| /* |
| * jcdctmgr.c |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1994-1996, Thomas G. Lane. |
| * libjpeg-turbo Modifications: |
| * Copyright (C) 1999-2006, MIYASAKA Masaru. |
| * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB |
| * Copyright (C) 2011, 2014-2015, D. R. Commander. |
| * For conditions of distribution and use, see the accompanying README.ijg |
| * file. |
| * |
| * This file contains the forward-DCT management logic. |
| * This code selects a particular DCT implementation to be used, |
| * and it performs related housekeeping chores including coefficient |
| * quantization. |
| */ |
| |
| #define JPEG_INTERNALS |
| #include "jinclude.h" |
| #include "jpeglib.h" |
| #include "jdct.h" /* Private declarations for DCT subsystem */ |
| #include "jsimddct.h" |
| |
| |
| /* Private subobject for this module */ |
| |
| typedef void (*forward_DCT_method_ptr) (DCTELEM *data); |
| typedef void (*float_DCT_method_ptr) (FAST_FLOAT *data); |
| |
| typedef void (*convsamp_method_ptr) (JSAMPARRAY sample_data, |
| JDIMENSION start_col, |
| DCTELEM *workspace); |
| typedef void (*float_convsamp_method_ptr) (JSAMPARRAY sample_data, |
| JDIMENSION start_col, |
| FAST_FLOAT *workspace); |
| |
| typedef void (*quantize_method_ptr) (JCOEFPTR coef_block, DCTELEM *divisors, |
| DCTELEM *workspace); |
| typedef void (*float_quantize_method_ptr) (JCOEFPTR coef_block, |
| FAST_FLOAT *divisors, |
| FAST_FLOAT *workspace); |
| |
| METHODDEF(void) quantize(JCOEFPTR, DCTELEM *, DCTELEM *); |
| |
| typedef struct { |
| struct jpeg_forward_dct pub; /* public fields */ |
| |
| /* Pointer to the DCT routine actually in use */ |
| forward_DCT_method_ptr dct; |
| convsamp_method_ptr convsamp; |
| quantize_method_ptr quantize; |
| |
| /* The actual post-DCT divisors --- not identical to the quant table |
| * entries, because of scaling (especially for an unnormalized DCT). |
| * Each table is given in normal array order. |
| */ |
| DCTELEM *divisors[NUM_QUANT_TBLS]; |
| |
| /* work area for FDCT subroutine */ |
| DCTELEM *workspace; |
| |
| #ifdef DCT_FLOAT_SUPPORTED |
| /* Same as above for the floating-point case. */ |
| float_DCT_method_ptr float_dct; |
| float_convsamp_method_ptr float_convsamp; |
| float_quantize_method_ptr float_quantize; |
| FAST_FLOAT *float_divisors[NUM_QUANT_TBLS]; |
| FAST_FLOAT *float_workspace; |
| #endif |
| } my_fdct_controller; |
| |
| typedef my_fdct_controller *my_fdct_ptr; |
| |
| |
| #if BITS_IN_JSAMPLE == 8 |
| |
| /* |
| * Find the highest bit in an integer through binary search. |
| */ |
| |
| LOCAL(int) |
| flss(UINT16 val) |
| { |
| int bit; |
| |
| bit = 16; |
| |
| if (!val) |
| return 0; |
| |
| if (!(val & 0xff00)) { |
| bit -= 8; |
| val <<= 8; |
| } |
| if (!(val & 0xf000)) { |
| bit -= 4; |
| val <<= 4; |
| } |
| if (!(val & 0xc000)) { |
| bit -= 2; |
| val <<= 2; |
| } |
| if (!(val & 0x8000)) { |
| bit -= 1; |
| val <<= 1; |
| } |
| |
| return bit; |
| } |
| |
| |
| /* |
| * Compute values to do a division using reciprocal. |
| * |
| * This implementation is based on an algorithm described in |
| * "How to optimize for the Pentium family of microprocessors" |
| * (http://www.agner.org/assem/). |
| * More information about the basic algorithm can be found in |
| * the paper "Integer Division Using Reciprocals" by Robert Alverson. |
| * |
| * The basic idea is to replace x/d by x * d^-1. In order to store |
| * d^-1 with enough precision we shift it left a few places. It turns |
| * out that this algoright gives just enough precision, and also fits |
