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Move UpSample to YuvConversion class

pull/1836/head
Brian Popow 4 years ago
parent
69c30f8ef7
commit
7191acaf34
2 changed files with 58 additions and 58 deletions
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  1. 62
      src/ImageSharp/Formats/Webp/Lossy/WebpLossyDecoder.cs
  2. 54
      src/ImageSharp/Formats/Webp/Lossy/YuvConversion.cs

62
src/ImageSharp/Formats/Webp/Lossy/WebpLossyDecoder.cs
View File

@ -696,12 +696,12 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
if (y == 0)
{
// First line is special cased. We mirror the u/v samples at boundary.
this.UpSample(curY, null, curU, curV, curU, curV, dst, null, mbw);
YuvConversion.UpSample(curY, null, curU, curV, curU, curV, dst, null, mbw);
}
else
{
// We can finish the left-over line from previous call.
this.UpSample(tmpYBuffer, curY, topU, topV, curU, curV, buf.Slice(dstStartIdx - bufferStride), dst, mbw);
YuvConversion.UpSample(tmpYBuffer, curY, topU, topV, curU, curV, buf.Slice(dstStartIdx - bufferStride), dst, mbw);
numLinesOut++;
}
@ -714,7 +714,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
topV = curV;
curU = curU.Slice(io.UvStride);
curV = curV.Slice(io.UvStride);
this.UpSample(curY.Slice(io.YStride), curY.Slice(ioStride2), topU, topV, curU, curV, dst.Slice(bufferStride), dst.Slice(bufferStride2), mbw);
YuvConversion.UpSample(curY.Slice(io.YStride), curY.Slice(ioStride2), topU, topV, curU, curV, dst.Slice(bufferStride), dst.Slice(bufferStride2), mbw);
curY = curY.Slice(ioStride2);
dst = dst.Slice(bufferStride2);
}
@ -736,67 +736,13 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
// Process the very last row of even-sized picture.
if ((yEnd & 1) == 0)
{
this.UpSample(curY, null, curU, curV, curU, curV, dst.Slice(bufferStride), null, mbw);
YuvConversion.UpSample(curY, null, curU, curV, curU, curV, dst.Slice(bufferStride), null, mbw);
}
}
return numLinesOut;
}
private void UpSample(Span<byte> topY, Span<byte> bottomY, Span<byte> topU, Span<byte> topV, Span<byte> curU, Span<byte> curV, Span<byte> topDst, Span<byte> bottomDst, int len)
{
int xStep = 3;
int lastPixelPair = (len - 1) >> 1;
uint tluv = YuvConversion.LoadUv(topU[0], topV[0]); // top-left sample
uint luv = YuvConversion.LoadUv(curU[0], curV[0]); // left-sample
uint uv0 = ((3 * tluv) + luv + 0x00020002u) >> 2;
YuvConversion.YuvToBgr(topY[0], (int)(uv0 & 0xff), (int)(uv0 >> 16), topDst);
if (bottomY != null)
{
uv0 = ((3 * luv) + tluv + 0x00020002u) >> 2;
YuvConversion.YuvToBgr(bottomY[0], (int)uv0 & 0xff, (int)(uv0 >> 16), bottomDst);
}
for (int x = 1; x <= lastPixelPair; x++)
{
uint tuv = YuvConversion.LoadUv(topU[x], topV[x]); // top sample
uint uv = YuvConversion.LoadUv(curU[x], curV[x]); // sample
// Precompute invariant values associated with first and second diagonals.
uint avg = tluv + tuv + luv + uv + 0x00080008u;
uint diag12 = (avg + (2 * (tuv + luv))) >> 3;
uint diag03 = (avg + (2 * (tluv + uv))) >> 3;
uv0 = (diag12 + tluv) >> 1;
uint uv1 = (diag03 + tuv) >> 1;
int xMul2 = x * 2;
YuvConversion.YuvToBgr(topY[xMul2 - 1], (int)(uv0 & 0xff), (int)(uv0 >> 16), topDst.Slice((xMul2 - 1) * xStep));
YuvConversion.YuvToBgr(topY[xMul2 - 0], (int)(uv1 & 0xff), (int)(uv1 >> 16), topDst.Slice((xMul2 - 0) * xStep));
if (bottomY != null)
{
uv0 = (diag03 + luv) >> 1;
uv1 = (diag12 + uv) >> 1;
YuvConversion.YuvToBgr(bottomY[xMul2 - 1], (int)(uv0 & 0xff), (int)(uv0 >> 16), bottomDst.Slice((xMul2 - 1) * xStep));
YuvConversion.YuvToBgr(bottomY[xMul2 + 0], (int)(uv1 & 0xff), (int)(uv1 >> 16), bottomDst.Slice((xMul2 + 0) * xStep));
}
tluv = tuv;
luv = uv;
}
if ((len & 1) == 0)
{
uv0 = ((3 * tluv) + luv + 0x00020002u) >> 2;
YuvConversion.YuvToBgr(topY[len - 1], (int)(uv0 & 0xff), (int)(uv0 >> 16), topDst.Slice((len - 1) * xStep));
if (bottomY != null)
{
uv0 = ((3 * luv) + tluv + 0x00020002u) >> 2;
YuvConversion.YuvToBgr(bottomY[len - 1], (int)(uv0 & 0xff), (int)(uv0 >> 16), bottomDst.Slice((len - 1) * xStep));
}
}
}
private void DoTransform(uint bits, Span<short> src, Span<byte> dst, Span<int> scratch)
{
switch (bits >> 30)

