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Fix some parsing mistakes

pull/1552/head
Brian Popow 6 years ago
parent
804f20969b
commit
6a1b61819f
4 changed files with 162 additions and 32 deletions
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  1. 52
      src/ImageSharp/Formats/WebP/LossyUtils.cs
  2. 20
      src/ImageSharp/Formats/WebP/Vp8BitReader.cs
  3. 18
      src/ImageSharp/Formats/WebP/Vp8Decoder.cs
  4. 104
      src/ImageSharp/Formats/WebP/WebPLossyDecoder.cs

52
src/ImageSharp/Formats/WebP/LossyUtils.cs
View File

@ -177,6 +177,56 @@ namespace SixLabors.ImageSharp.Formats.WebP
Put8x8uv((byte)(dc0 >> 3), dst);
}
public static void DC4_C(Span<byte> dst)
{
}
public static void TM4_C(Span<byte> dst)
{
}
public static void VE4_C(Span<byte> dst)
{
}
public static void HE4_C(Span<byte> dst)
{
}
public static void RD4_C(Span<byte> dst)
{
}
public static void VR4_C(Span<byte> dst)
{
}
public static void LD4_C(Span<byte> dst)
{
}
public static void VL4_C(Span<byte> dst)
{
}
public static void HD4_C(Span<byte> dst)
{
}
public static void HU4_C(Span<byte> dst)
{
}
public static void Transform(Span<short> src, Span<byte> dst, bool doTwo)
{
TransformOne(src, dst);
@ -311,7 +361,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
private static byte Clip8B(int v)
{
return (byte)((v & ~0xff) > 0 ? v : (v < 0) ? 0 : 255);
return (byte)((v & ~0xff) is 0 ? v : (v < 0) ? 0 : 255);
}
private static void Put8x8uv(byte value, Span<byte> dst)

20
src/ImageSharp/Formats/WebP/Vp8BitReader.cs
View File

@ -115,6 +115,26 @@ namespace SixLabors.ImageSharp.Formats.WebP
return bit ? 1 : 0;
}
// simplified version of VP8GetBit() for prob=0x80 (note shift is always 1 here)
public int GetSigned(int v)
{
if (this.bits < 0)
{
this.LoadNewBytes();
}
int pos = this.bits;
uint split = this.range >> 1;
ulong value = this.value >> pos;
ulong mask = (split - value) >> 31; // -1 or 0
this.bits -= 1;
this.range += (uint)mask;
this.range |= 1;
this.value -= ((split + 1) & mask) << pos;
return (v ^ (int)mask) - (int)mask;
}
public bool ReadBool()
{
return this.ReadValue(1) is 1;

18
src/ImageSharp/Formats/WebP/Vp8Decoder.cs
View File

@ -44,6 +44,14 @@ namespace SixLabors.ImageSharp.Formats.WebP
}
}
uint width = pictureHeader.Width;
uint height = pictureHeader.Height;
// TODO: use memory allocator
this.Y = new byte[width * height];
this.U = new byte[width * height];
this.V = new byte[width * height];
this.Vp8BitReaders = new Vp8BitReader[WebPConstants.MaxNumPartitions];
this.Init(io);
}
@ -139,6 +147,16 @@ namespace SixLabors.ImageSharp.Formats.WebP
public Vp8TopSamples[] YuvTopSamples { get; }
public byte[] Y { get; }
public byte[] U { get; }
public byte[] V { get; }
public int YStride { get; }
public int UvStride { get; }
/// <summary>
/// Gets or sets filter strength info.
/// </summary>

