Creator of IAv1TileReader

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

@@ -31,7 +31,7 @@ internal class Av1Decoder : IAv1TileReader
     public void Decode(Span<byte> buffer)
     {
         Av1BitStreamReader reader = new(buffer);
-        this.obuReader.ReadAll(ref reader, buffer.Length, this, false);
+        this.obuReader.ReadAll(ref reader, buffer.Length, () => this, false);
         Guard.NotNull(this.tileReader, nameof(this.tileReader));
         Guard.NotNull(this.SequenceHeader, nameof(this.SequenceHeader));
         Guard.NotNull(this.FrameHeader, nameof(this.FrameHeader));

src/ImageSharp/Formats/Heif/Av1/OpenBitstreamUnit/ObuReader.cs

@@ -39,6 +39,8 @@ internal class ObuReader
 
     private static readonly int[] SegmentationFeatureMax = [255, MaxLoopFilter, MaxLoopFilter, MaxLoopFilter, MaxLoopFilter, 7, 0, 0];
 
+    private IAv1TileReader? decoder;
+
     public ObuSequenceHeader? SequenceHeader { get; set; }
 
     public ObuFrameHeader? FrameHeader { get; set; }
@@ -46,7 +48,7 @@ internal class ObuReader
     /// <summary>
     /// Decode all OBU's in a frame.
     /// </summary>
-    public void ReadAll(ref Av1BitStreamReader reader, int dataSize, IAv1TileReader decoder, bool isAnnexB = false)
+    public void ReadAll(ref Av1BitStreamReader reader, int dataSize, Func<IAv1TileReader> creator, bool isAnnexB = false)
     {
         bool seenFrameHeader = false;
         bool frameDecodingFinished = false;
@@ -121,7 +123,8 @@ internal class ObuReader
                         throw new InvalidImageContentException("Corrupt frame");
                     }
 
-                    this.ReadTileGroup(ref reader, decoder, header, out frameDecodingFinished);
+                    this.decoder ??= creator();
+                    this.ReadTileGroup(ref reader, this.decoder, header, out frameDecodingFinished);
                     if (frameDecodingFinished)
                     {
                         seenFrameHeader = false;

src/ImageSharp/Formats/Heif/Av1/Tiling/Av1ParseLeftNeighbor4x4Context.cs

@@ -69,7 +69,7 @@ internal class Av1ParseLeftNeighbor4x4Context
         int startIndex = (modeInfoLocation.Y - superblockInfo.ModeInfoPosition.Y) & Av1PartitionContext.Mask;
         int bh = blockSize.Get4x4HighCount();
         int value = Av1PartitionContext.GetLeftContext(subSize);
-        DebugGuard.MustBeLessThanOrEqualTo(startIndex, this.LeftTransformHeight.Length - bh, nameof(startIndex));
+        DebugGuard.MustBeLessThanOrEqualTo(startIndex, this.LeftPartitionHeight.Length - bh, nameof(startIndex));
         Array.Fill(this.LeftPartitionHeight, value, startIndex, bh);
     }
 