54
src/ImageSharp/Formats/Webp/Lossy/YuvConversion.cs
View File

@ -18,6 +18,60 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
private const int YuvHalf = 1 << (YuvFix - 1);
public static void UpSample(Span<byte> topY, Span<byte> bottomY, Span<byte> topU, Span<byte> topV, Span<byte> curU, Span<byte> curV, Span<byte> topDst, Span<byte> bottomDst, int len)
{
int xStep = 3;
int lastPixelPair = (len - 1) >> 1;
uint tluv = LoadUv(topU[0], topV[0]); // top-left sample
uint luv = LoadUv(curU[0], curV[0]); // left-sample
uint uv0 = ((3 * tluv) + luv + 0x00020002u) >> 2;
YuvToBgr(topY[0], (int)(uv0 & 0xff), (int)(uv0 >> 16), topDst);
if (bottomY != null)
{
uv0 = ((3 * luv) + tluv + 0x00020002u) >> 2;
YuvToBgr(bottomY[0], (int)uv0 & 0xff, (int)(uv0 >> 16), bottomDst);
}
for (int x = 1; x <= lastPixelPair; x++)
{
uint tuv = LoadUv(topU[x], topV[x]); // top sample
uint uv = LoadUv(curU[x], curV[x]); // sample
// Precompute invariant values associated with first and second diagonals.
uint avg = tluv + tuv + luv + uv + 0x00080008u;
uint diag12 = (avg + (2 * (tuv + luv))) >> 3;
uint diag03 = (avg + (2 * (tluv + uv))) >> 3;
uv0 = (diag12 + tluv) >> 1;
uint uv1 = (diag03 + tuv) >> 1;
int xMul2 = x * 2;
YuvToBgr(topY[xMul2 - 1], (int)(uv0 & 0xff), (int)(uv0 >> 16), topDst.Slice((xMul2 - 1) * xStep));
YuvToBgr(topY[xMul2 - 0], (int)(uv1 & 0xff), (int)(uv1 >> 16), topDst.Slice((xMul2 - 0) * xStep));
if (bottomY != null)
{
uv0 = (diag03 + luv) >> 1;
uv1 = (diag12 + uv) >> 1;
YuvToBgr(bottomY[xMul2 - 1], (int)(uv0 & 0xff), (int)(uv0 >> 16), bottomDst.Slice((xMul2 - 1) * xStep));
YuvToBgr(bottomY[xMul2 + 0], (int)(uv1 & 0xff), (int)(uv1 >> 16), bottomDst.Slice((xMul2 + 0) * xStep));
}
tluv = tuv;
luv = uv;
}
if ((len & 1) == 0)
{
uv0 = ((3 * tluv) + luv + 0x00020002u) >> 2;
YuvToBgr(topY[len - 1], (int)(uv0 & 0xff), (int)(uv0 >> 16), topDst.Slice((len - 1) * xStep));
if (bottomY != null)
{
uv0 = ((3 * luv) + tluv + 0x00020002u) >> 2;
YuvToBgr(bottomY[len - 1], (int)(uv0 & 0xff), (int)(uv0 >> 16), bottomDst.Slice((len - 1) * xStep));
}
}
}
/// <summary>
/// Converts the RGB values of the image to YUV.
/// </summary>

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