diff --git a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs index 21763c522..6c781dc8d 100644 --- a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs +++ b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/ScanDecoder.cs @@ -25,7 +25,10 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components private int codeBits; private uint codeBuffer; private bool nomore; + private bool eof; private byte marker; + private bool badMarker; + private long markerPosition; private int todo; private int restartInterval; @@ -64,6 +67,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components this.stream = stream; this.components = components; this.marker = JpegConstants.Markers.XFF; + this.markerPosition = 0; this.componentIndex = componentIndex; this.componentsLength = componentsLength; this.restartInterval = restartInterval; @@ -104,13 +108,18 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components ref short blockDataRef = ref MemoryMarshal.GetReference(MemoryMarshal.Cast(component.SpectralBlocks.Span)); ref PdfJsHuffmanTable dcHuffmanTable = ref dcHuffmanTables[component.DCHuffmanTableId]; ref PdfJsHuffmanTable acHuffmanTable = ref acHuffmanTables[component.ACHuffmanTableId]; - Span fastAC = fastACTables.Tables.GetRowSpan(component.ACHuffmanTableId); + ReadOnlySpan fastAC = fastACTables.Tables.GetRowSpan(component.ACHuffmanTableId); int mcu = 0; for (int j = 0; j < h; j++) { for (int i = 0; i < w; i++) { + if (this.eof) + { + continue; + } + int blockRow = mcu / w; int blockCol = mcu % w; int offset = component.GetBlockBufferOffset(blockRow, blockCol); @@ -154,7 +163,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components ref short blockDataRef = ref MemoryMarshal.GetReference(MemoryMarshal.Cast(component.SpectralBlocks.Span)); ref PdfJsHuffmanTable dcHuffmanTable = ref dcHuffmanTables[component.DCHuffmanTableId]; ref PdfJsHuffmanTable acHuffmanTable = ref acHuffmanTables[component.ACHuffmanTableId]; - Span fastAC = fastACTables.Tables.GetRowSpan(component.ACHuffmanTableId); + ReadOnlySpan fastAC = fastACTables.Tables.GetRowSpan(component.ACHuffmanTableId); int h = component.HorizontalSamplingFactor; int v = component.VerticalSamplingFactor; @@ -164,6 +173,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components { for (int x = 0; x < h; x++) { + if (this.eof) + { + continue; + } + int mcuRow = mcu / mcusPerLine; int mcuCol = mcu % mcusPerLine; int blockRow = (mcuRow * v) + y; @@ -197,6 +211,138 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components } } } + else + { + if (this.componentsLength == 1) + { + PdfJsFrameComponent component = this.components[this.componentIndex]; + + // Non-interleaved data, we just need to process one block at a time, + // in trivial scanline order + // number of blocks to do just depends on how many actual "pixels" this + // component has, independent of interleaved MCU blocking and such + int w = component.WidthInBlocks; + int h = component.HeightInBlocks; + ref short blockDataRef = ref MemoryMarshal.GetReference(MemoryMarshal.Cast(component.SpectralBlocks.Span)); + ref PdfJsHuffmanTable dcHuffmanTable = ref dcHuffmanTables[component.DCHuffmanTableId]; + ref PdfJsHuffmanTable acHuffmanTable = ref acHuffmanTables[component.ACHuffmanTableId]; + ReadOnlySpan fastAC = fastACTables.Tables.GetRowSpan(component.ACHuffmanTableId); + + int mcu = 0; + for (int j = 0; j < h; j++) + { + for (int i = 0; i < w; i++) + { + if (this.eof) + { + continue; + } + + int blockRow = mcu / w; + int blockCol = mcu % w; + int offset = component.GetBlockBufferOffset(blockRow, blockCol); + + if (this.spectralStart == 0) + { + this.DecodeBlockProgressiveDC(component, ref Unsafe.Add(ref blockDataRef, offset), ref dcHuffmanTable); + } + else + { + this.DecodeBlockProgressiveAC(ref Unsafe.Add(ref blockDataRef, offset), ref acHuffmanTable, fastAC); + } + + mcu++; + + // Every data block is an MCU, so countdown the restart interval + if (--this.todo <= 0) + { + if (this.codeBits < 24) + { + this.GrowBufferUnsafe(); + } + + // If it's NOT a restart, then just bail, so we get corrupt data + // rather than no data + if (!this.IsRestartMarker(this.marker)) + { + return 1; + } + + this.Reset(); + } + } + } + } + else + { + // Interleaved + int mcu = 0; + int mcusPerColumn = frame.McusPerColumn; + int mcusPerLine = frame.McusPerLine; + for (int j = 0; j < mcusPerColumn; j++) + { + for (int i = 0; i < mcusPerLine; i++) + { + // Scan an interleaved mcu... process components in order + for (int k = 0; k < this.componentsLength; k++) + { + PdfJsFrameComponent component = this.components[k]; + ref short blockDataRef = ref MemoryMarshal.GetReference(MemoryMarshal.Cast(component.SpectralBlocks.Span)); + ref PdfJsHuffmanTable dcHuffmanTable = ref dcHuffmanTables[component.DCHuffmanTableId]; + ref PdfJsHuffmanTable acHuffmanTable = ref acHuffmanTables[component.ACHuffmanTableId]; + ReadOnlySpan fastAC = fastACTables.Tables.GetRowSpan(component.ACHuffmanTableId); + int h = component.HorizontalSamplingFactor; + int v = component.VerticalSamplingFactor; + + // Scan out an mcu's worth of this component; that's