Rename TileDecoder into TileReader

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

@@ -6,11 +6,10 @@ using SixLabors.ImageSharp.Formats.Heif.Av1.Symbol;
 
 namespace SixLabors.ImageSharp.Formats.Heif.Av1;
 
-internal class Av1Decoder : IAv1TileDecoder
+internal class Av1Decoder : IAv1TileReader
 {
     private readonly ObuReader obuReader;
-    private Av1TileDecoder? tileDecoder;
-    private Av1FrameBuffer? frameBuffer;
+    private Av1TileReader? tileReader;
 
     public Av1Decoder() => this.obuReader = new();
 
@@ -18,22 +17,26 @@ internal class Av1Decoder : IAv1TileDecoder
 
     public ObuSequenceHeader? SequenceHeader { get; private set; }
 
+    public Av1FrameBuffer? FrameBuffer { get; private set; }
+
     public void Decode(Span<byte> buffer)
     {
         Av1BitStreamReader reader = new(buffer);
         this.obuReader.ReadAll(ref reader, buffer.Length, this, false);
-        this.frameBuffer = this.tileDecoder?.FrameBuffer;
+        this.FrameBuffer = this.tileReader?.FrameBuffer;
+
+        // TODO: Decode the FrameBuffer
     }
 
-    public void DecodeTile(Span<byte> tileData, int tileNum)
+    public void ReadTile(Span<byte> tileData, int tileNum)
     {
-        if (this.tileDecoder == null)
+        if (this.tileReader == null)
         {
             this.SequenceHeader = this.obuReader.SequenceHeader;
             this.FrameHeader = this.obuReader.FrameHeader;
-            this.tileDecoder = new Av1TileDecoder(this.SequenceHeader!, this.FrameHeader!);
+            this.tileReader = new Av1TileReader(this.SequenceHeader!, this.FrameHeader!);
         }
 
-        this.tileDecoder.DecodeTile(tileData, tileNum);
+        this.tileReader.ReadTile(tileData, tileNum);
     }
 }

src/ImageSharp/Formats/Heif/Av1/IAv1TileDecoder.cs → src/ImageSharp/Formats/Heif/Av1/IAv1TileReader.cs

@@ -4,16 +4,16 @@
 namespace SixLabors.ImageSharp.Formats.Heif.Av1;
 
 /// <summary>
-/// Interface for decoding of image tiles.
+/// Interface for reading of image tiles.
 /// </summary>
-internal interface IAv1TileDecoder
+internal interface IAv1TileReader
 {
     /// <summary>
-    /// Decode a single tile.
+    /// Read the information for a single tile.
     /// </summary>
     /// <param name="tileData">
     /// The bytes of encoded data in the bitstream dedicated to this tile.
     /// </param>
-    /// <param name="tileNum">The index of the tile that is to be decoded.</param>
-    void DecodeTile(Span<byte> tileData, int tileNum);
+    /// <param name="tileNum">The index of the tile that is to be read.</param>
+    void ReadTile(Span<byte> tileData, int tileNum);
 }

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

@@ -45,7 +45,7 @@ internal class ObuReader
     /// <summary>
     /// Decode all OBU's in a frame.
     /// </summary>
-    public void ReadAll(ref Av1BitStreamReader reader, int dataSize, IAv1TileDecoder decoder, bool isAnnexB = false)
+    public void ReadAll(ref Av1BitStreamReader reader, int dataSize, IAv1TileReader decoder, bool isAnnexB = false)
     {
         bool seenFrameHeader = false;
         bool frameDecodingFinished = false;
@@ -1232,7 +1232,7 @@ internal class ObuReader
     /// <summary>
     /// 5.11.1. General tile group OBU syntax.
     /// </summary>
-    private void ReadTileGroup(ref Av1BitStreamReader reader, IAv1TileDecoder decoder, ObuHeader header, out bool isLastTileGroup)
+    private void ReadTileGroup(ref Av1BitStreamReader reader, IAv1TileReader decoder, ObuHeader header, out bool isLastTileGroup)
     {
         ObuSequenceHeader sequenceHeader = this.SequenceHeader!;
         ObuFrameHeader frameInfo = this.FrameHeader!;
@@ -1287,7 +1287,7 @@ internal class ObuReader
             }
 
