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Update encoder and decoder to handle restart interval

pull/2740/head
ardabada 2 years ago
parent
aa774411b3
commit
a34bca3b66
4 changed files with 101 additions and 20 deletions
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  1. 2
      src/ImageSharp/Formats/Jpeg/Components/Decoder/HuffmanScanDecoder.cs
  2. 78
      src/ImageSharp/Formats/Jpeg/Components/Encoder/HuffmanScanEncoder.cs
  3. 8
      src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs
  4. 33
      tests/ImageSharp.Tests/Formats/Jpg/JpegEncoderTests.cs

2
src/ImageSharp/Formats/Jpeg/Components/Decoder/HuffmanScanDecoder.cs
View File

@ -119,6 +119,8 @@ internal class HuffmanScanDecoder : IJpegScanDecoder
this.frame.AllocateComponents();
this.todo = this.restartInterval;
if (!this.frame.Progressive)
{
this.ParseBaselineData();

78
src/ImageSharp/Formats/Jpeg/Components/Encoder/HuffmanScanEncoder.cs
View File

@ -87,6 +87,8 @@ internal class HuffmanScanEncoder
/// </remarks>
private readonly byte[] streamWriteBuffer;
private readonly int restartInterval;
/// <summary>
/// Number of jagged bits stored in <see cref="accumulatedBits"/>
/// </summary>
@ -103,13 +105,16 @@ internal class HuffmanScanEncoder
/// Initializes a new instance of the <see cref="HuffmanScanEncoder"/> class.
/// </summary>
/// <param name="blocksPerCodingUnit">Amount of encoded 8x8 blocks per single jpeg macroblock.</param>
/// <param name="restartInterval">Numbers of MCUs between restart markers.</param>
/// <param name="outputStream">Output stream for saving encoded data.</param>
public HuffmanScanEncoder(int blocksPerCodingUnit, Stream outputStream)
public HuffmanScanEncoder(int blocksPerCodingUnit, int restartInterval, Stream outputStream)
{
int emitBufferByteLength = MaxBytesPerBlock * blocksPerCodingUnit;
this.emitBuffer = new uint[emitBufferByteLength / sizeof(uint)];
this.emitWriteIndex = this.emitBuffer.Length;
this.restartInterval = restartInterval;
this.streamWriteBuffer = new byte[emitBufferByteLength * OutputBufferLengthMultiplier];
this.target = outputStream;
@ -211,6 +216,9 @@ internal class HuffmanScanEncoder
ref HuffmanLut dcHuffmanTable = ref this.dcHuffmanTables[component.DcTableId];
ref HuffmanLut acHuffmanTable = ref this.acHuffmanTables[component.AcTableId];
int restarts = 0;
int restartsToGo = this.restartInterval;
for (int i = 0; i < h; i++)
{
cancellationToken.ThrowIfCancellationRequested();
@ -221,6 +229,13 @@ internal class HuffmanScanEncoder
for (nuint k = 0; k < (uint)w; k++)
{
if (this.restartInterval > 0 && restartsToGo == 0)
{
this.FlushRemainingBytes();
this.WriteRestart(restarts % 8);
component.DcPredictor = 0;
}
this.WriteBlock(
component,
ref Unsafe.Add(ref blockRef, k),
@ -231,6 +246,17 @@ internal class HuffmanScanEncoder
{
this.FlushToStream();
}
if (this.restartInterval > 0)
{
if (restartsToGo == 0)
{
restartsToGo = this.restartInterval;
restarts++;
}
restartsToGo--;
}
}
}
@ -241,9 +267,8 @@ internal class HuffmanScanEncoder
/// Encodes the DC coefficients for a given component's blocks in a scan.
/// </summary>
/// <param name="component">The component whose DC coefficients need to be encoded.</param>
/// <param name="restartInterval">Numbers of MCUs between restart markers.</param>
/// <param name="cancellationToken">The token to request cancellation.</param>
public void EncodeDcScan(Component component, int restartInterval, CancellationToken cancellationToken)
public void EncodeDcScan(Component component, CancellationToken cancellationToken)
{
int h = component.HeightInBlocks;
