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418 lines
18 KiB
C
418 lines
18 KiB
C
/*
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* jdct.h
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*
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* Copyright (C) 1994-1996, Thomas G. Lane.
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* Modified 2002-2015 by Guido Vollbeding.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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*
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* This include file contains common declarations for the forward and
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* inverse DCT modules. These declarations are private to the DCT managers
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* (jcdctmgr.c, jddctmgr.c) and the individual DCT algorithms.
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* The individual DCT algorithms are kept in separate files to ease
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* machine-dependent tuning (e.g., assembly coding).
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*/
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/*
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* A forward DCT routine is given a pointer to an input sample array and
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* a pointer to a work area of type DCTELEM[]; the DCT is to be performed
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* in-place in that buffer. Type DCTELEM is int for 8-bit samples, INT32
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* for 12-bit samples. (NOTE: Floating-point DCT implementations use an
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* array of type FAST_FLOAT, instead.)
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* The input data is to be fetched from the sample array starting at a
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* specified column. (Any row offset needed will be applied to the array
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* pointer before it is passed to the FDCT code.)
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* Note that the number of samples fetched by the FDCT routine is
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* DCT_h_scaled_size * DCT_v_scaled_size.
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* The DCT outputs are returned scaled up by a factor of 8; they therefore
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* have a range of +-8K for 8-bit data, +-128K for 12-bit data. This
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* convention improves accuracy in integer implementations and saves some
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* work in floating-point ones.
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* Quantization of the output coefficients is done by jcdctmgr.c.
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*/
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#if BITS_IN_JSAMPLE == 8
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typedef int DCTELEM; /* 16 or 32 bits is fine */
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#else
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typedef INT32 DCTELEM; /* must have 32 bits */
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#endif
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typedef JMETHOD(void, forward_DCT_method_ptr, (DCTELEM * data,
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JSAMPARRAY sample_data,
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JDIMENSION start_col));
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typedef JMETHOD(void, float_DCT_method_ptr, (FAST_FLOAT * data,
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JSAMPARRAY sample_data,
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JDIMENSION start_col));
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/*
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* An inverse DCT routine is given a pointer to the input JBLOCK and a pointer
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* to an output sample array. The routine must dequantize the input data as
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* well as perform the IDCT; for dequantization, it uses the multiplier table
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* pointed to by compptr->dct_table. The output data is to be placed into the
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* sample array starting at a specified column. (Any row offset needed will
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* be applied to the array pointer before it is passed to the IDCT code.)
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* Note that the number of samples emitted by the IDCT routine is
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* DCT_h_scaled_size * DCT_v_scaled_size.
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*/
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/* typedef inverse_DCT_method_ptr is declared in jpegint.h */
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/*
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* Each IDCT routine has its own ideas about the best dct_table element type.
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*/
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typedef MULTIPLIER ISLOW_MULT_TYPE; /* short or int, whichever is faster */
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#if BITS_IN_JSAMPLE == 8
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typedef MULTIPLIER IFAST_MULT_TYPE; /* 16 bits is OK, use short if faster */
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#define IFAST_SCALE_BITS 2 /* fractional bits in scale factors */
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#else
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typedef INT32 IFAST_MULT_TYPE; /* need 32 bits for scaled quantizers */
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#define IFAST_SCALE_BITS 13 /* fractional bits in scale factors */
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#endif
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typedef FAST_FLOAT FLOAT_MULT_TYPE; /* preferred floating type */
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/*
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* Each IDCT routine is responsible for range-limiting its results and
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* converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could
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* be quite far out of range if the input data is corrupt, so a bulletproof
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* range-limiting step is required. We use a mask-and-table-lookup method
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* to do the combined operations quickly, assuming that MAXJSAMPLE+1
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* is a power of 2. See the comments with prepare_range_limit_table
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* (in jdmaster.c) for more info.
