Add AVIF Decode ability

src/AVIFConfigurationModule.cs

@@ -0,0 +1,15 @@
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.Formats;
+
+
+namespace NeoSolve.ImageSharp.AVIF;
+
+public sealed class AVIFConfigurationModule : IImageFormatConfigurationModule
+{
+    public void Configure(Configuration configuration)
+    {
+        configuration.ImageFormatsManager.SetEncoder(AVIFFormat.Instance, new AVIFEncoder());
+        configuration.ImageFormatsManager.SetDecoder(AVIFFormat.Instance, AVIFDecoder.Instance);
+        configuration.ImageFormatsManager.AddImageFormatDetector(new AVIFImageFormatDetector());
+    }
+}

src/AVIFDecoder.cs

@@ -0,0 +1,224 @@
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.Formats;
+using SixLabors.ImageSharp.Metadata;
+using SixLabors.ImageSharp.PixelFormats;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+
+namespace NeoSolve.ImageSharp.AVIF;
+
+public class AVIFDecoder : IImageDecoder
+{
+    public static IImageDecoder Instance = new AVIFDecoder();
+
+    public Image<TPixel> Decode<TPixel>(DecoderOptions options, Stream stream)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        return DecodeAsync<TPixel>(options, stream, CancellationToken.None).Result;
+    }
+
+    public Image Decode(DecoderOptions options, Stream stream)
+    {
+        return DecodeAsync(options, stream, CancellationToken.None).Result;
+    }
+
+    /// <summary>
+    /// Decodes an AVIF image from a stream into an ImageSharp image,
+    /// piping the data through avifdec.
+    /// </summary>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    /// <param name="options">The decoder options.</param>
+    /// <param name="stream">The input stream containing the AVIF data.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A decoded image.</returns>
+    public async Task<Image<TPixel>> DecodeAsync<TPixel>(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
+    where TPixel : unmanaged, IPixel<TPixel>
+    {
+        string inputFilePath = Path.GetTempFileName();
+        string outputFilePath = Path.GetTempFileName() + ".png";
+
+        try
+        {
+            using (var fileStream = new FileStream(inputFilePath, FileMode.Create, FileAccess.Write, FileShare.None, 4096, true))
+            {
+                await stream.CopyToAsync(fileStream, cancellationToken);
+            }
+
+            var arguments = new List<string> { inputFilePath, outputFilePath };
+
+            var psi = new ProcessStartInfo
+            {
+                FileName = Native.CAVIFDEC,
+                Arguments = string.Join(' ', arguments),
+                UseShellExecute = false,
+                CreateNoWindow = true,
+                RedirectStandardError = true
+            };
+
+            var process = Process.Start(psi) ?? throw new InvalidOperationException("Failed to start avifdec process.");
+
+            await process.WaitForExitAsync(cancellationToken);
+
+            if (process.ExitCode != 0)
+            {
+                string error = await process.StandardError.ReadToEndAsync();
+                throw new InvalidOperationException($"AVIF decoding failed with exit code {process.ExitCode}. Error: {error}");
+            }
+
+            using (var outputStream = new FileStream(outputFilePath, FileMode.Open, FileAccess.Read, FileShare.None, 4096, true))
+            {
+                return await Image.LoadAsync<TPixel>(outputStream, cancellationToken);
+            }
+        }
+        finally
+        {
+            File.Delete(inputFilePath);
+            File.Delete(outputFilePath);
+        }
+    }
+
+
+    public async Task<Image> DecodeAsync(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
+    {
+        return await DecodeAsync<Rgba32>(options, stream, cancellationToken);
+    }
+
+
+    public ImageInfo Identify(DecoderOptions options, Stream stream)
+    {
+        return IdentifyAsync(options, stream, CancellationToken.None).Result;
+    }
+
+    public async Task<ImageInfo> IdentifyAsync(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
+    {
+        string tempFilePath = Path.GetTempFileName();
+
+        try
+        {
+            await using (var fileStream = new FileStream(tempFilePath, FileMode.Create, FileAccess.Write, FileShare.None, 4096, true))
