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ad67be3b366d82ea8234ed41681ac6c5b92ad56a
mozjpeg/jcdctmgr.c
Frank Bossen 1aa50b71d9 Use precomputed table 
From jpeglib-turbo r1221:
Integrate a slightly modified version of Mozilla's patch for
precomputing the bit-counting LUT.  This is useful if the table needs
to be shared among multiple processes, although the primary reason for
doing that is reduced footprint on mobile devices, which are probably
already covered by the clz intrinsic code.
2014-07-24 10:50:59 -04:00

976 lines
29 KiB
C
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/*
* 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 D. R. Commander
* mozjpeg Modifications:
* Copyright (C) 2014, Mozilla Corporation.
* 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 */
#include "jsimddct.h"
#include <assert.h>
#include <math.h>
/* Private subobject for this module */
typedef JMETHOD(void, forward_DCT_method_ptr, (DCTELEM * data));
typedef JMETHOD(void, float_DCT_method_ptr, (FAST_FLOAT * data));
typedef JMETHOD(void, convsamp_method_ptr,
(JSAMPARRAY sample_data, JDIMENSION start_col,
DCTELEM * workspace));
typedef JMETHOD(void, float_convsamp_method_ptr,
(JSAMPARRAY sample_data, JDIMENSION start_col,
FAST_FLOAT *workspace));
typedef JMETHOD(void, quantize_method_ptr,
(JCOEFPTR coef_block, DCTELEM * divisors,
DCTELEM * workspace));
typedef JMETHOD(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;
/*
* 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;
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 */
dtbl[DCTSIZE2 * 2] = (DCTELEM) (1 << (sizeof(DCTELEM)*8*2 - r)); /* scale */
dtbl[DCTSIZE2 * 3] = (DCTELEM) r - sizeof(DCTELEM)*8; /* shift */
if(r <= 16) return 0;
else return 1;
}
/*
* 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(!compute_reciprocal(qtbl->quantval[i] << 3, &dtbl[i])
&& fdct->quantize == jsimd_quantize)
fdct->quantize = quantize;
}
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(!compute_reciprocal(
DESCALE(MULTIPLY16V16((INT32) qtbl->quantval[i],
(INT32) aanscales[i]),
CONST_BITS-3), &dtbl[i])
&& fdct->quantize == jsimd_quantize)
fdct->quantize = quantize;
}
}
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;
UDCTELEM recip, corr, shift;
UDCTELEM2 product;
JCOEFPTR output_ptr = coef_block;
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 = product;
temp = -temp;
} else {
product = (UDCTELEM2)(temp + corr) * recip;
product >>= shift + sizeof(DCTELEM)*8;
temp = product;
}
output_ptr[i] = (JCOEF) temp;
}
}
/*
* 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, JBLOCKROW dst)
/* 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);
/* Save unquantized transform coefficients for later trellis quantization */
if (dst) {
int i;
if (cinfo->dct_method == JDCT_IFAST) {
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
};
for (i = 0; i < DCTSIZE2; i++) {
int x = workspace[i];
int s = aanscales[i];
x = (x >= 0) ? (x * 32768 + s) / (2*s) : (x * 32768 - s) / (2*s);
dst[bi][i] = x;
}
} else {
for (i = 0; i < DCTSIZE2; i++) {
dst[bi][i] = workspace[i];
}
}
}
/* 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, JBLOCKROW dst)
/* 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;
float v;
int x;
/* 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);
/* Save unquantized transform coefficients for later trellis quantization */
/* Currently save as integer values. Could save float values but would require */
/* modifications to memory allocation and trellis quantization */
if (dst) {
int i;
static const double aanscalefactor[DCTSIZE] = {
1.0, 1.387039845, 1.306562965, 1.175875602,
