Add data classes for decoding VP8 images

src/ImageSharp/Formats/WebP/Vp8FilterInfo.cs

@@ -0,0 +1,31 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    /// <summary>
+    /// Filter information.
+    /// </summary>
+    internal class Vp8FilterInfo
+    {
+        /// <summary>
+        /// Gets or sets the filter limit in [3..189], or 0 if no filtering.
+        /// </summary>
+        public sbyte Limit { get; set; }
+
+        /// <summary>
+        /// Gets or sets the inner limit in [1..63].
+        /// </summary>
+        public sbyte InnerLevel { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value indicating whether to do inner filtering.
+        /// </summary>
+        public bool InnerFiltering { get; set; }
+
+        /// <summary>
+        /// Gets or sets the high edge variance threshold in [0..2].
+        /// </summary>
+        public sbyte HighEdgeVarianceThreshold { get; set; }
+    }
+}

src/ImageSharp/Formats/WebP/Vp8FrameHeader.cs

@@ -0,0 +1,26 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    /// <summary>
+    /// Vp8 frame header information.
+    /// </summary>
+    internal class Vp8FrameHeader
+    {
+        /// <summary>
+        /// Gets or sets a value indicating whether this is a key frame.
+        /// </summary>
+        public bool KeyFrame { get; set; }
+
+        /// <summary>
+        /// Gets or sets Vp8 profile [0..3].
+        /// </summary>
+        public sbyte Profile { get; set; }
+
+        /// <summary>
+        /// Gets or sets the partition length.
+        /// </summary>
+        public uint PartitionLength { get; set; }
+    }
+}

src/ImageSharp/Formats/WebP/Vp8LDecoder.cs

@@ -5,6 +5,9 @@ using System.Collections.Generic;
 
 namespace SixLabors.ImageSharp.Formats.WebP
 {
+    /// <summary>
+    /// Holds information for decoding a lossless image.
+    /// </summary>
     internal class Vp8LDecoder
     {
         public Vp8LDecoder(int width, int height)
@@ -14,12 +17,24 @@ namespace SixLabors.ImageSharp.Formats.WebP
             this.Metadata = new Vp8LMetadata();
         }
 
+        /// <summary>
+        /// Gets or sets the width of the image to decode.
+        /// </summary>
         public int Width { get; set; }
 
+        /// <summary>
+        /// Gets or sets the height of the image to decode.
+        /// </summary>
         public int Height { get; set; }
 
+        /// <summary>
+        /// Gets or sets the necessary VP8L metadata (like huffman tables) to decode the image.
+        /// </summary>
         public Vp8LMetadata Metadata { get; set; }
 
+        /// <summary>
+        /// Gets or sets the transformations which needs to be reversed.
+        /// </summary>
         public List<Vp8LTransform> Transforms { get; set; }
     }
 }

src/ImageSharp/Formats/WebP/Vp8MacroBlock.cs

@@ -0,0 +1,21 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    /// <summary>
+    /// Info about a macro block.
+    /// </summary>
+    internal class Vp8MacroBlock
+    {
+        /// <summary>
+        /// Gets or sets non-zero AC/DC coeffs (4bit for luma + 4bit for chroma).
+        /// </summary>
+        public uint NoneZeroAcDcCoeffs { get; set; }
+
+        /// <summary>
+        /// Gets or sets non-zero DC coeff (1bit).
+        /// </summary>
+        public uint NoneZeroDcCoeffs { get; set; }
+    }
+}

src/ImageSharp/Formats/WebP/Vp8MacroBlockData.cs

@@ -0,0 +1,44 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    /// <summary>
+    /// Data needed to reconstruct a macroblock.
+    /// </summary>
+    internal class Vp8MacroBlockData
+    {
+        /// <summary>
+        /// Gets or sets the coefficient. 384 coeffs = (16+4+4) * 4*4.
+        /// </summary>
+        public short Coeffs { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value indicating whether its intra4x4.
+        /// </summary>
+        public bool IsI4x4 { get; set; }
+
+        /// <summary>
+        /// Gets or sets the modes. One 16x16 mode (#0) or sixteen 4x4 modes.
+        /// </summary>
+        public byte Modes { get; set; }
+
+        /// <summary>
+        /// Gets or sets the chroma prediction mode.
+        /// </summary>
+        public byte UvMode { get; set; }
+
+        public uint NonZeroY { get; set; }
+
+        public uint NonZeroUv { get; set; }
+
+        /// <summary>
+        /// Gets or sets the local dithering strength (deduced from NonZero_*).
+        /// </summary>
+        public byte Dither { get; set; }
+
+        public byte Skip { get; set; }
+
+        public byte Segment { get; set; }
+    }
+}

src/ImageSharp/Formats/WebP/Vp8PictureHeader.cs

@@ -0,0 +1,38 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    internal class Vp8PictureHeader
+    {
+        /// <summary>
+        /// Gets or sets the width of the image.
+        /// </summary>
+        public uint Width { get; set; }
+
+        /// <summary>
+        /// Gets or sets the Height of the image.
+        /// </summary>
+        public uint Height { get; set; }
+
+        /// <summary>
+        /// Gets or sets the horizontal scale.
+        /// </summary>
+        public sbyte XScale { get; set; }
+
+        /// <summary>
+        /// Gets or sets the vertical scale.
+        /// </summary>
+        public sbyte YScale { get; set; }
+
+        /// <summary>
+        /// Gets or sets the colorspace. 0 = YCbCr.
+        /// </summary>
+        public sbyte ColorSpace { get; set; }
+
+        /// <summary>
+        /// Gets or sets the clamp type.
+        /// </summary>
+        public sbyte ClampType { get; set; }
+    }
+}

src/ImageSharp/Formats/WebP/Vp8QuantMatrix.cs

@@ -0,0 +1,24 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    internal class Vp8QuantMatrix
+    {
+        public int[] Y1Mat { get; set; }
+
+        public int[] Y2Mat { get; set; }
+
+        public int[] UVMat { get; set; }
+
+        /// <summary>
+        /// Gets or sets the U/V quantizer value.
+        /// </summary>
+        public int UvQuant { get; set; }
+
+        /// <summary>
+        /// Gets or sets the dithering amplitude (0 = off, max=255).
+        /// </summary>
+        public int Dither { get; set; }
+    }
+}

src/ImageSharp/Formats/WebP/Vp8SegmentHeader.cs

@@ -0,0 +1,33 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    /// <summary>
+    /// Segment features.
+    /// </summary>
+    internal class Vp8SegmentHeader
+    {
+        public bool UseSegment { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value indicating whether to update the segment map or not.
+        /// </summary>
+        public bool UpdateMap { get; set; }
+
+        /// <summary>
+        /// Gets or sets the absolute or delta values for quantizer and filter.
+        /// </summary>
+        public int AbsoluteOrDelta { get; set; }
+
+        /// <summary>
+        /// Gets or sets quantization changes.
+        /// </summary>
+        public byte[] Quantizer { get; set; }
+
+        /// <summary>
+        /// Gets or sets the filter strength for segments.
+        /// </summary>
+        public byte[] FilterStrength { get; set; }
+    }
+}