* jcdctmgr.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
+ * Modified 2003-2013 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.
*
struct jpeg_forward_dct pub; /* public fields */
/* Pointer to the DCT routine actually in use */
- forward_DCT_method_ptr do_dct;
-
- /* 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];
+ forward_DCT_method_ptr do_dct[MAX_COMPONENTS];
#ifdef DCT_FLOAT_SUPPORTED
/* Same as above for the floating-point case. */
- float_DCT_method_ptr do_float_dct;
- FAST_FLOAT * float_divisors[NUM_QUANT_TBLS];
+ float_DCT_method_ptr do_float_dct[MAX_COMPONENTS];
#endif
} my_fdct_controller;
typedef my_fdct_controller * my_fdct_ptr;
-/*
- * 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.
+/* The allocated post-DCT divisor tables -- big enough for any
+ * supported variant and not identical to the quant table entries,
+ * because of scaling (especially for an unnormalized DCT) --
+ * are pointed to by dct_table in the per-component comp_info
+ * structures. Each table is given in normal array order.
*/
-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 * SIZEOF(DCTELEM));
- }
- dtbl = fdct->divisors[qtblno];
- for (i = 0; i < DCTSIZE2; i++) {
- dtbl[i] = ((DCTELEM) qtbl->quantval[i]) << 3;
- }
- break;
+typedef union {
+ DCTELEM int_array[DCTSIZE2];
+#ifdef DCT_FLOAT_SUPPORTED
+ FAST_FLOAT float_array[DCTSIZE2];
#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
+} divisor_table;
- if (fdct->divisors[qtblno] == NULL) {
- fdct->divisors[qtblno] = (DCTELEM *)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- DCTSIZE2 * SIZEOF(DCTELEM));
- }
- dtbl = fdct->divisors[qtblno];
- for (i = 0; i < DCTSIZE2; i++) {
- dtbl[i] = (DCTELEM)
- DESCALE(MULTIPLY16V16((INT32) qtbl->quantval[i],
- (INT32) aanscales[i]),
- CONST_BITS-3);
- }
- }
- 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;
+/* The current scaled-DCT routines require ISLOW-style divisor tables,
+ * so be sure to compile that code if either ISLOW or SCALING is requested.
+ */
+#ifdef DCT_ISLOW_SUPPORTED
+#define PROVIDE_ISLOW_TABLES
+#else
+#ifdef DCT_SCALING_SUPPORTED
+#define PROVIDE_ISLOW_TABLES
+#endif
#endif
- default:
- ERREXIT(cinfo, JERR_NOT_COMPILED);
- break;
- }
- }
-}
/*
{
/* This routine is heavily used, so it's worth coding it tightly. */
my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
- forward_DCT_method_ptr do_dct = fdct->do_dct;
- DCTELEM * divisors = fdct->divisors[compptr->quant_tbl_no];
+ forward_DCT_method_ptr do_dct = fdct->do_dct[compptr->component_index];
+ DCTELEM * divisors = (DCTELEM *) compptr->dct_table;
DCTELEM workspace[DCTSIZE2]; /* work area for FDCT subroutine */
JDIMENSION bi;
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 */
- { 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
- }
- }
-
+ for (bi = 0; bi < num_blocks; bi++, start_col += compptr->DCT_h_scaled_size) {
/* Perform the DCT */
- (*do_dct) (workspace);
+ (*do_dct) (workspace, sample_data, start_col);
/* Quantize/descale the coefficients, and store into coef_blocks[] */
{ register DCTELEM temp, qval;
{
/* This routine is heavily used, so it's worth coding it tightly. */
my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
- float_DCT_method_ptr do_dct = fdct->do_float_dct;
- FAST_FLOAT * divisors = fdct->float_divisors[compptr->quant_tbl_no];
+ float_DCT_method_ptr do_dct = fdct->do_float_dct[compptr->component_index];
+ FAST_FLOAT * divisors = (FAST_FLOAT *) compptr->dct_table;
FAST_FLOAT workspace[DCTSIZE2]; /* work area for FDCT subroutine */
JDIMENSION bi;
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 */
- { 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
- }
- }
-
+ for (bi = 0; bi < num_blocks; bi++, start_col += compptr->DCT_h_scaled_size) {
/* Perform the DCT */
- (*do_dct) (workspace);
+ (*do_dct) (workspace, sample_data, start_col);
/* Quantize/descale the coefficients, and store into coef_blocks[] */
{ register FAST_FLOAT temp;
/*
- * Initialize FDCT manager.
