Ryujinx/Ryujinx.Graphics/VDec/H264Decoder.cs

238 lines
9.1 KiB
C#
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using System.IO;
namespace Ryujinx.Graphics.VDec
{
class H264Decoder
{
private int _log2MaxPicOrderCntLsbMinus4;
private bool _deltaPicOrderAlwaysZeroFlag;
private bool _frameMbsOnlyFlag;
private int _picWidthInMbs;
private int _picHeightInMapUnits;
private bool _entropyCodingModeFlag;
private bool _bottomFieldPicOrderInFramePresentFlag;
private int _numRefIdxL0DefaultActiveMinus1;
private int _numRefIdxL1DefaultActiveMinus1;
private bool _deblockingFilterControlPresentFlag;
private bool _redundantPicCntPresentFlag;
private bool _transform8x8ModeFlag;
private bool _mbAdaptiveFrameFieldFlag;
private bool _direct8x8InferenceFlag;
private bool _weightedPredFlag;
private bool _constrainedIntraPredFlag;
private bool _fieldPicFlag;
private bool _bottomFieldFlag;
private int _log2MaxFrameNumMinus4;
private int _chromaFormatIdc;
private int _picOrderCntType;
private int _picInitQpMinus26;
private int _chromaQpIndexOffset;
private int _chromaQpIndexOffset2;
private int _weightedBipredIdc;
private int _frameNumber;
private byte[] _scalingMatrix4;
private byte[] _scalingMatrix8;
public void Decode(H264ParameterSets Params, H264Matrices matrices, byte[] frameData)
{
_log2MaxPicOrderCntLsbMinus4 = Params.Log2MaxPicOrderCntLsbMinus4;
_deltaPicOrderAlwaysZeroFlag = Params.DeltaPicOrderAlwaysZeroFlag;
_frameMbsOnlyFlag = Params.FrameMbsOnlyFlag;
_picWidthInMbs = Params.PicWidthInMbs;
_picHeightInMapUnits = Params.PicHeightInMapUnits;
_entropyCodingModeFlag = Params.EntropyCodingModeFlag;
_bottomFieldPicOrderInFramePresentFlag = Params.BottomFieldPicOrderInFramePresentFlag;
_numRefIdxL0DefaultActiveMinus1 = Params.NumRefIdxL0DefaultActiveMinus1;
_numRefIdxL1DefaultActiveMinus1 = Params.NumRefIdxL1DefaultActiveMinus1;
_deblockingFilterControlPresentFlag = Params.DeblockingFilterControlPresentFlag;
_redundantPicCntPresentFlag = Params.RedundantPicCntPresentFlag;
_transform8x8ModeFlag = Params.Transform8x8ModeFlag;
_mbAdaptiveFrameFieldFlag = ((Params.Flags >> 0) & 1) != 0;
_direct8x8InferenceFlag = ((Params.Flags >> 1) & 1) != 0;
_weightedPredFlag = ((Params.Flags >> 2) & 1) != 0;
_constrainedIntraPredFlag = ((Params.Flags >> 3) & 1) != 0;
_fieldPicFlag = ((Params.Flags >> 5) & 1) != 0;
_bottomFieldFlag = ((Params.Flags >> 6) & 1) != 0;
_log2MaxFrameNumMinus4 = (int)(Params.Flags >> 8) & 0xf;
_chromaFormatIdc = (int)(Params.Flags >> 12) & 0x3;
_picOrderCntType = (int)(Params.Flags >> 14) & 0x3;
_picInitQpMinus26 = (int)(Params.Flags >> 16) & 0x3f;
_chromaQpIndexOffset = (int)(Params.Flags >> 22) & 0x1f;
_chromaQpIndexOffset2 = (int)(Params.Flags >> 27) & 0x1f;
_weightedBipredIdc = (int)(Params.Flags >> 32) & 0x3;
_frameNumber = (int)(Params.Flags >> 46) & 0x1ffff;
_picInitQpMinus26 = (_picInitQpMinus26 << 26) >> 26;
_chromaQpIndexOffset = (_chromaQpIndexOffset << 27) >> 27;
_chromaQpIndexOffset2 = (_chromaQpIndexOffset2 << 27) >> 27;
_scalingMatrix4 = matrices.ScalingMatrix4;
_scalingMatrix8 = matrices.ScalingMatrix8;
if (FFmpegWrapper.IsInitialized)
{
FFmpegWrapper.DecodeFrame(frameData);
}
else
{
FFmpegWrapper.H264Initialize();
FFmpegWrapper.DecodeFrame(DecoderHelper.Combine(EncodeHeader(), frameData));
}
}
private byte[] EncodeHeader()
{
using (MemoryStream data = new MemoryStream())
{
H264BitStreamWriter writer = new H264BitStreamWriter(data);
//Sequence Parameter Set.
