitsType == FlacCommons.StreaminfoSizeInBitsType)
this.sampleSizeInBits = Streaminfo.BitsPerSample;
else if (FlacCommons.StaticSampleSizeInBits[sampleSizeInBitsType] > 0)
this.sampleSizeInBits = FlacCommons.StaticSampleSizeInBits[sampleSizeInBitsType];
else
throw new FlacException("Frame header sample size is defined as reserved");
if((data[3] & 1) != 0)
throw new FlacException("Frame header reserved bit (31) shall not be 1");
MemoryStream ms = new MemoryStream(20);
ms.Write(data, 0, FrameHeaderLength);
byte[] numberData;
if (variableBlockSize)
{
ReadUtf8Number(out this.sampleNumber, out numberData);
if (numberData.Length > 7)
throw new FlacException("Invalid variable block size");
}
else
{
ReadUtf8Number(out this.frameNumber, out numberData);
if (numberData.Length > 6)
throw new FlacException("Invalid frame number");
this.sampleNumber = this.frameNumber == 0 ? 0 :
previousBlockSize * this.frameNumber;
}
ms.Write(numberData, 0, numberData.Length);
byte[] blockSizeData = null;
switch (blockSizeSamplesType)
{
case FlacCommons.Bit8BlockSizeSamplesType:
blockSizeData = ReadExactly(1);
this.blockSize = (int)blockSizeData[0] + 1;
break;
case FlacCommons.Bit16BlockSizeSamplesType:
blockSizeData = ReadExactly(2);
this.blockSize = (blockSizeData[0] << 8 | blockSizeData[1]) + 1;
break;
}
if(blockSizeData != null)
ms.Write(blockSizeData, 0, blockSizeData.Length);
byte[] sampleRateData = null;
switch (sampleRateType)
{
case FlacCommons.StreaminfoSampleRateType:
this.sampleRate = Streaminfo.SampleRate;
break;
case FlacCommons.Bit8SampleRateType:
sampleRateData = ReadExactly(1);
this.sampleRate = sampleRateData[0];
break;
case FlacCommons.Bit16SampleRateType:
sampleRateData = ReadExactly(2);
this.sampleRate = sampleRateData[0] << 8 | sampleRateData[1];
break;
case FlacCommons.Bit16Mult10SampleRateType:
sampleRateData = ReadExactly(2);
this.sampleRate = (sampleRateData[0] << 8 | sampleRateData[1]) * 10;
break;
}
if (sampleRateData != null)
ms.Write(sampleRateData, 0, sampleRateData.Length);
byte[] readData = ms.ToArray();
byte crc8 = CrcUtils.Crc8(0, readData);
int headerCrc8 = BaseStream.ReadByte();
if (headerCrc8 < 0)
throw new FlacException("Unexpected end of stream: frame CRC8 expected");
else if(crc8 != headerCrc8)
throw new FlacException("Invalid frame CRC");
ushort currentCrc16 = CrcUtils.Crc16(
CrcUtils.Crc16(0, readData), (byte)headerCrc8);
bitReader = new FlacBitStreamReader(BaseStream, currentCrc16);
lastFrameHeaderData = new byte[readData.Length + 1];
Array.Copy(readData, lastFrameHeaderData, readData.Length);
lastFrameHeaderData[readData.Length] = crc8;
recordType = FlacRecordType.Frame;
}
public byte[] ReadFrameRawData()
{
if(recordType != FlacRecordType.Frame)
throw new FlacException("Cannot read non-frame data");
MemoryStream ms = new MemoryStream();
ms.Write(lastFrameHeaderData, 0, lastFrameHeaderData.Length);
// replace bitReader
ushort currentCrc16 = bitReader.Complete();
bitReader = new FlacBitStreamReader(
new SinkedStream(BaseStream, ms), currentCrc16);
// read subframes
for (int i = 0; i < FrameChannelCount; i++)
{
ReadSubframe();
SkipSampleValues();
}
bitReader.Complete();
bitReader = null;
// read footer
byte[] crc16 = ReadExactly(2);
recordType = FlacRecordType.FrameFooter;
int frameDataLength = checked((int)ms.Length);
ms.Write(crc16, 0, crc16.Length);
byte[] frameData = ms.ToArray();
// check CRC16
ushort dataCrc16 = CrcUtils.Crc16(0, frameData, 0, frameDataLength);
int footerCrc = (crc16[0] << 8) | crc16[1];
if(dataCrc16 != footerCrc)
throw new FlacException("Invalid frame footer CRC16");
return frameData;
}