| * into DCTELEM: |
| * |
| * b = (the number of significant bits in divisor) - 1 |
| * r = (word size) + b |
| * f = 2^r / divisor |
| * |
| * f will not be an integer for most cases, so we need to compensate |
| * for the rounding error introduced: |
| * |
| * no fractional part: |
| * |
| * result = input >> r |
| * |
| * fractional part of f < 0.5: |
| * |
| * round f down to nearest integer |
| * result = ((input + 1) * f) >> r |
| * |
| * fractional part of f > 0.5: |
| * |
| * round f up to nearest integer |
| * result = (input * f) >> r |
| * |
| * This is the original algorithm that gives truncated results. But we |
| * want properly rounded results, so we replace "input" with |
| * "input + divisor/2". |
| * |
| * In order to allow SIMD implementations we also tweak the values to |
| * allow the same calculation to be made at all times: |
| * |
| * dctbl[0] = f rounded to nearest integer |
| * dctbl[1] = divisor / 2 (+ 1 if fractional part of f < 0.5) |
| * dctbl[2] = 1 << ((word size) * 2 - r) |
| * dctbl[3] = r - (word size) |
| * |
| * dctbl[2] is for stupid instruction sets where the shift operation |
| * isn't member wise (e.g. MMX). |
| * |
| * The reason dctbl[2] and dctbl[3] reduce the shift with (word size) |
| * is that most SIMD implementations have a "multiply and store top |
| * half" operation. |
| * |
| * Lastly, we store each of the values in their own table instead |
| * of in a consecutive manner, yet again in order to allow SIMD |
| * routines. |
| */ |
| |
| LOCAL(int) |
| compute_reciprocal(UINT16 divisor, DCTELEM *dtbl) |
| { |
| UDCTELEM2 fq, fr; |
| UDCTELEM c; |
| int b, r; |
| |
| if (divisor == 1) { |
| /* divisor == 1 means unquantized, so these reciprocal/correction/shift |
| * values will cause the C quantization algorithm to act like the |
| * identity function. Since only the C quantization algorithm is used in |
| * these cases, the scale value is irrelevant. |
| */ |
| dtbl[DCTSIZE2 * 0] = (DCTELEM)1; /* reciprocal */ |
| dtbl[DCTSIZE2 * 1] = (DCTELEM)0; /* correction */ |
| dtbl[DCTSIZE2 * 2] = (DCTELEM)1; /* scale */ |
| dtbl[DCTSIZE2 * 3] = -(DCTELEM)(sizeof(DCTELEM) * 8); /* shift */ |
| return 0; |
| } |
| |
| b = flss(divisor) - 1; |
| r = sizeof(DCTELEM) * 8 + b; |
| |
| fq = ((UDCTELEM2)1 << r) / divisor; |
| fr = ((UDCTELEM2)1 << r) % divisor; |
| |
| c = divisor / 2; /* for rounding */ |
| |
| if (fr == 0) { /* divisor is power of two */ |
| /* fq will be one bit too large to fit in DCTELEM, so adjust */ |
| fq >>= 1; |
| r--; |
| } else if (fr <= (divisor / 2U)) { /* fractional part is < 0.5 */ |
| c++; |
| } else { /* fractional part is > 0.5 */ |
| fq++; |
| } |
| |
| dtbl[DCTSIZE2 * 0] = (DCTELEM)fq; /* reciprocal */ |
| dtbl[DCTSIZE2 * 1] = (DCTELEM)c; /* correction + roundfactor */ |
| #ifdef WITH_SIMD |
| dtbl[DCTSIZE2 * 2] = (DCTELEM)(1 << (sizeof(DCTELEM) * 8 * 2 - r)); /* scale */ |
| #else |
| dtbl[DCTSIZE2 * 2] = 1; |
| #endif |
| dtbl[DCTSIZE2 * 3] = (DCTELEM)r - sizeof(DCTELEM) * 8; /* shift */ |
| |
| if (r <= 16) return 0; |
| else return 1; |
| } |
| |
| #endif |
| |
| |
| /* |
| * Initialize for a processing pass. |
| * Verify that all referenced Q-tables are present, and set up |
| * the divisor table for each one. |
| * In the current implementation, DCT of all components is done during |
| * the first pass, even if only some components will be output in the |
| * first scan. Hence all components should be examined here. |
| */ |
| |
| METHODDEF(void) |
| start_pass_fdctmgr(j_compress_ptr cinfo) |
| { |
