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

Divided YCbCr converters into 444/420 subsampling categories

pull/1632/head
Dmitry Pentin 5 years ago
parent
0d94435d65
commit
13e7cf358f
3 changed files with 130 additions and 114 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 4
      src/ImageSharp/Formats/Jpeg/Components/Encoder/HuffmanScanEncoder.cs
  2. 118
      src/ImageSharp/Formats/Jpeg/Components/Encoder/YCbCrForwardConverter444{TPixel}.cs
  3. 122
      src/ImageSharp/Formats/Jpeg/Components/Encoder/YCbCrForwardConverter{TPixel}.cs

4
src/ImageSharp/Formats/Jpeg/Components/Encoder/HuffmanScanEncoder.cs
View File

@ -71,7 +71,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
// ReSharper disable once InconsistentNaming
int prevDCY = 0, prevDCCb = 0, prevDCCr = 0;
var pixelConverter = YCbCrForwardConverter<TPixel>.Create();
var pixelConverter = YCbCrForwardConverter444<TPixel>.Create();
ImageFrame<TPixel> frame = pixels.Frames.RootFrame;
Buffer2D<TPixel> pixelBuffer = frame.PixelBuffer;
RowOctet<TPixel> currentRows = default;
@ -125,7 +125,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
{
var unzig = ZigZag.CreateUnzigTable();
var pixelConverter = YCbCrForwardConverter<TPixel>.Create();
var pixelConverter = YCbCrForwardConverter444<TPixel>.Create();
// ReSharper disable once InconsistentNaming
int prevDCY = 0, prevDCCb = 0, prevDCCr = 0;

118
src/ImageSharp/Formats/Jpeg/Components/Encoder/YCbCrForwardConverter444{TPixel}.cs
View File

@ -0,0 +1,118 @@
// Copyright (c) Six Labors.
// Licensed under the Apache License, Version 2.0.
using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using SixLabors.ImageSharp.Advanced;
using SixLabors.ImageSharp.PixelFormats;
namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
{
/// <summary>
/// On-stack worker struct to efficiently encapsulate the TPixel -> Rgb24 -> YCbCr conversion chain of 8x8 pixel blocks.
/// </summary>
/// <typeparam name="TPixel">The pixel type to work on</typeparam>
internal ref struct YCbCrForwardConverter444<TPixel>
where TPixel : unmanaged, IPixel<TPixel>
{
/// <summary>
/// The Y component
/// </summary>
public Block8x8F Y;
/// <summary>
/// The Cb component
/// </summary>
public Block8x8F Cb;
/// <summary>
/// The Cr component
/// </summary>
public Block8x8F Cr;
/// <summary>
/// The color conversion tables
/// </summary>
private RgbToYCbCrConverterLut colorTables;
/// <summary>
/// Temporal 8x8 block to hold TPixel data
/// </summary>
private Span<TPixel> pixelSpan;
/// <summary>
/// Temporal RGB block
/// </summary>
private Span<Rgb24> rgbSpan;
public Span<Block8x8F> twinBlocksY;
public static YCbCrForwardConverter444<TPixel> Create()
{
var result = default(YCbCrForwardConverter444<TPixel>);
// creating rgb pixel bufferr
// TODO: this is subject to discuss
const int twoBlocksByteSizeWithPadding = 384 + 8; // converter.Convert comments for +8 padding
result.rgbSpan = MemoryMarshal.Cast<byte, Rgb24>(new byte[twoBlocksByteSizeWithPadding].AsSpan());
// TODO: this size should be configurable
result.pixelSpan = new TPixel[128].AsSpan();
result.twinBlocksY = new Block8x8F[2].AsSpan();
// Avoid creating lookup tables, when vectorized converter is supported
if (!RgbToYCbCrConverterVectorized.IsSupported)
{
result.colorTables = RgbToYCbCrConverterLut.Create();
}
return result;
}
/// <summary>
/// Converts a 8x8 image area inside 'pixels' at position (x,y) placing the result members of the structure (<see cref="Y"/>, <see cref="Cb"/>, <see cref="Cr"/>)
/// </summary>
public void Convert(ImageFrame<TPixel> frame, int x, int y, ref RowOctet<TPixel> currentRows)
{
Memory.Buffer2D<TPixel> buffer = frame.PixelBuffer;
YCbCrForwardConverter<TPixel>.LoadAndStretchEdges(currentRows, this.pixelSpan, new Point(x, y), new Size(8), new Size(buffer.Width, buffer.Height));
PixelOperations<TPixel>.Instance.ToRgb24(frame.GetConfiguration(), this.pixelSpan, this.rgbSpan);
ref Block8x8F yBlock = ref this.Y;
ref Block8x8F cbBlock = ref this.Cb;
ref Block8x8F crBlock = ref this.Cr;
if (RgbToYCbCrConverterVectorized.IsSupported)
{
RgbToYCbCrConverterVectorized.Convert(this.rgbSpan, ref yBlock, ref cbBlock, ref crBlock);
}
else
{
this.colorTables.Convert(this.rgbSpan, ref yBlock, ref cbBlock, ref crBlock);
}
}
/// <summary>
/// Converts a 8x8 image area inside 'pixels' at position (x,y) placing the result members of the structure (<see cref="Y"/>, <see cref="Cb"/>, <see cref="Cr"/>)
/// </summary>
public void Convert420(ImageFrame<TPixel> frame, int x, int y, ref RowOctet<TPixel> currentRows, int idx)
{
Memory.Buffer2D<TPixel> buffer = frame.PixelBuffer;
YCbCrForwardConverter<TPixel>.LoadAndStretchEdges(currentRows, this.pixelSpan, new Point(x, y), new Size(16, 8), new Size(buffer.Width, buffer.Height));
PixelOperations<TPixel>.Instance.ToRgb24(frame.GetConfiguration(), this.pixelSpan, this.rgbSpan);
if (RgbToYCbCrConverterVectorized.IsSupported)
{
RgbToYCbCrConverterVectorized.Convert420_16x8(this.rgbSpan, this.twinBlocksY, ref this.Cb, ref this.Cr, idx);
}
else
{
throw new NotSupportedException("This is not yet implemented");
//this.colorTables.Convert(this.rgbSpan, ref yBlock, ref cbBlock, ref crBlock);
}
}
}
}