int w = component.WidthInBlocks;
@ -251,7 +276,7 @@ internal class HuffmanScanEncoder
ref HuffmanLut dcHuffmanTable = ref this.dcHuffmanTables[component.DcTableId];
int restarts = 0;
int restartsToGo = restartInterval;
int restartsToGo = this.restartInterval;
for (int i = 0; i < h; i++)
{
@ -262,7 +287,7 @@ internal class HuffmanScanEncoder
for (nuint k = 0; k < (uint)w; k++)
{
if (restartInterval > 0 && restartsToGo == 0)
if (this.restartInterval > 0 && restartsToGo == 0)
{
this.FlushRemainingBytes();
this.WriteRestart(restarts % 8);
@ -279,13 +304,12 @@ internal class HuffmanScanEncoder
this.FlushToStream();
}
if (restartInterval > 0)
if (this.restartInterval > 0)
{
if (restartsToGo == 0)
{
restartsToGo = restartInterval;
restartsToGo = this.restartInterval;
restarts++;
restarts &= 7;
}
restartsToGo--;
@ -302,15 +326,14 @@ internal class HuffmanScanEncoder
/// <param name="component">The component whose AC coefficients need to be encoded.</param>
/// <param name="start">The starting index of the AC coefficient range to encode.</param>
/// <param name="end">The ending index of the AC coefficient range to encode.</param>
/// <param name="restartInterval">Numbers of MCUs between restart markers.</param>
/// <param name="cancellationToken">The token to request cancellation.</param>
public void EncodeAcScan(Component component, nint start, nint end, int restartInterval, CancellationToken cancellationToken)
public void EncodeAcScan(Component component, nint start, nint end, CancellationToken cancellationToken)
{
int h = component.HeightInBlocks;
int w = component.WidthInBlocks;
int restarts = 0;
int restartsToGo = restartInterval;
int restartsToGo = this.restartInterval;
ref HuffmanLut acHuffmanTable = ref this.acHuffmanTables[component.AcTableId];
@ -323,7 +346,7 @@ internal class HuffmanScanEncoder
for (nuint k = 0; k < (uint)w; k++)
{
if (restartInterval > 0 && restartsToGo == 0)
if (this.restartInterval > 0 && restartsToGo == 0)
{
this.FlushRemainingBytes();
this.WriteRestart(restarts % 8);
@ -340,13 +363,12 @@ internal class HuffmanScanEncoder
this.FlushToStream();
}
if (restartInterval > 0)
if (this.restartInterval > 0)
{
if (restartsToGo == 0)
{
restartsToGo = restartInterval;
restartsToGo = this.restartInterval;
restarts++;
restarts &= 7;
}
restartsToGo--;
@ -370,6 +392,9 @@ internal class HuffmanScanEncoder
int mcusPerColumn = frame.McusPerColumn;
int mcusPerLine = frame.McusPerLine;
int restarts = 0;
int restartsToGo = this.restartInterval;
for (int j = 0; j < mcusPerColumn; j++)
{
cancellationToken.ThrowIfCancellationRequested();
@ -380,6 +405,16 @@ internal class HuffmanScanEncoder
// Encode spectral to binary
for (int i = 0; i < mcusPerLine; i++)
{
if (this.restartInterval > 0 && restartsToGo == 0)
{
this.FlushRemainingBytes();
this.WriteRestart(restarts % 8);
foreach (var component in frame.Components)
{
component.DcPredictor = 0;
}
}
// Scan an interleaved mcu... process components in order
int mcuCol = mcu % mcusPerLine;
for (int k = 0; k < frame.Components.Length; k++)
@ -420,6 +455,17 @@ internal class HuffmanScanEncoder
{
this.FlushToStream();
}
if (this.restartInterval > 0)
{
if (restartsToGo == 0)
{
restartsToGo = this.restartInterval;
restarts++;
}
restartsToGo--;
}
}
}
@ -554,7 +600,7 @@ internal class HuffmanScanEncoder
}
private void WriteRestart(int restart) =>
this.target.Write([0xff, (byte)(JpegConstants.Markers.RST0 + restart)]);
this.target.Write([0xff, (byte)(JpegConstants.Markers.RST0 + restart)], 0, 2);
/// <summary>
/// Emits the most significant count of bits to the buffer.

