mirror of https://github.com/SixLabors/ImageSharp
James Jackson-South
8 years ago
454 changed files with 3078 additions and 2852 deletions
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using System.Diagnostics; |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System.Diagnostics; |
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using SixLabors.ImageSharp.PixelFormats; |
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namespace SixLabors.ImageSharp.Processing.Drawing.Brushes.GradientBrushes |
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namespace SixLabors.ImageSharp.Processing |
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{ |
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/// <summary>
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/// A struct that defines a single color stop.
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@ -1,9 +1,12 @@ |
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using System; |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System; |
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.Primitives; |
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namespace SixLabors.ImageSharp.Processing.Drawing.Brushes.GradientBrushes |
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namespace SixLabors.ImageSharp.Processing |
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{ |
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/// <summary>
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/// Gradient Brush with elliptic shape.
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@ -1,11 +1,14 @@ |
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using System; |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System; |
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using System.Numerics; |
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.ImageSharp.PixelFormats.PixelBlenders; |
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using SixLabors.Primitives; |
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namespace SixLabors.ImageSharp.Processing.Drawing.Brushes.GradientBrushes |
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namespace SixLabors.ImageSharp.Processing |
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{ |
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/// <summary>
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/// Base class for Gradient brushes
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@ -1,4 +1,7 @@ |
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namespace SixLabors.ImageSharp.Processing.Drawing.Brushes.GradientBrushes |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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namespace SixLabors.ImageSharp.Processing |
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{ |
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/// <summary>
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/// Modes to repeat a gradient.
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@ -1,9 +1,12 @@ |
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using System; |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System; |
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.Primitives; |
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namespace SixLabors.ImageSharp.Processing.Drawing.Brushes.GradientBrushes |
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namespace SixLabors.ImageSharp.Processing |
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{ |
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/// <summary>
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/// Provides an implementation of a brush for painting linear gradients within areas.
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@ -1,9 +1,12 @@ |
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using System; |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System; |
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.Primitives; |
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namespace SixLabors.ImageSharp.Processing.Drawing.Brushes.GradientBrushes |
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namespace SixLabors.ImageSharp.Processing |
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{ |
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/// <summary>
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/// A Circular Gradient Brush, defined by center point and radius.
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@ -1,46 +0,0 @@ |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System.Collections.Generic; |
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namespace SixLabors.ImageSharp.Common.Extensions |
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{ |
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/// <summary>
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/// Encapsulates a series of time saving extension methods to the <see cref="T:System.Collections.Generic.List"/> class.
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/// </summary>
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internal static class ListExtensions |
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{ |
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/// <summary>
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/// Inserts an item at the given index automatically expanding the capacity if required.
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/// </summary>
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/// <typeparam name="T">The type of object within the list</typeparam>
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/// <param name="list">The list</param>
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/// <param name="index">The index</param>
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/// <param name="item">The item to insert</param>
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public static void SafeInsert<T>(this List<T> list, int index, T item) |
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{ |
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if (index >= list.Count) |
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{ |
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list.Add(item); |
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} |
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else |
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{ |
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list[index] = item; |
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} |
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} |
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/// <summary>
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/// Removes the last element from a list and returns that element. This method changes the length of the list.
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/// </summary>
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/// <typeparam name="T">The type of object within the list</typeparam>
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/// <param name="list">The list</param>
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/// <returns>The last element in the specified sequence.</returns>
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public static T Pop<T>(this List<T> list) |
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{ |
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int last = list.Count - 1; |
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T item = list[last]; |
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list.RemoveAt(last); |
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return item; |
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} |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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// Uncomment this for verbose profiler results:
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// #define PROFILING
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using System.Runtime.CompilerServices; |
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namespace SixLabors.ImageSharp |
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{ |
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/// <summary>
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/// Global inlining options. Helps temporarily disable inling for better profiler output.
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/// </summary>
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internal static class InliningOptions |
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{ |
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#if PROFILING
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public const MethodImplOptions ShortMethod = 0; |
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#else
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public const MethodImplOptions ShortMethod = MethodImplOptions.AggressiveInlining; |
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#endif
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public const MethodImplOptions ColdPath = MethodImplOptions.NoInlining; |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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namespace SixLabors.ImageSharp.Formats.Gif |
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{ |
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/// <summary>
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/// Provides enumeration for the available Gif color table modes.
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/// </summary>
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public enum GifColorTableMode |
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{ |
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/// <summary>
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/// A single color table is calculated from the first frame and reused for subsequent frames.
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/// </summary>
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Global, |
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/// <summary>
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/// A unique color table is calculated for each frame.
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/// </summary>
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Local |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System.Runtime.CompilerServices; |
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namespace SixLabors.ImageSharp.Formats.Jpeg |
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{ |
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internal static class JpegThrowHelper |
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{ |
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/// <summary>
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/// Cold path optimization for throwing <see cref="ImageFormatException"/>-s
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/// </summary>
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/// <param name="errorMessage">The error message for the exception</param>
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[MethodImpl(MethodImplOptions.NoInlining)] |
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public static void ThrowImageFormatException(string errorMessage) |
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{ |
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throw new ImageFormatException(errorMessage); |
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} |
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[MethodImpl(MethodImplOptions.NoInlining)] |
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public static void ThrowBadHuffmanCode() |
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{ |
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throw new ImageFormatException("Bad Huffman code."); |
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} |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System; |
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using System.Runtime.CompilerServices; |
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using SixLabors.Memory; |
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namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components |
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{ |
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/// <summary>
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/// The collection of lookup tables used for fast AC entropy scan decoding.
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/// </summary>
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internal sealed class FastACTables : IDisposable |
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{ |
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private Buffer2D<short> tables; |
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/// <summary>
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/// Initializes a new instance of the <see cref="FastACTables"/> class.
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/// </summary>
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/// <param name="memoryAllocator">The memory allocator used to allocate memory for image processing operations.</param>
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public FastACTables(MemoryAllocator memoryAllocator) |
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{ |
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this.tables = memoryAllocator.AllocateClean2D<short>(512, 4); |
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} |
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/// <summary>
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/// Gets the <see cref="Span{Int16}"/> representing the table at the index in the collection.
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/// </summary>
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/// <param name="index">The table index.</param>
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/// <returns><see cref="Span{Int16}"/></returns>
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[MethodImpl(MethodImplOptions.AggressiveInlining)] |
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public ReadOnlySpan<short> GetTableSpan(int index) |
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{ |
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return this.tables.GetRowSpan(index); |
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} |
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/// <summary>
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/// Gets a reference to the first element of the AC table indexed by <see cref="PdfJsFrameComponent.ACHuffmanTableId"/>
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/// </summary>
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[MethodImpl(MethodImplOptions.AggressiveInlining)] |
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public ref short GetAcTableReference(PdfJsFrameComponent component) |
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{ |
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return ref this.tables.GetRowSpan(component.ACHuffmanTableId)[0]; |
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} |
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/// <summary>
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/// Builds a lookup table for fast AC entropy scan decoding.