1.0, 0.785694958, 0.541196100, 0.275899379
};
for (i = 0; i < DCTSIZE2; i++) {
v = workspace[i];
v /= aanscalefactor[i%8];
v /= aanscalefactor[i/8];
x = (v >= 0.0) ? (int)(v + 0.5) : (int)(v - 0.5);
dst[bi][i] = x;
}
}
/* Quantize/descale the coefficients, and store into coef_blocks[] */
(*do_quantize) (coef_blocks[bi], divisors, workspace);
}
}
#endif /* DCT_FLOAT_SUPPORTED */
#include "jchuff.h"
#include "jpeg_nbits_table.h"
static const float jpeg_lambda_weights_flat[64] = {
1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f
};
static const float jpeg_lambda_weights_csf_luma[64] = {
3.35630f, 3.59892f, 3.20921f, 2.28102f, 1.42378f, 0.88079f, 0.58190f, 0.43454f,
3.59893f, 3.21284f, 2.71282f, 1.98092f, 1.30506f, 0.83852f, 0.56346f, 0.42146f,
3.20921f, 2.71282f, 2.12574f, 1.48616f, 0.99660f, 0.66132f, 0.45610f, 0.34609f,
2.28102f, 1.98092f, 1.48616f, 0.97492f, 0.64622f, 0.43812f, 0.31074f, 0.24072f,
1.42378f, 1.30506f, 0.99660f, 0.64623f, 0.42051f, 0.28446f, 0.20380f, 0.15975f,
0.88079f, 0.83852f, 0.66132f, 0.43812f, 0.28446f, 0.19092f, 0.13635f, 0.10701f,
0.58190f, 0.56346f, 0.45610f, 0.31074f, 0.20380f, 0.13635f, 0.09674f, 0.07558f,
0.43454f, 0.42146f, 0.34609f, 0.24072f, 0.15975f, 0.10701f, 0.07558f, 0.05875f,
};
GLOBAL(void)
quantize_trellis(j_compress_ptr cinfo, c_derived_tbl *actbl, JBLOCKROW coef_blocks, JBLOCKROW src, JDIMENSION num_blocks,
JQUANT_TBL * qtbl, double *norm_src, double *norm_coef)
{
int i, j, k;
float accumulated_zero_dist[DCTSIZE2];
float accumulated_cost[DCTSIZE2];
int run_start[DCTSIZE2];
int bi;
float best_cost;
int last_coeff_idx; /* position of last nonzero coefficient */
float norm = 0.0;
float lambda_base;
float lambda;
const float *lambda_tbl = (cinfo->use_lambda_weight_tbl) ? jpeg_lambda_weights_csf_luma : jpeg_lambda_weights_flat;
int Ss, Se;
float *accumulated_zero_block_cost = NULL;
float *accumulated_block_cost = NULL;
int *block_run_start = NULL;
int *requires_eob = NULL;
int has_eob;
float cost_all_zeros;
float best_cost_skip;
float cost;
int zero_run;
int run_bits;
int rate;
Ss = cinfo->Ss;
Se = cinfo->Se;
if (Ss == 0)
Ss = 1;
if (Se < Ss)
return;
if (cinfo->trellis_eob_opt) {
accumulated_zero_block_cost = (float *)malloc((num_blocks + 1) * SIZEOF(float));
accumulated_block_cost = (float *)malloc((num_blocks + 1) * SIZEOF(float));
block_run_start = (int *)malloc(num_blocks * SIZEOF(int));
requires_eob = (int *)malloc((num_blocks + 1) * SIZEOF(int));
accumulated_zero_block_cost[0] = 0;
accumulated_block_cost[0] = 0;
requires_eob[0] = 0;
}
norm = 0.0;
for (i = 1; i < DCTSIZE2; i++) {
norm += qtbl->quantval[i] * qtbl->quantval[i];
}
norm /= 63.0;
lambda_base = 1.0 / norm;
for (bi = 0; bi < num_blocks; bi++) {
norm = 0.0;
for (i = 1; i < DCTSIZE2; i++) {
norm += src[bi][i] * src[bi][i];
}
norm /= 63.0;
if (cinfo->lambda_log_scale2 > 0.0)
lambda = pow(2.0, cinfo->lambda_log_scale1) * lambda_base / (pow(2.0, cinfo->lambda_log_scale2) + norm);
else
lambda = pow(2.0, cinfo->lambda_log_scale1-12.0) * lambda_base;
accumulated_zero_dist[Ss-1] = 0.0;
accumulated_cost[Ss-1] = 0.0;
for (i = Ss; i <= Se; i++) {
int z = jpeg_natural_order[i];
int sign = src[bi][z] >> 31;
int x = abs(src[bi][z]);
int q = 8 * qtbl->quantval[z];
int candidate[16];
int candidate_bits[16];
float candidate_dist[16];
int num_candidates;
int qval;
accumulated_zero_dist[i] = x * x * lambda * lambda_tbl[z] + accumulated_zero_dist[i-1];
qval = (x + q/2) / q; /* quantized value (round nearest) */
if (qval == 0) {
coef_blocks[bi][z] = 0;
accumulated_cost[i] = 1e38; /* Shouldn't be needed */
continue;
}
num_candidates = jpeg_nbits_table[qval];
