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Diffstat (limited to 'src/jpeg-8c/jdct.h')
-rw-r--r-- | src/jpeg-8c/jdct.h | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/src/jpeg-8c/jdct.h b/src/jpeg-8c/jdct.h new file mode 100644 index 00000000..360dec80 --- /dev/null +++ b/src/jpeg-8c/jdct.h @@ -0,0 +1,393 @@ +/* + * jdct.h + * + * Copyright (C) 1994-1996, Thomas G. Lane. + * 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. See the comments with + * prepare_range_limit_table (in jdmaster.c) for more info. + */ + +#define IDCT_range_limit(cinfo) ((cinfo)->sample_range_limit + CENTERJSAMPLE) + +#define RANGE_MASK (MAXJSAMPLE * 4 + 3) /* 2 bits wider than legal samples */ + + +/* 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 |