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/// </summary>
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/// <param name="index">The table index.</param>
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/// <param name="acHuffmanTables">The collection of AC Huffman tables.</param>
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public void BuildACTableLut(int index, PdfJsHuffmanTables acHuffmanTables) |
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{ |
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const int FastBits = ScanDecoder.FastBits; |
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Span<short> fastAC = this.tables.GetRowSpan(index); |
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ref PdfJsHuffmanTable huffman = ref acHuffmanTables[index]; |
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int i; |
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for (i = 0; i < (1 << FastBits); i++) |
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{ |
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byte fast = huffman.Lookahead[i]; |
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fastAC[i] = 0; |
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if (fast < byte.MaxValue) |
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{ |
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int rs = huffman.Values[fast]; |
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int run = (rs >> 4) & 15; |
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int magbits = rs & 15; |
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int len = huffman.Sizes[fast]; |
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if (magbits > 0 && len + magbits <= FastBits) |
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{ |
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// Magnitude code followed by receive_extend code
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int k = ((i << len) & ((1 << FastBits) - 1)) >> (FastBits - magbits); |
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int m = 1 << (magbits - 1); |
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if (k < m) |
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{ |
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k += (int)((~0U << magbits) + 1); |
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} |
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// if the result is small enough, we can fit it in fastAC table
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if (k >= -128 && k <= 127) |
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{ |
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fastAC[i] = (short)((k * 256) + (run * 16) + (len + magbits)); |
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} |
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} |
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} |
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} |
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} |
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/// <inheritdoc />
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public void Dispose() |
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{ |
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this.tables?.Dispose(); |
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this.tables = null; |
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} |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System.Runtime.CompilerServices; |
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using System.Runtime.InteropServices; |
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namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components |
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{ |
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[StructLayout(LayoutKind.Sequential)] |
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internal unsafe struct FixedByteBuffer512 |
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{ |
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public fixed byte Data[1 << ScanDecoder.FastBits]; |
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public byte this[int idx] |
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{ |
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[MethodImpl(MethodImplOptions.AggressiveInlining)] |
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get |
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{ |
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ref byte self = ref Unsafe.As<FixedByteBuffer512, byte>(ref this); |
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return Unsafe.Add(ref self, idx); |
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} |
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} |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System; |
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#if DEBUG
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using System.Diagnostics; |
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#endif
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using System.Runtime.CompilerServices; |
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using System.Runtime.InteropServices; |
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using SixLabors.ImageSharp.Formats.Jpeg.Components; |
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using SixLabors.Memory; |
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namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components |
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{ |
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/// <summary>
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/// Provides the means to decode a spectral scan
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/// </summary>
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internal struct PdfJsScanDecoder |
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{ |
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private ZigZag dctZigZag; |
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private byte[] markerBuffer; |
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private int mcuToRead; |
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private int mcusPerLine; |
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private int mcu; |
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private int bitsData; |
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private int bitsCount; |
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private int specStart; |
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private int specEnd; |
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private int eobrun; |
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private int compIndex; |
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private int successiveState; |
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private int successiveACState; |
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private int successiveACNextValue; |
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private bool endOfStreamReached; |
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private bool unexpectedMarkerReached; |
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/// <summary>
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/// Decodes the spectral scan
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/// </summary>
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/// <param name="frame">The image frame</param>
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/// <param name="stream">The input stream</param>
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/// <param name="dcHuffmanTables">The DC Huffman tables</param>
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/// <param name="acHuffmanTables">The AC Huffman tables</param>
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/// <param name="components">The scan components</param>
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/// <param name="componentIndex">The component index within the array</param>
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/// <param name="componentsLength">The length of the components. Different to the array length</param>
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/// <param name="resetInterval">The reset interval</param>
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/// <param name="spectralStart">The spectral selection start</param>
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/// <param name="spectralEnd">The spectral selection end</param>
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/// <param name="successivePrev">The successive approximation bit high end</param>
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/// <param name="successive">The successive approximation bit low end</param>
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public void DecodeScan( |
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PdfJsFrame frame, |
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DoubleBufferedStreamReader stream, |
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PdfJsHuffmanTables dcHuffmanTables, |
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PdfJsHuffmanTables acHuffmanTables, |
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PdfJsFrameComponent[] components, |
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int componentIndex, |
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int componentsLength, |
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ushort resetInterval, |
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int spectralStart, |
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int spectralEnd, |
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int successivePrev, |
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int successive) |
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{ |
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this.dctZigZag = ZigZag.CreateUnzigTable(); |
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this.markerBuffer = new byte[2]; |
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this.compIndex = componentIndex; |
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this.specStart = spectralStart; |
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this.specEnd = spectralEnd; |
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this.successiveState = successive; |
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this.endOfStreamReached = false; |
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this.unexpectedMarkerReached = false; |
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bool progressive = frame.Progressive; |
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this.mcusPerLine = frame.McusPerLine; |
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this.mcu = 0; |
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int mcuExpected; |
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if (componentsLength == 1) |
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{ |
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mcuExpected = components[this.compIndex].WidthInBlocks * components[this.compIndex].HeightInBlocks; |
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} |
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else |
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{ |
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mcuExpected = this.mcusPerLine * frame.McusPerColumn; |
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} |
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while (this.mcu < mcuExpected) |
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{ |
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// Reset interval stuff
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this.mcuToRead = resetInterval != 0 ? Math.Min(mcuExpected - this.mcu, resetInterval) : mcuExpected; |
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for (int i = 0; i < components.Length; i++) |
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{ |
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PdfJsFrameComponent c = components[i]; |
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c.DcPredictor = 0; |
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} |
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this.eobrun = 0; |
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if (!progressive) |
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{ |
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this.DecodeScanBaseline(dcHuffmanTables, acHuffmanTables, components, componentsLength, stream); |
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} |
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else |
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{ |
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bool isAc = this.specStart != 0; |
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bool isFirst = successivePrev == 0; |
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PdfJsHuffmanTables huffmanTables = isAc ? acHuffmanTables : dcHuffmanTables; |
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this.DecodeScanProgressive(huffmanTables, isAc, isFirst, components, componentsLength, stream); |
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} |
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// Reset
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// TODO: I do not understand why these values are reset? We should surely be tracking the bits across mcu's?
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this.bitsCount = 0; |
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this.bitsData = 0; |
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this.unexpectedMarkerReached = false; |
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// Some images include more scan blocks than expected, skip past those and
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// attempt to find the next valid marker
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PdfJsFileMarker fileMarker = PdfJsJpegDecoderCore.FindNextFileMarker(this.markerBuffer, stream); |
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byte marker = fileMarker.Marker; |
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// RSTn - We've already read the bytes and altered the position so no need to skip
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if (marker >= JpegConstants.Markers.RST0 && marker <= JpegConstants.Markers.RST7) |
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{ |
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continue; |
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} |
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if (!fileMarker.Invalid) |
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{ |
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// We've found a valid marker.
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// Rewind the stream to the position of the marker and break
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stream.Position = fileMarker.Position; |
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break; |
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} |
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#if DEBUG
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Debug.WriteLine($"DecodeScan - Unexpected MCU data at {stream.Position}, next marker is: {fileMarker.Marker:X}"); |
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#endif
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} |
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} |
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private void DecodeScanBaseline( |
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PdfJsHuffmanTables dcHuffmanTables, |
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PdfJsHuffmanTables acHuffmanTables, |
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PdfJsFrameComponent[] components, |
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int componentsLength, |
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DoubleBufferedStreamReader stream) |
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{ |
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if (componentsLength == 1) |
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{ |
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PdfJsFrameComponent component = components[this.compIndex]; |
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ref short blockDataRef = ref MemoryMarshal.GetReference(MemoryMarshal.Cast<Block8x8, short>(component.SpectralBlocks.GetSpan())); |
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ref PdfJsHuffmanTable dcHuffmanTable = ref dcHuffmanTables[component.DCHuffmanTableId]; |
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ref PdfJsHuffmanTable acHuffmanTable = ref acHuffmanTables[component.ACHuffmanTableId]; |
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for (int n = 0; n < this.mcuToRead; n++) |
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{ |
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if (this.endOfStreamReached || this.unexpectedMarkerReached) |
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{ |
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continue; |
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} |
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this.DecodeBlockBaseline(ref dcHuffmanTable, ref acHuffmanTable, component, ref blockDataRef, stream); |
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this.mcu++; |
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} |
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} |
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else |
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{ |
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for (int n = 0; n < this.mcuToRead; n++) |
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{ |
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for (int i = 0; i < componentsLength; i++) |
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{ |
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PdfJsFrameComponent component = components[i]; |
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ref short blockDataRef = ref MemoryMarshal.GetReference(MemoryMarshal.Cast<Block8x8, short>(component.SpectralBlocks.GetSpan())); |
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ref PdfJsHuffmanTable dcHuffmanTable = ref dcHuffmanTables[component.DCHuffmanTableId]; |
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ref PdfJsHuffmanTable acHuffmanTable = ref acHuffmanTables[component.ACHuffmanTableId]; |
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int h = component.HorizontalSamplingFactor; |
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int v = component.VerticalSamplingFactor; |
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for (int j = 0; j < v; j++) |
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{ |
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for (int k = 0; k < h; k++) |
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{ |
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if (this.endOfStreamReached || this.unexpectedMarkerReached) |
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{ |
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continue; |
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} |
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this.DecodeMcuBaseline(ref dcHuffmanTable, ref acHuffmanTable, component, ref blockDataRef, j, k, stream); |
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} |
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} |
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} |
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this.mcu++; |
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} |
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} |
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} |
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private void DecodeScanProgressive( |
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PdfJsHuffmanTables huffmanTables, |
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bool isAC, |
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bool isFirst, |
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PdfJsFrameComponent[] components, |
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int componentsLength, |
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DoubleBufferedStreamReader stream) |
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{ |
|||
if (componentsLength == 1) |
|||
{ |
|||
PdfJsFrameComponent component = components[this.compIndex]; |
|||
ref short blockDataRef = ref MemoryMarshal.GetReference(MemoryMarshal.Cast<Block8x8, short>(component.SpectralBlocks.GetSpan())); |
|||
ref PdfJsHuffmanTable huffmanTable = ref huffmanTables[isAC ? component.ACHuffmanTableId : component.DCHuffmanTableId]; |
|||
|
|||
for (int n = 0; n < this.mcuToRead; n++) |
|||
{ |
|||
if (this.endOfStreamReached || this.unexpectedMarkerReached) |
|||
{ |
|||
continue; |
|||
} |
|||
|
|||
if (isAC) |
|||
{ |
|||
if (isFirst) |
|||
{ |
|||
this.DecodeBlockACFirst(ref huffmanTable, component, ref blockDataRef, stream); |
|||
} |
|||
else |
|||
{ |
|||
this.DecodeBlockACSuccessive(ref huffmanTable, component, ref blockDataRef, stream); |
|||
} |
|||
} |
|||
else |
|||
{ |
|||
if (isFirst) |
|||
{ |
|||
this.DecodeBlockDCFirst(ref huffmanTable, component, ref blockDataRef, stream); |
|||
} |
|||
else |
|||
{ |
|||
this.DecodeBlockDCSuccessive(component, ref blockDataRef, stream); |
|||
} |
|||
} |
|||
|
|||
this.mcu++; |
|||
} |
|||
} |
|||
else |
|||
{ |
|||
for (int n = 0; n < this.mcuToRead; n++) |
|||
{ |
|||
for (int i = 0; i < componentsLength; i++) |
|||
{ |
|||
PdfJsFrameComponent component = components[i]; |
|||
ref short blockDataRef = ref MemoryMarshal.GetReference(MemoryMarshal.Cast<Block8x8, short>(component.SpectralBlocks.GetSpan())); |
|||
ref PdfJsHuffmanTable huffmanTable = ref huffmanTables[isAC ? component.ACHuffmanTableId : component.DCHuffmanTableId]; |
|||
int h = component.HorizontalSamplingFactor; |
|||
int v = component.VerticalSamplingFactor; |
|||
|
|||
for (int j = 0; j < v; j++) |
|||
{ |
|||
for (int k = 0; k < h; k++) |
|||
{ |
|||
// No need to continue here.
