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Move Vp8 specific parsing into LossyDecoder

pull/1147/head
Brian Popow 6 years ago
parent
09b2cf3cc3
commit
011719a4b6
3 changed files with 217 additions and 209 deletions
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  1. 198
      src/ImageSharp/Formats/WebP/WebPDecoderCore.cs
  2. 10
      src/ImageSharp/Formats/WebP/WebPImageInfo.cs
  3. 218
      src/ImageSharp/Formats/WebP/WebPLossyDecoder.cs

198
src/ImageSharp/Formats/WebP/WebPDecoderCore.cs
View File

@ -366,117 +366,14 @@ namespace SixLabors.ImageSharp.Formats.WebP
sbyte clampType = (sbyte)bitReader.ReadValue(1);
var vp8PictureHeader = new Vp8PictureHeader()
{
Width = width,
Height = height,
Width = (uint)width,
Height = (uint)height,
XScale = xScale,
YScale = yScale,
ColorSpace = colorSpace,
ClampType = clampType
};
// Paragraph 9.3: Parse the segment header.
bool hasValue;
var proba = new Vp8Proba();
Vp8SegmentHeader vp8SegmentHeader = ParseSegmentHeader(bitReader, proba);
// Paragraph 9.4: Parse the filter specs.
Vp8FilterHeader vp8FilterHeader = ParseFilterHeader(bitReader);
// TODO: Review Paragraph 9.5: ParsePartitions.
int numPartsMinusOne = (1 << (int)bitReader.ReadValue(2)) - 1;
int lastPart = numPartsMinusOne;
// TODO: check if we have enough data available here, throw exception if not
int partStart = bitReader.Pos + (lastPart * 3);
// Paragraph 9.6: Dequantization Indices.
int baseQ0 = (int)bitReader.ReadValue(7);
hasValue = bitReader.ReadBool();
int dqy1Dc = hasValue ? bitReader.ReadSignedValue(4) : 0;
hasValue = bitReader.ReadBool();
int dqy2Dc = hasValue ? bitReader.ReadSignedValue(4) : 0;
hasValue = bitReader.ReadBool();
int dqy2Ac = hasValue ? bitReader.ReadSignedValue(4) : 0;
hasValue = bitReader.ReadBool();
int dquvDc = hasValue ? bitReader.ReadSignedValue(4) : 0;
hasValue = bitReader.ReadBool();
int dquvAc = hasValue ? bitReader.ReadSignedValue(4) : 0;
for (int i = 0; i < WebPConstants.NumMbSegments; ++i)
{
int q;
if (vp8SegmentHeader.UseSegment)
{
q = vp8SegmentHeader.Quantizer[i];
if (!vp8SegmentHeader.Delta)
{
q += baseQ0;
}
}
else
{
if (i > 0)
{
// dec->dqm_[i] = dec->dqm_[0];
continue;
}
else
{
q = baseQ0;
}
}
var m = new Vp8QuantMatrix();
m.Y1Mat[0] = WebPConstants.DcTable[this.Clip(q + dqy1Dc, 127)];
m.Y1Mat[1] = WebPConstants.AcTable[this.Clip(q + 0, 127)];
m.Y2Mat[0] = WebPConstants.DcTable[this.Clip(q + dqy2Dc, 127)] * 2;
// For all x in [0..284], x*155/100 is bitwise equal to (x*101581) >> 16.
// The smallest precision for that is '(x*6349) >> 12' but 16 is a good word size.
m.Y2Mat[1] = (WebPConstants.AcTable[this.Clip(q + dqy2Ac, 127)] * 101581) >> 16;
if (m.Y2Mat[1] < 8)
{
m.Y2Mat[1] = 8;
}
m.UvMat[0] = WebPConstants.DcTable[this.Clip(q + dquvDc, 117)];
m.UvMat[1] = WebPConstants.AcTable[this.Clip(q + dquvAc, 127)];
// For dithering strength evaluation.
m.UvQuant = q + dquvAc;
}
// Ignore the value of update_proba
bitReader.ReadBool();
// Paragraph 13.4: Parse probabilities.
for (int t = 0; t < WebPConstants.NumTypes; ++t)
{
for (int b = 0; b < WebPConstants.NumBands; ++b)
{
for (int c = 0; c < WebPConstants.NumCtx; ++c)
{
for (int p = 0; p < WebPConstants.NumProbas; ++p)
{
var prob = WebPConstants.CoeffsUpdateProba[t, b, c, p];
int v = bitReader.GetBit(prob) == 0 ? (int)bitReader.ReadValue(8) : WebPConstants.DefaultCoeffsProba[t, b, c, p];
proba.Bands[t, b].Probabilities[c].Probabilities[p] = (uint)v;
}
}
}
for (int b = 0; b < 16 + 1; ++b)
{
// TODO: This needs to be reviewed and fixed.