| my_fdct_ptr fdct = (my_fdct_ptr)cinfo->fdct; |
| int ci, qtblno, i; |
| jpeg_component_info *compptr; |
| JQUANT_TBL *qtbl; |
| DCTELEM *dtbl; |
| |
| for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
| ci++, compptr++) { |
| qtblno = compptr->quant_tbl_no; |
| /* Make sure specified quantization table is present */ |
| if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS || |
| cinfo->quant_tbl_ptrs[qtblno] == NULL) |
| ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno); |
| qtbl = cinfo->quant_tbl_ptrs[qtblno]; |
| /* Compute divisors for this quant table */ |
| /* We may do this more than once for same table, but it's not a big deal */ |
| switch (cinfo->dct_method) { |
| #ifdef DCT_ISLOW_SUPPORTED |
| case JDCT_ISLOW: |
| /* For LL&M IDCT method, divisors are equal to raw quantization |
| * coefficients multiplied by 8 (to counteract scaling). |
| */ |
| if (fdct->divisors[qtblno] == NULL) { |
| fdct->divisors[qtblno] = (DCTELEM *) |
| (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
| (DCTSIZE2 * 4) * sizeof(DCTELEM)); |
| } |
| dtbl = fdct->divisors[qtblno]; |
| for (i = 0; i < DCTSIZE2; i++) { |
| #if BITS_IN_JSAMPLE == 8 |
| if (!compute_reciprocal(qtbl->quantval[i] << 3, &dtbl[i]) && |
| fdct->quantize == jsimd_quantize) |
| fdct->quantize = quantize; |
| #else |
| dtbl[i] = ((DCTELEM)qtbl->quantval[i]) << 3; |
| #endif |
| } |
| break; |
| #endif |
| #ifdef DCT_IFAST_SUPPORTED |
| case JDCT_IFAST: |
| { |
| /* For AA&N IDCT method, divisors are equal to quantization |
| * coefficients scaled by scalefactor[row]*scalefactor[col], where |
| * scalefactor[0] = 1 |
| * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7 |
| * We apply a further scale factor of 8. |
| */ |
| #define CONST_BITS 14 |
| static const INT16 aanscales[DCTSIZE2] = { |
| /* precomputed values scaled up by 14 bits */ |
| 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520, |
| 22725, 31521, 29692, 26722, 22725, 17855, 12299, 6270, |
| 21407, 29692, 27969, 25172, 21407, 16819, 11585, 5906, |
| 19266, 26722, 25172, 22654, 19266, 15137, 10426, 5315, |
| 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520, |
| 12873, 17855, 16819, 15137, 12873, 10114, 6967, 3552, |
| 8867, 12299, 11585, 10426, 8867, 6967, 4799, 2446, |
| 4520, 6270, 5906, 5315, 4520, 3552, 2446, 1247 |
| }; |
| SHIFT_TEMPS |
| |
| if (fdct->divisors[qtblno] == NULL) { |
| fdct->divisors[qtblno] = (DCTELEM *) |
| (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
| (DCTSIZE2 * 4) * sizeof(DCTELEM)); |
| } |
| dtbl = fdct->divisors[qtblno]; |
| for (i = 0; i < DCTSIZE2; i++) { |
| #if BITS_IN_JSAMPLE == 8 |
| if (!compute_reciprocal( |
| DESCALE(MULTIPLY16V16((JLONG)qtbl->quantval[i], |
| (JLONG)aanscales[i]), |
| CONST_BITS - 3), &dtbl[i]) && |
| fdct->quantize == jsimd_quantize) |
| fdct->quantize = quantize; |
| #else |
| dtbl[i] = (DCTELEM) |
| DESCALE(MULTIPLY16V16((JLONG)qtbl->quantval[i], |
| (JLONG)aanscales[i]), |
| CONST_BITS - 3); |
| #endif |
| } |
| } |
| break; |
| #endif |
| #ifdef DCT_FLOAT_SUPPORTED |
| case JDCT_FLOAT: |
| { |
| /* For float AA&N IDCT method, divisors are equal to quantization |
| * coefficients scaled by scalefactor[row]*scalefactor[col], where |
| * scalefactor[0] = 1 |
| * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7 |
| * We apply a further scale factor of 8. |
| * What's actually stored is 1/divisor so that the inner loop can |
| * use a multiplication rather than a division. |
| */ |
| FAST_FLOAT *fdtbl; |
| int row, col; |
| static const double aanscalefactor[DCTSIZE] = { |