|
|||
if (this.endOfStreamReached || this.unexpectedMarkerReached) |
|||
{ |
|||
break; |
|||
} |
|||
|
|||
if (isAC) |
|||
{ |
|||
if (isFirst) |
|||
{ |
|||
this.DecodeMcuACFirst(ref huffmanTable, component, ref blockDataRef, j, k, stream); |
|||
} |
|||
else |
|||
{ |
|||
this.DecodeMcuACSuccessive(ref huffmanTable, component, ref blockDataRef, j, k, stream); |
|||
} |
|||
} |
|||
else |
|||
{ |
|||
if (isFirst) |
|||
{ |
|||
this.DecodeMcuDCFirst(ref huffmanTable, component, ref blockDataRef, j, k, stream); |
|||
} |
|||
else |
|||
{ |
|||
this.DecodeMcuDCSuccessive(component, ref blockDataRef, j, k, stream); |
|||
} |
|||
} |
|||
} |
|||
} |
|||
} |
|||
|
|||
this.mcu++; |
|||
} |
|||
} |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeBlockBaseline(ref PdfJsHuffmanTable dcHuffmanTable, ref PdfJsHuffmanTable acHuffmanTable, PdfJsFrameComponent component, ref short blockDataRef, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int blockRow = this.mcu / component.WidthInBlocks; |
|||
int blockCol = this.mcu % component.WidthInBlocks; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeBaseline(component, ref blockDataRef, offset, ref dcHuffmanTable, ref acHuffmanTable, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeMcuBaseline(ref PdfJsHuffmanTable dcHuffmanTable, ref PdfJsHuffmanTable acHuffmanTable, PdfJsFrameComponent component, ref short blockDataRef, int row, int col, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int mcuRow = this.mcu / this.mcusPerLine; |
|||
int mcuCol = this.mcu % this.mcusPerLine; |
|||
int blockRow = (mcuRow * component.VerticalSamplingFactor) + row; |
|||
int blockCol = (mcuCol * component.HorizontalSamplingFactor) + col; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeBaseline(component, ref blockDataRef, offset, ref dcHuffmanTable, ref acHuffmanTable, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeBlockDCFirst(ref PdfJsHuffmanTable dcHuffmanTable, PdfJsFrameComponent component, ref short blockDataRef, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int blockRow = this.mcu / component.WidthInBlocks; |
|||
int blockCol = this.mcu % component.WidthInBlocks; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeDCFirst(component, ref blockDataRef, offset, ref dcHuffmanTable, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeMcuDCFirst(ref PdfJsHuffmanTable dcHuffmanTable, PdfJsFrameComponent component, ref short blockDataRef, int row, int col, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int mcuRow = this.mcu / this.mcusPerLine; |
|||
int mcuCol = this.mcu % this.mcusPerLine; |
|||
int blockRow = (mcuRow * component.VerticalSamplingFactor) + row; |
|||
int blockCol = (mcuCol * component.HorizontalSamplingFactor) + col; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeDCFirst(component, ref blockDataRef, offset, ref dcHuffmanTable, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeBlockDCSuccessive(PdfJsFrameComponent component, ref short blockDataRef, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int blockRow = this.mcu / component.WidthInBlocks; |
|||
int blockCol = this.mcu % component.WidthInBlocks; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeDCSuccessive(component, ref blockDataRef, offset, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeMcuDCSuccessive(PdfJsFrameComponent component, ref short blockDataRef, int row, int col, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int mcuRow = this.mcu / this.mcusPerLine; |
|||
int mcuCol = this.mcu % this.mcusPerLine; |
|||
int blockRow = (mcuRow * component.VerticalSamplingFactor) + row; |
|||
int blockCol = (mcuCol * component.HorizontalSamplingFactor) + col; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeDCSuccessive(component, ref blockDataRef, offset, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeBlockACFirst(ref PdfJsHuffmanTable acHuffmanTable, PdfJsFrameComponent component, ref short blockDataRef, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int blockRow = this.mcu / component.WidthInBlocks; |
|||
int blockCol = this.mcu % component.WidthInBlocks; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeACFirst(ref blockDataRef, offset, ref acHuffmanTable, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeMcuACFirst(ref PdfJsHuffmanTable acHuffmanTable, PdfJsFrameComponent component, ref short blockDataRef, int row, int col, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int mcuRow = this.mcu / this.mcusPerLine; |
|||
int mcuCol = this.mcu % this.mcusPerLine; |
|||
int blockRow = (mcuRow * component.VerticalSamplingFactor) + row; |
|||
int blockCol = (mcuCol * component.HorizontalSamplingFactor) + col; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeACFirst(ref blockDataRef, offset, ref acHuffmanTable, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeBlockACSuccessive(ref PdfJsHuffmanTable acHuffmanTable, PdfJsFrameComponent component, ref short blockDataRef, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int blockRow = this.mcu / component.WidthInBlocks; |
|||
int blockCol = this.mcu % component.WidthInBlocks; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeACSuccessive(ref blockDataRef, offset, ref acHuffmanTable, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeMcuACSuccessive(ref PdfJsHuffmanTable acHuffmanTable, PdfJsFrameComponent component, ref short blockDataRef, int row, int col, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int mcuRow = this.mcu / this.mcusPerLine; |
|||
int mcuCol = this.mcu % this.mcusPerLine; |
|||
int blockRow = (mcuRow * component.VerticalSamplingFactor) + row; |
|||
int blockCol = (mcuCol * component.HorizontalSamplingFactor) + col; |
|||
int offset = component.GetBlockBufferOffset(blockRow, blockCol); |
|||
this.DecodeACSuccessive(ref blockDataRef, offset, ref acHuffmanTable, stream); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private bool TryReadBit(DoubleBufferedStreamReader stream, out int bit) |
|||
{ |
|||
if (this.bitsCount == 0) |
|||
{ |
|||
if (!this.TryFillBits(stream)) |
|||
{ |
|||
bit = 0; |
|||
return false; |
|||
} |
|||
} |
|||
|
|||
this.bitsCount--; |
|||
bit = (this.bitsData >> this.bitsCount) & 1; |
|||
return true; |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.NoInlining)] |
|||
private bool TryFillBits(DoubleBufferedStreamReader stream) |
|||
{ |
|||
// TODO: Read more then 1 byte at a time.
|
|||
// In LibJpegTurbo this is be 25 bits (32-7) but I cannot get this to work
|
|||
// for some images, I'm assuming because I am crossing MCU boundaries and not maintining the correct buffer state.
|
|||
const int MinGetBits = 7; |
|||
|
|||
if (!this.unexpectedMarkerReached) |
|||
{ |
|||
// Attempt to load to the minimum bit count.
|
|||
while (this.bitsCount < MinGetBits) |
|||
{ |
|||
int c = stream.ReadByte(); |
|||
|
|||
switch (c) |
|||
{ |
|||
case -0x1: |
|||
|
|||
// We've encountered the end of the file stream which means there's no EOI marker in the image.
