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Move end-of-block position reading to Av1SymbolDecoder

pull/2633/head
Ynse Hoornenborg 2 years ago
parent
3ea42d050a
commit
e58a775cc0
2 changed files with 60 additions and 58 deletions
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  1. 77
      src/ImageSharp/Formats/Heif/Av1/Tiling/Av1SymbolDecoder.cs
  2. 41
      src/ImageSharp/Formats/Heif/Av1/Tiling/Av1TileReader.cs

77
src/ImageSharp/Formats/Heif/Av1/Tiling/Av1SymbolDecoder.cs
View File

@ -10,6 +10,8 @@ internal ref struct Av1SymbolDecoder
{
private static readonly int[] IntraModeContext = [0, 1, 2, 3, 4, 4, 4, 4, 3, 0, 1, 2, 0];
private static readonly int[] AlphaVContexts = [-1, 0, 3, -1, 1, 4, -1, 2, 5];
private static readonly int[] EndOfBlockOffsetBits = [0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
private static readonly int[] EndOfBlockGroupStart = [0, 1, 2, 3, 5, 9, 17, 33, 65, 129, 257, 513];
private readonly Av1Distribution tileIntraBlockCopy = Av1DefaultDistributions.IntraBlockCopy;
private readonly Av1Distribution[] tilePartitionTypes = Av1DefaultDistributions.PartitionTypes;
@ -177,26 +179,12 @@ internal ref struct Av1SymbolDecoder
return transformSize;
}
public int ReadEndOfBlockFlag(Av1PlaneType planeType, Av1TransformClass transformClass, Av1TransformSize transformSize)
{
int endOfBlockContext = transformClass == Av1TransformClass.Class2D ? 0 : 1;
int endOfBlockMultiSize = transformSize.GetLog2Minus4();
ref Av1SymbolReader r = ref this.reader;
return r.ReadSymbol(this.endOfBlockFlag[endOfBlockMultiSize][(int)planeType][endOfBlockContext]) + 1;
}
public bool ReadTransformBlockSkip(Av1TransformSize transformSizeContext, int skipContext)
{
ref Av1SymbolReader r = ref this.reader;
return r.ReadSymbol(this.transformBlockSkip[(int)transformSizeContext][skipContext]) > 0;
}
public bool ReadEndOfBlockExtra(Av1TransformSize transformSizeContext, Av1PlaneType planeType, int endOfBlockContext)
{
ref Av1SymbolReader r = ref this.reader;
return r.ReadSymbol(this.endOfBlockExtra[(int)transformSizeContext][(int)planeType][endOfBlockContext]) > 0;
}
public int ReadChromFromLumaSign()
{
ref Av1SymbolReader r = ref this.reader;
@ -217,6 +205,34 @@ internal ref struct Av1SymbolDecoder
return r.ReadSymbol(this.chromeForLumaAlpha[context]);
}
public int ReadEndOfBlockPosition(Av1TransformSize transformSize, Av1TransformClass transformClass, Av1TransformSize transformSizeContext, Av1PlaneType planeType)
{
int endOfBlockExtra = 0;
int endOfBlockPoint = this.ReadEndOfBlockFlag(planeType, transformClass, transformSize);
int endOfBlockShift = EndOfBlockOffsetBits[endOfBlockPoint];
if (endOfBlockShift > 0)
{
int endOfBlockContext = endOfBlockPoint;
bool bit = this.ReadEndOfBlockExtra(transformSizeContext, planeType, endOfBlockContext);
if (bit)
{
endOfBlockExtra += 1 << (endOfBlockShift - 1);
}
else
{
for (int j = 1; j < endOfBlockShift; j++)
{
if (this.ReadLiteral(1) != 0)
{
endOfBlockExtra += 1 << (endOfBlockShift - 1 - j);
}
}
}
}
return RecordEndOfBlockPosition(endOfBlockPoint, endOfBlockExtra);
}
public void ReadCoefficientsEndOfBlock(Av1TransformClass transformClass, int endOfBlock, int height, ReadOnlySpan<short> scan, int bwl, Span<int> levels, Av1TransformSize transformSizeContext, Av1PlaneType planeType)
{
int i = endOfBlock - 1;
@ -240,9 +256,9 @@ internal ref struct Av1SymbolDecoder
levels[GetPaddedIndex(pos, bwl)] = level;
}
public void ReadCoefficientsReverse2d(Av1TransformSize transformSize, int startSi, int endSi, ReadOnlySpan<short> scan, int bwl, Span<int> levels, Av1TransformSize transformSizeContext, Av1PlaneType planeType)
public void ReadCoefficientsReverse2d(Av1TransformSize transformSize, int startScanIndex, int endScanIndex, ReadOnlySpan<short> scan, int bwl, Span<int> levels, Av1TransformSize transformSizeContext, Av1PlaneType planeType)
{
for (int c = endSi; c >= startSi; --c)
for (int c = endScanIndex; c >= startScanIndex; --c)
{
int pos = scan[c];
int coefficientContext = GetLowerLevelsContext2d(levels, pos, bwl, transformSize);
@ -265,9 +281,9 @@ internal ref struct Av1SymbolDecoder
}
}
public void ReadCoefficientsReverse(Av1TransformSize transformSize, Av1TransformClass transformClass, int startSi, int endSi, ReadOnlySpan<short> scan, int bwl, Span<int> levels, Av1TransformSize transformSizeContext, Av1PlaneType planeType)
public void ReadCoefficientsReverse(Av1TransformSize transformSize, Av1TransformClass transformClass, int startScanIndex, int endScanIndex, ReadOnlySpan<short> scan, int bwl, Span<int> levels, Av1TransformSize transformSizeContext, Av1PlaneType planeType)
{
for (int c = endSi; c >= startSi; --c)
for (int c = endScanIndex; c >= startScanIndex; --c)
{
int pos = scan[c];
int coefficientContext = GetLowerLevelsContext(levels, pos, bwl, transformSize, transformClass);
@ -335,6 +351,20 @@ internal ref struct Av1SymbolDecoder
return culLevel;
}
private int ReadEndOfBlockFlag(Av1PlaneType planeType, Av1TransformClass transformClass, Av1TransformSize transformSize)
{
int endOfBlockContext = transformClass == Av1TransformClass.Class2D ? 0 : 1;
int endOfBlockMultiSize = transformSize.GetLog2Minus4();
ref Av1SymbolReader r = ref this.reader;
return r.ReadSymbol(this.endOfBlockFlag[endOfBlockMultiSize][(int)planeType][endOfBlockContext]) + 1;
}
private bool ReadEndOfBlockExtra(Av1TransformSize transformSizeContext, Av1PlaneType planeType, int endOfBlockContext)
{
ref Av1SymbolReader r = ref this.reader;
return r.ReadSymbol(this.endOfBlockExtra[(int)transformSizeContext][(int)planeType][endOfBlockContext]) > 0;
}
private int ReadCoefficientsBaseRange(Av1TransformSize transformSizeContext, Av1PlaneType planeType, int baseRangeContext)
{
ref Av1SymbolReader r = ref this.reader;
@ -359,6 +389,17 @@ internal ref struct Av1SymbolDecoder
return r.ReadSymbol(this.coefficientsBase[(int)transformSizeContext][(int)planeType][coefficientContext]);
}
private static int RecordEndOfBlockPosition(int endOfBlockPoint, int endOfBlockExtra)
{
int endOfBlock = EndOfBlockGroupStart[endOfBlockPoint];
if (endOfBlock > 2)
{
endOfBlock += endOfBlockExtra;
}
return endOfBlock;
}
private static int GetBaseRangeContextEndOfBlock(int pos, int bwl, Av1TransformClass transformClass)
{
int row = pos >> bwl;