122
src/ImageSharp/Formats/Jpeg/Components/Encoder/YCbCrForwardConverter{TPixel}.cs
View File

@ -4,134 +4,32 @@
using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using SixLabors.ImageSharp.Advanced;
using SixLabors.ImageSharp.PixelFormats;
namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
{
/// <summary>
/// On-stack worker struct to efficiently encapsulate the TPixel -> Rgb24 -> YCbCr conversion chain of 8x8 pixel blocks.
/// </summary>
/// <typeparam name="TPixel">The pixel type to work on</typeparam>
internal ref struct YCbCrForwardConverter<TPixel>
internal static class YCbCrForwardConverter<TPixel>
where TPixel : unmanaged, IPixel<TPixel>
{
/// <summary>
/// The Y component
/// </summary>
public Block8x8F Y;
/// <summary>
/// The Cb component
/// </summary>
public Block8x8F Cb;
/// <summary>
/// The Cr component
/// </summary>
public Block8x8F Cr;
/// <summary>
/// The color conversion tables
/// </summary>
private RgbToYCbCrConverterLut colorTables;
/// <summary>
/// Temporal 8x8 block to hold TPixel data
/// </summary>
private Span<TPixel> pixelSpan;
/// <summary>
/// Temporal RGB block
/// </summary>
private Span<Rgb24> rgbSpan;
public Span<Block8x8F> twinBlocksY;
public static YCbCrForwardConverter<TPixel> Create()
{
var result = default(YCbCrForwardConverter<TPixel>);
// creating rgb pixel bufferr
// TODO: this is subject to discuss
const int twoBlocksByteSizeWithPadding = 384 + 8; // converter.Convert comments for +8 padding
result.rgbSpan = MemoryMarshal.Cast<byte, Rgb24>(new byte[twoBlocksByteSizeWithPadding].AsSpan());
// TODO: this size should be configurable
result.pixelSpan = new TPixel[128].AsSpan();
result.twinBlocksY = new Block8x8F[2].AsSpan();
// Avoid creating lookup tables, when vectorized converter is supported
if (!RgbToYCbCrConverterVectorized.IsSupported)
{
result.colorTables = RgbToYCbCrConverterLut.Create();
}
return result;
}
/// <summary>
/// Converts a 8x8 image area inside 'pixels' at position (x,y) placing the result members of the structure (<see cref="Y"/>, <see cref="Cb"/>, <see cref="Cr"/>)
/// </summary>
public void Convert(ImageFrame<TPixel> frame, int x, int y, ref RowOctet<TPixel> currentRows)
public static void LoadAndStretchEdges(RowOctet<TPixel> source, Span<TPixel> dest, Point start, Size sampleSize, Size totalSize)
{
Memory.Buffer2D<TPixel> buffer = frame.PixelBuffer;
LoadAndStretchEdges(currentRows, this.pixelSpan, x, y, new Size(8), new Size(buffer.Width, buffer.Height));
PixelOperations<TPixel>.Instance.ToRgb24(frame.GetConfiguration(), this.pixelSpan, this.rgbSpan);
ref Block8x8F yBlock = ref this.Y;
ref Block8x8F cbBlock = ref this.Cb;