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*/
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#define RANGE_MASK (MAXJSAMPLE * 4 + 3) /* 2 bits wider than legal samples */
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#define RANGE_CENTER (MAXJSAMPLE * 2 + 2)
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#define RANGE_SUBSET (RANGE_CENTER - CENTERJSAMPLE)
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#define IDCT_range_limit(cinfo) ((cinfo)->sample_range_limit - RANGE_SUBSET)
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/* Short forms of external names for systems with brain-damaged linkers. */
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#ifdef NEED_SHORT_EXTERNAL_NAMES
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#define jpeg_fdct_islow jFDislow
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#define jpeg_fdct_ifast jFDifast
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#define jpeg_fdct_float jFDfloat
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#define jpeg_fdct_7x7 jFD7x7
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#define jpeg_fdct_6x6 jFD6x6
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#define jpeg_fdct_5x5 jFD5x5
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#define jpeg_fdct_4x4 jFD4x4
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#define jpeg_fdct_3x3 jFD3x3
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#define jpeg_fdct_2x2 jFD2x2
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#define jpeg_fdct_1x1 jFD1x1
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#define jpeg_fdct_9x9 jFD9x9
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#define jpeg_fdct_10x10 jFD10x10
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#define jpeg_fdct_11x11 jFD11x11
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#define jpeg_fdct_12x12 jFD12x12
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#define jpeg_fdct_13x13 jFD13x13
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#define jpeg_fdct_14x14 jFD14x14
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#define jpeg_fdct_15x15 jFD15x15
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#define jpeg_fdct_16x16 jFD16x16
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#define jpeg_fdct_16x8 jFD16x8
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#define jpeg_fdct_14x7 jFD14x7
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#define jpeg_fdct_12x6 jFD12x6
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#define jpeg_fdct_10x5 jFD10x5
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#define jpeg_fdct_8x4 jFD8x4
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#define jpeg_fdct_6x3 jFD6x3
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#define jpeg_fdct_4x2 jFD4x2
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#define jpeg_fdct_2x1 jFD2x1
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#define jpeg_fdct_8x16 jFD8x16
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#define jpeg_fdct_7x14 jFD7x14
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#define jpeg_fdct_6x12 jFD6x12
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#define jpeg_fdct_5x10 jFD5x10
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#define jpeg_fdct_4x8 jFD4x8
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#define jpeg_fdct_3x6 jFD3x6
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#define jpeg_fdct_2x4 jFD2x4
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#define jpeg_fdct_1x2 jFD1x2
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#define jpeg_idct_islow jRDislow
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#define jpeg_idct_ifast jRDifast
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#define jpeg_idct_float jRDfloat
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#define jpeg_idct_7x7 jRD7x7
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#define jpeg_idct_6x6 jRD6x6
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#define jpeg_idct_5x5 jRD5x5
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#define jpeg_idct_4x4 jRD4x4
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#define jpeg_idct_3x3 jRD3x3
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#define jpeg_idct_2x2 jRD2x2
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#define jpeg_idct_1x1 jRD1x1
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#define jpeg_idct_9x9 jRD9x9
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#define jpeg_idct_10x10 jRD10x10
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#define jpeg_idct_11x11 jRD11x11
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#define jpeg_idct_12x12 jRD12x12
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#define jpeg_idct_13x13 jRD13x13
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#define jpeg_idct_14x14 jRD14x14
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#define jpeg_idct_15x15 jRD15x15
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#define jpeg_idct_16x16 jRD16x16
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#define jpeg_idct_16x8 jRD16x8
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#define jpeg_idct_14x7 jRD14x7
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#define jpeg_idct_12x6 jRD12x6
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#define jpeg_idct_10x5 jRD10x5
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#define jpeg_idct_8x4 jRD8x4
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#define jpeg_idct_6x3 jRD6x3
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#define jpeg_idct_4x2 jRD4x2
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#define jpeg_idct_2x1 jRD2x1
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#define jpeg_idct_8x16 jRD8x16
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#define jpeg_idct_7x14 jRD7x14
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#define jpeg_idct_6x12 jRD6x12
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#define jpeg_idct_5x10 jRD5x10
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#define jpeg_idct_4x8 jRD4x8
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#define jpeg_idct_3x6 jRD3x8
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#define jpeg_idct_2x4 jRD2x4
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#define jpeg_idct_1x2 jRD1x2
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#endif /* NEED_SHORT_EXTERNAL_NAMES */
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/* Extern declarations for the forward and inverse DCT routines. */
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EXTERN(void) jpeg_fdct_islow
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_ifast
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_float
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JPP((FAST_FLOAT * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_7x7
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_6x6
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_5x5
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_4x4
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_3x3
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_2x2
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_1x1
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_9x9
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_10x10
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_11x11
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_12x12
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_13x13
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_14x14
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_15x15
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_16x16
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_16x8
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_14x7
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_12x6
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_10x5
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_8x4
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_6x3
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_4x2
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_2x1
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_8x16
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_7x14
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_6x12
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_5x10
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_4x8
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_3x6
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_2x4
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_fdct_1x2
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JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
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EXTERN(void) jpeg_idct_islow
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_ifast
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_float
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_7x7
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_6x6
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_5x5
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_4x4
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_3x3
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_2x2
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_1x1
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_9x9
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_10x10
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_11x11
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_12x12
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_13x13
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_14x14
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_15x15
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_16x16
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_16x8
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_14x7
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_12x6
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_10x5
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_8x4
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_6x3
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_4x2
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_2x1
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_8x16
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_7x14
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_6x12
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_5x10
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_4x8
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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EXTERN(void) jpeg_idct_3x6
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
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|
EXTERN(void) jpeg_idct_2x4
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JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
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|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_1x2
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|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
|
|
|
|
/*
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|
* Macros for handling fixed-point arithmetic; these are used by many
|
|
* but not all of the DCT/IDCT modules.