104
src/ImageSharp/Formats/WebP/WebPLossyDecoder.cs
View File

@ -63,14 +63,15 @@ namespace SixLabors.ImageSharp.Formats.WebP
this.ParsePartitions(decoder);
// Paragraph 9.6: Dequantization Indices.
this.ParseDequantizationIndices(decoder.SegmentHeader);
this.ParseDequantizationIndices(decoder);
// Ignore the value of update_proba
this.bitReader.ReadBool();
// Paragraph 13.4: Parse probabilities.
this.ParseProbabilities(decoder, decoder.Probabilities);
this.ParseProbabilities(decoder);
// Decode image data.
this.ParseFrame(decoder, vp8Io);
}
@ -219,8 +220,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
// Init top-left sample on left column too.
if (mby > 0)
{
// TODO:
// yDst[-1 - WebPConstants.Bps] = uDst[-1 - WebPConstants.Bps] = vDst[-1 - WebPConstants.Bps] = 129;
yuv[yOff - 1 - WebPConstants.Bps] = yuv[uOff - 1 - WebPConstants.Bps] = yuv[vOff - 1 - WebPConstants.Bps] = 129;
}
else
{
@ -286,12 +286,13 @@ namespace SixLabors.ImageSharp.Formats.WebP
// Predict and add residuals.
if (block.IsI4x4)
{
// uint32_t* const top_right = (uint32_t*)(y_dst - BPS + 16);
if (mby > 0)
{
if (mbx >= dec.MbWidth - 1)
{
// On rightmost border.
//memset(top_right, top_yuv[0].y[15], sizeof(*top_right));
// memset(top_right, top_yuv[0].y[15], sizeof(*top_right));
}
else
{
@ -300,38 +301,49 @@ namespace SixLabors.ImageSharp.Formats.WebP
}
// Replicate the top-right pixels below.
// top_right[BPS] = top_right[2 * BPS] = top_right[3 * BPS] = top_right[0];
// Predict and add residuals for all 4x4 blocks in turn.
for (int n = 0; n < 16; ++n, bits <<= 2)
{
// uint8_t * const dst = y_dst + kScan[n];
Span<byte> dst = yDst.Slice(WebPConstants.KScan[n]);
byte lumaMode = block.Modes[n];
switch (lumaMode)
{
case 0:
LossyUtils.DC4_C(dst);
break;
case 1:
LossyUtils.TM4_C(dst);
break;
case 2:
LossyUtils.VE4_C(dst);
break;
case 3:
LossyUtils.HE4_C(dst);
break;
case 4:
LossyUtils.RD4_C(dst);
break;
case 5:
LossyUtils.VR4_C(dst);
break;
case 6:
LossyUtils.LD4_C(dst);
break;
case 7:
LossyUtils.VL4_C(dst);
break;
case 8:
LossyUtils.HD4_C(dst);
break;
case 9:
LossyUtils.HU4_C(dst);
break;
}
//DoTransform(bits, coeffs + n * 16, dst);
this.DoTransform(bits, coeffs.AsSpan(n * 16), dst);
}
}
else
@ -409,6 +421,32 @@ namespace SixLabors.ImageSharp.Formats.WebP
this.DoUVTransform(bitsUv >> 0, coeffs.AsSpan(16 * 16), uDst);
this.DoUVTransform(bitsUv >> 8, coeffs.AsSpan(20 * 16), vDst);
// Stash away top samples for next block.
if (mby < dec.MbHeight - 1)
{
yDst.Slice(15 * WebPConstants.Bps, 16).CopyTo(topYuv.Y);
uDst.Slice(7 * WebPConstants.Bps, 8).CopyTo(topYuv.U);
vDst.Slice(7 * WebPConstants.Bps, 8).CopyTo(topYuv.V);
}
// Transfer reconstructed samples from yuv_b_ cache to final destination.
int cacheId = 0; // TODO: what should be cacheId?
int yOffset = cacheId * 16 * dec.YStride;
int uvOffset = cacheId * 8 * dec.UvStride;
Span<byte> yOut = dec.Y.AsSpan((mbx * 16) + yOffset);
Span<byte> uOut = dec.U.AsSpan((mbx * 8) + uvOffset);
Span<byte> vOut = dec.V.AsSpan((mbx * 8) + uvOffset);
for (int j = 0; j < 16; ++j)
{
yDst.Slice(j * WebPConstants.Bps, 16).CopyTo(yOut.Slice(j * dec.YStride));
}
for (int j = 0; j < 8; ++j)
{
uDst.Slice(j * WebPConstants.Bps, 8).CopyTo(uOut);
vDst.Slice(j * WebPConstants.Bps, 8).CopyTo(vOut);
}
}
}
@ -504,13 +542,13 @@ namespace SixLabors.ImageSharp.Formats.WebP
uint nonZeroY = 0;
uint nonZeroUv = 0;
int first;
var dst = new short[384];
int dstOffset = 0;
Vp8MacroBlockData block = dec.MacroBlockData[dec.MbX];
Vp8QuantMatrix q = dec.DeQuantMatrices[block.Segment];
Vp8BandProbas[,] bands = dec.Probabilities.BandsPtr;
Vp8BandProbas[] acProba;
Vp8MacroBlock leftMb = dec.MacroBlockInfo[0];
short[] dst = block.Coeffs;
if (!block.IsI4x4)
{
@ -519,7 +557,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
int ctx = (int)(mb.NoneZeroDcCoeffs + leftMb.NoneZeroDcCoeffs);
int nz = this.GetCoeffs(br, GetBandsRow(bands, 1), ctx, q.Y2Mat, 0, dc);