ref Block8x8F crBlock = ref this.Cr;
DebugGuard.MustBeBetweenOrEqualTo(start.X, 1, totalSize.Width - 1, nameof(start.X));
DebugGuard.MustBeBetweenOrEqualTo(start.Y, 1, totalSize.Height - 1, nameof(start.Y));
if (RgbToYCbCrConverterVectorized.IsSupported)
{
RgbToYCbCrConverterVectorized.Convert(this.rgbSpan, ref yBlock, ref cbBlock, ref crBlock);
}
else
{
this.colorTables.Convert(this.rgbSpan, ref yBlock, ref cbBlock, ref crBlock);
}
}
/// <summary>
/// Converts a 8x8 image area inside 'pixels' at position (x,y) placing the result members of the structure (<see cref="Y"/>, <see cref="Cb"/>, <see cref="Cr"/>)
/// </summary>
public void Convert420(ImageFrame<TPixel> frame, int x, int y, ref RowOctet<TPixel> currentRows, int idx)
{
Memory.Buffer2D<TPixel> buffer = frame.PixelBuffer;
LoadAndStretchEdges(currentRows, this.pixelSpan, x, y, new Size(16, 8), new Size(buffer.Width, buffer.Height));
PixelOperations<TPixel>.Instance.ToRgb24(frame.GetConfiguration(), this.pixelSpan, this.rgbSpan);
if (RgbToYCbCrConverterVectorized.IsSupported)
{
RgbToYCbCrConverterVectorized.Convert420_16x8(this.rgbSpan, this.twinBlocksY, ref this.Cb, ref this.Cr, idx);
}
else
{
throw new NotSupportedException("This is not yet implemented");
//this.colorTables.Convert(this.rgbSpan, ref yBlock, ref cbBlock, ref crBlock);
}
}
private static void LoadAndStretchEdges(RowOctet<TPixel> source, Span<TPixel> dest, int startX, int startY, Size areaSize, Size borders)
{
int width = Math.Min(areaSize.Width, borders.Width - startX);
int height = Math.Min(areaSize.Height, borders.Height - startY);
int width = Math.Min(sampleSize.Width, totalSize.Width - start.X);
int height = Math.Min(sampleSize.Height, totalSize.Height - start.Y);
uint byteWidth = (uint)(width * Unsafe.SizeOf<TPixel>());
int remainderXCount = areaSize.Width - width;
int remainderXCount = sampleSize.Width - width;
ref byte blockStart = ref MemoryMarshal.GetReference(MemoryMarshal.Cast<TPixel, byte>(dest));
int rowSizeInBytes = areaSize.Width * Unsafe.SizeOf<TPixel>();
int rowSizeInBytes = sampleSize.Width * Unsafe.SizeOf<TPixel>();
for (int y = 0; y < height; y++)
{
Span<TPixel> row = source[y];
ref byte s = ref Unsafe.As<TPixel, byte>(ref row[startX]);
ref byte s = ref Unsafe.As<TPixel, byte>(ref row[start.X]);
ref byte d = ref Unsafe.Add(ref blockStart, y * rowSizeInBytes);
Unsafe.CopyBlock(ref d, ref s, byteWidth);
@ -144,7 +42,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
}
}
int remainderYCount = areaSize.Height - height;
int remainderYCount = sampleSize.Height - height;
if (remainderYCount == 0)
{

Write Preview
Loading…
Cancel
Save