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authorQt by Nokia <qt-info@nokia.com>2011-04-27 12:05:43 +0200
committeraxis <qt-info@nokia.com>2011-04-27 12:05:43 +0200
commit38be0d13830efd2d98281c645c3a60afe05ffece (patch)
tree6ea73f3ec77f7d153333779883e8120f82820abe /src/3rdparty/libjpeg/jcdctmgr.c
Initial import from the monolithic Qt.
This is the beginning of revision history for this module. If you want to look at revision history older than this, please refer to the Qt Git wiki for how to use Git history grafting. At the time of writing, this wiki is located here: http://qt.gitorious.org/qt/pages/GitIntroductionWithQt If you have already performed the grafting and you don't see any history beyond this commit, try running "git log" with the "--follow" argument. Branched from the monolithic repo, Qt master branch, at commit 896db169ea224deb96c59ce8af800d019de63f12
Diffstat (limited to 'src/3rdparty/libjpeg/jcdctmgr.c')
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diff --git a/src/3rdparty/libjpeg/jcdctmgr.c b/src/3rdparty/libjpeg/jcdctmgr.c
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+++ b/src/3rdparty/libjpeg/jcdctmgr.c
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+/*
+ * jcdctmgr.c
+ *
+ * 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 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 */
+
+
+/* Private subobject for this module */
+
+typedef struct {
+ struct jpeg_forward_dct pub; /* public fields */
+
+ /* Pointer to the DCT routine actually in use */
+ forward_DCT_method_ptr do_dct[MAX_COMPONENTS];
+
+ /* 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];
+
+#ifdef DCT_FLOAT_SUPPORTED
+ /* Same as above for the floating-point case. */
+ float_DCT_method_ptr do_float_dct[MAX_COMPONENTS];
+ FAST_FLOAT * float_divisors[NUM_QUANT_TBLS];
+#endif
+} my_fdct_controller;
+
+typedef my_fdct_controller * my_fdct_ptr;
+
+
+/* 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
+
+
+/*
+ * 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;
+ forward_DCT_method_ptr do_dct = fdct->do_dct[compptr->component_index];
+ DCTELEM * divisors = fdct->divisors[compptr->quant_tbl_no];
+ 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 += compptr->DCT_h_scaled_size) {
+ /* Perform the DCT */
+ (*do_dct) (workspace, sample_data, start_col);
+
+ /* Quantize/descale the coefficients, and store into coef_blocks[] */
+ { register DCTELEM temp, qval;
+ register int i;
+ register JCOEFPTR output_ptr = coef_blocks[bi];
+
+ 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;
+ }
+ }
+ }
+}
+
+
+#ifdef DCT_FLOAT_SUPPORTED
+
+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;
+ float_DCT_method_ptr do_dct = fdct->do_float_dct[compptr->component_index];
+ FAST_FLOAT * divisors = fdct->float_divisors[compptr->quant_tbl_no];
+ 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 += compptr->DCT_h_scaled_size) {
+ /* Perform the DCT */
+ (*do_dct) (workspace, sample_data, start_col);
+
+ /* Quantize/descale the coefficients, and store into coef_blocks[] */
+ { register FAST_FLOAT temp;
+ register int i;
+ register JCOEFPTR output_ptr = coef_blocks[bi];
+
+ 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);
+ }
+ }
+ }
+}
+
+#endif /* DCT_FLOAT_SUPPORTED */
+
+
+/*
+ * 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;
+ int method = 0;
+ JQUANT_TBL * qtbl;
+ DCTELEM * dtbl;
+
+ 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->do_dct[ci] = jpeg_fdct_islow;
+ method = JDCT_ISLOW;
+ break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+ case JDCT_IFAST:
+ fdct->do_dct[ci] = jpeg_fdct_ifast;
+ method = JDCT_IFAST;
+ break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+ case JDCT_FLOAT:
+ fdct->do_float_dct[ci] = jpeg_fdct_float;
+ method = JDCT_FLOAT;
+ break;
+#endif
+ 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];
+ /* Compute divisors for this quant table */
+ /* We may do this more than once for same table, but it's not a big deal */
+ 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).
+ */
+ 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;
+ }
+ 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
+
+ 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);
+ }
+ }
+ fdct->pub.forward_DCT[ci] = forward_DCT;
+ 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++;
+ }
+ }
+ }
+ 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 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;
+
+ /* 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
+ }
+}