// proba->bands_ptr_[t][b] = &proba->bands_[t][kBands[b]];
}
}
// TODO: those values needs to be stored somewhere
bool useSkipProba = bitReader.ReadBool();
if (useSkipProba)
{
var skipP = bitReader.ReadValue(8);
}
return new WebPImageInfo()
{
Width = width,
@ -486,97 +383,11 @@ namespace SixLabors.ImageSharp.Formats.WebP
Features = features,
Vp8Profile = (sbyte)version,
Vp8FrameHeader = vp8FrameHeader,
Vp8SegmentHeader = vp8SegmentHeader,
Vp8FilterHeader = vp8FilterHeader,
Vp8PictureHeader = vp8PictureHeader,
Vp8BitReader = bitReader
};
}
private static Vp8FilterHeader ParseFilterHeader(Vp8BitReader bitReader)
{
var vp8FilterHeader = new Vp8FilterHeader();
vp8FilterHeader.LoopFilter = bitReader.ReadBool() ? LoopFilter.Simple : LoopFilter.Complex;
vp8FilterHeader.Level = (int)bitReader.ReadValue(6);
vp8FilterHeader.Sharpness = (int)bitReader.ReadValue(3);
vp8FilterHeader.UseLfDelta = bitReader.ReadBool();
// TODO: use enum here?
// 0 = 0ff, 1 = simple, 2 = complex
int filterType = (vp8FilterHeader.Level is 0) ? 0 : vp8FilterHeader.LoopFilter is LoopFilter.Simple ? 1 : 2;
bool hasValue;
if (vp8FilterHeader.UseLfDelta)
{
// Update lf-delta?
if (bitReader.ReadBool())
{
for (int i = 0; i < vp8FilterHeader.RefLfDelta.Length; i++)
{
hasValue = bitReader.ReadBool();
if (hasValue)
{
vp8FilterHeader.RefLfDelta[i] = bitReader.ReadSignedValue(6);
}
}
for (int i = 0; i < vp8FilterHeader.ModeLfDelta.Length; i++)
{
hasValue = bitReader.ReadBool();
if (hasValue)
{
vp8FilterHeader.ModeLfDelta[i] = bitReader.ReadSignedValue(6);
}
}
}
}
return vp8FilterHeader;
}
private static Vp8SegmentHeader ParseSegmentHeader(Vp8BitReader bitReader, Vp8Proba proba)
{
var vp8SegmentHeader = new Vp8SegmentHeader();
vp8SegmentHeader.UseSegment = bitReader.ReadBool();
bool hasValue;
if (vp8SegmentHeader.UseSegment)
{
vp8SegmentHeader.UpdateMap = bitReader.ReadBool();
bool updateData = bitReader.ReadBool();
if (updateData)
{
vp8SegmentHeader.Delta = bitReader.ReadBool();
for (int i = 0; i < vp8SegmentHeader.Quantizer.Length; i++)
{
hasValue = bitReader.ReadBool();
uint quantizeValue = hasValue ? bitReader.ReadValue(7) : 0;
vp8SegmentHeader.Quantizer[i] = (byte)quantizeValue;
}
for (int i = 0; i < vp8SegmentHeader.FilterStrength.Length; i++)
{
hasValue = bitReader.ReadBool();
uint filterStrengthValue = hasValue ? bitReader.ReadValue(6) : 0;
vp8SegmentHeader.FilterStrength[i] = (byte)filterStrengthValue;
}
if (vp8SegmentHeader.UpdateMap)
{
for (int s = 0; s < proba.Segments.Length; ++s)
{
hasValue = bitReader.ReadBool();
proba.Segments[s] = hasValue ? bitReader.ReadValue(8) : 255;
}
}
}
}
else
{
vp8SegmentHeader.UpdateMap = false;
}
return vp8SegmentHeader;
}
/// <summary>
/// Reads the header of a lossless webp image.
/// </summary>
@ -695,10 +506,5 @@ namespace SixLabors.ImageSharp.Formats.WebP
throw new ImageFormatException("Invalid WebP data.");
}
private int Clip(int v, int M)
{
return v < 0 ? 0 : v > M ? M : v;
}
}
}

10
src/ImageSharp/Formats/WebP/WebPImageInfo.cs
View File

@ -45,16 +45,6 @@ namespace SixLabors.ImageSharp.Formats.WebP
/// </summary>
public Vp8PictureHeader Vp8PictureHeader { get; set; }
/// <summary>
/// Gets or sets the VP8 segment header.
/// </summary>
public Vp8SegmentHeader Vp8SegmentHeader { get; set; }
/// <summary>
/// Gets or sets the VP8 filter header.
/// </summary>
public Vp8FilterHeader Vp8FilterHeader { get; set; }
/// <summary>
/// Gets or sets the VP8L bitreader. Will be null, if its not lossless image.
/// </summary>