             Span<byte> tileData = reader.GetSymbolReader(tileDataSize);
-            decoder.DecodeTile(tileData, tileNum);
+            decoder.ReadTile(tileData, tileNum);
         }
 
         if (tileGroupEnd != tileCount - 1)

src/ImageSharp/Formats/Heif/Av1/Tiling/Av1TileDecoder.cs → src/ImageSharp/Formats/Heif/Av1/Tiling/Av1TileReader.cs

@@ -8,7 +8,7 @@ using SixLabors.ImageSharp.Formats.Heif.Av1.Transform;
 
 namespace SixLabors.ImageSharp.Formats.Heif.Av1.Symbol;
 
-internal class Av1TileDecoder : IAv1TileDecoder
+internal class Av1TileReader : IAv1TileReader
 {
     private static readonly int[] SgrprojXqdMid = [-32, 31];
     private static readonly int[] WienerTapsMid = [3, -7, 15];
@@ -34,7 +34,7 @@ internal class Av1TileDecoder : IAv1TileDecoder
     private readonly int[] firstTransformOffset = new int[2];
     private readonly int[] coefficientIndex = [];
 
-    public Av1TileDecoder(ObuSequenceHeader sequenceHeader, ObuFrameHeader frameInfo)
+    public Av1TileReader(ObuSequenceHeader sequenceHeader, ObuFrameHeader frameInfo)
     {
         this.FrameInfo = frameInfo;
         this.SequenceHeader = sequenceHeader;
@@ -69,7 +69,7 @@ internal class Av1TileDecoder : IAv1TileDecoder
 
     public Av1FrameBuffer FrameBuffer { get; }
 
-    public void DecodeTile(Span<byte> tileData, int tileNum)
+    public void ReadTile(Span<byte> tileData, int tileNum)
     {
         Av1SymbolDecoder reader = new(tileData, this.FrameInfo.QuantizationParameters.BaseQIndex);
         int tileColumnIndex = tileNum % this.FrameInfo.TilesInfo.TileColumnCount;
@@ -740,8 +740,8 @@ internal class Av1TileDecoder : IAv1TileDecoder
         for (int c = endSi; c >= startSi; --c)
         {
             int pos = scan[c];
-            int coeff_ctx = GetLowerLevelsContext(levels, pos, bwl, transformSize, transformClass);
-            int level = reader.ReadCoefficientsBase(coeff_ctx, transformSizeContext, planeType);
+            int coefficientContext = GetLowerLevelsContext(levels, pos, bwl, transformSize, transformClass);
+            int level = reader.ReadCoefficientsBase(coefficientContext, transformSizeContext, planeType);
             if (level > Av1Constants.BaseLevelsCount)
             {
                 int baseRangeContext = GetBaseRangeContext(levels, pos, bwl, transformClass);

tests/ImageSharp.Tests/Formats/Heif/Av1/Av1TileDecoderStub.cs

@@ -5,17 +5,10 @@ using SixLabors.ImageSharp.Formats.Heif.Av1;
 
 namespace SixLabors.ImageSharp.Tests.Formats.Heif.Av1;
 
-internal class Av1TileDecoderStub : IAv1TileDecoder
+internal class Av1TileDecoderStub : IAv1TileReader
 {
-    public void StartDecodeTiles()
-    {
-    }
-
-    public void DecodeTile(Span<byte> tileData, int tileNum)
-    {
-    }
-
-    public void FinishDecodeTiles(bool doCdef, bool doLoopRestoration)
+    public void ReadTile(Span<byte> tileData, int tileNum)
     {
+        // Intentionally left blank.
     }
 }

