Mono AOT decoder workaround for slow jpeg decoding.

src/ImageSharp/Advanced/AotCompilerTools.cs

@@ -10,10 +10,13 @@
 using SixLabors.ImageSharp.Formats.Gif;
 using SixLabors.ImageSharp.Formats.Jpeg;
 using SixLabors.ImageSharp.Formats.Jpeg.Components;
+using SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder;
 using SixLabors.ImageSharp.Formats.Pbm;
 using SixLabors.ImageSharp.Formats.Png;
+using SixLabors.ImageSharp.Formats.Qoi;
 using SixLabors.ImageSharp.Formats.Tga;
 using SixLabors.ImageSharp.Formats.Tiff;
+using SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors;
 using SixLabors.ImageSharp.Formats.Webp;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
@@ -129,6 +132,7 @@ private static void Seed<TPixel>()
         AotCompileImageDecoderInternals<TPixel>();
         AotCompileImageEncoders<TPixel>();
         AotCompileImageDecoders<TPixel>();
+        AotCompileSpectralConverter<TPixel>();
         AotCompileImageProcessors<TPixel>();
         AotCompileGenericImageProcessors<TPixel>();
         AotCompileResamplers<TPixel>();
@@ -195,39 +199,41 @@ private static void AotCompileImageProcessingContextFactory<TPixel>()
             => default(DefaultImageOperationsProviderFactory).CreateImageProcessingContext<TPixel>(default, default, default);
 
     /// <summary>
-    /// This method pre-seeds the all <see cref="IImageEncoderInternals"/> in the AoT compiler.
+    /// This method pre-seeds the all core encoders in the AoT compiler.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
     [Preserve]
     private static void AotCompileImageEncoderInternals<TPixel>()
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        default(WebpEncoderCore).Encode<TPixel>(default, default, default);
         default(BmpEncoderCore).Encode<TPixel>(default, default, default);
         default(GifEncoderCore).Encode<TPixel>(default, default, default);
         default(JpegEncoderCore).Encode<TPixel>(default, default, default);
         default(PbmEncoderCore).Encode<TPixel>(default, default, default);
         default(PngEncoderCore).Encode<TPixel>(default, default, default);
+        default(QoiEncoderCore).Encode<TPixel>(default, default, default);
         default(TgaEncoderCore).Encode<TPixel>(default, default, default);
         default(TiffEncoderCore).Encode<TPixel>(default, default, default);
+        default(WebpEncoderCore).Encode<TPixel>(default, default, default);
     }
 
     /// <summary>
-    /// This method pre-seeds the all <see cref="IImageDecoderInternals"/> in the AoT compiler.
+    /// This method pre-seeds the all <see cref="ImageDecoderCore"/> in the AoT compiler.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
     [Preserve]
     private static void AotCompileImageDecoderInternals<TPixel>()
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        default(WebpDecoderCore).Decode<TPixel>(default, default);
-        default(BmpDecoderCore).Decode<TPixel>(default, default);
-        default(GifDecoderCore).Decode<TPixel>(default, default);
-        default(JpegDecoderCore).Decode<TPixel>(default, default);
-        default(PbmDecoderCore).Decode<TPixel>(default, default);
-        default(PngDecoderCore).Decode<TPixel>(default, default);
-        default(TgaDecoderCore).Decode<TPixel>(default, default);
-        default(TiffDecoderCore).Decode<TPixel>(default, default);
+        default(BmpDecoderCore).Decode<TPixel>(default, default, default);
+        default(GifDecoderCore).Decode<TPixel>(default, default, default);
+        default(JpegDecoderCore).Decode<TPixel>(default, default, default);
+        default(PbmDecoderCore).Decode<TPixel>(default, default, default);
+        default(PngDecoderCore).Decode<TPixel>(default, default, default);
+        default(QoiDecoderCore).Decode<TPixel>(default, default, default);
+        default(TgaDecoderCore).Decode<TPixel>(default, default, default);
+        default(TiffDecoderCore).Decode<TPixel>(default, default, default);
+        default(WebpDecoderCore).Decode<TPixel>(default, default, default);
     }
 
     /// <summary>
@@ -266,6 +272,17 @@ private static void AotCompileImageDecoders<TPixel>()
         AotCompileImageDecoder<TPixel, TiffDecoder>();
     }
 