just determined + // by the basic H and V specified for the component + for (int y = 0; y < v; y++) + { + for (int x = 0; x < h; x++) + { + if (this.eof) + { + continue; + } + + int mcuRow = mcu / mcusPerLine; + int mcuCol = mcu % mcusPerLine; + int blockRow = (mcuRow * v) + y; + int blockCol = (mcuCol * h) + x; + int offset = component.GetBlockBufferOffset(blockRow, blockCol); + this.DecodeBlockProgressiveDC(component, ref Unsafe.Add(ref blockDataRef, offset), ref dcHuffmanTable); + } + } + } + + // After all interleaved components, that's an interleaved MCU, + // so now count down the restart interval + mcu++; + if (--this.todo <= 0) + { + if (this.codeBits < 24) + { + this.GrowBufferUnsafe(); + } + + // If it's NOT a restart, then just bail, so we get corrupt data + // rather than no data + if (!this.IsRestartMarker(this.marker)) + { + return 1; + } + + this.Reset(); + } + } + } + } + } + + if (this.badMarker) + { + this.stream.Position = this.markerPosition; + } return 1; } @@ -206,7 +352,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components ref short blockDataRef, ref PdfJsHuffmanTable dcTable, ref PdfJsHuffmanTable acTable, - Span fastAc) + ReadOnlySpan fastAc) { this.CheckBits(); int t = this.DecodeHuffman(ref dcTable); @@ -295,7 +441,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components { // First scan for DC coefficient, must be first int t = this.DecodeHuffman(ref dcTable); - int diff = t > 0 ? this.ExtendReceive(t) : 0; + int diff = t != 0 ? this.ExtendReceive(t) : 0; int dc = component.DcPredictor + diff; component.DcPredictor = dc; @@ -305,7 +451,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components else { // Refinement scan for DC coefficient - if (this.GetBit() > 0) + if (this.GetBit() != 0) { blockDataRef += (short)(1 << this.successiveLow); } @@ -315,10 +461,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components } private int DecodeBlockProgressiveAC( - PdfJsFrameComponent component, ref short blockDataRef, ref PdfJsHuffmanTable acTable, - Span fac) + ReadOnlySpan fastAc) { int k; @@ -331,7 +476,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components { int shift = this.successiveLow; - if (this.eobrun > 0) + if (this.eobrun != 0) { this.eobrun--; return 1; @@ -345,9 +490,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components this.CheckBits(); int c = this.PeekBits(); - int r = fac[c]; + int r = fastAc[c]; - if (r > 0) + if (r != 0) { // Fast AC path k += (r >> 4) & 15; // Run @@ -376,7 +521,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components if (r < 15) { this.eobrun = 1 << r; - if (r > 0) + if (r != 0) { this.eobrun += this.GetBits(r); } @@ -402,15 +547,15 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components // Refinement scan for these AC coefficients short bit = (short)(1 << this.successiveLow); - if (this.eobrun > 0) + if (this.eobrun != 0) { this.eobrun--; - for (k = this.spectralStart; k < this.spectralEnd; k++) + for (k = this.spectralStart; k <= this.spectralEnd; k++) { ref short p = ref Unsafe.Add(ref blockDataRef, this.dctZigZag[k]); if (p != 0) { - if (this.GetBit() > 0) + if (this.GetBit() != 0) { if ((p & bit) == 0) { @@ -450,7 +595,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components { this.eobrun = (1 << r) - 1; - if (r > 0) + if (r != 0) { this.eobrun += this.GetBits(r); } @@ -466,13 +611,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components } // Sign bit - if (this.GetBit() > 0) + if (this.GetBit() != 0) { s = bit; } else { - s -= bit; + s = -bit; } } @@ -482,7 +627,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components ref short p = ref Unsafe.Add(ref blockDataRef, this.dctZigZag[k++]); if (p != 0) { - if (this.GetBit() > 0) + if (this.GetBit() != 0) { if ((p & bit) == 0) { @@ -553,18 +698,38 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components { // TODO: EOF int b = this.nomore ? 0 : this.stream.ReadByte(); + + if (b == -1) + { + this.eof = true; + b = 0; + } + if (b == JpegConstants.Markers.XFF) { + this.markerPosition = this.stream.Position - 1; int c = this.stream.ReadByte(); while (c == JpegConstants.Markers.XFF) { c = this.stream.ReadByte(); + + if (c == -1) + { + this.eof = true; + c = 0; + break; + } } if (c != 0) { this.marker = (byte)c; this.nomore = true; + if (!this.IsRestartMarker(this.marker)) + { + this.badMarker = true; + } + return; } } @@ -688,7 +853,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components { this.codeBits = 0; this.codeBuffer = 0; - this.nomore = false; for (int i = 0; i < this.components.Length; i++) { @@ -696,11 +860,14 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components c.DcPredictor = 0; } + this.nomore = false; this.marker = JpegConstants.Markers.XFF; + this.markerPosition = 0; + this.badMarker = false; this.eobrun = 0; // No more than 1<<31 MCUs if no restartInterval? that's plenty safe since we don't even allow 1<<30 pixels - this.todo = this.restartInterval > 0 ? this.restartInterval : 0x7FFFFFFF; + this.todo = this.restartInterval > 0 ? this.restartInterval : int.MaxValue; } } } \ No newline at end of file