+            {
+                await stream.CopyToAsync(fileStream, cancellationToken);
+            }
+
+            stream.Position = 0;
+
+            var process = new Process
+            {
+                StartInfo = new ProcessStartInfo
+                {
+                    FileName = Native.CAVIFDEC,
+                    Arguments = $"--info \"{tempFilePath}\"",
+                    RedirectStandardOutput = true,
+                    RedirectStandardError = true,
+                    UseShellExecute = false,
+                    CreateNoWindow = true
+                }
+            };
+
+            process.Start();
+            await process.WaitForExitAsync(cancellationToken);
+
+            if (process.ExitCode == 0)
+            {                
+                string output = await process.StandardOutput.ReadToEndAsync();
+                var avifInfo = ParseAVIFInfo(output);
+                var imageMetadata = new ImageMetadata(); 
+
+                Size size = new(avifInfo.Width, avifInfo.Height);
+                return new ImageInfo(new PixelTypeInfo(avifInfo.BitDepth), size, imageMetadata);
+            }
+            else
+            {
+                string error = await process.StandardError.ReadToEndAsync();
+                return null;
+            }
+        }
+        finally
+        {
+            if (File.Exists(tempFilePath))
+            {
+                File.Delete(tempFilePath);
+            }
+        }
+    }
+
+    public static AVIFInfo ParseAVIFInfo(string text)
+    {
+        var avifInfo = new AVIFInfo();
+        var reader = new StringReader(text);
+        string line;
+
+        while ((line = reader.ReadLine()) != null)
+        {
+            if (string.IsNullOrWhiteSpace(line) || !line.Contains(":"))
+            {
+                continue;
+            }
+
+            var parts = line.Split(':', 2, StringSplitOptions.TrimEntries);
+            var key = parts[0].Trim().Replace("*", "").Trim();
+            var value = parts[1].Trim();
+
+            switch (key)
+            {
+                case "Resolution":
+                    var resolutionParts = value.Split('x');
+                    if (resolutionParts.Length == 2)
+                    {
+                        avifInfo.Width = int.Parse(resolutionParts[0].Trim());
+                        avifInfo.Height = int.Parse(resolutionParts[1].Trim());
+                    }
+                    break;
+                case "Bit Depth":
+                    avifInfo.BitDepth = int.Parse(value);
+                    break;
+                case "Format":
+                    avifInfo.Format = value;
+                    break;
+                case "Chroma Sam. Pos":
+                    avifInfo.ChromaSamPos = int.Parse(value);
+                    break;
+                case "Alpha":
+                    avifInfo.Alpha = value;
+                    break;
+                case "Range":
+                    avifInfo.Range = value;
+                    break;
+                case "Color Primaries":
+                    avifInfo.ColorPrimaries = int.Parse(value);
+                    break;
+                case "Transfer Char.":
+                    avifInfo.TransferChar = int.Parse(value);
+                    break;
+                case "Matrix Coeffs.":
+                    avifInfo.MatrixCoeffs = int.Parse(value);
+                    break;
+                case "ICC Profile":
+                    avifInfo.IccProfile = value;
+                    break;
+                case "XMP Metadata":
+                    avifInfo.XmpMetadata = value;
+                    break;
+                case "Exif Metadata":
+                    avifInfo.ExifMetadata = value;
+                    break;
+                case "Transformations":
+                    avifInfo.Transformations = value;
+                    break;
+                case "Progressive":
+                    avifInfo.Progressive = value;
+                    break;
+                case "Gain map":
+                    avifInfo.GainMap = value;
+                    break;
+            }
+        }
+
+        return avifInfo;
+    }
+}