+    [Preserve]
+    private static void AotCompileSpectralConverter<TPixel>()
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        default(SpectralConverter<TPixel>).GetPixelBuffer(default);
+        default(GrayJpegSpectralConverter<TPixel>).GetPixelBuffer(default);
+        default(RgbJpegSpectralConverter<TPixel>).GetPixelBuffer(default);
+        default(TiffJpegSpectralConverter<TPixel>).GetPixelBuffer(default);
+        default(TiffOldJpegSpectralConverter<TPixel>).GetPixelBuffer(default);
+    }
+
     /// <summary>
     /// This method pre-seeds the <see cref="IImageEncoder"/> in the AoT compiler.
     /// </summary>

src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs

@@ -21,7 +21,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp;
 /// <remarks>
 /// A useful decoding source example can be found at <see href="https://dxr.mozilla.org/mozilla-central/source/image/decoders/nsBMPDecoder.cpp"/>
 /// </remarks>
-internal sealed class BmpDecoderCore : IImageDecoderInternals
+internal sealed class BmpDecoderCore : ImageDecoderCore
 {
     /// <summary>
     /// The default mask for the red part of the color for 16 bit rgb bitmaps.
@@ -104,22 +104,15 @@ internal sealed class BmpDecoderCore : IImageDecoderInternals
     /// </summary>
     /// <param name="options">The options.</param>
     public BmpDecoderCore(BmpDecoderOptions options)
+        : base(options.GeneralOptions)
     {
-        this.Options = options.GeneralOptions;
         this.rleSkippedPixelHandling = options.RleSkippedPixelHandling;
         this.configuration = options.GeneralOptions.Configuration;
         this.memoryAllocator = this.configuration.MemoryAllocator;
     }
 
     /// <inheritdoc />
-    public DecoderOptions Options { get; }
-
-    /// <inheritdoc />
-    public Size Dimensions => new(this.infoHeader.Width, this.infoHeader.Height);
-
-    /// <inheritdoc />
-    public Image<TPixel> Decode<TPixel>(BufferedReadStream stream, CancellationToken cancellationToken)
-        where TPixel : unmanaged, IPixel<TPixel>
+    protected override Image<TPixel> Decode<TPixel>(BufferedReadStream stream, CancellationToken cancellationToken)
     {
         Image<TPixel>? image = null;
         try
@@ -205,7 +198,7 @@ public Image<TPixel> Decode<TPixel>(BufferedReadStream stream, CancellationToken
     }
 
     /// <inheritdoc />
-    public ImageInfo Identify(BufferedReadStream stream, CancellationToken cancellationToken)
+    protected override ImageInfo Identify(BufferedReadStream stream, CancellationToken cancellationToken)
     {
         this.ReadImageHeaders(stream, out _, out _);
         return new ImageInfo(new PixelTypeInfo(this.infoHeader.BitsPerPixel), new(this.infoHeader.Width, this.infoHeader.Height), this.metadata);
@@ -1369,6 +1362,8 @@ private void ReadInfoHeader(BufferedReadStream stream)
         this.bmpMetadata = this.metadata.GetBmpMetadata();
         this.bmpMetadata.InfoHeaderType = infoHeaderType;
         this.bmpMetadata.BitsPerPixel = (BmpBitsPerPixel)bitsPerPixel;
+
+        this.Dimensions = new(this.infoHeader.Width, this.infoHeader.Height);
     }
 
     /// <summary>

src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs

@@ -4,7 +4,6 @@
 using System.Buffers;
 using System.Buffers.Binary;
 using System.Runtime.InteropServices;
-using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Common.Helpers;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Metadata;
@@ -17,7 +16,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp;
 /// <summary>
 /// Image encoder for writing an image to a stream as a Windows bitmap.
 /// </summary>
-internal sealed class BmpEncoderCore : IImageEncoderInternals
+internal sealed class BmpEncoderCore
 {
     /// <summary>
     /// The amount to pad each row by.

src/ImageSharp/Formats/Gif/GifDecoderCore.cs

@@ -17,7 +17,7 @@ namespace SixLabors.ImageSharp.Formats.Gif;
 /// <summary>
 /// Performs the gif decoding operation.
 /// </summary>
-internal sealed class GifDecoderCore : IImageDecoderInternals
+internal sealed class GifDecoderCore : ImageDecoderCore
 {
     /// <summary>
     /// The temp buffer used to reduce allocations.
@@ -94,23 +94,16 @@ internal sealed class GifDecoderCore : IImageDecoderInternals
     /// </summary>
     /// <param name="options">The decoder options.</param>
     public GifDecoderCore(DecoderOptions options)
+        : base(options)
     {
-        this.Options = options;
         this.configuration = options.Configuration;
         this.skipMetadata = options.SkipMetadata;
         this.maxFrames = options.MaxFrames;
         this.memoryAllocator = this.configuration.MemoryAllocator;
     }
 