|
|||
this.endOfStreamReached = true; |
|||
return false; |
|||
|
|||
case JpegConstants.Markers.XFF: |
|||
int nextByte = stream.ReadByte(); |
|||
|
|||
if (nextByte == -0x1) |
|||
{ |
|||
this.endOfStreamReached = true; |
|||
return false; |
|||
} |
|||
|
|||
if (nextByte != 0) |
|||
{ |
|||
#if DEBUG
|
|||
Debug.WriteLine($"DecodeScan - Unexpected marker {(c << 8) | nextByte:X} at {stream.Position}"); |
|||
#endif
|
|||
|
|||
// We've encountered an unexpected marker. Reverse the stream and exit.
|
|||
this.unexpectedMarkerReached = true; |
|||
stream.Position -= 2; |
|||
|
|||
// TODO: double check we need this.
|
|||
// Fill buffer with zero bits.
|
|||
if (this.bitsCount == 0) |
|||
{ |
|||
this.bitsData <<= MinGetBits; |
|||
this.bitsCount = MinGetBits; |
|||
} |
|||
|
|||
return true; |
|||
} |
|||
|
|||
break; |
|||
} |
|||
|
|||
// OK, load the next byte into bitsData
|
|||
this.bitsData = (this.bitsData << 8) | c; |
|||
this.bitsCount += 8; |
|||
} |
|||
} |
|||
|
|||
return true; |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private int PeekBits(int count) |
|||
{ |
|||
return this.bitsData >> (this.bitsCount - count) & ((1 << count) - 1); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DropBits(int count) |
|||
{ |
|||
this.bitsCount -= count; |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private bool TryDecodeHuffman(ref PdfJsHuffmanTable tree, DoubleBufferedStreamReader stream, out short value) |
|||
{ |
|||
value = -1; |
|||
|
|||
// TODO: Implement fast Huffman decoding.
|
|||
// In LibJpegTurbo a minimum of 25 bits (32-7) is collected from the stream
|
|||
// Then a LUT is used to avoid the loop when decoding the Huffman value.
|
|||
// using 3 methods: FillBits, PeekBits, and DropBits.
|
|||
// The LUT has been ported from LibJpegTurbo as has this code but it doesn't work.
|
|||
// this.TryFillBits(stream);
|
|||
//
|
|||
// const int LookAhead = 8;
|
|||
// int look = this.PeekBits(LookAhead);
|
|||
// look = tree.Lookahead[look];
|
|||
// int bits = look >> LookAhead;
|
|||
//
|
|||
// if (bits <= LookAhead)
|
|||
// {
|
|||
// this.DropBits(bits);
|
|||
// value = (short)(look & ((1 << LookAhead) - 1));
|
|||
// return true;
|
|||
// }
|
|||
if (!this.TryReadBit(stream, out int bit)) |
|||
{ |
|||
return false; |
|||
} |
|||
|
|||
short code = (short)bit; |
|||
|
|||
// "DECODE", section F.2.2.3, figure F.16, page 109 of T.81
|
|||
int i = 1; |
|||
|
|||
while (code > tree.MaxCode[i]) |
|||
{ |
|||
if (!this.TryReadBit(stream, out bit)) |
|||
{ |
|||
return false; |
|||
} |
|||
|
|||
code <<= 1; |
|||
code |= (short)bit; |
|||
i++; |
|||
} |
|||
|
|||
int j = tree.ValOffset[i]; |
|||
value = tree.HuffVal[(j + code) & 0xFF]; |
|||
return true; |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private bool TryReceive(int length, DoubleBufferedStreamReader stream, out int value) |
|||
{ |
|||
value = 0; |
|||
while (length > 0) |
|||
{ |
|||
if (!this.TryReadBit(stream, out int bit)) |
|||
{ |
|||
return false; |
|||
} |
|||
|
|||
value = (value << 1) | bit; |
|||
length--; |
|||
} |
|||
|
|||
return true; |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private bool TryReceiveAndExtend(int length, DoubleBufferedStreamReader stream, out int value) |
|||
{ |
|||
if (length == 1) |
|||
{ |
|||
if (!this.TryReadBit(stream, out value)) |
|||
{ |
|||
return false; |
|||
} |
|||
|
|||
value = value == 1 ? 1 : -1; |
|||
} |
|||
else |
|||
{ |
|||
if (!this.TryReceive(length, stream, out value)) |
|||
{ |
|||
return false; |
|||
} |
|||
|
|||
if (value < 1 << (length - 1)) |
|||
{ |
|||
value += (-1 << length) + 1; |
|||
} |
|||
} |
|||
|
|||
return true; |
|||
} |
|||
|
|||
private void DecodeBaseline(PdfJsFrameComponent component, ref short blockDataRef, int offset, ref PdfJsHuffmanTable dcHuffmanTable, ref PdfJsHuffmanTable acHuffmanTable, DoubleBufferedStreamReader stream) |
|||
{ |
|||
if (!this.TryDecodeHuffman(ref dcHuffmanTable, stream, out short t)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int diff = 0; |
|||
if (t != 0) |
|||
{ |
|||
if (!this.TryReceiveAndExtend(t, stream, out diff)) |
|||
{ |
|||
return; |
|||
} |
|||
} |
|||
|
|||
Unsafe.Add(ref blockDataRef, offset) = (short)(component.DcPredictor += diff); |
|||
|
|||
int k = 1; |
|||
while (k < 64) |
|||
{ |
|||
if (!this.TryDecodeHuffman(ref acHuffmanTable, stream, out short rs)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int s = rs & 15; |
|||
int r = rs >> 4; |
|||
|
|||
if (s == 0) |
|||
{ |
|||
if (r < 15) |
|||
{ |
|||
break; |
|||
} |
|||
|
|||
k += 16; |
|||
continue; |
|||
} |
|||
|
|||
k += r; |
|||
|
|||
byte z = this.dctZigZag[k]; |
|||
|
|||
if (!this.TryReceiveAndExtend(s, stream, out int re)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
Unsafe.Add(ref blockDataRef, offset + z) = (short)re; |
|||
k++; |
|||
} |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeDCFirst(PdfJsFrameComponent component, ref short blockDataRef, int offset, ref PdfJsHuffmanTable dcHuffmanTable, DoubleBufferedStreamReader stream) |
|||
{ |
|||
if (!this.TryDecodeHuffman(ref dcHuffmanTable, stream, out short t)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int diff = 0; |
|||
if (t != 0) |
|||
{ |
|||
if (!this.TryReceiveAndExtend(t, stream, out diff)) |
|||
{ |
|||
return; |
|||
} |
|||
} |
|||
|
|||
Unsafe.Add(ref blockDataRef, offset) = (short)(component.DcPredictor += diff << this.successiveState); |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private void DecodeDCSuccessive(PdfJsFrameComponent component, ref short blockDataRef, int offset, DoubleBufferedStreamReader stream) |
|||
{ |
|||
if (!this.TryReadBit(stream, out int bit)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
Unsafe.Add(ref blockDataRef, offset) |= (short)(bit << this.successiveState); |
|||
} |
|||
|
|||
private void DecodeACFirst(ref short blockDataRef, int offset, ref PdfJsHuffmanTable acHuffmanTable, DoubleBufferedStreamReader stream) |
|||
{ |
|||
if (this.eobrun > 0) |
|||
{ |
|||
this.eobrun--; |
|||
return; |
|||
} |
|||
|
|||
int k = this.specStart; |
|||
int e = this.specEnd; |
|||
while (k <= e) |
|||
{ |
|||
if (!this.TryDecodeHuffman(ref acHuffmanTable, stream, out short rs)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int s = rs & 15; |
|||
int r = rs >> 4; |
|||
|
|||
if (s == 0) |
|||
{ |
|||
if (r < 15) |
|||
{ |
|||
if (!this.TryReceive(r, stream, out int eob)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
this.eobrun = eob + (1 << r) - 1; |
|||
break; |
|||
} |
|||
|
|||
k += 16; |
|||
continue; |
|||
} |
|||
|
|||
k += r; |
|||
|
|||
byte z = this.dctZigZag[k]; |
|||
|
|||
if (!this.TryReceiveAndExtend(s, stream, out int v)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
Unsafe.Add(ref blockDataRef, offset + z) = (short)(v * (1 << this.successiveState)); |
|||
k++; |
|||
} |
|||
} |
|||
|
|||
private void DecodeACSuccessive(ref short blockDataRef, int offset, ref PdfJsHuffmanTable acHuffmanTable, DoubleBufferedStreamReader stream) |
|||
{ |
|||
int k = this.specStart; |
|||
int e = this.specEnd; |
|||
int r = 0; |
|||
|
|||
while (k <= e) |
|||
{ |
|||
int offsetZ = offset + this.dctZigZag[k]; |
|||
ref short blockOffsetZRef = ref Unsafe.Add(ref blockDataRef, offsetZ); |
|||
int sign = blockOffsetZRef < 0 ? -1 : 1; |
|||
|
|||
switch (this.successiveACState) |
|||
{ |
|||
case 0: // Initial state
|
|||
|
|||
if (!this.TryDecodeHuffman(ref acHuffmanTable, stream, out short rs)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int s = rs & 15; |
|||
r = rs >> 4; |
|||
if (s == 0) |
|||
{ |
|||
if (r < 15) |
|||
{ |
|||
if (!this.TryReceive(r, stream, out int eob)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
this.eobrun = eob + (1 << r); |
|||
this.successiveACState = 4; |
|||
} |
|||
else |
|||
{ |
|||
r = 16; |
|||
this.successiveACState = 1; |
|||
} |
|||
} |
|||
else |
|||
{ |
|||
if (s != 1) |
|||
{ |
|||
throw new ImageFormatException("Invalid ACn encoding"); |
|||
} |
|||
|
|||
if (!this.TryReceiveAndExtend(s, stream, out int v)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
this.successiveACNextValue = v; |
|||
this.successiveACState = r > 0 ? 2 : 3; |
|||
} |
|||
|
|||
continue; |
|||
case 1: // Skipping r zero items
|
|||
case 2: |
|||
if (blockOffsetZRef != 0) |
|||
{ |
|||
if (!this.TryReadBit(stream, out int bit)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
blockOffsetZRef += (short)(sign * (bit << this.successiveState)); |
|||
} |
|||
else |
|||
{ |
|||
r--; |
|||
if (r == 0) |
|||
{ |
|||
this.successiveACState = this.successiveACState == 2 ? 3 : 0; |
|||
} |
|||
} |
|||
|
|||
break; |
|||
case 3: // Set value for a zero item
|
|||
if (blockOffsetZRef != 0) |
|||
{ |
|||
if (!this.TryReadBit(stream, out int bit)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
blockOffsetZRef += (short)(sign * (bit << this.successiveState)); |
|||
} |
|||
else |
|||
{ |
|||
blockOffsetZRef = (short)(this.successiveACNextValue << this.successiveState); |
|||
this.successiveACState = 0; |
|||
} |
|||
|
|||
break; |
|||
case 4: // Eob
|
|||
if (blockOffsetZRef != 0) |
|||
{ |
|||
if (!this.TryReadBit(stream, out int bit)) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
blockOffsetZRef += (short)(sign * (bit << this.successiveState)); |
|||
} |
|||
|
|||
break; |
|||
} |
|||
|
|||
k++; |
|||
} |
|||
|
|||
if (this.successiveACState == 4) |
|||
{ |
|||
this.eobrun--; |
|||
if (this.eobrun == 0) |
|||
{ |
|||
this.successiveACState = 0; |
|||
} |
|||
} |
|||
} |
|||
} |
|||
} |
|||
@ -0,0 +1,958 @@ |
|||
// Copyright (c) Six Labors and contributors.