for (k = 0; k < num_candidates; k++) {
int delta;
candidate[k] = (k < num_candidates - 1) ? (2 << k) - 1 : qval;
delta = candidate[k] * q - x;
candidate_bits[k] = k+1;
candidate_dist[k] = delta * delta * lambda * lambda_tbl[z];
}
accumulated_cost[i] = 1e38;
for (j = Ss-1; j < i; j++) {
int zz = jpeg_natural_order[j];
if (j != Ss-1 && coef_blocks[bi][zz] == 0)
continue;
zero_run = i - 1 - j;
if ((zero_run >> 4) && actbl->ehufsi[0xf0] == 0)
continue;
run_bits = (zero_run >> 4) * actbl->ehufsi[0xf0];
zero_run &= 15;
for (k = 0; k < num_candidates; k++) {
int coef_bits = actbl->ehufsi[16 * zero_run + candidate_bits[k]];
if (coef_bits == 0)
continue;
rate = coef_bits + candidate_bits[k] + run_bits;
cost = rate + candidate_dist[k];
cost += accumulated_zero_dist[i-1] - accumulated_zero_dist[j] + accumulated_cost[j];
if (cost < accumulated_cost[i]) {
coef_blocks[bi][z] = (candidate[k] ^ sign) - sign;
accumulated_cost[i] = cost;
run_start[i] = j;
}
}
}
}
last_coeff_idx = Ss-1;
best_cost = accumulated_zero_dist[Se] + actbl->ehufsi[0];
cost_all_zeros = accumulated_zero_dist[Se];
best_cost_skip = cost_all_zeros;
for (i = Ss; i <= Se; i++) {
int z = jpeg_natural_order[i];
if (coef_blocks[bi][z] != 0) {
float cost = accumulated_cost[i] + accumulated_zero_dist[Se] - accumulated_zero_dist[i];
float cost_wo_eob = cost;
if (i < Se)
cost += actbl->ehufsi[0];
if (cost < best_cost) {
best_cost = cost;
last_coeff_idx = i;
best_cost_skip = cost_wo_eob;
}
}
}
has_eob = (last_coeff_idx < Se) + (last_coeff_idx == Ss-1);
/* Zero out coefficients that are part of runs */
i = Se;
while (i >= Ss)
{
while (i > last_coeff_idx) {
int z = jpeg_natural_order[i];
coef_blocks[bi][z] = 0;
i--;
}
last_coeff_idx = run_start[i];
i--;
}
if (cinfo->trellis_eob_opt) {
accumulated_zero_block_cost[bi+1] = accumulated_zero_block_cost[bi];
accumulated_zero_block_cost[bi+1] += cost_all_zeros;
requires_eob[bi+1] = has_eob;
best_cost = 1e38;
if (has_eob != 2) {
for (i = 0; i <= bi; i++) {
int zero_block_run;
int nbits;
float cost;
if (requires_eob[i] == 2)
continue;
cost = best_cost_skip; /* cost of coding a nonzero block */
cost += accumulated_zero_block_cost[bi];
cost -= accumulated_zero_block_cost[i];
cost += accumulated_block_cost[i];
zero_block_run = bi - i + requires_eob[i];
nbits = jpeg_nbits_table[zero_block_run];
cost += actbl->ehufsi[16*nbits] + nbits;
if (cost < best_cost) {
block_run_start[bi] = i;
best_cost = cost;
accumulated_block_cost[bi+1] = cost;
}
}
}
}
}
if (cinfo->trellis_eob_opt) {
int last_block = num_blocks;
best_cost = 1e38;
for (i = 0; i <= num_blocks; i++) {
int zero_block_run;
int nbits;
float cost = 0.0;
if (requires_eob[i] == 2)
continue;
cost += accumulated_zero_block_cost[num_blocks];
cost -= accumulated_zero_block_cost[i];
zero_block_run = num_blocks - i + requires_eob[i];
nbits = jpeg_nbits_table[zero_block_run];
cost += actbl->ehufsi[16*nbits] + nbits;
if (cost < best_cost) {
best_cost = cost;
last_block = i;
}
}
last_block--;
bi = num_blocks - 1;
while (bi >= 0) {
while (bi > last_block) {
for (j = Ss; j <= Se; j++) {
int z = jpeg_natural_order[j];
coef_blocks[bi][z] = 0;
}
bi--;
}
last_block = block_run_start[bi]-1;
bi--;
}
free(accumulated_zero_block_cost);
free(accumulated_block_cost);
free(block_run_start);
free(requires_eob);
}
if (cinfo->trellis_q_opt) {
for (bi = 0; bi < num_blocks; bi++) {
for (i = 1; i < DCTSIZE2; i++) {
norm_src[i] += src[bi][i] * coef_blocks[bi][i];
norm_coef[i] += 8 * coef_blocks[bi][i] * coef_blocks[bi][i];
}
}
}
}
/*
* 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
}
}
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