     /// <inheritdoc />
-    public DecoderOptions Options { get; }
-
-    /// <inheritdoc />
-    public Size Dimensions => new(this.imageDescriptor.Width, this.imageDescriptor.Height);
-
-    /// <inheritdoc />
-    public Image<TPixel> Decode<TPixel>(BufferedReadStream stream, CancellationToken cancellationToken)
-        where TPixel : unmanaged, IPixel<TPixel>
+    protected override Image<TPixel> Decode<TPixel>(BufferedReadStream stream, CancellationToken cancellationToken)
     {
         uint frameCount = 0;
         Image<TPixel>? image = null;
@@ -181,7 +174,7 @@ public Image<TPixel> Decode<TPixel>(BufferedReadStream stream, CancellationToken
     }
 
     /// <inheritdoc />
-    public ImageInfo Identify(BufferedReadStream stream, CancellationToken cancellationToken)
+    protected override ImageInfo Identify(BufferedReadStream stream, CancellationToken cancellationToken)
     {
         uint frameCount = 0;
         ImageFrameMetadata? previousFrame = null;
@@ -287,6 +280,8 @@ private void ReadImageDescriptor(BufferedReadStream stream)
         {
             GifThrowHelper.ThrowInvalidImageContentException("Width or height should not be 0");
         }
+
+        this.Dimensions = new(this.imageDescriptor.Width, this.imageDescriptor.Height);
     }
 
     /// <summary>

src/ImageSharp/Formats/Gif/GifEncoderCore.cs

@@ -19,7 +19,7 @@ namespace SixLabors.ImageSharp.Formats.Gif;
 /// <summary>
 /// Implements the GIF encoding protocol.
 /// </summary>
-internal sealed class GifEncoderCore : IImageEncoderInternals
+internal sealed class GifEncoderCore
 {
     /// <summary>
     /// Used for allocating memory during processing operations.

src/ImageSharp/Formats/ImageDecoder.cs

@@ -189,7 +189,7 @@ internal static T WithSeekableStream<T>(
             throw new NotSupportedException("Cannot read from the stream.");
         }
 
-        T PeformActionAndResetPosition(Stream s, long position)
+        T PerformActionAndResetPosition(Stream s, long position)
         {
             T result = action(s);
 
@@ -206,7 +206,7 @@ T PeformActionAndResetPosition(Stream s, long position)
 
         if (stream.CanSeek)
         {
-            return PeformActionAndResetPosition(stream, stream.Position);
+            return PerformActionAndResetPosition(stream, stream.Position);
         }
 
         Configuration configuration = options.Configuration;
@@ -231,7 +231,7 @@ internal static Task<T> WithSeekableMemoryStreamAsync<T>(
             throw new NotSupportedException("Cannot read from the stream.");
         }
 
-        Task<T> PeformActionAndResetPosition(Stream s, long position, CancellationToken ct)
+        Task<T> PerformActionAndResetPosition(Stream s, long position, CancellationToken ct)
         {
             try
             {
@@ -263,15 +263,15 @@ Task<T> PeformActionAndResetPosition(Stream s, long position, CancellationToken
         // code below to copy the stream to an in-memory buffer before invoking the action.
         if (stream is MemoryStream ms)
         {
-            return PeformActionAndResetPosition(ms, ms.Position, cancellationToken);
+            return PerformActionAndResetPosition(ms, ms.Position, cancellationToken);
         }
 
         if (stream is ChunkedMemoryStream cms)
         {
-            return PeformActionAndResetPosition(cms, cms.Position, cancellationToken);
+            return PerformActionAndResetPosition(cms, cms.Position, cancellationToken);
         }
 
-        return CopyToMemoryStreamAndActionAsync(options, stream, PeformActionAndResetPosition, cancellationToken);
+        return CopyToMemoryStreamAndActionAsync(options, stream, PerformActionAndResetPosition, cancellationToken);
     }
 
     private static async Task<T> CopyToMemoryStreamAndActionAsync<T>(
@@ -282,7 +282,7 @@ private static async Task<T> CopyToMemoryStreamAndActionAsync<T>(
     {
         long position = stream.CanSeek ? stream.Position : 0;
         Configuration configuration = options.Configuration;
-        using ChunkedMemoryStream memoryStream = new(configuration.MemoryAllocator);
+        await using ChunkedMemoryStream memoryStream = new(configuration.MemoryAllocator);
         await stream.CopyToAsync(memoryStream, configuration.StreamProcessingBufferSize, cancellationToken).ConfigureAwait(false);
         memoryStream.Position = 0;
         return await action(memoryStream, position, cancellationToken).ConfigureAwait(false);