mirror of
https://github.com/ZDoom/Raze.git
synced 2024-11-29 23:42:08 +00:00
718112a8fe
Currently none of these is being used, but eventually they will, once more code gets ported over. So it's better to have them right away and avoid editing the project file too much, only to revert that later.
416 lines
18 KiB
C
416 lines
18 KiB
C
/*
|
|
* jdct.h
|
|
*
|
|
* Copyright (C) 1994-1996, Thomas G. Lane.
|
|
* Modified 2002-2017 by Guido Vollbeding.
|
|
* This file is part of the Independent JPEG Group's software.
|
|
* For conditions of distribution and use, see the accompanying README file.
|
|
*
|
|
* This include file contains common declarations for the forward and
|
|
* inverse DCT modules. These declarations are private to the DCT managers
|
|
* (jcdctmgr.c, jddctmgr.c) and the individual DCT algorithms.
|
|
* The individual DCT algorithms are kept in separate files to ease
|
|
* machine-dependent tuning (e.g., assembly coding).
|
|
*/
|
|
|
|
|
|
/*
|
|
* A forward DCT routine is given a pointer to an input sample array and
|
|
* a pointer to a work area of type DCTELEM[]; the DCT is to be performed
|
|
* in-place in that buffer. Type DCTELEM is int for 8-bit samples, INT32
|
|
* for 12-bit samples. (NOTE: Floating-point DCT implementations use an
|
|
* array of type FAST_FLOAT, instead.)
|
|
* The input data is to be fetched from the sample array starting at a
|
|
* specified column. (Any row offset needed will be applied to the array
|
|
* pointer before it is passed to the FDCT code.)
|
|
* Note that the number of samples fetched by the FDCT routine is
|
|
* DCT_h_scaled_size * DCT_v_scaled_size.
|
|
* The DCT outputs are returned scaled up by a factor of 8; they therefore
|
|
* have a range of +-8K for 8-bit data, +-128K for 12-bit data. This
|
|
* convention improves accuracy in integer implementations and saves some
|
|
* work in floating-point ones.
|
|
* Quantization of the output coefficients is done by jcdctmgr.c.
|
|
*/
|
|
|
|
#if BITS_IN_JSAMPLE == 8
|
|
typedef int DCTELEM; /* 16 or 32 bits is fine */
|
|
#else
|
|
typedef INT32 DCTELEM; /* must have 32 bits */
|
|
#endif
|
|
|
|
typedef JMETHOD(void, forward_DCT_method_ptr, (DCTELEM * data,
|
|
JSAMPARRAY sample_data,
|
|
JDIMENSION start_col));
|
|
typedef JMETHOD(void, float_DCT_method_ptr, (FAST_FLOAT * data,
|
|
JSAMPARRAY sample_data,
|
|
JDIMENSION start_col));
|
|
|
|
|
|
/*
|
|
* An inverse DCT routine is given a pointer to the input JBLOCK and a pointer
|
|
* to an output sample array. The routine must dequantize the input data as
|
|
* well as perform the IDCT; for dequantization, it uses the multiplier table
|
|
* pointed to by compptr->dct_table. The output data is to be placed into the
|
|
* sample array starting at a specified column. (Any row offset needed will
|
|
* be applied to the array pointer before it is passed to the IDCT code.)
|
|
* Note that the number of samples emitted by the IDCT routine is
|
|
* DCT_h_scaled_size * DCT_v_scaled_size.
|
|
*/
|
|
|
|
/* typedef inverse_DCT_method_ptr is declared in jpegint.h */
|
|
|
|
/*
|
|
* Each IDCT routine has its own ideas about the best dct_table element type.
|
|
*/
|
|
|
|
typedef MULTIPLIER ISLOW_MULT_TYPE; /* short or int, whichever is faster */
|
|
#if BITS_IN_JSAMPLE == 8
|
|
typedef MULTIPLIER IFAST_MULT_TYPE; /* 16 bits is OK, use short if faster */
|
|
#define IFAST_SCALE_BITS 2 /* fractional bits in scale factors */
|
|
#else
|
|
typedef INT32 IFAST_MULT_TYPE; /* need 32 bits for scaled quantizers */
|
|
#define IFAST_SCALE_BITS 13 /* fractional bits in scale factors */
|
|
#endif
|
|
typedef FAST_FLOAT FLOAT_MULT_TYPE; /* preferred floating type */
|
|
|
|
|
|
/*
|
|
* Each IDCT routine is responsible for range-limiting its results and
|
|
* converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could
|
|
* be quite far out of range if the input data is corrupt, so a bulletproof
|
|
* range-limiting step is required. We use a mask-and-table-lookup method
|
|
* to do the combined operations quickly, assuming that RANGE_CENTER
|
|
* (defined in jpegint.h) is a power of 2. See the comments with
|
|
* prepare_range_limit_table (in jdmaster.c) for more info.
