diff --git a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/FixedByteBuffer257.cs b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/FixedByteBuffer257.cs new file mode 100644 index 0000000000..3015243168 --- /dev/null +++ b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/FixedByteBuffer257.cs @@ -0,0 +1,24 @@ +// Copyright (c) Six Labors and contributors. +// Licensed under the Apache License, Version 2.0. + +using System.Runtime.CompilerServices; +using System.Runtime.InteropServices; + +namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components +{ + [StructLayout(LayoutKind.Sequential)] + internal unsafe struct FixedByteBuffer257 + { + public fixed byte Data[257]; + + public byte this[int idx] + { + [MethodImpl(MethodImplOptions.AggressiveInlining)] + get + { + ref byte self = ref Unsafe.As(ref this); + return Unsafe.Add(ref self, idx); + } + } + } +} \ No newline at end of file diff --git a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsHuffmanTable.cs b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsHuffmanTable.cs index 1cc342f5ac..a63573030f 100644 --- a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsHuffmanTable.cs +++ b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsHuffmanTable.cs @@ -50,69 +50,69 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components const int Length = 257; using (IBuffer huffcode = memoryManager.Allocate(Length)) { - // Span codes = huffcode.Span; + Span codes = huffcode.Span; ref short huffcodeRef = ref MemoryMarshal.GetReference(huffcode.Span); this.GenerateSizeTable(count); - //int k = 0; - //fixed (short* sizesRef = this.Sizes.Data) - //fixed (short* deltaRef = this.ValOffset.Data) - //fixed (long* maxcodeRef = this.MaxCode.Data) - //{ - // uint code = 0; - // int j; - // for (j = 1; j <= 16; j++) - // { - // // Compute delta to add to code to compute symbol id. - // deltaRef[j] = (short)(k - code); - // if (sizesRef[k] == j) - // { - // while (sizesRef[k] == j) - // { - // codes[k++] = (short)code++; - - // // Unsafe.Add(ref huffcodeRef, k++) = (short)code++; - - // // TODO: Throw if invalid? - // } - // } - - // // Compute largest code + 1 for this size. preshifted as neeed later. - // maxcodeRef[j] = code << (16 - j); - // code <<= 1; - // } - - // maxcodeRef[j] = 0xFFFFFFFF; - //} - - //fixed (short* lookaheadRef = this.Lookahead.Data) - //{ - // const int FastBits = ScanDecoder.FastBits; - // var fast = new Span(lookaheadRef, 1 << FastBits); - // fast.Fill(255); // Flag for non-accelerated - - // fixed (short* sizesRef = this.Sizes.Data) - // { - // for (int i = 0; i < k; i++) - // { - // int s = sizesRef[i]; - // if (s <= ScanDecoder.FastBits) - // { - // int c = codes[i] << (FastBits - s); - // int m = 1 << (FastBits - s); - // for (int j = 0; j < m; j++) - // { - // fast[c + j] = (byte)i; - // } - // } - // } - // } - //} - - this.GenerateCodeTable(ref huffcodeRef, Length, out int k); - this.GenerateDecoderTables(count, ref huffcodeRef); - this.GenerateLookaheadTables(count, values, ref huffcodeRef, k); + int k = 0; + fixed (short* size = this.Sizes.Data) + fixed (short* delta = this.ValOffset.Data) + fixed (long* maxcode = this.MaxCode.Data) + { + uint code = 0; + int j; + for (j = 1; j <= 16; j++) + { + // Compute delta to add to code to compute symbol id. + delta[j] = (short)(k - code); + if (size[k] == j) + { + while (size[k] == j) + { + codes[k++] = (short)code++; + + // Unsafe.Add(ref huffcodeRef, k++) = (short)code++; + + // TODO: Throw if invalid? + } + } + + // Compute largest code + 1 for this size. preshifted as neeed later. + maxcode[j] = code << (16 - j); + code <<= 1; + } + + maxcode[j] = 0xFFFFFFFF; + } + + fixed (byte* lookaheadRef = this.Lookahead.Data) + { + const int FastBits = ScanDecoder.FastBits; + var fast = new Span(lookaheadRef, 1 << FastBits); + fast.Fill(255); // Flag for non-accelerated + + fixed (short* sizesRef = this.Sizes.Data) + { + for (int i = 0; i < k; i++) + { + int s = sizesRef[i]; + if (s <= ScanDecoder.FastBits) + { + int c = codes[i] << (FastBits - s); + int m = 1 << (FastBits - s); + for (int j = 0; j < m; j++) + { + fast[c + j] = (byte)i; + } + } + } + } + } + + // this.GenerateCodeTable(ref huffcodeRef, Length, out int k); + // this.GenerateDecoderTables(count, ref huffcodeRef); + // this.GenerateLookaheadTables(count, values, ref huffcodeRef, k); } fixed (byte* huffValRef = this.Values.Data) @@ -224,7 +224,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components const int FastBits = ScanDecoder.FastBits; var lookaheadSpan = new Span(lookaheadRef, 1 << ScanDecoder.FastBits); - lookaheadSpan.Fill(255); // Flag for non-accelerated + lookaheadSpan.Fill(byte.MaxValue); // Flag for non-accelerated fixed (short* sizesRef = this.Sizes.Data) { for (int i = 0; i < k; ++i) diff --git a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsScanDecoder.cs b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsScanDecoder.cs index 62c8f984f0..0736fd342b 100644 --- a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsScanDecoder.cs +++ b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsScanDecoder.cs @@ -860,14 +860,5 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components } } } - - private void Reset() - { - // Reset - // TODO: I do not understand why these values are reset? We should surely be tracking the bits across mcu's? - this.bitsCount = 0; - this.bitsData = 0; - this.unexpectedMarkerReached = false; - } } } \ No newline at end of file diff --git a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs index 217b3cb62b..8322be2fe3 100644 --- a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs +++ b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs @@ -607,7 +607,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components // wants to be compared against something shifted to have 16; // that way we don't need to shift inside the loop. uint temp = this.codeBuffer >> 16; - for (k = FastBits + 1; ; ++k) + for (k = FastBits + 1; ; k++) { if (temp < table.MaxCode[k]) {