Introduce Av1FrameBuffer class and renaming others

src/ImageSharp/Formats/Heif/Av1/Av1Decoder.cs

@@ -19,7 +19,7 @@ internal class Av1Decoder : IAv1TileReader
 
     public ObuSequenceHeader? SequenceHeader { get; private set; }
 
-    public Av1FrameBuffer? FrameBuffer { get; private set; }
+    public Av1FrameInfo? FrameInfo { get; private set; }
 
     public void Decode(Span<byte> buffer)
     {
@@ -29,8 +29,8 @@ public void Decode(Span<byte> buffer)
         Guard.NotNull(this.SequenceHeader, nameof(this.SequenceHeader));
         Guard.NotNull(this.FrameHeader, nameof(this.FrameHeader));
 
-        this.FrameBuffer = this.tileReader.FrameBuffer;
-        this.frameDecoder = new(this.SequenceHeader, this.FrameHeader, this.FrameBuffer);
+        this.FrameInfo = this.tileReader.FrameInfo;
+        this.frameDecoder = new(this.SequenceHeader, this.FrameHeader, this.FrameInfo);
         this.frameDecoder.DecodeFrame();
     }
 

src/ImageSharp/Formats/Heif/Av1/Av1FrameBuffer.cs

@@ -0,0 +1,188 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using SixLabors.ImageSharp.Formats.Heif.Av1.OpenBitstreamUnit;
+using SixLabors.ImageSharp.Memory;
+
+namespace SixLabors.ImageSharp.Formats.Heif.Av1;
+
+/// <summary>
+/// Buffer for the pixels of a single frame.
+/// </summary>
+internal class Av1FrameBuffer : IDisposable
+{
+    private const int DecoderPaddingValue = 72;
+    private const int PictureBufferYFlag = 1 << 0;
+    private const int PictureBufferCbFlag = 1 << 1;
+    private const int PictureBufferCrFlag = 1 << 2;
+    private const int PictureBufferLumaMask = PictureBufferYFlag;
+    private const int PictureBufferFullMask = PictureBufferYFlag | PictureBufferCbFlag | PictureBufferCrFlag;
+
+    public Av1FrameBuffer(Configuration configuration, ObuSequenceHeader sequenceHeader, Av1ColorFormat maxColorFormat, bool is16BitPipeline)
+    {
+        Av1ColorFormat colorFormat = sequenceHeader.ColorConfig.IsMonochrome ? Av1ColorFormat.Yuv400 : maxColorFormat;
+        this.MaxWidth = sequenceHeader.MaxFrameWidth;
+        this.MaxHeight = sequenceHeader.MaxFrameHeight;
+        this.BitDepth = (Av1BitDepth)sequenceHeader.ColorConfig.BitDepth;
+        int bitsPerPixel = this.BitDepth > Av1BitDepth.EightBit || is16BitPipeline ? 2 : 1;
+        this.ColorFormat = colorFormat;
+        this.BufferEnableMask = sequenceHeader.ColorConfig.IsMonochrome ? PictureBufferLumaMask : PictureBufferFullMask;
+
+        int leftPadding = DecoderPaddingValue;
+        int rightPadding = DecoderPaddingValue;
+        int topPadding = DecoderPaddingValue;
+        int bottomPadding = DecoderPaddingValue;
+
+        this.Width = this.MaxWidth;
+        this.Height = this.MaxHeight;
+        int strideY = this.MaxWidth + leftPadding + rightPadding;
+        int heightY = this.MaxHeight + topPadding + bottomPadding;
+        this.OriginX = leftPadding;
+        this.OriginY = topPadding;
+        this.OriginOriginY = bottomPadding;
+        int strideChroma = 0;
+        int heightChroma = 0;
+        switch (this.ColorFormat)
+        {
+            case Av1ColorFormat.Yuv420:
+                strideChroma = (strideY + 1) >> 1;
+                heightChroma = (this.Height + 1) >> 1;
+                break;
+            case Av1ColorFormat.Yuv422:
+                strideChroma = (strideY + 1) >> 1;
+                heightChroma = this.Height;
+                break;
+            case Av1ColorFormat.Yuv444:
+                strideChroma = strideY;
+                heightChroma = this.Height;
+                break;
+        }
+
+        this.PackedFlag = false;
+
+        this.BufferY = null;
+        this.BufferCb = null;