8
src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs
View File

@ -100,7 +100,7 @@ internal sealed unsafe partial class JpegEncoderCore : IImageEncoderInternals
this.WriteStartOfFrame(image.Width, image.Height, frameConfig, buffer);
// Write the Huffman tables.
HuffmanScanEncoder scanEncoder = new(frame.BlocksPerMcu, stream);
HuffmanScanEncoder scanEncoder = new(frame.BlocksPerMcu, this.encoder.RestartInterval, stream);
this.WriteDefineHuffmanTables(frameConfig.HuffmanTables, scanEncoder, buffer);
// Write the quantization tables.
@ -445,7 +445,7 @@ internal sealed unsafe partial class JpegEncoderCore : IImageEncoderInternals
buffer[1] = (byte)(restartInterval & 0xff);
buffer[0] = (byte)(restartInterval >> 8);
this.outputStream.Write(buffer);
this.outputStream.Write(buffer, 0, 2);
}
/// <summary>
@ -764,7 +764,7 @@ internal sealed unsafe partial class JpegEncoderCore : IImageEncoderInternals
{
this.WriteStartOfScan(components.Slice(i, 1), buffer, 0x00, 0x00);
encoder.EncodeDcScan(frame.Components[i], this.encoder.RestartInterval, cancellationToken);
encoder.EncodeDcScan(frame.Components[i], cancellationToken);
}
// Phase 2: AC scans
@ -779,7 +779,7 @@ internal sealed unsafe partial class JpegEncoderCore : IImageEncoderInternals
{
this.WriteStartOfScan(components.Slice(i, 1), buffer, (byte)start, (byte)(end - 1));
encoder.EncodeAcScan(frame.Components[i], start, end, this.encoder.RestartInterval, cancellationToken);
encoder.EncodeAcScan(frame.Components[i], start, end, cancellationToken);
}
}
}

33
tests/ImageSharp.Tests/Formats/Jpg/JpegEncoderTests.cs
View File

@ -178,6 +178,39 @@ public partial class JpegEncoderTests
image.VerifyEncoder(provider, "jpeg", info, encoder, comparer, referenceImageExtension: "jpg");
}
[Theory]
[WithFile(TestImages.Png.CalliphoraPartial, nameof(NonSubsampledEncodingSetups), PixelTypes.Rgb24)]
[WithFile(TestImages.Png.CalliphoraPartial, nameof(SubsampledEncodingSetups), PixelTypes.Rgb24)]
[WithFile(TestImages.Png.BikeGrayscale, nameof(LuminanceEncodingSetups), PixelTypes.L8)]
[WithFile(TestImages.Jpeg.Baseline.Cmyk, nameof(CmykEncodingSetups), PixelTypes.Rgb24)]
[WithFile(TestImages.Jpeg.Baseline.Ycck, nameof(YcckEncodingSetups), PixelTypes.Rgb24)]
public void EncodeProgressive_CustomNumberOfScans<TPixel>(TestImageProvider<TPixel> provider, JpegEncodingColor colorType, int quality, float tolerance)
where TPixel : unmanaged, IPixel<TPixel>
{
using Image<TPixel> image = provider.GetImage();
JpegEncoder encoder = new()
{
Quality = quality,
ColorType = colorType,
Progressive = true,
ProgressiveScans = 4,
RestartInterval = 7
};
string info = $"{colorType}-Q{quality}";
using MemoryStream ms = new();
image.SaveAsJpeg(ms, encoder);
ms.Position = 0;
// TEMP: Save decoded output as PNG so we can do a pixel compare.
using Image<TPixel> image2 = Image.Load<TPixel>(ms);
image2.DebugSave(provider, testOutputDetails: info, extension: "png");
ImageComparer comparer = new TolerantImageComparer(tolerance);
image.VerifyEncoder(provider, "jpeg", info, encoder, comparer, referenceImageExtension: "jpg");
}
[Theory]
[InlineData(JpegEncodingColor.YCbCrRatio420)]
[InlineData(JpegEncodingColor.YCbCrRatio444)]

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