|
|
*/
|
|
|
|
#define RANGE_MASK (RANGE_CENTER * 2 - 1)
|
|
#define RANGE_SUBSET (RANGE_CENTER - CENTERJSAMPLE)
|
|
|
|
#define IDCT_range_limit(cinfo) ((cinfo)->sample_range_limit - RANGE_SUBSET)
|
|
|
|
|
|
/* Short forms of external names for systems with brain-damaged linkers. */
|
|
|
|
#ifdef NEED_SHORT_EXTERNAL_NAMES
|
|
#define jpeg_fdct_islow jFDislow
|
|
#define jpeg_fdct_ifast jFDifast
|
|
#define jpeg_fdct_float jFDfloat
|
|
#define jpeg_fdct_7x7 jFD7x7
|
|
#define jpeg_fdct_6x6 jFD6x6
|
|
#define jpeg_fdct_5x5 jFD5x5
|
|
#define jpeg_fdct_4x4 jFD4x4
|
|
#define jpeg_fdct_3x3 jFD3x3
|
|
#define jpeg_fdct_2x2 jFD2x2
|
|
#define jpeg_fdct_1x1 jFD1x1
|
|
#define jpeg_fdct_9x9 jFD9x9
|
|
#define jpeg_fdct_10x10 jFD10x10
|
|
#define jpeg_fdct_11x11 jFD11x11
|
|
#define jpeg_fdct_12x12 jFD12x12
|
|
#define jpeg_fdct_13x13 jFD13x13
|
|
#define jpeg_fdct_14x14 jFD14x14
|
|
#define jpeg_fdct_15x15 jFD15x15
|
|
#define jpeg_fdct_16x16 jFD16x16
|
|
#define jpeg_fdct_16x8 jFD16x8
|
|
#define jpeg_fdct_14x7 jFD14x7
|
|
#define jpeg_fdct_12x6 jFD12x6
|
|
#define jpeg_fdct_10x5 jFD10x5
|
|
#define jpeg_fdct_8x4 jFD8x4
|
|
#define jpeg_fdct_6x3 jFD6x3
|
|
#define jpeg_fdct_4x2 jFD4x2
|
|
#define jpeg_fdct_2x1 jFD2x1
|
|
#define jpeg_fdct_8x16 jFD8x16
|
|
#define jpeg_fdct_7x14 jFD7x14
|
|
#define jpeg_fdct_6x12 jFD6x12
|
|
#define jpeg_fdct_5x10 jFD5x10
|
|
#define jpeg_fdct_4x8 jFD4x8
|
|
#define jpeg_fdct_3x6 jFD3x6
|
|
#define jpeg_fdct_2x4 jFD2x4
|
|
#define jpeg_fdct_1x2 jFD1x2
|
|
#define jpeg_idct_islow jRDislow
|
|
#define jpeg_idct_ifast jRDifast
|
|
#define jpeg_idct_float jRDfloat
|
|
#define jpeg_idct_7x7 jRD7x7
|
|
#define jpeg_idct_6x6 jRD6x6
|
|
#define jpeg_idct_5x5 jRD5x5
|
|
#define jpeg_idct_4x4 jRD4x4
|
|
#define jpeg_idct_3x3 jRD3x3
|
|
#define jpeg_idct_2x2 jRD2x2
|
|
#define jpeg_idct_1x1 jRD1x1
|
|
#define jpeg_idct_9x9 jRD9x9
|
|
#define jpeg_idct_10x10 jRD10x10
|
|
#define jpeg_idct_11x11 jRD11x11
|
|
#define jpeg_idct_12x12 jRD12x12
|
|
#define jpeg_idct_13x13 jRD13x13
|
|
#define jpeg_idct_14x14 jRD14x14
|
|
#define jpeg_idct_15x15 jRD15x15
|
|
#define jpeg_idct_16x16 jRD16x16
|
|
#define jpeg_idct_16x8 jRD16x8
|
|
#define jpeg_idct_14x7 jRD14x7
|
|
#define jpeg_idct_12x6 jRD12x6
|
|
#define jpeg_idct_10x5 jRD10x5
|
|
#define jpeg_idct_8x4 jRD8x4
|
|
#define jpeg_idct_6x3 jRD6x3
|
|
#define jpeg_idct_4x2 jRD4x2
|
|
#define jpeg_idct_2x1 jRD2x1
|
|
#define jpeg_idct_8x16 jRD8x16
|
|
#define jpeg_idct_7x14 jRD7x14
|
|
#define jpeg_idct_6x12 jRD6x12
|
|
#define jpeg_idct_5x10 jRD5x10
|
|
#define jpeg_idct_4x8 jRD4x8
|
|
#define jpeg_idct_3x6 jRD3x8
|
|
#define jpeg_idct_2x4 jRD2x4
|
|
#define jpeg_idct_1x2 jRD1x2
|
|
#endif /* NEED_SHORT_EXTERNAL_NAMES */
|
|
|
|
/* Extern declarations for the forward and inverse DCT routines. */
|
|
|
|
EXTERN(void) jpeg_fdct_islow
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_ifast
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_float
|
|
JPP((FAST_FLOAT * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_7x7
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_6x6
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_5x5
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_4x4
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_3x3
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_2x2
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_1x1
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_9x9
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_10x10
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_11x11
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_12x12
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_13x13
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_14x14
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_15x15
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_16x16
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_16x8
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_14x7
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_12x6
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_10x5
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_8x4
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_6x3
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_4x2
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_2x1
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_8x16
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_7x14
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_6x12
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_5x10
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_4x8
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_3x6
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_2x4
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_1x2
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
|
|
EXTERN(void) jpeg_idct_islow
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_ifast
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_float
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_7x7
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_6x6
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_5x5
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_4x4
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_3x3
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_2x2
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_1x1
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_9x9
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_10x10
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_11x11
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_12x12
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_13x13
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_14x14
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_15x15
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_16x16
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_16x8
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_14x7
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_12x6
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_10x5
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_8x4
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_6x3
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_4x2
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_2x1
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_8x16
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_7x14
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_6x12
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_5x10
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_4x8
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_3x6
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_2x4
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_1x2
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
|
|
|
|
/*
|
|
* 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.
|
|
* Fractional constants are scaled left by CONST_BITS bits.
|
|
* CONST_BITS is defined within each module using these macros,
|
|
* and may differ from one module to the next.
|
|
*/
|
|
|
|
#define ONE ((INT32) 1)
|
|
#define CONST_SCALE (ONE << CONST_BITS)
|
|
|
|
/* 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))
|
|
|
|
/* 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 */
|
|
#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
|