tsai
/
ImageSharp
mirror of https://github.com/SixLabors/ImageSharp
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

Change huffman code to a struct

pull/1846/head
Brian Popow 5 years ago
parent
3de317f6d5
commit
40b6f4e55b
8 changed files with 35 additions and 38 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 4
      src/ImageSharp/Formats/Webp/Lossless/HTreeGroup.cs
  2. 2
      src/ImageSharp/Formats/Webp/Lossless/HuffmanCode.cs
  3. 45
      src/ImageSharp/Formats/Webp/Lossless/HuffmanUtils.cs
  4. 14
      src/ImageSharp/Formats/Webp/Lossless/WebpLosslessDecoder.cs
  5. 2
      tests/ImageSharp.Tests/Formats/WebP/ColorSpaceTransformUtilsTests.cs
  6. 2
      tests/ImageSharp.Tests/Formats/WebP/LossyUtilsTests.cs
  7. 2
      tests/ImageSharp.Tests/Formats/WebP/QuantEncTests.cs
  8. 2
      tests/ImageSharp.Tests/Formats/WebP/Vp8EncodingTests.cs

4
src/ImageSharp/Formats/Webp/Lossless/HTreeGroup.cs
View File

@ -19,10 +19,6 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
{ {
this.HTrees = new List<HuffmanCode[]>(WebpConstants.HuffmanCodesPerMetaCode); this.HTrees = new List<HuffmanCode[]>(WebpConstants.HuffmanCodesPerMetaCode);
this.PackedTable = new HuffmanCode[packedTableSize]; this.PackedTable = new HuffmanCode[packedTableSize];
for (int i = 0; i < packedTableSize; i++)
{
this.PackedTable[i] = new HuffmanCode();
}
} }
/// <summary> /// <summary>

2
src/ImageSharp/Formats/Webp/Lossless/HuffmanCode.cs
View File

@ -9,7 +9,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
/// A classic way to do entropy coding where a smaller number of bits are used for more frequent codes. /// A classic way to do entropy coding where a smaller number of bits are used for more frequent codes.
/// </summary> /// </summary>
[DebuggerDisplay("BitsUsed: {BitsUsed}, Value: {Value}")] [DebuggerDisplay("BitsUsed: {BitsUsed}, Value: {Value}")]
internal class HuffmanCode internal struct HuffmanCode
{ {
/// <summary> /// <summary>
/// Gets or sets the number of bits used for this symbol. /// Gets or sets the number of bits used for this symbol.