41
src/ImageSharp/Formats/Heif/Av1/Tiling/Av1TileReader.cs
View File

@ -22,9 +22,6 @@ internal class Av1TileReader : IAv1TileReader
private static readonly int[][] SkipContexts = [
[1, 2, 2, 2, 3], [1, 4, 4, 4, 5], [1, 4, 4, 4, 5], [1, 4, 4, 4, 5], [1, 4, 4, 4, 6]];
private static readonly int[] EndOfBlockGroupStart = [0, 1, 2, 3, 5, 9, 17, 33, 65, 129, 257, 513];
private static readonly int[] EndOfBlockOffsetBits = [0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
private int[][] referenceSgrXqd = [];
private int[][][] referenceLrWiener = [];
private readonly Av1ParseAboveNeighbor4x4Context aboveNeighborContext;
@ -585,37 +582,12 @@ internal class Av1TileReader : IAv1TileReader
return 0;
}
int endOfBlockExtra = 0;
int endOfBlockPoint = 0;
transformInfo.Type = this.ComputeTransformType(planeType, partitionInfo, transformSize, transformInfo);
Av1TransformClass transformClass = transformInfo.Type.ToClass();
Av1ScanOrder scanOrder = Av1ScanOrderConstants.GetScanOrder(transformSize, transformInfo.Type);
ReadOnlySpan<short> scan = scanOrder.Scan;
endOfBlockPoint = reader.ReadEndOfBlockFlag(planeType, transformClass, transformSize);
int endOfBlockShift = EndOfBlockOffsetBits[endOfBlockPoint];
if (endOfBlockShift > 0)
{
int endOfBlockContext = endOfBlockPoint;
bool bit = reader.ReadEndOfBlockExtra(transformSizeContext, planeType, endOfBlockContext);
if (bit)
{
endOfBlockExtra += 1 << (endOfBlockShift - 1);
}
else
{
for (int j = 1; j < endOfBlockShift; j++)
{
if (reader.ReadLiteral(1) != 0)
{
endOfBlockExtra += 1 << (endOfBlockShift - 1 - j);
}
}
}
}
endOfBlock = RecordEndOfBlockPosition(endOfBlockPoint, endOfBlockExtra);
endOfBlock = reader.ReadEndOfBlockPosition(transformSize, transformClass, transformSizeContext, planeType);
if (endOfBlock > 1)
{
Array.Fill(levelsBuffer, 0, 0, ((width + Av1Constants.TransformPadHorizontal) * (height + Av1Constants.TransformPadVertical)) + Av1Constants.TransformPadEnd);
@ -679,17 +651,6 @@ internal class Av1TileReader : IAv1TileReader
}
}
private static int RecordEndOfBlockPosition(int endOfBlockPoint, int endOfBlockExtra)
{
int endOfBlock = EndOfBlockGroupStart[endOfBlockPoint];
if (endOfBlock > 2)
{
endOfBlock += endOfBlockExtra;
}
return endOfBlock;
}
private Av1TransformType ComputeTransformType(Av1PlaneType planeType, Av1PartitionInfo partitionInfo, Av1TransformSize transformSize, Av1TransformInfo transformInfo)
{
Av1TransformType transformType = Av1TransformType.DctDct;

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