+ * 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.
*/
-GLOBAL(void)
-jinit_forward_dct (j_compress_ptr cinfo)
+METHODDEF(void)
+start_pass_fdctmgr (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;
+ my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
+ int ci, qtblno, i;
+ jpeg_component_info *compptr;
+ int method = 0;
+ JQUANT_TBL * qtbl;
+ DCTELEM * dtbl;
- switch (cinfo->dct_method) {
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Select the proper DCT routine for this component's scaling */
+ switch ((compptr->DCT_h_scaled_size << 8) + compptr->DCT_v_scaled_size) {
+#ifdef DCT_SCALING_SUPPORTED
+ case ((1 << 8) + 1):
+ fdct->do_dct[ci] = jpeg_fdct_1x1;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((2 << 8) + 2):
+ fdct->do_dct[ci] = jpeg_fdct_2x2;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((3 << 8) + 3):
+ fdct->do_dct[ci] = jpeg_fdct_3x3;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((4 << 8) + 4):
+ fdct->do_dct[ci] = jpeg_fdct_4x4;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((5 << 8) + 5):
+ fdct->do_dct[ci] = jpeg_fdct_5x5;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((6 << 8) + 6):
+ fdct->do_dct[ci] = jpeg_fdct_6x6;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((7 << 8) + 7):
+ fdct->do_dct[ci] = jpeg_fdct_7x7;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((9 << 8) + 9):
+ fdct->do_dct[ci] = jpeg_fdct_9x9;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((10 << 8) + 10):
+ fdct->do_dct[ci] = jpeg_fdct_10x10;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((11 << 8) + 11):
+ fdct->do_dct[ci] = jpeg_fdct_11x11;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((12 << 8) + 12):
+ fdct->do_dct[ci] = jpeg_fdct_12x12;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((13 << 8) + 13):
+ fdct->do_dct[ci] = jpeg_fdct_13x13;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((14 << 8) + 14):
+ fdct->do_dct[ci] = jpeg_fdct_14x14;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((15 << 8) + 15):
+ fdct->do_dct[ci] = jpeg_fdct_15x15;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((16 << 8) + 16):
+ fdct->do_dct[ci] = jpeg_fdct_16x16;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((16 << 8) + 8):
+ fdct->do_dct[ci] = jpeg_fdct_16x8;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((14 << 8) + 7):
+ fdct->do_dct[ci] = jpeg_fdct_14x7;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((12 << 8) + 6):
+ fdct->do_dct[ci] = jpeg_fdct_12x6;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((10 << 8) + 5):
+ fdct->do_dct[ci] = jpeg_fdct_10x5;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((8 << 8) + 4):
+ fdct->do_dct[ci] = jpeg_fdct_8x4;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((6 << 8) + 3):
+ fdct->do_dct[ci] = jpeg_fdct_6x3;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((4 << 8) + 2):
+ fdct->do_dct[ci] = jpeg_fdct_4x2;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((2 << 8) + 1):
+ fdct->do_dct[ci] = jpeg_fdct_2x1;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((8 << 8) + 16):
+ fdct->do_dct[ci] = jpeg_fdct_8x16;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((7 << 8) + 14):
+ fdct->do_dct[ci] = jpeg_fdct_7x14;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((6 << 8) + 12):
+ fdct->do_dct[ci] = jpeg_fdct_6x12;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((5 << 8) + 10):
+ fdct->do_dct[ci] = jpeg_fdct_5x10;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((4 << 8) + 8):
