private void Decode(Stream stream, FlacMetadataStreamInfo streamInfo)
{
Header = new FlacFrameHeader(stream, streamInfo);
_stream = stream;
_streamInfo = streamInfo;
HasError = Header.HasError;
if (!HasError)
{
ReadSubFrames();
FreeBuffers();
}
}
public unsafe FlacSubFrameFixed(FlacBitReader reader, FlacFrameHeader header, FlacSubFrameData data, int bitsPerSample, int order)
: base(header)
{
for (int i = 0; i < order; i++) //order = predictor order
{
data.ResidualBuffer[i] = data.DestinationBuffer[i] = reader.ReadBitsSigned(bitsPerSample);
}
var residual = new FlacResidual(reader, header, data, order); //necessary for decoding
RestoreSignal(data, header.BlockSize - order, order);
#if FLAC_DEBUG
Residual = residual;
#endif
}
/// <summary>
/// Indicates whether the format of the current <see cref="FlacFrameHeader"/> is equal to the format of another <see cref="FlacFrameHeader"/>.
/// </summary>
/// <param name="other">A <see cref="FlacFrameHeader"/> which provides the format to compare with the format of the current <see cref="FlacFrameHeader"/>.</param>
/// <returns><c>true</c> if the format of the current <see cref="FlacFrameHeader"/> is equal to the format of the <paramref name="other"/> <see cref="FlacFrameHeader"/>.</returns>
public bool IsFormatEqualTo(FlacFrameHeader other)
{
return(BitsPerSample == other.BitsPerSample &&
Channels == other.Channels &&
SampleRate == other.SampleRate);
}
protected FlacSubFrameBase(FlacFrameHeader header)
{
#if FLAC_DEBUG
Header = header;
#endif
}
public unsafe static FlacSubFrameBase GetSubFrame(FlacBitReader reader, FlacSubFrameData data, FlacFrameHeader header, int bitsPerSample)
{
int wastedBits = 0, order;
uint firstByte = reader.ReadBits(8);
if ((firstByte & 0x80) != 0) //Zero bit padding, to prevent sync-fooling string of 1s
{
Debug.WriteLine("Flacdecoder subframe-header got no zero-bit padding.");
return(null);
}
bool hasWastedBits = (firstByte & 1) != 0; //Wasted bits-per-sample' flag
if (hasWastedBits)
{
int k = (int)reader.ReadUnary();
wastedBits = k + 1; //"k-1" follows -> add 1
bitsPerSample -= wastedBits;
}
FlacSubFrameBase subFrame;
var subframeType = (firstByte & 0x7E) >> 1; //0111 1110
if (subframeType == 0) //000000
{
subFrame = new FlacSubFrameConstant(reader, header, data, bitsPerSample);
}
else if (subframeType == 1) //000001
{
subFrame = new FlacSubFrameVerbatim(reader, header, data, bitsPerSample);
}
else if ((subframeType & 0x20) != 0) //100000 = 0x20
{
order = (int)(subframeType & 0x1F) + 1;
subFrame = new FlacSubFrameLPC(reader, header, data, bitsPerSample, order);
}
else if ((subframeType & 0x08) != 0) //001000 = 0x08
{
order = (int)(subframeType & 0x07);
if (order > 4)
{
return(null);
}
subFrame = new FlacSubFrameFixed(reader, header, data, bitsPerSample, order);
}
else
{
Debug.WriteLine(String.Format("Invalid Flac-SubframeType. SubframeType: 0x{0:x}.", subframeType));
return(null);
}
if (hasWastedBits)
{
int *destination = data.DestinationBuffer;
for (int i = 0; i < header.BlockSize; i++)
{
*(destination++) <<= wastedBits;
}
}
#if FLAC_DEBUG
subFrame.WastedBits = wastedBits;
#endif
return(subFrame);
}