| 1.0, 1.387039845, 1.306562965, 1.175875602, |
| 1.0, 0.785694958, 0.541196100, 0.275899379 |
| }; |
| |
| if (fdct->float_divisors[qtblno] == NULL) { |
| fdct->float_divisors[qtblno] = (FAST_FLOAT *) |
| (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
| DCTSIZE2 * sizeof(FAST_FLOAT)); |
| } |
| fdtbl = fdct->float_divisors[qtblno]; |
| i = 0; |
| for (row = 0; row < DCTSIZE; row++) { |
| for (col = 0; col < DCTSIZE; col++) { |
| fdtbl[i] = (FAST_FLOAT) |
| (1.0 / (((double)qtbl->quantval[i] * |
| aanscalefactor[row] * aanscalefactor[col] * 8.0))); |
| i++; |
| } |
| } |
| } |
| break; |
| #endif |
| default: |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| break; |
| } |
| } |
| } |
| |
| |
| /* |
| * Load data into workspace, applying unsigned->signed conversion. |
| */ |
| |
| METHODDEF(void) |
| convsamp(JSAMPARRAY sample_data, JDIMENSION start_col, DCTELEM *workspace) |
| { |
| register DCTELEM *workspaceptr; |
| register JSAMPROW elemptr; |
| register int elemr; |
| |
| workspaceptr = workspace; |
| for (elemr = 0; elemr < DCTSIZE; elemr++) { |
| elemptr = sample_data[elemr] + start_col; |
| |
| #if DCTSIZE == 8 /* unroll the inner loop */ |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| #else |
| { |
| register int elemc; |
| for (elemc = DCTSIZE; elemc > 0; elemc--) |
| *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
| } |
| #endif |
| } |
| } |
| |
| |
| /* |
| * Quantize/descale the coefficients, and store into coef_blocks[]. |
| */ |
| |
| METHODDEF(void) |
| quantize(JCOEFPTR coef_block, DCTELEM *divisors, DCTELEM *workspace) |
| { |
| int i; |
| DCTELEM temp; |
| JCOEFPTR output_ptr = coef_block; |
| |
| #if BITS_IN_JSAMPLE == 8 |
| |
| UDCTELEM recip, corr; |
| int shift; |
| UDCTELEM2 product; |
| |
| for (i = 0; i < DCTSIZE2; i++) { |
| temp = workspace[i]; |
| recip = divisors[i + DCTSIZE2 * 0]; |
| corr = divisors[i + DCTSIZE2 * 1]; |
| shift = divisors[i + DCTSIZE2 * 3]; |
| |
| if (temp < 0) { |
| temp = -temp; |
| product = (UDCTELEM2)(temp + corr) * recip; |
| product >>= shift + sizeof(DCTELEM) * 8; |
| temp = (DCTELEM)product; |
| temp = -temp; |
| } else { |
| product = (UDCTELEM2)(temp + corr) * recip; |
| product >>= shift + sizeof(DCTELEM) * 8; |
| temp = (DCTELEM)product; |
| } |
| output_ptr[i] = (JCOEF)temp; |
| } |
| |
| #else |
| |
| register DCTELEM qval; |
| |
| for (i = 0; i < DCTSIZE2; i++) { |
| qval = divisors[i]; |
| temp = workspace[i]; |
| /* Divide the coefficient value by qval, ensuring proper rounding. |
| * Since C does not specify the direction of rounding for negative |
| * quotients, we have to force the dividend positive for portability. |
| * |
| * In most files, at least half of the output values will be zero |
| * (at default quantization settings, more like three-quarters...) |
| * so we should ensure that this case is fast. On many machines, |
| * a comparison is enough cheaper than a divide to make a special test |
| * a win. Since both inputs will be nonnegative, we need only test |
| * for a < b to discover whether a/b is 0. |
| * If your machine's division is fast enough, define FAST_DIVIDE. |
| */ |
| #ifdef FAST_DIVIDE |
| #define DIVIDE_BY(a, b) a /= b |
| #else |
| #define DIVIDE_BY(a, b) if (a >= b) a /= b; else a = 0 |
| #endif |
| if (temp < 0) { |
| temp = -temp; |
| temp += qval >> 1; /* for rounding */ |
| DIVIDE_BY(temp, qval); |
| temp = -temp; |
| } else { |
| temp += qval >> 1; /* for rounding */ |
| DIVIDE_BY(temp, qval); |
| } |
| output_ptr[i] = (JCOEF)temp; |
| } |
| |
| #endif |
| |
| } |
| |
| |