+ fdct->do_dct[ci] = jpeg_fdct_4x8;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((3 << 8) + 6):
+ fdct->do_dct[ci] = jpeg_fdct_3x6;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((2 << 8) + 4):
+ fdct->do_dct[ci] = jpeg_fdct_2x4;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+ case ((1 << 8) + 2):
+ fdct->do_dct[ci] = jpeg_fdct_1x2;
+ method = JDCT_ISLOW; /* jfdctint uses islow-style table */
+ break;
+#endif
+ case ((DCTSIZE << 8) + DCTSIZE):
+ switch (cinfo->dct_method) {
#ifdef DCT_ISLOW_SUPPORTED
- case JDCT_ISLOW:
- fdct->pub.forward_DCT = forward_DCT;
- fdct->do_dct = jpeg_fdct_islow;
- break;
+ case JDCT_ISLOW:
+ fdct->do_dct[ci] = jpeg_fdct_islow;
+ method = JDCT_ISLOW;
+ break;
#endif
#ifdef DCT_IFAST_SUPPORTED
- case JDCT_IFAST:
- fdct->pub.forward_DCT = forward_DCT;
- fdct->do_dct = jpeg_fdct_ifast;
- break;
+ case JDCT_IFAST:
+ fdct->do_dct[ci] = jpeg_fdct_ifast;
+ method = JDCT_IFAST;
+ break;
#endif
#ifdef DCT_FLOAT_SUPPORTED
- case JDCT_FLOAT:
- fdct->pub.forward_DCT = forward_DCT_float;
- fdct->do_float_dct = jpeg_fdct_float;
- break;
+ case JDCT_FLOAT:
+ fdct->do_float_dct[ci] = jpeg_fdct_float;
+ method = JDCT_FLOAT;
+ break;
#endif
- default:
- ERREXIT(cinfo, JERR_NOT_COMPILED);
- break;
- }
+ default:
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+ break;
+ }
+ break;
+ default:
+ ERREXIT2(cinfo, JERR_BAD_DCTSIZE,
+ compptr->DCT_h_scaled_size, compptr->DCT_v_scaled_size);
+ break;
+ }
+ 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];
+ /* Create divisor table from quant table */
+ switch (method) {
+#ifdef PROVIDE_ISLOW_TABLES
+ case JDCT_ISLOW:
+ /* For LL&M IDCT method, divisors are equal to raw quantization
+ * coefficients multiplied by 8 (to counteract scaling).
+ */
+ dtbl = (DCTELEM *) compptr->dct_table;
+ for (i = 0; i < DCTSIZE2; i++) {
+ dtbl[i] =
+ ((DCTELEM) qtbl->quantval[i]) << (compptr->component_needed ? 4 : 3);
+ }
+ fdct->pub.forward_DCT[ci] = forward_DCT;
+ 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
- /* Mark divisor tables unallocated */
- for (i = 0; i < NUM_QUANT_TBLS; i++) {
- fdct->divisors[i] = NULL;
+ dtbl = (DCTELEM *) compptr->dct_table;
+ for (i = 0; i < DCTSIZE2; i++) {
+ dtbl[i] = (DCTELEM)
+ DESCALE(MULTIPLY16V16((INT32) qtbl->quantval[i],
+ (INT32) aanscales[i]),
+ compptr->component_needed ? CONST_BITS-4 : CONST_BITS-3);
+ }
+ }
+ fdct->pub.forward_DCT[ci] = forward_DCT;
+ break;
+#endif
#ifdef DCT_FLOAT_SUPPORTED
- fdct->float_divisors[i] = NULL;
+ 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 = (FAST_FLOAT *) compptr->dct_table;
+ int row, col;
+ static const double aanscalefactor[DCTSIZE] = {
+ 1.0, 1.387039845, 1.306562965, 1.175875602,
+ 1.0, 0.785694958, 0.541196100, 0.275899379
+ };
+
+ 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] *
+ (compptr->component_needed ? 16.0 : 8.0)));
+ i++;
+ }
+ }
+ }
+ fdct->pub.forward_DCT[ci] = forward_DCT_float;
+ break;
#endif
+ default:
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+ break;
+ }
+ }
+}
+
+
+/*
+ * Initialize FDCT manager.
+ */
+
+GLOBAL(void)
+jinit_forward_dct (j_compress_ptr cinfo)
+{
+ my_fdct_ptr fdct;
+ int ci;
+ jpeg_component_info *compptr;
+
+ fdct = (my_fdct_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_fdct_controller));
+ cinfo->fdct = &fdct->pub;
+ fdct->pub.start_pass = start_pass_fdctmgr;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Allocate a divisor table for each component */
+ compptr->dct_table =
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(divisor_table));
}
}
Ecere Software / sdk / blobdiff