|
|||
// Licensed under the Apache License, Version 2.0.
|
|||
|
|||
using System.Runtime.CompilerServices; |
|||
using System.Runtime.InteropServices; |
|||
using SixLabors.ImageSharp.Formats.Jpeg.Components; |
|||
|
|||
namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components |
|||
{ |
|||
/// <summary>
|
|||
/// Decodes the Huffman encoded spectral scan.
|
|||
/// Originally ported from <see href="https://github.com/rds1983/StbSharp"/>
|
|||
/// with additional fixes for both performance and common encoding errors.
|
|||
/// </summary>
|
|||
internal class ScanDecoder |
|||
{ |
|||
// The number of bits that can be read via a LUT.
|
|||
public const int FastBits = 9; |
|||
|
|||
// LUT mask for n rightmost bits. Bmask[n] = (1 << n) - 1
|
|||
private static readonly uint[] Bmask = { 0, 1, 3, 7, 15, 31, 63, 127, 255, 511, 1023, 2047, 4095, 8191, 16383, 32767, 65535 }; |
|||
|
|||
// LUT Bias[n] = (-1 << n) + 1
|
|||
private static readonly int[] Bias = { 0, -1, -3, -7, -15, -31, -63, -127, -255, -511, -1023, -2047, -4095, -8191, -16383, -32767 }; |
|||
|
|||
private readonly PdfJsFrame frame; |
|||
private readonly PdfJsHuffmanTables dcHuffmanTables; |
|||
private readonly PdfJsHuffmanTables acHuffmanTables; |
|||
private readonly FastACTables fastACTables; |
|||
|
|||
private readonly DoubleBufferedStreamReader stream; |
|||
private readonly PdfJsFrameComponent[] components; |
|||
private readonly ZigZag dctZigZag; |
|||
|
|||
// The restart interval.
|
|||
private readonly int restartInterval; |
|||
|
|||
// The current component index.
|
|||
private readonly int componentIndex; |
|||
|
|||
// The number of interleaved components.
|
|||
private readonly int componentsLength; |
|||
|
|||
// The spectral selection start.
|
|||
private readonly int spectralStart; |
|||
|
|||
// The spectral selection end.
|
|||
private readonly int spectralEnd; |
|||
|
|||
// The successive approximation high bit end.
|
|||
private readonly int successiveHigh; |
|||
|
|||
// The successive approximation low bit end.
|
|||
private readonly int successiveLow; |
|||
|
|||
// The number of valid bits left to read in the buffer.
|
|||
private int codeBits; |
|||
|
|||
// The entropy encoded code buffer.
|
|||
private uint codeBuffer; |
|||
|
|||
// Whether there is more data to pull from the stream for the current mcu.
|
|||
private bool nomore; |
|||
|
|||
// Whether we have prematurely reached the end of the file.
|
|||
private bool eof; |
|||
|
|||
// The current, if any, marker in the input stream.
|
|||
private byte marker; |
|||
|
|||
// Whether we have a bad marker, I.E. One that is not between RST0 and RST7
|
|||
private bool badMarker; |
|||
|
|||
// The opening position of an identified marker.
|
|||
private long markerPosition; |
|||
|
|||
// How many mcu's are left to do.
|
|||
private int todo; |
|||
|
|||
// The End-Of-Block countdown for ending the sequence prematurely when the remaining coefficients are zero.
|
|||
private int eobrun; |
|||
|
|||
/// <summary>
|
|||
/// Initializes a new instance of the <see cref="ScanDecoder"/> class.
|
|||
/// </summary>
|
|||
/// <param name="stream">The input stream.</param>
|
|||
/// <param name="frame">The image frame.</param>
|
|||
/// <param name="dcHuffmanTables">The DC Huffman tables.</param>
|
|||
/// <param name="acHuffmanTables">The AC Huffman tables.</param>
|
|||
/// <param name="fastACTables">The fast AC decoding tables.</param>
|
|||
/// <param name="componentIndex">The component index within the array.</param>
|
|||
/// <param name="componentsLength">The length of the components. Different to the array length.</param>
|
|||
/// <param name="restartInterval">The reset interval.</param>
|
|||
/// <param name="spectralStart">The spectral selection start.</param>
|
|||
/// <param name="spectralEnd">The spectral selection end.</param>
|
|||
/// <param name="successiveHigh">The successive approximation bit high end.</param>
|
|||
/// <param name="successiveLow">The successive approximation bit low end.</param>
|
|||
public ScanDecoder( |
|||
DoubleBufferedStreamReader stream, |
|||
PdfJsFrame frame, |
|||
PdfJsHuffmanTables dcHuffmanTables, |
|||
PdfJsHuffmanTables acHuffmanTables, |
|||
FastACTables fastACTables, |
|||
int componentIndex, |
|||
int componentsLength, |
|||
int restartInterval, |
|||
int spectralStart, |
|||
int spectralEnd, |
|||
int successiveHigh, |
|||
int successiveLow) |
|||
{ |
|||
this.dctZigZag = ZigZag.CreateUnzigTable(); |
|||
this.stream = stream; |
|||
this.frame = frame; |
|||
this.dcHuffmanTables = dcHuffmanTables; |
|||
this.acHuffmanTables = acHuffmanTables; |
|||
this.fastACTables = fastACTables; |
|||
this.components = frame.Components; |
|||
this.marker = JpegConstants.Markers.XFF; |
|||
this.markerPosition = 0; |
|||
this.componentIndex = componentIndex; |
|||
this.componentsLength = componentsLength; |
|||
this.restartInterval = restartInterval; |
|||
this.spectralStart = spectralStart; |
|||
this.spectralEnd = spectralEnd; |
|||
this.successiveHigh = successiveHigh; |
|||
this.successiveLow = successiveLow; |
|||
} |
|||
|
|||
/// <summary>
|
|||
/// Decodes the entropy coded data.