45
src/ImageSharp/Formats/Webp/Lossless/HuffmanUtils.cs
View File

@ -2,6 +2,7 @@
// Licensed under the Apache License, Version 2.0. // Licensed under the Apache License, Version 2.0.
using System; using System;
using System.Runtime.CompilerServices;
namespace SixLabors.ImageSharp.Formats.Webp.Lossless namespace SixLabors.ImageSharp.Formats.Webp.Lossless
{ {
@ -307,9 +308,9 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
public static int BuildHuffmanTable(Span<HuffmanCode> table, int rootBits, int[] codeLengths, int codeLengthsSize) public static int BuildHuffmanTable(Span<HuffmanCode> table, int rootBits, int[] codeLengths, int codeLengthsSize)
{ {
Guard.MustBeGreaterThan(rootBits, 0, nameof(rootBits)); DebugGuard.MustBeGreaterThan(rootBits, 0, nameof(rootBits));
Guard.NotNull(codeLengths, nameof(codeLengths)); DebugGuard.NotNull(codeLengths, nameof(codeLengths));
Guard.MustBeGreaterThan(codeLengthsSize, 0, nameof(codeLengthsSize)); DebugGuard.MustBeGreaterThan(codeLengthsSize, 0, nameof(codeLengthsSize));
// sorted[codeLengthsSize] is a pre-allocated array for sorting symbols by code length. // sorted[codeLengthsSize] is a pre-allocated array for sorting symbols by code length.
int[] sorted = new int[codeLengthsSize]; int[] sorted = new int[codeLengthsSize];
@ -467,27 +468,27 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
break; break;
} }
else if (repetitions < 11)
if (repetitions < 11)
{ {
tokens[pos].Code = 17; tokens[pos].Code = 17;
tokens[pos].ExtraBits = (byte)(repetitions - 3); tokens[pos].ExtraBits = (byte)(repetitions - 3);
pos++; pos++;
break; break;
} }
else if (repetitions < 139)
if (repetitions < 139)
{ {
tokens[pos].Code = 18; tokens[pos].Code = 18;
tokens[pos].ExtraBits = (byte)(repetitions - 11); tokens[pos].ExtraBits = (byte)(repetitions - 11);
pos++; pos++;
break; break;
} }
else
{ tokens[pos].Code = 18;
tokens[pos].Code = 18; tokens[pos].ExtraBits = 0x7f; // 138 repeated 0s
tokens[pos].ExtraBits = 0x7f; // 138 repeated 0s pos++;
pos++; repetitions -= 138;
repetitions -= 138;
}
} }
return pos; return pos;
@ -519,20 +520,19 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
break; break;
} }
else if (repetitions < 7)
if (repetitions < 7)
{ {
tokens[pos].Code = 16; tokens[pos].Code = 16;
tokens[pos].ExtraBits = (byte)(repetitions - 3); tokens[pos].ExtraBits = (byte)(repetitions - 3);
pos++; pos++;
break; break;
} }
else
{ tokens[pos].Code = 16;
tokens[pos].Code = 16; tokens[pos].ExtraBits = 3;
tokens[pos].ExtraBits = 3; pos++;
pos++; repetitions -= 6;
repetitions -= 6;
}
} }
return pos; return pos;
@ -541,7 +541,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
/// <summary> /// <summary>
/// Get the actual bit values for a tree of bit depths. /// Get the actual bit values for a tree of bit depths.
/// </summary> /// </summary>
/// <param name="tree">The hiffman tree.</param> /// <param name="tree">The huffman tree.</param>
private static void ConvertBitDepthsToSymbols(HuffmanTreeCode tree) private static void ConvertBitDepthsToSymbols(HuffmanTreeCode tree)
{ {
// 0 bit-depth means that the symbol does not exist. // 0 bit-depth means that the symbol does not exist.
@ -628,7 +628,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
/// </summary> /// </summary>
private static void ReplicateValue(Span<HuffmanCode> table, int step, int end, HuffmanCode code) private static void ReplicateValue(Span<HuffmanCode> table, int step, int end, HuffmanCode code)
{ {
Guard.IsTrue(end % step == 0, nameof(end), "end must be a multiple of step"); DebugGuard.IsTrue(end % step == 0, nameof(end), "end must be a multiple of step");
do do
{ {
@ -656,6 +656,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
/// <summary> /// <summary>
/// Heuristics for selecting the stride ranges to collapse. /// Heuristics for selecting the stride ranges to collapse.
/// </summary> /// </summary>
[MethodImpl(InliningOptions.ShortMethod)]
private static bool ValuesShouldBeCollapsedToStrideAverage(int a, int b) => Math.Abs(a - b) < 4; private static bool ValuesShouldBeCollapsedToStrideAverage(int a, int b) => Math.Abs(a - b) < 4;
} }
} }

