Introduce VP8 Profile which contains the reconstruction filter and the loop filter

src/ImageSharp/Formats/WebP/LoopFilter.cs

@@ -0,0 +1,12 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    internal enum LoopFilter
+    {
+        Normal,
+        Simple,
+        None
+    }
+}

src/ImageSharp/Formats/WebP/ReconstructionFilter.cs

@@ -0,0 +1,12 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.WebP
+{
+    internal enum ReconstructionFilter
+    {
+        None,
+        Bicubic,
+        Bilinear
+    }
+}

src/ImageSharp/Formats/WebP/Vp8Profile.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>
+    /// The version number setting enables or disables certain features in the bitstream.
+    /// </summary>
+    internal class Vp8Profile
+    {
+        /// <summary>
+        /// Gets or sets the reconstruction filter.
+        /// </summary>
+        public ReconstructionFilter ReconstructionFilter { get; set; }
+
+        /// <summary>
+        /// Gets or sets the loop filter.
+        /// </summary>
+        public LoopFilter LoopFilter { get; set; }
+    }
+}

src/ImageSharp/Formats/WebP/WebPDecoderCore.cs

@@ -343,6 +343,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
                        IsLossLess = false,
                        ImageDataSize = dataSize,
                        Features = features,
+                       Vp8Profile = (sbyte)version
                    };
         }
 

src/ImageSharp/Formats/WebP/WebPImageInfo.cs

@@ -36,9 +36,9 @@ namespace SixLabors.ImageSharp.Formats.WebP
         public uint ImageDataSize { get; set; }
 
         /// <summary>
-        /// Gets or sets the VP8 profile / version. Valid values are between 0 and 3.
+        /// Gets or sets the VP8 profile / version. Valid values are between 0 and 3. Default value will be the invalid value -1.
         /// </summary>
-        public byte Vp8Profile { get; set; }
+        public int Vp8Profile { get; set; } = -1;
 
         /// <summary>
         /// Gets or sets Vp8L bitreader. Will be null if its not lossless image.

src/ImageSharp/Formats/WebP/WebPLossyDecoder.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
-using System;
 using System.IO;
 
 using SixLabors.ImageSharp.Memory;
@@ -16,7 +15,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
 
         private readonly Stream currentStream;
 
-        private MemoryAllocator memoryAllocator;
+        private readonly MemoryAllocator memoryAllocator;
 
         public WebPLossyDecoder(Configuration configuration, Stream currentStream)
         {
@@ -25,7 +24,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
             this.memoryAllocator = configuration.MemoryAllocator;
         }
 
-        public void Decode<TPixel>(Buffer2D<TPixel> pixels, int width, int height, uint imageDataSize, byte vp8Version)
+        public void Decode<TPixel>(Buffer2D<TPixel> pixels, int width, int height, uint imageDataSize, int vp8Version)
             where TPixel : struct, IPixel<TPixel>
         {
             // we need buffers for Y U and V in size of the image
@@ -37,40 +36,30 @@ namespace SixLabors.ImageSharp.Formats.WebP
 
             // TODO residue signal from DCT: 4x4 blocks of DCT transforms, 16Y, 4U, 4V
             var bitReader = new Vp8BitReader(this.currentStream, imageDataSize, this.memoryAllocator);
-            (ReconstructionFilter rec, LoopFilter loop) = this.DecodeVersion(vp8Version);
+            Vp8Profile vp8Profile = this.DecodeProfile(vp8Version);
         }
 
-        private (ReconstructionFilter, LoopFilter) DecodeVersion(byte version)
+        private Vp8Profile DecodeProfile(int version)
         {
-            var rec = ReconstructionFilter.None;
-            var loop = LoopFilter.None;
-
             switch (version)
             {
                 case 0:
-                    return (ReconstructionFilter.Bicubic, LoopFilter.Normal);
+                    return new Vp8Profile { ReconstructionFilter = ReconstructionFilter.Bicubic, LoopFilter = LoopFilter.Normal };
                 case 1:
-                    return (ReconstructionFilter.Bilinear, LoopFilter.Simple);
+                    return new Vp8Profile { ReconstructionFilter = ReconstructionFilter.Bilinear, LoopFilter = LoopFilter.Simple };
                 case 2:
-                    return (ReconstructionFilter.Bilinear, LoopFilter.None);
+                    return new Vp8Profile { ReconstructionFilter = ReconstructionFilter.Bilinear, LoopFilter = LoopFilter.None };
                 case 3:
-                    return (ReconstructionFilter.None, LoopFilter.None);
+                    return new Vp8Profile { ReconstructionFilter = ReconstructionFilter.None, LoopFilter = LoopFilter.None };
                 default:
                     // Reserved for future use in Spec.
                     // https://tools.ietf.org/html/rfc6386#page-30
                     WebPThrowHelper.ThrowNotSupportedException($"unsupported VP8 version {version} found");
-                    return (rec, loop);
+                    return new Vp8Profile();
             }
         }
     }
 
-    enum ReconstructionFilter
-    {
-        None,
-        Bicubic,
-        Bilinear
-    }
-
     enum LoopFilter
     {
         Normal,