|
|||
/// </summary>
|
|||
public void ParseEntropyCodedData() |
|||
{ |
|||
this.Reset(); |
|||
|
|||
if (!this.frame.Progressive) |
|||
{ |
|||
this.ParseBaselineData(); |
|||
} |
|||
else |
|||
{ |
|||
this.ParseProgressiveData(); |
|||
} |
|||
|
|||
if (this.badMarker) |
|||
{ |
|||
this.stream.Position = this.markerPosition; |
|||
} |
|||
} |
|||
|
|||
[MethodImpl(MethodImplOptions.AggressiveInlining)] |
|||
private static uint LRot(uint x, int y) => (x << y) | (x >> (32 - y)); |
|||
|
|||
private void ParseBaselineData() |
|||
{ |
|||
if (this.componentsLength == 1) |
|||
{ |
|||
this.ParseBaselineDataNonInterleaved(); |
|||
} |
|||
else |
|||
{ |
|||
this.ParseBaselineDataInterleaved(); |
|||
} |
|||
} |
|||
|
|||
private void ParseBaselineDataInterleaved() |
|||
{ |
|||
// Interleaved
|
|||
int mcu = 0; |
|||
int mcusPerColumn = this.frame.McusPerColumn; |
|||
int mcusPerLine = this.frame.McusPerLine; |
|||
for (int j = 0; j < mcusPerColumn; j++) |
|||
{ |
|||
for (int i = 0; i < mcusPerLine; i++) |
|||
{ |
|||
// Scan an interleaved mcu... process components in order
|
|||
for (int k = 0; k < this.componentsLength; k++) |
|||
{ |
|||
PdfJsFrameComponent component = this.components[k]; |
|||
|
|||
ref PdfJsHuffmanTable dcHuffmanTable = ref this.dcHuffmanTables[component.DCHuffmanTableId]; |
|||
ref PdfJsHuffmanTable acHuffmanTable = ref this.acHuffmanTables[component.ACHuffmanTableId]; |
|||
ref short fastACRef = ref this.fastACTables.GetAcTableReference(component); |
|||
int h = component.HorizontalSamplingFactor; |
|||
int v = component.VerticalSamplingFactor; |
|||
|
|||
// Scan out an mcu's worth of this component; that's just determined
|
|||
// by the basic H and V specified for the component
|
|||
for (int y = 0; y < v; y++) |
|||
{ |
|||
for (int x = 0; x < h; x++) |
|||
{ |
|||
if (this.eof) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int mcuRow = mcu / mcusPerLine; |
|||
int mcuCol = mcu % mcusPerLine; |
|||
int blockRow = (mcuRow * v) + y; |
|||
int blockCol = (mcuCol * h) + x; |
|||
|
|||
this.DecodeBlockBaseline( |
|||
component, |
|||
blockRow, |
|||
blockCol, |
|||
ref dcHuffmanTable, |
|||
ref acHuffmanTable, |
|||
ref fastACRef); |
|||
} |
|||
} |
|||
} |
|||
|
|||
// After all interleaved components, that's an interleaved MCU,
|
|||
// so now count down the restart interval
|
|||
mcu++; |
|||
if (!this.ContinueOnMcuComplete()) |
|||
{ |
|||
return; |
|||
} |
|||
} |
|||
} |
|||
} |
|||
|
|||
/// <summary>
|
|||
/// Non-interleaved data, we just need to process one block at a ti
|
|||
/// in trivial scanline order
|
|||
/// number of blocks to do just depends on how many actual "pixels"
|
|||
/// component has, independent of interleaved MCU blocking and such
|
|||
/// </summary>
|
|||
private void ParseBaselineDataNonInterleaved() |
|||
{ |
|||
PdfJsFrameComponent component = this.components[this.componentIndex]; |
|||
|
|||
int w = component.WidthInBlocks; |
|||
int h = component.HeightInBlocks; |
|||
|
|||
ref PdfJsHuffmanTable dcHuffmanTable = ref this.dcHuffmanTables[component.DCHuffmanTableId]; |
|||
ref PdfJsHuffmanTable acHuffmanTable = ref this.acHuffmanTables[component.ACHuffmanTableId]; |
|||
ref short fastACRef = ref this.fastACTables.GetAcTableReference(component); |
|||
|
|||
int mcu = 0; |
|||
for (int j = 0; j < h; j++) |
|||
{ |
|||
for (int i = 0; i < w; i++) |
|||
{ |
|||
if (this.eof) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int blockRow = mcu / w; |
|||
int blockCol = mcu % w; |
|||
|
|||
this.DecodeBlockBaseline( |
|||
component, |
|||
blockRow, |
|||
blockCol, |
|||
ref dcHuffmanTable, |
|||
ref acHuffmanTable, |
|||
ref fastACRef); |
|||
|
|||
// Every data block is an MCU, so countdown the restart interval
|
|||
mcu++; |
|||
if (!this.ContinueOnMcuComplete()) |
|||
{ |
|||
return; |
|||
} |
|||
} |
|||
} |
|||
} |
|||
|
|||
private void ParseProgressiveData() |
|||
{ |
|||
if (this.componentsLength == 1) |
|||
{ |
|||
this.ParseProgressiveDataNonInterleaved(); |
|||
} |
|||
else |
|||
{ |
|||
this.ParseProgressiveDataInterleaved(); |
|||
} |
|||
} |
|||
|
|||
private void ParseProgressiveDataInterleaved() |
|||
{ |
|||
// Interleaved
|
|||
int mcu = 0; |
|||
int mcusPerColumn = this.frame.McusPerColumn; |
|||
int mcusPerLine = this.frame.McusPerLine; |
|||
for (int j = 0; j < mcusPerColumn; j++) |
|||
{ |
|||
for (int i = 0; i < mcusPerLine; i++) |
|||
{ |
|||
// Scan an interleaved mcu... process components in order
|
|||
for (int k = 0; k < this.componentsLength; k++) |
|||
{ |
|||
PdfJsFrameComponent component = this.components[k]; |
|||
ref PdfJsHuffmanTable dcHuffmanTable = ref this.dcHuffmanTables[component.DCHuffmanTableId]; |
|||
int h = component.HorizontalSamplingFactor; |
|||
int v = component.VerticalSamplingFactor; |
|||
|
|||
// Scan out an mcu's worth of this component; that's just determined
|
|||
// by the basic H and V specified for the component
|
|||
for (int y = 0; y < v; y++) |
|||
{ |
|||
for (int x = 0; x < h; x++) |
|||
{ |
|||
if (this.eof) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int mcuRow = mcu / mcusPerLine; |
|||
int mcuCol = mcu % mcusPerLine; |
|||
int blockRow = (mcuRow * v) + y; |
|||
int blockCol = (mcuCol * h) + x; |
|||
|
|||
this.DecodeBlockProgressiveDC( |
|||
component, |
|||
blockRow, |
|||
blockCol, |
|||
ref dcHuffmanTable); |
|||
} |
|||
} |
|||
} |
|||
|
|||
// After all interleaved components, that's an interleaved MCU,
|
|||
// so now count down the restart interval
|
|||
mcu++; |
|||
if (!this.ContinueOnMcuComplete()) |
|||
{ |
|||
return; |
|||
} |
|||
} |
|||
} |
|||
} |
|||
|
|||
/// <summary>
|
|||
/// Non-interleaved data, we just need to process one block at a time,
|
|||
/// in trivial scanline order
|
|||
/// number of blocks to do just depends on how many actual "pixels" this
|
|||
/// component has, independent of interleaved MCU blocking and such
|
|||
/// </summary>
|
|||
private void ParseProgressiveDataNonInterleaved() |
|||
{ |
|||
PdfJsFrameComponent component = this.components[this.componentIndex]; |
|||
|
|||
int w = component.WidthInBlocks; |
|||
int h = component.HeightInBlocks; |
|||
|
|||
ref PdfJsHuffmanTable dcHuffmanTable = ref this.dcHuffmanTables[component.DCHuffmanTableId]; |
|||
ref PdfJsHuffmanTable acHuffmanTable = ref this.acHuffmanTables[component.ACHuffmanTableId]; |
|||
ref short fastACRef = ref this.fastACTables.GetAcTableReference(component); |
|||
|
|||
int mcu = 0; |
|||
for (int j = 0; j < h; j++) |
|||
{ |
|||
for (int i = 0; i < w; i++) |
|||
{ |
|||
if (this.eof) |
|||
{ |
|||
return; |
|||
} |
|||
|
|||
int blockRow = mcu / w; |
|||
int blockCol = mcu % w; |
|||
|
|||
if (this.spectralStart == 0) |
|||
{ |
|||
this.DecodeBlockProgressiveDC( |
|||
component, |
|||
blockRow, |
|||
blockCol, |
|||
ref dcHuffmanTable); |
|||
} |
|||
else |
|||
{ |
|||
this.DecodeBlockProgressiveAC( |
|||
component, |
|||
blockRow, |
|||
blockCol, |
|||
ref acHuffmanTable, |
|||
ref fastACRef); |
|||
} |
|||
|
|||
// Every data block is an MCU, so countdown the restart interval
|
|||
mcu++; |
|||
if (!this.ContinueOnMcuComplete()) |
|||
{ |
|||
return; |
|||
} |
|||
} |
|||
} |
|||
} |
|||
|
|||
private void DecodeBlockBaseline( |
|||
PdfJsFrameComponent component, |
|||
int row, |
|||
int col, |
|||
ref PdfJsHuffmanTable dcTable, |
|||
ref PdfJsHuffmanTable acTable, |
|||
ref short fastACRef) |
|||