mb.NoneZeroDcCoeffs = leftMb.NoneZeroDcCoeffs = (uint)(nz > 0 ? 1 : 0);
if (nz > 0)
if (nz > 1)
{
// More than just the DC -> perform the full transform.
this.TransformWht(dc, dst);
@ -534,7 +572,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
}
first = 1;
acProba = GetBandsRow(bands, 1);
acProba = GetBandsRow(bands, 0);
}
else
{
@ -615,14 +653,14 @@ namespace SixLabors.ImageSharp.Formats.WebP
Vp8ProbaArray p = prob[n].Probabilities[ctx];
for (; n < 16; ++n)
{
if (this.bitReader.GetBit((int)p.Probabilities[0]) is 0)
if (br.GetBit(p.Probabilities[0]) is 0)
{
// Previous coeff was last non - zero coeff.
return n;
}
// Sequence of zero coeffs.
while (br.GetBit((int)p.Probabilities[1]) is 0)
while (br.GetBit(p.Probabilities[1]) is 0)
{
p = prob[++n].Probabilities[0];
if (n is 16)
@ -633,57 +671,57 @@ namespace SixLabors.ImageSharp.Formats.WebP
// Non zero coeffs.
int v;
if (br.GetBit((int)p.Probabilities[2]) is 0)
if (br.GetBit(p.Probabilities[2]) is 0)
{
v = 1;
p = prob[n + 1].Probabilities[1];
}
else
{
v = this.GetLargeValue(p.Probabilities);
v = this.GetLargeValue(br, p.Probabilities);
p = prob[n + 1].Probabilities[2];
}
int idx = n > 0 ? 1 : 0;
coeffs[WebPConstants.Zigzag[n]] = (short)(br.ReadSignedValue(v) * dq[idx]);
coeffs[WebPConstants.Zigzag[n]] = (short)(br.GetSigned(v) * dq[idx]);
}
return 16;
}
private int GetLargeValue(byte[] p)
private int GetLargeValue(Vp8BitReader br, byte[] p)
{
// See section 13 - 2: http://tools.ietf.org/html/rfc6386#section-13.2
int v;
if (this.bitReader.GetBit(p[3]) is 0)
if (br.GetBit(p[3]) is 0)
{
if (this.bitReader.GetBit(p[4]) is 0)
if (br.GetBit(p[4]) is 0)
{
v = 2;
}
else
{
v = 3 + this.bitReader.GetBit(p[5]);
v = 3 + br.GetBit(p[5]);
}
}
else
{
if (this.bitReader.GetBit(p[6]) is 0)
if (br.GetBit(p[6]) is 0)
{
if (this.bitReader.GetBit(p[7]) is 0)
if (br.GetBit(p[7]) is 0)
{
v = 5 + this.bitReader.GetBit(159);
v = 5 + br.GetBit(159);
}
else
{
v = 7 + (2 * this.bitReader.GetBit(165));
v += this.bitReader.GetBit(145);
v = 7 + (2 * br.GetBit(165));
v += br.GetBit(145);
}
}
else
{
int bit1 = this.bitReader.GetBit(p[8]);
int bit0 = this.bitReader.GetBit(p[9] + bit1);
int bit1 = br.GetBit(p[8]);
int bit0 = br.GetBit(p[9] + bit1);
int cat = (2 * bit1) + bit0;
v = 0;
byte[] tab = null;
@ -708,7 +746,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
for (int i = 0; i < tab.Length; i++)
{
v += v + this.bitReader.GetBit(tab[i]);
v += v + br.GetBit(tab[i]);
}
v += 3 + (8 << cat);
@ -866,8 +904,10 @@ namespace SixLabors.ImageSharp.Formats.WebP
dec.Vp8BitReaders[lastPart] = new Vp8BitReader(this.bitReader.Data, (uint)sizeLeft, partStart);
}
private void ParseDequantizationIndices(Vp8SegmentHeader vp8SegmentHeader)
private void ParseDequantizationIndices(Vp8Decoder decoder)
{
Vp8SegmentHeader vp8SegmentHeader = decoder.SegmentHeader;
int baseQ0 = (int)this.bitReader.ReadValue(7);
bool hasValue = this.bitReader.ReadBool();
int dqy1Dc = hasValue ? this.bitReader.ReadSignedValue(4) : 0;
@ -894,7 +934,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
{
if (i > 0)
{
// dec->dqm_[i] = dec->dqm_[0];
decoder.DeQuantMatrices[i] = decoder.DeQuantMatrices[0];
continue;
}
else
@ -903,7 +943,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
}
}
var m = new Vp8QuantMatrix();
Vp8QuantMatrix m = decoder.DeQuantMatrices[i];
m.Y1Mat[0] = WebPConstants.DcTable[Clip(q + dqy1Dc, 127)];
m.Y1Mat[1] = WebPConstants.AcTable[Clip(q + 0, 127)];
m.Y2Mat[0] = WebPConstants.DcTable[Clip(q + dqy2Dc, 127)] * 2;
@ -924,8 +964,10 @@ namespace SixLabors.ImageSharp.Formats.WebP
}
}
private void ParseProbabilities(Vp8Decoder dec, Vp8Proba proba)
private void ParseProbabilities(Vp8Decoder dec)
{
Vp8Proba proba = dec.Probabilities;
for (int t = 0; t < WebPConstants.NumTypes; ++t)
{
for (int b = 0; b < WebPConstants.NumBands; ++b)

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