| /* |
| * Perform forward DCT on one or more blocks of a component. |
| * |
| * The input samples are taken from the sample_data[] array starting at |
| * position start_row/start_col, and moving to the right for any additional |
| * blocks. The quantized coefficients are returned in coef_blocks[]. |
| */ |
| |
| METHODDEF(void) |
| forward_DCT(j_compress_ptr cinfo, jpeg_component_info *compptr, |
| JSAMPARRAY sample_data, JBLOCKROW coef_blocks, |
| JDIMENSION start_row, JDIMENSION start_col, JDIMENSION num_blocks) |
| /* This version is used for integer DCT implementations. */ |
| { |
| /* This routine is heavily used, so it's worth coding it tightly. */ |
| my_fdct_ptr fdct = (my_fdct_ptr)cinfo->fdct; |
| DCTELEM *divisors = fdct->divisors[compptr->quant_tbl_no]; |
| DCTELEM *workspace; |
| JDIMENSION bi; |
| |
| /* Make sure the compiler doesn't look up these every pass */ |
| forward_DCT_method_ptr do_dct = fdct->dct; |
| convsamp_method_ptr do_convsamp = fdct->convsamp; |
| quantize_method_ptr do_quantize = fdct->quantize; |
| workspace = fdct->workspace; |
| |
| sample_data += start_row; /* fold in the vertical offset once */ |
| |
| for (bi = 0; bi < num_blocks; bi++, start_col += DCTSIZE) { |
| /* Load data into workspace, applying unsigned->signed conversion */ |
| (*do_convsamp) (sample_data, start_col, workspace); |
| |
| /* Perform the DCT */ |
| (*do_dct) (workspace); |
| |
| /* Quantize/descale the coefficients, and store into coef_blocks[] */ |
| (*do_quantize) (coef_blocks[bi], divisors, workspace); |
| } |
| } |
| |
| |
| #ifdef DCT_FLOAT_SUPPORTED |
| |
| METHODDEF(void) |
| convsamp_float(JSAMPARRAY sample_data, JDIMENSION start_col, |
| FAST_FLOAT *workspace) |
| { |
| register FAST_FLOAT *workspaceptr; |
| register JSAMPROW elemptr; |
| register int elemr; |
| |
| workspaceptr = workspace; |
| for (elemr = 0; elemr < DCTSIZE; elemr++) { |
| elemptr = sample_data[elemr] + start_col; |
| #if DCTSIZE == 8 /* unroll the inner loop */ |
| *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| #else |
| { |
| register int elemc; |
| for (elemc = DCTSIZE; elemc > 0; elemc--) |
| *workspaceptr++ = (FAST_FLOAT) |
| (GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
| } |
| #endif |
| } |
| } |
| |
| |
| METHODDEF(void) |
| quantize_float(JCOEFPTR coef_block, FAST_FLOAT *divisors, |
| FAST_FLOAT *workspace) |
| { |
| register FAST_FLOAT temp; |
| register int i; |
| register JCOEFPTR output_ptr = coef_block; |
| |
| for (i = 0; i < DCTSIZE2; i++) { |
| /* Apply the quantization and scaling factor */ |
| temp = workspace[i] * divisors[i]; |
| |
| /* Round to nearest integer. |
| * Since C does not specify the direction of rounding for negative |
| * quotients, we have to force the dividend positive for portability. |
| * The maximum coefficient size is +-16K (for 12-bit data), so this |
| * code should work for either 16-bit or 32-bit ints. |
| */ |
| output_ptr[i] = (JCOEF)((int)(temp + (FAST_FLOAT)16384.5) - 16384); |
| } |
| } |
| |
| |
| METHODDEF(void) |
| forward_DCT_float(j_compress_ptr cinfo, jpeg_component_info *compptr, |
| JSAMPARRAY sample_data, JBLOCKROW coef_blocks, |
| JDIMENSION start_row, JDIMENSION start_col, |
| JDIMENSION num_blocks) |
| /* This version is used for floating-point DCT implementations. */ |
| { |
| /* This routine is heavily used, so it's worth coding it tightly. */ |
| my_fdct_ptr fdct = (my_fdct_ptr)cinfo->fdct; |
| FAST_FLOAT *divisors = fdct->float_divisors[compptr->quant_tbl_no]; |
| FAST_FLOAT *workspace; |
| JDIMENSION bi; |
| |
| |