+        this.BufferCr = null;
+        if ((this.BufferEnableMask & PictureBufferYFlag) != 0)
+        {
+            this.BufferY = configuration.MemoryAllocator.Allocate2D<byte>(strideY * bitsPerPixel, heightY);
+        }
+
+        if ((this.BufferEnableMask & PictureBufferCbFlag) != 0)
+        {
+            this.BufferCb = configuration.MemoryAllocator.Allocate2D<byte>(strideChroma * bitsPerPixel, heightChroma);
+        }
+
+        if ((this.BufferEnableMask & PictureBufferCrFlag) != 0)
+        {
+            this.BufferCr = configuration.MemoryAllocator.Allocate2D<byte>(strideChroma * bitsPerPixel, heightChroma);
+        }
+
+        this.BitIncrementY = null;
+        this.BitIncrementCb = null;
+        this.BitIncrementCr = null;
+        this.BitIncrementY = null;
+        this.BitIncrementCb = null;
+        this.BitIncrementCr = null;
+    }
+
+    /// <summary>
+    /// Gets the Y luma buffer.
+    /// </summary>
+    public Buffer2D<byte>? BufferY { get; private set; }
+
+    /// <summary>
+    /// Gets the U chroma buffer.
+    /// </summary>
+    public Buffer2D<byte>? BufferCb { get; private set; }
+
+    /// <summary>
+    /// Gets the V chroma buffer.
+    /// </summary>
+    public Buffer2D<byte>? BufferCr { get; private set; }
+
+    public Buffer2D<byte>? BitIncrementY { get; private set; }
+
+    public Buffer2D<byte>? BitIncrementCb { get; private set; }
+
+    public Buffer2D<byte>? BitIncrementCr { get; private set; }
+
+    /// <summary>
+    /// Gets or sets the horizontal padding distance.
+    /// </summary>
+    public int OriginX { get; set; }
+
+    /// <summary>
+    /// Gets or sets the vertical padding distance.
+    /// </summary>
+    public int OriginY { get; set; }
+
+    /// <summary>
+    /// Gets or sets the vertical bottom padding distance
+    /// </summary>
+    public int OriginOriginY { get; set; }
+
+    /// <summary>
+    /// Gets or sets the Luma picture width, which excludes the padding.
+    /// </summary>
+    public int Width { get; set; }
+
+    /// <summary>
+    /// Gets or sets the Luma picture height, which excludes the padding.
+    /// </summary>
+    public int Height { get; set; }
+
+    /// <summary>
+    /// Gets or sets the Lume picture width.
+    /// </summary>
+    public int MaxWidth { get; set; }
+
+    /// <summary>
+    /// Gets or sets the pixel bit depth.
+    /// </summary>
+    public Av1BitDepth BitDepth { get; set; }
+
+    /// <summary>
+    /// Gets or sets the chroma subsampling.
+    /// </summary>
+    public Av1ColorFormat ColorFormat { get; set; }
+
+    /// <summary>
+    /// Gets or sets the Luma picture height.
+    /// </summary>
+    public int MaxHeight { get; set; }
+
+    public int LumaSize { get; }
+
+    public int ChromaSize { get; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether the bytes of the buffers are packed.
+    /// </summary>
+    public bool PackedFlag { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether film grain parameters are present for this frame.
+    /// </summary>
+    public bool FilmGrainFlag { get; set; }
+
+    public int BufferEnableMask { get; set; }
+
+    public bool Is16BitPipeline { get; set; }
+
+    public void Dispose()
+    {
+        this.BufferY?.Dispose();
+        this.BufferY = null;
+        this.BufferCb?.Dispose();
+        this.BufferCb = null;
+        this.BufferCr?.Dispose();
+        this.BufferCr = null;
+        this.BitIncrementY?.Dispose();
+        this.BitIncrementY = null;
+        this.BitIncrementCb?.Dispose();
+        this.BitIncrementCb = null;
+        this.BitIncrementCr?.Dispose();
+        this.BitIncrementCr = null;
+    }
+}