writer.WriteU(1, 24);
writer.WriteU(0, 1);
writer.WriteU(3, 2);
writer.WriteU(7, 5);
writer.WriteU(100, 8);
writer.WriteU(0, 8);
writer.WriteU(31, 8);
writer.WriteUe(0);
writer.WriteUe(_chromaFormatIdc);
if (_chromaFormatIdc == 3)
{
writer.WriteBit(false);
}
writer.WriteUe(0);
writer.WriteUe(0);
writer.WriteBit(false);
writer.WriteBit(false); //Scaling matrix present flag
writer.WriteUe(_log2MaxFrameNumMinus4);
writer.WriteUe(_picOrderCntType);
if (_picOrderCntType == 0)
{
writer.WriteUe(_log2MaxPicOrderCntLsbMinus4);
}
else if (_picOrderCntType == 1)
{
writer.WriteBit(_deltaPicOrderAlwaysZeroFlag);
writer.WriteSe(0);
writer.WriteSe(0);
writer.WriteUe(0);
}
int picHeightInMbs = _picHeightInMapUnits / (_frameMbsOnlyFlag ? 1 : 2);
writer.WriteUe(16);
writer.WriteBit(false);
writer.WriteUe(_picWidthInMbs - 1);
writer.WriteUe(picHeightInMbs - 1);
writer.WriteBit(_frameMbsOnlyFlag);
if (!_frameMbsOnlyFlag)
{
writer.WriteBit(_mbAdaptiveFrameFieldFlag);
}
writer.WriteBit(_direct8x8InferenceFlag);
writer.WriteBit(false); //Frame cropping flag
writer.WriteBit(false); //VUI parameter present flag
writer.End();
//Picture Parameter Set.
writer.WriteU(1, 24);
writer.WriteU(0, 1);
writer.WriteU(3, 2);
writer.WriteU(8, 5);
writer.WriteUe(0);
writer.WriteUe(0);
writer.WriteBit(_entropyCodingModeFlag);
writer.WriteBit(false);
writer.WriteUe(0);
writer.WriteUe(_numRefIdxL0DefaultActiveMinus1);
writer.WriteUe(_numRefIdxL1DefaultActiveMinus1);
writer.WriteBit(_weightedPredFlag);
writer.WriteU(_weightedBipredIdc, 2);
writer.WriteSe(_picInitQpMinus26);
writer.WriteSe(0);
writer.WriteSe(_chromaQpIndexOffset);
writer.WriteBit(_deblockingFilterControlPresentFlag);
writer.WriteBit(_constrainedIntraPredFlag);
writer.WriteBit(_redundantPicCntPresentFlag);
writer.WriteBit(_transform8x8ModeFlag);
writer.WriteBit(true);
for (int index = 0; index < 6; index++)
{
writer.WriteBit(true);
WriteScalingList(writer, _scalingMatrix4, index * 16, 16);
}
if (_transform8x8ModeFlag)
{
for (int index = 0; index < 2; index++)
{
writer.WriteBit(true);
WriteScalingList(writer, _scalingMatrix8, index * 64, 64);
}
}
writer.WriteSe(_chromaQpIndexOffset2);
writer.End();
return data.ToArray();
}
}
//ZigZag LUTs from libavcodec.
private static readonly byte[] ZigZagDirect = new byte[]
{
0, 1, 8, 16, 9, 2, 3, 10,
17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34,
27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36,
29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46,
53, 60, 61, 54, 47, 55, 62, 63
};
private static readonly byte[] ZigZagScan = new byte[]
{
0 + 0 * 4, 1 + 0 * 4, 0 + 1 * 4, 0 + 2 * 4,
1 + 1 * 4, 2 + 0 * 4, 3 + 0 * 4, 2 + 1 * 4,
1 + 2 * 4, 0 + 3 * 4, 1 + 3 * 4, 2 + 2 * 4,
3 + 1 * 4, 3 + 2 * 4, 2 + 3 * 4, 3 + 3 * 4
};
private static void WriteScalingList(H264BitStreamWriter writer, byte[] list, int start, int count)
{
byte[] scan = count == 16 ? ZigZagScan : ZigZagDirect;
int lastScale = 8;
for (int index = 0; index < count; index++)
{
byte value = list[start + scan[index]];
int deltaScale = value - lastScale;
writer.WriteSe(deltaScale);
lastScale = value;
}
}
}
}