{ |
|||
this.CheckBits(); |
|||
int t = this.DecodeHuffman(ref dcTable); |
|||
|
|||
if (t < 0) |
|||
{ |
|||
JpegThrowHelper.ThrowBadHuffmanCode(); |
|||
} |
|||
|
|||
ref short blockDataRef = ref component.GetBlockDataReference(row, col); |
|||
|
|||
int diff = t != 0 ? this.ExtendReceive(t) : 0; |
|||
int dc = component.DcPredictor + diff; |
|||
component.DcPredictor = dc; |
|||
blockDataRef = (short)dc; |
|||
|
|||
// Decode AC Components, See Jpeg Spec
|
|||
int k = 1; |
|||
do |
|||
{ |
|||
int zig; |
|||
int s; |
|||
|
|||
this.CheckBits(); |
|||
int c = this.PeekBits(); |
|||
int r = Unsafe.Add(ref fastACRef, c); |
|||
|
|||
if (r != 0) |
|||
{ |
|||
// Fast AC path
|
|||
k += (r >> 4) & 15; // Run
|
|||
s = r & 15; // Combined Length
|
|||
this.codeBuffer <<= s; |
|||
this.codeBits -= s; |
|||
|
|||
// Decode into unzigzag location
|
|||
zig = this.dctZigZag[k++]; |
|||
Unsafe.Add(ref blockDataRef, zig) = (short)(r >> 8); |
|||
} |
|||
else |
|||
{ |
|||
int rs = this.DecodeHuffman(ref acTable); |
|||
|
|||
if (rs < 0) |
|||
{ |
|||
JpegThrowHelper.ThrowBadHuffmanCode(); |
|||
} |
|||
|
|||
s = rs & 15; |
|||
r = rs >> 4; |
|||
|
|||
if (s == 0) |
|||
{ |
|||
if (rs != 0xF0) |
|||
{ |
|||
break; // End block
|
|||
} |
|||
|
|||
k += 16; |
|||
} |
|||
else |
|||
{ |
|||
k += r; |
|||
|
|||
// Decode into unzigzag location
|
|||
zig = this.dctZigZag[k++]; |
|||
Unsafe.Add(ref blockDataRef, zig) = (short)this.ExtendReceive(s); |
|||
} |
|||
} |
|||
} while (k < 64); |
|||
} |
|||
|
|||
private void DecodeBlockProgressiveDC( |
|||
PdfJsFrameComponent component, |
|||
int row, |
|||
int col, |
|||
ref PdfJsHuffmanTable dcTable) |
|||
{ |
|||
if (this.spectralEnd != 0) |
|||
{ |
|||
JpegThrowHelper.ThrowImageFormatException("Can't merge DC and AC."); |
|||
} |
|||
|
|||
this.CheckBits(); |
|||
|
|||
ref short blockDataRef = ref component.GetBlockDataReference(row, col); |
|||
|
|||
if (this.successiveHigh == 0) |
|||
{ |
|||
// First scan for DC coefficient, must be first
|
|||
int t = this.DecodeHuffman(ref dcTable); |
|||
int diff = t != 0 ? this.ExtendReceive(t) : 0; |
|||
|
|||
int dc = component.DcPredictor + diff; |
|||
component.DcPredictor = dc; |
|||
|
|||
blockDataRef = (short)(dc << this.successiveLow); |
|||
} |
|||
else |
|||
{ |
|||
// Refinement scan for DC coefficient
|
|||
if (this.GetBit() != 0) |
|||
{ |
|||
blockDataRef += (short)(1 << this.successiveLow); |
|||
} |
|||
} |
|||
} |
|||
|
|||
private void DecodeBlockProgressiveAC( |
|||
PdfJsFrameComponent component, |
|||
int row, |
|||
int col, |
|||
ref PdfJsHuffmanTable acTable, |
|||
ref short fastACRef) |
|||
{ |
|||
if (this.spectralStart == 0) |
|||
{ |
|||
JpegThrowHelper.ThrowImageFormatException("Can't merge DC and AC."); |
|||
} |
|||
|
|||
ref short blockDataRef = ref component.GetBlockDataReference(row, col); |
|||
|
|||
if (this.successiveHigh == 0) |
|||
{ |
|||
// MCU decoding for AC initial scan (either spectral selection,
|
|||
// or first pass of successive approximation).
|
|||
int shift = this.successiveLow; |
|||
|
|||
if (this.eobrun != 0) |
|||
{ |
|||
this.eobrun--; |
|||
return; |
|||
} |
|||
|
|||
int k = this.spectralStart; |
|||
do |
|||
{ |
|||
int zig; |
|||
int s; |
|||
|
|||
this.CheckBits(); |
|||
int c = this.PeekBits(); |
|||
int r = Unsafe.Add(ref fastACRef, c); |
|||
|
|||
if (r != 0) |
|||
{ |
|||
// Fast AC path
|
|||
k += (r >> 4) & 15; // Run
|
|||
s = r & 15; // Combined length
|
|||
this.codeBuffer <<= s; |
|||
this.codeBits -= s; |
|||
|
|||
// Decode into unzigzag location
|
|||
zig = this.dctZigZag[k++]; |
|||
Unsafe.Add(ref blockDataRef, zig) = (short)((r >> 8) << shift); |
|||
} |
|||
else |
|||
{ |
|||
int rs = this.DecodeHuffman(ref acTable); |
|||
|
|||
if (rs < 0) |
|||
{ |
|||
JpegThrowHelper.ThrowBadHuffmanCode(); |
|||
} |
|||
|
|||
s = rs & 15; |
|||
r = rs >> 4; |
|||
|
|||
if (s == 0) |
|||
{ |
|||
if (r < 15) |
|||
{ |
|||
this.eobrun = 1 << r; |
|||
if (r != 0) |
|||
{ |
|||
this.eobrun += this.GetBits(r); |
|||
} |
|||
|
|||
this.eobrun--; |
|||
break; |
|||
} |
|||
|
|||
k += 16; |
|||
} |
|||
else |
|||
{ |
|||
k += r; |
|||
zig = this.dctZigZag[k++]; |
|||
Unsafe.Add(ref blockDataRef, zig) = (short)(this.ExtendReceive(s) << shift); |
|||
} |
|||
} |
|||
} |
|||
while (k <= this.spectralEnd); |
|||
} |
|||
else |
|||
{ |
|||
// Refinement scan for these AC coefficients
|
|||
this.DecodeBlockProgressiveACRefined(ref blockDataRef, ref acTable); |
|||
} |
|||
} |
|||
|
|||
private void DecodeBlockProgressiveACRefined(ref short blockDataRef, ref PdfJsHuffmanTable acTable) |
|||
{ |
|||
int k; |
|||
|
|||
// Refinement scan for these AC coefficients
|
|||
short bit = (short)(1 << this.successiveLow); |
|||
|
|||
if (this.eobrun != 0) |
|||
{ |
|||
this.eobrun--; |
|||
for (k = this.spectralStart; k <= this.spectralEnd; k++) |
|||
{ |
|||
ref short p = ref Unsafe.Add(ref blockDataRef, this.dctZigZag[k]); |
|||
if (p != 0) |
|||
{ |
|||
if (this.GetBit() != 0) |
|||
{ |
|||
if ((p & bit) == 0) |
|||
{ |
|||
if (p > 0) |
|||
{ |
|||
p += bit; |
|||
} |
|||
else |
|||
{ |
|||
p -= bit; |
|||
} |
|||
} |
|||
} |
|||
} |
|||
} |
|||
} |
|||
else |
|||
{ |
|||
k = this.spectralStart; |
|||
do |
|||
{ |
|||
int rs = this.DecodeHuffman(ref acTable); |
|||
if (rs < 0) |
|||
{ |
|||
JpegThrowHelper.ThrowBadHuffmanCode(); |
|||
} |
|||
|
|||
int s = rs & 15; |
|||
int r = rs >> 4; |
|||
|
|||
if (s == 0) |
|||
{ |
|||
// r=15 s=0 should write 16 0s, so we just do
|
|||
// a run of 15 0s and then write s (which is 0),
|
|||
// so we don't have to do anything special here
|
|||
if (r < 15) |
|||
{ |
|||
this.eobrun = (1 << r) - 1; |
|||
|
|||
if (r != 0) |
|||
{ |
|||
this.eobrun += this.GetBits(r); |
|||
} |
|||
|
|||
r = 64; // Force end of block
|
|||
} |
|||
} |
|||
else |
|||
{ |
|||
if (s != 1) |
|||
{ |
|||
JpegThrowHelper.ThrowBadHuffmanCode(); |
|||
} |
|||
|
|||
// Sign bit
|
|||
if (this.GetBit() != 0) |
|||
{ |
|||
s = bit; |
|||
} |
|||
else |
|||
{ |
|||
s = -bit; |
|||
} |
|||
} |
|||
|
|||
// Advance by r
|
|||
while (k <= this.spectralEnd) |
|||
{ |
|||
ref short p = ref Unsafe.Add(ref blockDataRef, this.dctZigZag[k++]); |
|||
if (p != 0) |
|||
{ |
|||
if (this.GetBit() != 0) |
|||
{ |
|||
if ((p & bit) == 0) |
|||
{ |
|||
if (p > 0) |
|||
{ |
|||
p += bit; |
|||
} |
|||
else |
|||
{ |
|||
p -= bit; |
|||
} |
|||
} |
|||
} |
|||
} |
|||
else |
|||
{ |
|||
if (r == 0) |
|||
{ |
|||
p = (short)s; |
|||
break; |
|||
} |
|||
|
|||
r--; |
|||
} |
|||
} |
|||
} |
|||
while (k <= this.spectralEnd); |
|||
} |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ShortMethod)] |
|||
private int GetBits(int n) |
|||
{ |
|||
if (this.codeBits < n) |
|||
{ |
|||
this.FillBuffer(); |
|||
} |
|||
|
|||
uint k = LRot(this.codeBuffer, n); |
|||
this.codeBuffer = k & ~Bmask[n]; |
|||
k &= Bmask[n]; |
|||
this.codeBits -= n; |
|||
return (int)k; |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ShortMethod)] |
|||
private int GetBit() |
|||
{ |
|||
if (this.codeBits < 1) |
|||
{ |
|||
this.FillBuffer(); |
|||
} |
|||
|
|||
uint k = this.codeBuffer; |
|||
this.codeBuffer <<= 1; |
|||
this.codeBits--; |
|||
|
|||
return (int)(k & 0x80000000); |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ColdPath)] |
|||
private void FillBuffer() |
|||
{ |
|||
// Attempt to load at least the minimum nbumber of required bits into the buffer.
