Skip to content

Jpeg new IDCT & fused zigzag/transpose steps #1847

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 14 commits into from
Nov 24, 2021
Merged

Jpeg new IDCT & fused zigzag/transpose steps #1847

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
14 commits
Select commit Hold shift + click to select a range
408462a
Added new IDCT implementation
Nov 21, 2021
2294693
Fused transpose with zig-zag ordering
Nov 21, 2021
eaa7373
Comments
Nov 21, 2021
af0b8ac
Fixed compilation errors, fixed tests
Nov 21, 2021
a66ff59
Merge branch 'master' into jpeg-idct-zigzag-optimization
Nov 21, 2021
1631e9d
Updated benchmark results
Nov 21, 2021
50b0f0b
Test qol fixes
Nov 22, 2021
cf4cf23
Shared infrastructure subproject commit hash
Nov 22, 2021
3069dd1
Fixed failing tests
Nov 23, 2021
42315dc
Updated benchmarks
Nov 23, 2021
92445c3
Added test for TransposeInplace
Nov 23, 2021
2814705
Removed bound checks from DCT adjustment methods
Nov 23, 2021
586df2e
Fixed crash bug
Nov 23, 2021
da82761
Merge branch 'master' into jpeg-idct-zigzag-optimization
JimBobSquarePants Nov 24, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion shared-infrastructure
Open in desktop
Submodule shared-infrastructure updated 3 files
+0 −11 codecov.yml
+1 −1 msbuild/props/SixLabors.Tests.props
+1 −1 msbuild/targets/SixLabors.Src.targets
58 changes: 58 additions & 0 deletions src/ImageSharp/Formats/Jpeg/Components/Block8x8.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -337,6 +337,64 @@ public nint GetLastNonZeroIndex()
}
}

/// <summary>
/// Transpose the block inplace.
/// </summary>
[MethodImpl(InliningOptions.ShortMethod)]
public void TransposeInplace()
{
ref short elemRef = ref Unsafe.As<Block8x8, short>(ref this);

// row #0
Swap(ref Unsafe.Add(ref elemRef, 1), ref Unsafe.Add(ref elemRef, 8));
Swap(ref Unsafe.Add(ref elemRef, 2), ref Unsafe.Add(ref elemRef, 16));
Swap(ref Unsafe.Add(ref elemRef, 3), ref Unsafe.Add(ref elemRef, 24));
Swap(ref Unsafe.Add(ref elemRef, 4), ref Unsafe.Add(ref elemRef, 32));
Swap(ref Unsafe.Add(ref elemRef, 5), ref Unsafe.Add(ref elemRef, 40));
Swap(ref Unsafe.Add(ref elemRef, 6), ref Unsafe.Add(ref elemRef, 48));
Swap(ref Unsafe.Add(ref elemRef, 7), ref Unsafe.Add(ref elemRef, 56));

// row #1
Swap(ref Unsafe.Add(ref elemRef, 10), ref Unsafe.Add(ref elemRef, 17));
Swap(ref Unsafe.Add(ref elemRef, 11), ref Unsafe.Add(ref elemRef, 25));
Swap(ref Unsafe.Add(ref elemRef, 12), ref Unsafe.Add(ref elemRef, 33));
Swap(ref Unsafe.Add(ref elemRef, 13), ref Unsafe.Add(ref elemRef, 41));
Swap(ref Unsafe.Add(ref elemRef, 14), ref Unsafe.Add(ref elemRef, 49));
Swap(ref Unsafe.Add(ref elemRef, 15), ref Unsafe.Add(ref elemRef, 57));

// row #2
Swap(ref Unsafe.Add(ref elemRef, 19), ref Unsafe.Add(ref elemRef, 26));
Swap(ref Unsafe.Add(ref elemRef, 20), ref Unsafe.Add(ref elemRef, 34));
Swap(ref Unsafe.Add(ref elemRef, 21), ref Unsafe.Add(ref elemRef, 42));
Swap(ref Unsafe.Add(ref elemRef, 22), ref Unsafe.Add(ref elemRef, 50));
Swap(ref Unsafe.Add(ref elemRef, 23), ref Unsafe.Add(ref elemRef, 58));

// row #3
Swap(ref Unsafe.Add(ref elemRef, 28), ref Unsafe.Add(ref elemRef, 35));
Swap(ref Unsafe.Add(ref elemRef, 29), ref Unsafe.Add(ref elemRef, 43));
Swap(ref Unsafe.Add(ref elemRef, 30), ref Unsafe.Add(ref elemRef, 51));
Swap(ref Unsafe.Add(ref elemRef, 31), ref Unsafe.Add(ref elemRef, 59));