218
src/ImageSharp/Formats/WebP/WebPLossyDecoder.cs
View File

@ -1,11 +1,8 @@
// Copyright (c) Six Labors and contributors.
// Licensed under the Apache License, Version 2.0.
using System;
using System.Collections.Generic;
using System.IO;
using SixLabors.ImageSharp.Formats.Png.Filters;
using SixLabors.ImageSharp.Memory;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.Memory;
@ -36,6 +33,28 @@ namespace SixLabors.ImageSharp.Formats.WebP
// TODO residue signal from DCT: 4x4 blocks of DCT transforms, 16Y, 4U, 4V
Vp8Profile vp8Profile = this.DecodeProfile(vp8Version);
// Paragraph 9.3: Parse the segment header.
var proba = new Vp8Proba();
Vp8SegmentHeader vp8SegmentHeader = this.ParseSegmentHeader(proba);
// Paragraph 9.4: Parse the filter specs.
Vp8FilterHeader vp8FilterHeader = this.ParseFilterHeader();
// TODO: Review Paragraph 9.5: ParsePartitions.
int numPartsMinusOne = (1 << (int)this.bitReader.ReadValue(2)) - 1;
int lastPart = numPartsMinusOne;
// TODO: check if we have enough data available here, throw exception if not
int partStart = this.bitReader.Pos + (lastPart * 3);
// Paragraph 9.6: Dequantization Indices.
this.ParseDequantizationIndices(vp8SegmentHeader);
// Ignore the value of update_proba
this.bitReader.ReadBool();
// Paragraph 13.4: Parse probabilities.
this.ParseProbabilities(proba);
}
private Vp8Profile DecodeProfile(int version)
@ -58,11 +77,191 @@ namespace SixLabors.ImageSharp.Formats.WebP
}
}
private Vp8SegmentHeader ParseSegmentHeader(Vp8Proba proba)
{
var vp8SegmentHeader = new Vp8SegmentHeader
{
UseSegment = this.bitReader.ReadBool()
};
if (vp8SegmentHeader.UseSegment)
{
vp8SegmentHeader.UpdateMap = this.bitReader.ReadBool();
bool updateData = this.bitReader.ReadBool();
if (updateData)
{
vp8SegmentHeader.Delta = this.bitReader.ReadBool();
bool hasValue;
for (int i = 0; i < vp8SegmentHeader.Quantizer.Length; i++)
{
hasValue = this.bitReader.ReadBool();
uint quantizeValue = hasValue ? this.bitReader.ReadValue(7) : 0;
vp8SegmentHeader.Quantizer[i] = (byte)quantizeValue;
}
for (int i = 0; i < vp8SegmentHeader.FilterStrength.Length; i++)
{
hasValue = this.bitReader.ReadBool();
uint filterStrengthValue = hasValue ? this.bitReader.ReadValue(6) : 0;
vp8SegmentHeader.FilterStrength[i] = (byte)filterStrengthValue;
}
if (vp8SegmentHeader.UpdateMap)
{
for (int s = 0; s < proba.Segments.Length; ++s)
{
hasValue = bitReader.ReadBool();
proba.Segments[s] = hasValue ? bitReader.ReadValue(8) : 255;
}
}
}
}
else
{
vp8SegmentHeader.UpdateMap = false;
}
return vp8SegmentHeader;
}
private Vp8FilterHeader ParseFilterHeader()
{
var vp8FilterHeader = new Vp8FilterHeader();
vp8FilterHeader.LoopFilter = this.bitReader.ReadBool() ? LoopFilter.Simple : LoopFilter.Complex;
vp8FilterHeader.Level = (int)this.bitReader.ReadValue(6);
vp8FilterHeader.Sharpness = (int)this.bitReader.ReadValue(3);
vp8FilterHeader.UseLfDelta = this.bitReader.ReadBool();
// TODO: use enum here?
// 0 = 0ff, 1 = simple, 2 = complex
int filterType = (vp8FilterHeader.Level is 0) ? 0 : vp8FilterHeader.LoopFilter is LoopFilter.Simple ? 1 : 2;
if (vp8FilterHeader.UseLfDelta)
{
// Update lf-delta?
if (this.bitReader.ReadBool())
{
bool hasValue;
for (int i = 0; i < vp8FilterHeader.RefLfDelta.Length; i++)
{
hasValue = this.bitReader.ReadBool();
if (hasValue)
{
vp8FilterHeader.RefLfDelta[i] = this.bitReader.ReadSignedValue(6);