src/AVIFEncoder.cs

@@ -3,9 +3,6 @@
 using System.Diagnostics;
 using System.Globalization;
 using System.IO;
-using System.Linq;
-using System.Reflection.Emit;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp;
@@ -58,7 +55,7 @@ public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, Cancel
 
         var psi = new ProcessStartInfo
         {
-            FileName = Native.CAVIF,
+            FileName = Native.CAVIFENC,
             Arguments = string.Join(' ', arguments),
             RedirectStandardInput = true,
             RedirectStandardOutput = true

src/AVIFFormat.cs

@@ -1,14 +1,19 @@
-using System;
+using SixLabors.ImageSharp.Metadata;
 using System.Collections.Generic;
 using SixLabors.ImageSharp.Formats;
 
 namespace NeoSolve.ImageSharp.AVIF; 
 public class AVIFFormat : IImageFormat {
     public string Name => "AVIF";
+    public static AVIFFormat Instance { get; } = new AVIFFormat();
 
     public string DefaultMimeType => "image/avif";
 
     public IEnumerable<string> MimeTypes => AVIFConstants.MimeTypes;
 
     public IEnumerable<string> FileExtensions => AVIFConstants.FileExtensions;
+    public IImageDecoder Decoder { get; } = new AVIFDecoder();
+    public IImageEncoder Encoder { get; } = new AVIFEncoder();
+
+    public ImageMetadata CreateDefaultFormatMetadata() => new();
 }

src/AVIFImageFormatDetector.cs

@@ -0,0 +1,34 @@
+using SixLabors.ImageSharp.Formats;
+using System;
+using System.Diagnostics.CodeAnalysis;
+
+namespace NeoSolve.ImageSharp.AVIF;
+
+public class AVIFImageFormatDetector : IImageFormatDetector
+{
+    public int HeaderSize => 12;
+
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat format)
+    {
+        bool isAVIF = header.Length <= HeaderSize && IsAvif(header);
+        format = isAVIF ? AVIFFormat.Instance : null;
+        return isAVIF;
+    }
+
+    private static bool IsAvif(ReadOnlySpan<byte> header)
+    {
+        // Check for the 'ftyp' box type at byte offset 4.
+        if (header[4] != 'f' || header[5] != 't' || header[6] != 'y' || header[7] != 'p')
+        {
+            return false;
+        }
+
+        // Check for the 'avif' brand at byte offset 8.
+        if (header[8] == 'a' && header[9] == 'v' && header[10] == 'i' && header[11] == 'f')
+        {
+            return true;
+        }
+
+        return false;
+    }
+}

src/AVIFInfo.cs

@@ -0,0 +1,21 @@
+namespace NeoSolve.ImageSharp.AVIF;
+
+public class AVIFInfo
+{
+    public int Width { get; set; }
+    public int Height { get; set; }
+    public int BitDepth { get; set; }
+    public string Format { get; set; }
+    public int ChromaSamPos { get; set; }
+    public string Alpha { get; set; }
+    public string Range { get; set; }
+    public int ColorPrimaries { get; set; }
+    public int TransferChar { get; set; }
+    public int MatrixCoeffs { get; set; }
+    public string IccProfile { get; set; }
+    public string XmpMetadata { get; set; }
+    public string ExifMetadata { get; set; }
+    public string Transformations { get; set; }
+    public string Progressive { get; set; }
+    public string GainMap { get; set; }
+}

src/Native.cs

@@ -5,7 +5,8 @@
 namespace NeoSolve.ImageSharp.AVIF;
 
 public static class Native {
-    public static string CAVIF => Path.Combine("native", OSFolder, "avifenc") + ExecutableExtension;
+    public static string CAVIFENC => Path.Combine("native", OSFolder, "avifenc") + ExecutableExtension;
+    public static string CAVIFDEC => Path.Combine("native", OSFolder, "avifdec") + ExecutableExtension;
 
     private static string OSFolder {
         get {