private unsafe bool IsFrame(ref byte *buffer, FlacMetadataStreamInfo streamInfo, out FlacFrameHeader header)
{
header = new FlacFrameHeader(ref buffer, streamInfo, true, false);
return(!header.HasError);
}
private unsafe List <FlacFrameInformation> ScanThisShit(FlacMetadataStreamInfo streamInfo)
{
Stream stream = _stream;
//if (!(stream is BufferedStream))
// stream = new BufferedStream(stream);
byte[] buffer = new byte[BufferSize];
stream.Position = 4; //fLaC
//skip the metadata
FlacMetadata.SkipMetadata(stream);
List <FlacFrameInformation> frames = new List <FlacFrameInformation>();
FlacFrameInformation frameInfo = new FlacFrameInformation();
frameInfo.IsFirstFrame = true;
FlacFrameHeader baseHeader = null;
while (true)
{
int read = stream.Read(buffer, 0, buffer.Length);
if (read <= FlacConstant.FrameHeaderSize)
break;
fixed(byte *bufferPtr = buffer)
{
byte *ptr = bufferPtr;
//for (int i = 0; i < read - FlacConstant.FrameHeaderSize; i++)
while ((bufferPtr + read - FlacConstant.FrameHeaderSize) > ptr)
{
if (*ptr++ == 0xFF && (*ptr & 0xF8) == 0xF8) //check sync
{
byte *ptrSafe = ptr;
ptr--;
FlacFrameHeader tmp;
if (IsFrame(ref ptr, streamInfo, out tmp))
{
FlacFrameHeader header = tmp;
if (frameInfo.IsFirstFrame)
{
baseHeader = header;
frameInfo.IsFirstFrame = false;
}
if (baseHeader != null && baseHeader.IsFormatEqualTo(header))
{
frameInfo.StreamOffset = stream.Position - read + ((ptrSafe - 1) - bufferPtr);
frameInfo.Header = header;
frames.Add(frameInfo);
frameInfo.SampleOffset += header.BlockSize;
}
else
{
ptr = ptrSafe;
}
}
else
{
ptr = ptrSafe;
}
}
}
}
stream.Position -= FlacConstant.FrameHeaderSize;
}
return(frames);
}
public unsafe FlacSubFrameLPC(FlacBitReader reader, FlacFrameHeader header, FlacSubFrameData data, int bitsPerSample, int order)
: base(header)
{
var warmup = new int[order];
for (int i = 0; i < order; i++)
{
warmup[i] = data.ResidualBuffer[i] = reader.ReadBitsSigned(bitsPerSample);
}
int coefPrecision = (int)reader.ReadBits(4);
if (coefPrecision == 0x0F)
{
throw new FlacException("Invalid \"quantized linear predictor coefficients' precision in bits\" was invalid. Must not be 0x0F.",
FlacLayer.SubFrame);
}
coefPrecision += 1;
int shiftNeeded = reader.ReadBitsSigned(5);
if (shiftNeeded < 0)
{
throw new FlacException("'\"Quantized linear predictor coefficient shift needed in bits\" was negative.", FlacLayer.SubFrame);
}
var q = new int[order];
for (int i = 0; i < order; i++)
{
q[i] = reader.ReadBitsSigned(coefPrecision);
}
//decode the residual
var residual = new FlacResidual(reader, header, data, order);
for (int i = 0; i < order; i++)
{
data.DestinationBuffer[i] = data.ResidualBuffer[i];
}
int *residualBuffer0 = data.ResidualBuffer + order;
int *destinationBuffer0 = data.DestinationBuffer + order;
int blockSizeToProcess = header.BlockSize - order;
if (bitsPerSample + coefPrecision + Log2(order) <= 32)
{
RestoreLPCSignal32(residualBuffer0, destinationBuffer0, blockSizeToProcess, order, q, shiftNeeded);
}
else
{
RestoreLPCSignal64(residualBuffer0, destinationBuffer0, blockSizeToProcess, order, q, shiftNeeded);
}
#if FLAC_DEBUG
QLPCoeffPrecision = coefPrecision;
LPCShiftNeeded = shiftNeeded;
Warmup = warmup;
Residual = residual;
QLPCoeffs = q;
#endif
}