| /* Make sure the compiler doesn't look up these every pass */ |
| float_DCT_method_ptr do_dct = fdct->float_dct; |
| float_convsamp_method_ptr do_convsamp = fdct->float_convsamp; |
| float_quantize_method_ptr do_quantize = fdct->float_quantize; |
| workspace = fdct->float_workspace; |
| |
| sample_data += start_row; /* fold in the vertical offset once */ |
| |
| for (bi = 0; bi < num_blocks; bi++, start_col += DCTSIZE) { |
| /* Load data into workspace, applying unsigned->signed conversion */ |
| (*do_convsamp) (sample_data, start_col, workspace); |
| |
| /* Perform the DCT */ |
| (*do_dct) (workspace); |
| |
| /* Quantize/descale the coefficients, and store into coef_blocks[] */ |
| (*do_quantize) (coef_blocks[bi], divisors, workspace); |
| } |
| } |
| |
| #endif /* DCT_FLOAT_SUPPORTED */ |
| |
| |
| /* |
| * Initialize FDCT manager. |
| */ |
| |
| GLOBAL(void) |
| jinit_forward_dct(j_compress_ptr cinfo) |
| { |
| my_fdct_ptr fdct; |
| int i; |
| |
| fdct = (my_fdct_ptr) |
| (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
| sizeof(my_fdct_controller)); |
| cinfo->fdct = (struct jpeg_forward_dct *)fdct; |
| fdct->pub.start_pass = start_pass_fdctmgr; |
| |
| /* First determine the DCT... */ |
| switch (cinfo->dct_method) { |
| #ifdef DCT_ISLOW_SUPPORTED |
| case JDCT_ISLOW: |
| fdct->pub.forward_DCT = forward_DCT; |
| if (jsimd_can_fdct_islow()) |
| fdct->dct = jsimd_fdct_islow; |
| else |
| fdct->dct = jpeg_fdct_islow; |
| break; |
| #endif |
| #ifdef DCT_IFAST_SUPPORTED |
| case JDCT_IFAST: |
| fdct->pub.forward_DCT = forward_DCT; |
| if (jsimd_can_fdct_ifast()) |
| fdct->dct = jsimd_fdct_ifast; |
| else |
| fdct->dct = jpeg_fdct_ifast; |
| break; |
| #endif |
| #ifdef DCT_FLOAT_SUPPORTED |
| case JDCT_FLOAT: |
| fdct->pub.forward_DCT = forward_DCT_float; |
| if (jsimd_can_fdct_float()) |
| fdct->float_dct = jsimd_fdct_float; |
| else |
| fdct->float_dct = jpeg_fdct_float; |
| break; |
| #endif |
| default: |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| break; |
| } |
| |
| /* ...then the supporting stages. */ |
| switch (cinfo->dct_method) { |
| #ifdef DCT_ISLOW_SUPPORTED |
| case JDCT_ISLOW: |
| #endif |
| #ifdef DCT_IFAST_SUPPORTED |
| case JDCT_IFAST: |
| #endif |
| #if defined(DCT_ISLOW_SUPPORTED) || defined(DCT_IFAST_SUPPORTED) |
| if (jsimd_can_convsamp()) |
| fdct->convsamp = jsimd_convsamp; |
| else |
| fdct->convsamp = convsamp; |
| if (jsimd_can_quantize()) |
| fdct->quantize = jsimd_quantize; |
| else |
| fdct->quantize = quantize; |
| break; |
| #endif |
| #ifdef DCT_FLOAT_SUPPORTED |
| case JDCT_FLOAT: |
| if (jsimd_can_convsamp_float()) |
| fdct->float_convsamp = jsimd_convsamp_float; |
| else |
| fdct->float_convsamp = convsamp_float; |
| if (jsimd_can_quantize_float()) |
| fdct->float_quantize = jsimd_quantize_float; |
| else |
| fdct->float_quantize = quantize_float; |
| break; |
| #endif |
| default: |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| break; |
| } |
| |
| /* Allocate workspace memory */ |
| #ifdef DCT_FLOAT_SUPPORTED |
| if (cinfo->dct_method == JDCT_FLOAT) |
| fdct->float_workspace = (FAST_FLOAT *) |
| (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
| sizeof(FAST_FLOAT) * DCTSIZE2); |
| else |
| #endif |
| fdct->workspace = (DCTELEM *) |
| (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
| sizeof(DCTELEM) * DCTSIZE2); |
| |
| /* Mark divisor tables unallocated */ |
| for (i = 0; i < NUM_QUANT_TBLS; i++) { |
| fdct->divisors[i] = NULL; |
| #ifdef DCT_FLOAT_SUPPORTED |
| fdct->float_divisors[i] = NULL; |
| #endif |
| } |
| } |
