af265e7562
* tag '2.1.5': (41 commits) BUILDING.md: Specify install prefix for MinGW/Un*x Java: Guard against int overflow in size methods turbojpeg.c: Fix UBSan warning tjPlane*(): Guard against int overflow Java doc: TJ.pixelSize --> TJ.getPixelSize() TJBench: Unset TJ*OPT_CROP when disabling tiling TJExample: Remove "underlying codec" references GitHub: Update to actions/checkout@v3 TJBench: Set TJ*OPT_PROGRESSIVE with -progressive TJBench/Java: Fix parsing of quality ranges TJBench: Strictly check all non-boolean arguments TurboJPEG: More documentation improvements TJDecompressor.java: Exception message tweak 12-bit: Set alpha channel to 4095 rather than 255 TJDecompressor.java: "YUV" = "planar YUV" Java: Don't allow int overflow in buf size methods tjDecompressToYUV2: Use scaled dims for plane calc TurboJPEG: Numerous documentation improvements TurboJPEG: Don't use backward compatibility macros TurboJPEG: Ensure 'pad' arg is a power of 2 ...
58 lines
2.2 KiB
C
58 lines
2.2 KiB
C
/*
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* jchuff.h
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*
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* This file was part of the Independent JPEG Group's software:
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* Copyright (C) 1991-1997, Thomas G. Lane.
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* libjpeg-turbo Modifications:
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* Copyright (C) 2022, D. R. Commander.
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* For conditions of distribution and use, see the accompanying README.ijg
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* file.
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* mozjpeg Modifications:
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* Copyright (C) 2014, Mozilla Corporation.
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*
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* This file contains declarations for Huffman entropy encoding routines
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* that are shared between the sequential encoder (jchuff.c) and the
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* progressive encoder (jcphuff.c). No other modules need to see these.
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*/
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/* The legal range of a DCT coefficient is
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* -1024 .. +1023 for 8-bit data;
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* -16384 .. +16383 for 12-bit data.
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* Hence the magnitude should always fit in 10 or 14 bits respectively.
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*/
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#if BITS_IN_JSAMPLE == 8
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#define MAX_COEF_BITS 10
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#else
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#define MAX_COEF_BITS 14
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#endif
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/* The progressive Huffman encoder uses an unsigned 16-bit data type to store
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* absolute values of coefficients, because it is possible to inject a
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* coefficient value of -32768 into the encoder by attempting to transform a
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* malformed 12-bit JPEG image, and the absolute value of -32768 would overflow
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* a signed 16-bit integer.
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*/
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typedef unsigned short UJCOEF;
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/* Derived data constructed for each Huffman table */
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typedef struct {
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unsigned int ehufco[256]; /* code for each symbol */
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char ehufsi[256]; /* length of code for each symbol */
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/* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */
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} c_derived_tbl;
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/* Expand a Huffman table definition into the derived format */
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EXTERN(void) jpeg_make_c_derived_tbl(j_compress_ptr cinfo, boolean isDC,
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int tblno, c_derived_tbl **pdtbl);
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/* Generate an optimal table definition given the specified counts */
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EXTERN(void) jpeg_gen_optimal_table
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(j_compress_ptr cinfo, JHUFF_TBL *htbl, long freq[]);
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EXTERN(void) quantize_trellis
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(j_compress_ptr cinfo, c_derived_tbl *dctbl, c_derived_tbl *actbl, JBLOCKROW coef_blocks, JBLOCKROW src, JDIMENSION num_blocks,
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JQUANT_TBL * qtbl, double *norm_src, double *norm_coef, JCOEF *last_dc_val,
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JBLOCKROW coef_blocks_above, JBLOCKROW src_above);
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