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

@@ -20,16 +20,16 @@ public class Av1TilingTests
         byte[] content = File.ReadAllBytes(filePath);
         Span<byte> headerSpan = content.AsSpan(dataOffset, dataSize);
         Span<byte> tileSpan = content.AsSpan(tileOffset, dataSize - tileOffset);
-        Av1BitStreamReader reader = new(headerSpan);
-        IAv1TileDecoder stub = new Av1TileDecoderStub();
+        Av1BitStreamReader bitStreamReader = new(headerSpan);
+        IAv1TileReader stub = new Av1TileDecoderStub();
         ObuReader obuReader = new();
-        obuReader.ReadAll(ref reader, dataSize, stub);
-        Av1TileDecoder decoder = new(obuReader.SequenceHeader, obuReader.FrameHeader);
+        obuReader.ReadAll(ref bitStreamReader, dataSize, stub);
+        Av1TileReader tileReader = new(obuReader.SequenceHeader, obuReader.FrameHeader);
 
         // Act
-        decoder.DecodeTile(tileSpan, 0);
+        tileReader.ReadTile(tileSpan, 0);
 
         // Assert
-        Assert.Equal(dataSize * 8, reader.BitPosition);
+        Assert.Equal(dataSize * 8, bitStreamReader.BitPosition);
     }
 }

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

@@ -33,7 +33,7 @@ public class ObuFrameHeaderTests
         byte[] content = File.ReadAllBytes(filePath);
         Span<byte> span = content.AsSpan(fileOffset, blockSize);
         Av1BitStreamReader reader = new(span);
-        IAv1TileDecoder decoder = new Av1TileDecoderStub();
+        IAv1TileReader decoder = new Av1TileDecoderStub();
         ObuReader obuReader = new();
 
         // Act
@@ -83,7 +83,7 @@ public class ObuFrameHeaderTests
         string filePath = Path.Combine(TestEnvironment.InputImagesDirectoryFullPath, filename);
         byte[] content = File.ReadAllBytes(filePath);
         Span<byte> span = content.AsSpan(fileOffset, blockSize);
-        IAv1TileDecoder tileDecoder = new Av1TileDecoderStub();
+        IAv1TileReader tileDecoder = new Av1TileDecoderStub();
         Av1BitStreamReader reader = new(span);
         ObuReader obuReader1 = new();
 
@@ -98,7 +98,7 @@ public class ObuFrameHeaderTests
 
         // Assign 2
         Span<byte> encodedBuffer = encoded.ToArray();
-        IAv1TileDecoder tileDecoder2 = new Av1TileDecoderStub();
+        IAv1TileReader tileDecoder2 = new Av1TileDecoderStub();
         Av1BitStreamReader reader2 = new(span);
         ObuReader obuReader2 = new();
 
@@ -118,7 +118,7 @@ public class ObuFrameHeaderTests
         // Arrange
         Av1BitStreamReader reader = new(DefaultTemporalDelimiterBitStream);
         ObuReader obuReader = new();
-        IAv1TileDecoder tileDecoder = new Av1TileDecoderStub();
+        IAv1TileReader tileDecoder = new Av1TileDecoderStub();
 
         // Act
         obuReader.ReadAll(ref reader, DefaultTemporalDelimiterBitStream.Length, tileDecoder);
@@ -135,7 +135,7 @@ public class ObuFrameHeaderTests
         byte[] bitStream = [0x10];
         Av1BitStreamReader reader = new(bitStream);
         ObuReader obuReader = new();
-        IAv1TileDecoder tileDecoder = new Av1TileDecoderStub();
+        IAv1TileReader tileDecoder = new Av1TileDecoderStub();
 
         // Act
         obuReader.ReadAll(ref reader, bitStream.Length, tileDecoder);
@@ -152,7 +152,7 @@ public class ObuFrameHeaderTests
         byte[] bitStream = DefaultSequenceHeaderBitStream;
         Av1BitStreamReader reader = new(bitStream);
         ObuReader obuReader = new();
-        IAv1TileDecoder tileDecoder = new Av1TileDecoderStub();
+        IAv1TileReader tileDecoder = new Av1TileDecoderStub();
         ObuSequenceHeader expected = GetDefaultSequenceHeader();
 
         // Act