}
}
for (int i = 0; i < vp8FilterHeader.ModeLfDelta.Length; i++)
{
hasValue = this.bitReader.ReadBool();
if (hasValue)
{
vp8FilterHeader.ModeLfDelta[i] = this.bitReader.ReadSignedValue(6);
}
}
}
}
return vp8FilterHeader;
}
private void ParseDequantizationIndices(Vp8SegmentHeader vp8SegmentHeader)
{
int baseQ0 = (int)this.bitReader.ReadValue(7);
bool hasValue = this.bitReader.ReadBool();
int dqy1Dc = hasValue ? this.bitReader.ReadSignedValue(4) : 0;
hasValue = this.bitReader.ReadBool();
int dqy2Dc = hasValue ? this.bitReader.ReadSignedValue(4) : 0;
hasValue = this.bitReader.ReadBool();
int dqy2Ac = hasValue ? this.bitReader.ReadSignedValue(4) : 0;
hasValue = this.bitReader.ReadBool();
int dquvDc = hasValue ? this.bitReader.ReadSignedValue(4) : 0;
hasValue = this.bitReader.ReadBool();
int dquvAc = hasValue ? this.bitReader.ReadSignedValue(4) : 0;
for (int i = 0; i < WebPConstants.NumMbSegments; ++i)
{
int q;
if (vp8SegmentHeader.UseSegment)
{
q = vp8SegmentHeader.Quantizer[i];
if (!vp8SegmentHeader.Delta)
{
q += baseQ0;
}
}
else
{
if (i > 0)
{
// dec->dqm_[i] = dec->dqm_[0];
continue;
}
else
{
q = baseQ0;
}
}
var m = new Vp8QuantMatrix();
m.Y1Mat[0] = WebPConstants.DcTable[this.Clip(q + dqy1Dc, 127)];
m.Y1Mat[1] = WebPConstants.AcTable[this.Clip(q + 0, 127)];
m.Y2Mat[0] = WebPConstants.DcTable[this.Clip(q + dqy2Dc, 127)] * 2;
// For all x in [0..284], x*155/100 is bitwise equal to (x*101581) >> 16.
// The smallest precision for that is '(x*6349) >> 12' but 16 is a good word size.
m.Y2Mat[1] = (WebPConstants.AcTable[this.Clip(q + dqy2Ac, 127)] * 101581) >> 16;
if (m.Y2Mat[1] < 8)
{
m.Y2Mat[1] = 8;
}
m.UvMat[0] = WebPConstants.DcTable[this.Clip(q + dquvDc, 117)];
m.UvMat[1] = WebPConstants.AcTable[this.Clip(q + dquvAc, 127)];
// For dithering strength evaluation.
m.UvQuant = q + dquvAc;
}
}
private void ParseProbabilities(Vp8Proba proba)
{
for (int t = 0; t < WebPConstants.NumTypes; ++t)
{
for (int b = 0; b < WebPConstants.NumBands; ++b)
{
for (int c = 0; c < WebPConstants.NumCtx; ++c)
{
for (int p = 0; p < WebPConstants.NumProbas; ++p)
{
var prob = WebPConstants.CoeffsUpdateProba[t, b, c, p];
int v = this.bitReader.GetBit(prob) == 0
? (int)this.bitReader.ReadValue(8)
: WebPConstants.DefaultCoeffsProba[t, b, c, p];
proba.Bands[t, b].Probabilities[c].Probabilities[p] = (uint)v;
}
}
}
for (int b = 0; b < 16 + 1; ++b)
{
// TODO: This needs to be reviewed and fixed.
// proba->bands_ptr_[t][b] = &proba->bands_[t][kBands[b]];
}
}
// TODO: those values needs to be stored somewhere
bool useSkipProba = this.bitReader.ReadBool();
if (useSkipProba)
{
var skipP = this.bitReader.ReadValue(8);
}
}
static bool Is8bOptimizable(Vp8LMetadata hdr)
{
int i;
if (hdr.ColorCacheSize > 0)
{
return false;
}
// When the Huffman tree contains only one symbol, we can skip the
// call to ReadSymbol() for red/blue/alpha channels.
@ -70,15 +269,28 @@ namespace SixLabors.ImageSharp.Formats.WebP
{
List<HuffmanCode[]> htrees = hdr.HTreeGroups[i].HTrees;
if (htrees[HuffIndex.Red][0].Value > 0)
{
return false;
}
if (htrees[HuffIndex.Blue][0].Value > 0)
{
return false;
}
if (htrees[HuffIndex.Alpha][0].Value > 0)
{
return false;
}
}
return true;
}
private int Clip(int v, int M)
{
return v < 0 ? 0 : v > M ? M : v;
}
}
struct YUVPixel

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