|
|
*
|
|
* All values are expected to be of type INT32.
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|
* Fractional constants are scaled left by CONST_BITS bits.
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|
* CONST_BITS is defined within each module using these macros,
|
|
* and may differ from one module to the next.
|
|
*/
|
|
|
|
#define ONE ((INT32) 1)
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|
#define CONST_SCALE (ONE << CONST_BITS)
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|
|
|
/* Convert a positive real constant to an integer scaled by CONST_SCALE.
|
|
* Caution: some C compilers fail to reduce "FIX(constant)" at compile time,
|
|
* thus causing a lot of useless floating-point operations at run time.
|
|
*/
|
|
|
|
#define FIX(x) ((INT32) ((x) * CONST_SCALE + 0.5))
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|
|
|
/* Descale and correctly round an INT32 value that's scaled by N bits.
|
|
* We assume RIGHT_SHIFT rounds towards minus infinity, so adding
|
|
* the fudge factor is correct for either sign of X.
|
|
*/
|
|
|
|
#define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
|
|
|
|
/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
|
|
* This macro is used only when the two inputs will actually be no more than
|
|
* 16 bits wide, so that a 16x16->32 bit multiply can be used instead of a
|
|
* full 32x32 multiply. This provides a useful speedup on many machines.
|
|
* Unfortunately there is no way to specify a 16x16->32 multiply portably
|
|
* in C, but some C compilers will do the right thing if you provide the
|
|
* correct combination of casts.
|
|
*/
|
|
|
|
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
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|
#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT16) (const)))
|
|
#endif
|
|
#ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */
|
|
#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT32) (const)))
|
|
#endif
|
|
|
|
#ifndef MULTIPLY16C16 /* default definition */
|
|
#define MULTIPLY16C16(var,const) ((var) * (const))
|
|
#endif
|
|
|
|
/* Same except both inputs are variables. */
|
|
|
|
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
|
|
#define MULTIPLY16V16(var1,var2) (((INT16) (var1)) * ((INT16) (var2)))
|
|
#endif
|
|
|
|
#ifndef MULTIPLY16V16 /* default definition */
|
|
#define MULTIPLY16V16(var1,var2) ((var1) * (var2))
|
|
#endif
|
|
|
|
/* Like RIGHT_SHIFT, but applies to a DCTELEM.
|
|
* We assume that int right shift is unsigned if INT32 right shift is.
|
|
*/
|
|
|
|
#ifdef RIGHT_SHIFT_IS_UNSIGNED
|
|
#define ISHIFT_TEMPS DCTELEM ishift_temp;
|
|
#if BITS_IN_JSAMPLE == 8
|
|
#define DCTELEMBITS 16 /* DCTELEM may be 16 or 32 bits */
|
|
#else
|
|
#define DCTELEMBITS 32 /* DCTELEM must be 32 bits */
|
|
#endif
|
|
#define IRIGHT_SHIFT(x,shft) \
|
|
((ishift_temp = (x)) < 0 ? \
|
|
(ishift_temp >> (shft)) | ((~((DCTELEM) 0)) << (DCTELEMBITS-(shft))) : \
|
|
(ishift_temp >> (shft)))
|
|
#else
|
|
#define ISHIFT_TEMPS
|
|
#define IRIGHT_SHIFT(x,shft) ((x) >> (shft))
|
|
#endif
|