tests/ImageSharp.Tests/Formats/Heif/Av1/Av1TilingTests.cs

@@ -23,7 +23,7 @@ public class Av1TilingTests
         Av1BitStreamReader bitStreamReader = new(headerSpan);
         IAv1TileReader stub = new Av1TileDecoderStub();
         ObuReader obuReader = new();
-        obuReader.ReadAll(ref bitStreamReader, dataSize, stub);
+        obuReader.ReadAll(ref bitStreamReader, dataSize, () => stub);
         Av1FrameBuffer frameBuffer = new(Configuration.Default, obuReader.SequenceHeader, Av1ColorFormat.Yuv444, false);
         Av1FrameInfo frameInfo = new(obuReader.SequenceHeader);
         Av1FrameDecoderStub frameDecoder = new();
@@ -36,4 +36,26 @@ public class Av1TilingTests
         Assert.Equal(dataSize * 8, bitStreamReader.BitPosition);
         Assert.Equal(superblockCount, frameDecoder.SuperblockCount);
     }
+
+    [Theory]
+    // [InlineData(TestImages.Heif.XnConvert, 0x010E, 0x03CC, 18, 16)]
+    [InlineData(TestImages.Heif.Orange4x4, 0x010E, 0x001d, 21, 1)]
+    public void DecodeFirstTile(string filename, int dataOffset, int dataSize, int tileOffset, int superblockCount)
+    {
+        // Assign
+        string filePath = Path.Combine(TestEnvironment.InputImagesDirectoryFullPath, filename);
+        byte[] content = File.ReadAllBytes(filePath);
+        Span<byte> headerSpan = content.AsSpan(dataOffset, dataSize);
+        Span<byte> tileSpan = content.AsSpan(tileOffset, dataSize - tileOffset);
+        Av1BitStreamReader bitStreamReader = new(headerSpan);
+        ObuReader obuReader = new();
+        Av1FrameDecoderStub frameDecoder = new();
+
+        // Act
+        obuReader.ReadAll(ref bitStreamReader, dataSize, () => new Av1TileReader(Configuration.Default, obuReader.SequenceHeader, obuReader.FrameHeader, frameDecoder));
+
+        // Assert
+        Assert.Equal(dataSize * 8, bitStreamReader.BitPosition);
+        Assert.Equal(superblockCount, frameDecoder.SuperblockCount);
+    }
 }

tests/ImageSharp.Tests/Formats/Heif/Av1/ObuFrameHeaderTests.cs

@@ -39,7 +39,7 @@ public class ObuFrameHeaderTests
         ObuReader obuReader = new();
 
         // Act
-        obuReader.ReadAll(ref reader, blockSize, decoder);
+        obuReader.ReadAll(ref reader, blockSize, () => decoder);
 
         // Assert
         Assert.NotNull(obuReader.SequenceHeader);
@@ -63,7 +63,7 @@ public class ObuFrameHeaderTests
         ObuReader obuReader = new();
 
         // Act 1
-        obuReader.ReadAll(ref reader, blockSize, tileStub);
+        obuReader.ReadAll(ref reader, blockSize, () => tileStub);
 
         // Assign 2
         MemoryStream encoded = new();
@@ -91,7 +91,7 @@ public class ObuFrameHeaderTests
         ObuReader obuReader1 = new();
 
         // Act 1
-        obuReader1.ReadAll(ref reader, blockSize, tileStub);
+        obuReader1.ReadAll(ref reader, blockSize, () => tileStub);
 
         // Assign 2
         MemoryStream encoded = new();
@@ -107,7 +107,7 @@ public class ObuFrameHeaderTests
         ObuReader obuReader2 = new();
 
         // Act 2
-        obuReader2.ReadAll(ref reader2, encodedBuffer.Length, tileDecoder2);
+        obuReader2.ReadAll(ref reader2, encodedBuffer.Length, () => tileDecoder2);
 
         // Assert
         Assert.Equal(ObuPrettyPrint.PrettyPrintProperties(obuReader1.SequenceHeader.ColorConfig), ObuPrettyPrint.PrettyPrintProperties(obuReader2.SequenceHeader.ColorConfig));
@@ -125,7 +125,7 @@ public class ObuFrameHeaderTests
         IAv1TileReader tileDecoder = new Av1TileDecoderStub();
 
         // Act
-        obuReader.ReadAll(ref reader, DefaultTemporalDelimiterBitStream.Length, tileDecoder);
+        obuReader.ReadAll(ref reader, DefaultTemporalDelimiterBitStream.Length, () => tileDecoder);
 
         // Assert
         Assert.Null(obuReader.SequenceHeader);
@@ -142,7 +142,7 @@ public class ObuFrameHeaderTests
         IAv1TileReader tileDecoder = new Av1TileDecoderStub();
 
         // Act
-        obuReader.ReadAll(ref reader, bitStream.Length, tileDecoder);
+        obuReader.ReadAll(ref reader, bitStream.Length, () => tileDecoder);
 
         // Assert
         Assert.Null(obuReader.SequenceHeader);
@@ -160,7 +160,7 @@ public class ObuFrameHeaderTests
         ObuSequenceHeader expected = GetDefaultSequenceHeader();
 
         // Act
-        obuReader.ReadAll(ref reader, bitStream.Length, tileDecoder);
+        obuReader.ReadAll(ref reader, bitStream.Length, () => tileDecoder);
 
         // Assert
         Assert.NotNull(obuReader.SequenceHeader);