// row #4
Swap(ref Unsafe.Add(ref elemRef, 37), ref Unsafe.Add(ref elemRef, 44));
Swap(ref Unsafe.Add(ref elemRef, 38), ref Unsafe.Add(ref elemRef, 52));
Swap(ref Unsafe.Add(ref elemRef, 39), ref Unsafe.Add(ref elemRef, 60));

// row #5
Swap(ref Unsafe.Add(ref elemRef, 46), ref Unsafe.Add(ref elemRef, 53));
Swap(ref Unsafe.Add(ref elemRef, 47), ref Unsafe.Add(ref elemRef, 61));

// row #6
Swap(ref Unsafe.Add(ref elemRef, 55), ref Unsafe.Add(ref elemRef, 62));

static void Swap(ref short a, ref short b)
{
short tmp = a;
a = b;
b = tmp;
}
}

/// <summary>
/// Calculate the total sum of absolute differences of elements in 'a' and 'b'.
/// </summary>
Expand Down
10 changes: 5 additions & 5 deletions src/ImageSharp/Formats/Jpeg/Components/Decoder/HuffmanScanDecoder.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -502,7 +502,7 @@ private void DecodeBlockBaseline(
{
i += r;
s = buffer.Receive(s);
Unsafe.Add(ref blockDataRef, ZigZag.ZigZagOrder[i++]) = (short)s;
Unsafe.Add(ref blockDataRef, ZigZag.TransposingOrder[i++]) = (short)s;
}
else
{
Expand Down Expand Up @@ -571,7 +571,7 @@ private void DecodeBlockProgressiveAC(ref Block8x8 block, ref HuffmanTable acTab
if (s != 0)
{
s = buffer.Receive(s);
Unsafe.Add(ref blockDataRef, ZigZag.ZigZagOrder[i]) = (short)(s << low);
Unsafe.Add(ref blockDataRef, ZigZag.TransposingOrder[i]) = (short)(s << low);
}
else
{
Expand Down Expand Up @@ -647,7 +647,7 @@ private void DecodeBlockProgressiveACRefined(ref short blockDataRef, ref Huffman

do
{
ref short coef = ref Unsafe.Add(ref blockDataRef, ZigZag.ZigZagOrder[k]);
ref short coef = ref Unsafe.Add(ref blockDataRef, ZigZag.TransposingOrder[k]);
if (coef != 0)
{
buffer.CheckBits();
Expand All @@ -673,7 +673,7 @@ private void DecodeBlockProgressiveACRefined(ref short blockDataRef, ref Huffman

if ((s != 0) && (k < 64))
{
Unsafe.Add(ref blockDataRef, ZigZag.ZigZagOrder[k]) = (short)s;
Unsafe.Add(ref blockDataRef, ZigZag.TransposingOrder[k]) = (short)s;
}
}
}
Expand All @@ -682,7 +682,7 @@ private void DecodeBlockProgressiveACRefined(ref short blockDataRef, ref Huffman
{
for (; k <= end; k++)
{
ref short coef = ref Unsafe.Add(ref blockDataRef, ZigZag.ZigZagOrder[k]);
ref short coef = ref Unsafe.Add(ref blockDataRef, ZigZag.TransposingOrder[k]);

if (coef != 0)
{
Expand Down
8 changes: 1 addition & 7 deletions src/ImageSharp/Formats/Jpeg/Components/Decoder/JpegBlockPostProcessor.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,11 +18,6 @@ internal struct JpegBlockPostProcessor
/// </summary>
public Block8x8F SourceBlock;

/// <summary>
/// Temporal block to store intermediate computation results.
/// </summary>
public Block8x8F WorkspaceBlock;

/// <summary>
/// The quantization table as <see cref="Block8x8F"/>.
/// </summary>
Expand All @@ -45,7 +40,6 @@ public JpegBlockPostProcessor(IRawJpegData decoder, IJpegComponent component)
this.subSamplingDivisors = component.SubSamplingDivisors;

this.SourceBlock = default;
this.WorkspaceBlock = default;
}

/// <summary>
Expand All @@ -71,7 +65,7 @@ public void ProcessBlockColorsInto(
// Dequantize:
block.MultiplyInPlace(ref this.DequantiazationTable);

FastFloatingPointDCT.TransformIDCT(ref block, ref this.WorkspaceBlock);
FastFloatingPointDCT.TransformIDCT(ref block);

// To conform better to libjpeg we actually NEED TO loose precision here.
// This is because they store blocks as Int16 between all the operations.
Expand Down
Loading