14
src/ImageSharp/Formats/Webp/Lossless/WebpLosslessDecoder.cs
View File

@ -834,10 +834,10 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
private void BuildPackedTable(HTreeGroup hTreeGroup) private void BuildPackedTable(HTreeGroup hTreeGroup)
{ {
for (uint code = 0; code < HuffmanUtils.HuffmanPackedTableSize; ++code) for (uint code = 0; code < HuffmanUtils.HuffmanPackedTableSize; code++)
{ {
uint bits = code; uint bits = code;
HuffmanCode huff = hTreeGroup.PackedTable[bits]; ref HuffmanCode huff = ref hTreeGroup.PackedTable[bits];
HuffmanCode hCode = hTreeGroup.HTrees[HuffIndex.Green][bits]; HuffmanCode hCode = hTreeGroup.HTrees[HuffIndex.Green][bits];
if (hCode.Value >= WebpConstants.NumLiteralCodes) if (hCode.Value >= WebpConstants.NumLiteralCodes)
{ {
@ -848,10 +848,10 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
{ {
huff.BitsUsed = 0; huff.BitsUsed = 0;
huff.Value = 0; huff.Value = 0;
bits >>= AccumulateHCode(hCode, 8, huff); bits >>= AccumulateHCode(hCode, 8, ref huff);
bits >>= AccumulateHCode(hTreeGroup.HTrees[HuffIndex.Red][bits], 16, huff); bits >>= AccumulateHCode(hTreeGroup.HTrees[HuffIndex.Red][bits], 16, ref huff);
bits >>= AccumulateHCode(hTreeGroup.HTrees[HuffIndex.Blue][bits], 0, huff); bits >>= AccumulateHCode(hTreeGroup.HTrees[HuffIndex.Blue][bits], 0, ref huff);
bits >>= AccumulateHCode(hTreeGroup.HTrees[HuffIndex.Alpha][bits], 24, huff); bits >>= AccumulateHCode(hTreeGroup.HTrees[HuffIndex.Alpha][bits], 24, ref huff);
} }
} }
} }
@ -992,7 +992,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
} }
[MethodImpl(InliningOptions.ShortMethod)] [MethodImpl(InliningOptions.ShortMethod)]
private static int AccumulateHCode(HuffmanCode hCode, int shift, HuffmanCode huff) private static int AccumulateHCode(HuffmanCode hCode, int shift, ref HuffmanCode huff)
{ {
huff.BitsUsed += hCode.BitsUsed; huff.BitsUsed += hCode.BitsUsed;
huff.Value |= hCode.Value << shift; huff.Value |= hCode.Value << shift;

2
tests/ImageSharp.Tests/Formats/WebP/ColorSpaceTransformUtilsTests.cs
View File

@ -5,7 +5,7 @@ using SixLabors.ImageSharp.Formats.Webp.Lossless;
using SixLabors.ImageSharp.Tests.TestUtilities; using SixLabors.ImageSharp.Tests.TestUtilities;
using Xunit; using Xunit;
namespace SixLabors.ImageSharp.Tests.Formats.WebP namespace SixLabors.ImageSharp.Tests.Formats.Webp
{ {
[Trait("Format", "Webp")] [Trait("Format", "Webp")]
public class ColorSpaceTransformUtilsTests public class ColorSpaceTransformUtilsTests

2
tests/ImageSharp.Tests/Formats/WebP/LossyUtilsTests.cs
View File

@ -6,7 +6,7 @@ using SixLabors.ImageSharp.Formats.Webp.Lossy;
using SixLabors.ImageSharp.Tests.TestUtilities; using SixLabors.ImageSharp.Tests.TestUtilities;
using Xunit; using Xunit;
namespace SixLabors.ImageSharp.Tests.Formats.WebP namespace SixLabors.ImageSharp.Tests.Formats.Webp
{ {
[Trait("Format", "Webp")] [Trait("Format", "Webp")]
public class LossyUtilsTests public class LossyUtilsTests

2
tests/ImageSharp.Tests/Formats/WebP/QuantEncTests.cs
View File

@ -6,7 +6,7 @@ using SixLabors.ImageSharp.Formats.Webp.Lossy;
using SixLabors.ImageSharp.Tests.TestUtilities; using SixLabors.ImageSharp.Tests.TestUtilities;
using Xunit; using Xunit;
namespace SixLabors.ImageSharp.Tests.Formats.WebP namespace SixLabors.ImageSharp.Tests.Formats.Webp
{ {
[Trait("Format", "Webp")] [Trait("Format", "Webp")]
public class QuantEncTests public class QuantEncTests

2
tests/ImageSharp.Tests/Formats/WebP/Vp8EncodingTests.cs
View File

@ -6,7 +6,7 @@ using SixLabors.ImageSharp.Formats.Webp.Lossy;
using SixLabors.ImageSharp.Tests.TestUtilities; using SixLabors.ImageSharp.Tests.TestUtilities;
using Xunit; using Xunit;
namespace SixLabors.ImageSharp.Tests.Formats.WebP namespace SixLabors.ImageSharp.Tests.Formats.Webp
{ {
[Trait("Format", "Webp")] [Trait("Format", "Webp")]
public class Vp8EncodingTests public class Vp8EncodingTests

Write Preview
Loading…
Cancel
Save