|
|||
// We fail to do so only if we hit a marker or reach the end of the input stream.
|
|||
do |
|||
{ |
|||
int b = this.nomore ? 0 : this.stream.ReadByte(); |
|||
|
|||
if (b == -1) |
|||
{ |
|||
// We've encountered the end of the file stream which means there's no EOI marker in the image
|
|||
// or the SOS marker has the wrong dimensions set.
|
|||
this.eof = true; |
|||
b = 0; |
|||
} |
|||
|
|||
// Found a marker.
|
|||
if (b == JpegConstants.Markers.XFF) |
|||
{ |
|||
this.markerPosition = this.stream.Position - 1; |
|||
int c = this.stream.ReadByte(); |
|||
while (c == JpegConstants.Markers.XFF) |
|||
{ |
|||
c = this.stream.ReadByte(); |
|||
|
|||
if (c == -1) |
|||
{ |
|||
this.eof = true; |
|||
c = 0; |
|||
break; |
|||
} |
|||
} |
|||
|
|||
if (c != 0) |
|||
{ |
|||
this.marker = (byte)c; |
|||
this.nomore = true; |
|||
if (!this.HasRestart()) |
|||
{ |
|||
this.badMarker = true; |
|||
} |
|||
|
|||
return; |
|||
} |
|||
} |
|||
|
|||
this.codeBuffer |= (uint)b << (24 - this.codeBits); |
|||
this.codeBits += 8; |
|||
} |
|||
while (this.codeBits <= 24); |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ShortMethod)] |
|||
private int DecodeHuffman(ref PdfJsHuffmanTable table) |
|||
{ |
|||
this.CheckBits(); |
|||
|
|||
// Look at the top FastBits and determine what symbol ID it is,
|
|||
// if the code is <= FastBits.
|
|||
int c = this.PeekBits(); |
|||
int k = table.Lookahead[c]; |
|||
if (k < 0xFF) |
|||
{ |
|||
int s = table.Sizes[k]; |
|||
if (s > this.codeBits) |
|||
{ |
|||
return -1; |
|||
} |
|||
|
|||
this.codeBuffer <<= s; |
|||
this.codeBits -= s; |
|||
return table.Values[k]; |
|||
} |
|||
|
|||
return this.DecodeHuffmanSlow(ref table); |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ColdPath)] |
|||
private int DecodeHuffmanSlow(ref PdfJsHuffmanTable table) |
|||
{ |
|||
// Naive test is to shift the code_buffer down so k bits are
|
|||
// valid, then test against MaxCode. To speed this up, we've
|
|||
// preshifted maxcode left so that it has (16-k) 0s at the
|
|||
// end; in other words, regardless of the number of bits, it
|
|||
// wants to be compared against something shifted to have 16;
|
|||
// that way we don't need to shift inside the loop.
|
|||
uint temp = this.codeBuffer >> 16; |
|||
int k; |
|||
for (k = FastBits + 1; ; k++) |
|||
{ |
|||
if (temp < table.MaxCode[k]) |
|||
{ |
|||
break; |
|||
} |
|||
} |
|||
|
|||
if (k == 17) |
|||
{ |
|||
// Error! code not found
|
|||
this.codeBits -= 16; |
|||
return -1; |
|||
} |
|||
|
|||
if (k > this.codeBits) |
|||
{ |
|||
return -1; |
|||
} |
|||
|
|||
// Convert the huffman code to the symbol id
|
|||
int c = (int)(((this.codeBuffer >> (32 - k)) & Bmask[k]) + table.ValOffset[k]); |
|||
|
|||
// Convert the id to a symbol
|
|||
this.codeBits -= k; |
|||
this.codeBuffer <<= k; |
|||
return table.Values[c]; |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ShortMethod)] |
|||
private int ExtendReceive(int n) |
|||
{ |
|||
if (this.codeBits < n) |
|||
{ |
|||
this.FillBuffer(); |
|||
} |
|||
|
|||
int sgn = (int)this.codeBuffer >> 31; |
|||
uint k = LRot(this.codeBuffer, n); |
|||
this.codeBuffer = k & ~Bmask[n]; |
|||
k &= Bmask[n]; |
|||
this.codeBits -= n; |
|||
return (int)(k + (Bias[n] & ~sgn)); |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ShortMethod)] |
|||
private void CheckBits() |
|||
{ |
|||
if (this.codeBits < 16) |
|||
{ |
|||
this.FillBuffer(); |
|||
} |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ShortMethod)] |
|||
private int PeekBits() => (int)((this.codeBuffer >> (32 - FastBits)) & ((1 << FastBits) - 1)); |
|||
|
|||
[MethodImpl(InliningOptions.ShortMethod)] |
|||
private bool ContinueOnMcuComplete() |
|||
{ |
|||
if (--this.todo > 0) |
|||
{ |
|||
return true; |
|||
} |
|||
|
|||
if (this.codeBits < 24) |
|||
{ |
|||
this.FillBuffer(); |
|||
} |
|||
|
|||
// If it's NOT a restart, then just bail, so we get corrupt data rather than no data.
|
|||
// Reset the stream to before any bad markers to ensure we can read sucessive segments.
|
|||
if (this.badMarker) |
|||
{ |
|||
this.stream.Position = this.markerPosition; |
|||
} |
|||
|
|||
if (!this.HasRestart()) |
|||
{ |
|||
return false; |
|||
} |
|||
|
|||
this.Reset(); |
|||
|
|||
return true; |
|||
} |
|||
|
|||
[MethodImpl(InliningOptions.ShortMethod)] |
|||
private bool HasRestart() |
|||
{ |
|||
byte m = this.marker; |
|||
return m >= JpegConstants.Markers.RST0 && m <= JpegConstants.Markers.RST7; |
|||
} |
|||
|
|||
private void Reset() |
|||
{ |
|||
this.codeBits = 0; |
|||
this.codeBuffer = 0; |
|||
|
|||
for (int i = 0; i < this.components.Length; i++) |
|||
{ |
|||
PdfJsFrameComponent c = this.components[i]; |
|||
c.DcPredictor = 0; |
|||
} |
|||
|
|||
this.nomore = false; |
|||
this.marker = JpegConstants.Markers.XFF; |
|||
this.markerPosition = 0; |
|||
this.badMarker = false; |
|||
this.eobrun = 0; |
|||
|
|||
// No more than 1<<31 MCUs if no restartInterval? that's plenty safe since we don't even allow 1<<30 pixels
|
|||
this.todo = this.restartInterval > 0 ? this.restartInterval : int.MaxValue; |
|||
} |
|||
} |
|||
} |
|||
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Reference in new issue