1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libjpeg/jddctmgr.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,338 @@
1.4 +/*
1.5 + * jddctmgr.c
1.6 + *
1.7 + * This file was part of the Independent JPEG Group's software:
1.8 + * Copyright (C) 1994-1996, Thomas G. Lane.
1.9 + * Modified 2002-2010 by Guido Vollbeding.
1.10 + * libjpeg-turbo Modifications:
1.11 + * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
1.12 + * Copyright (C) 2010, D. R. Commander.
1.13 + * For conditions of distribution and use, see the accompanying README file.
1.14 + *
1.15 + * This file contains the inverse-DCT management logic.
1.16 + * This code selects a particular IDCT implementation to be used,
1.17 + * and it performs related housekeeping chores. No code in this file
1.18 + * is executed per IDCT step, only during output pass setup.
1.19 + *
1.20 + * Note that the IDCT routines are responsible for performing coefficient
1.21 + * dequantization as well as the IDCT proper. This module sets up the
1.22 + * dequantization multiplier table needed by the IDCT routine.
1.23 + */
1.24 +
1.25 +#define JPEG_INTERNALS
1.26 +#include "jinclude.h"
1.27 +#include "jpeglib.h"
1.28 +#include "jdct.h" /* Private declarations for DCT subsystem */
1.29 +#include "jsimddct.h"
1.30 +#include "jpegcomp.h"
1.31 +
1.32 +
1.33 +/*
1.34 + * The decompressor input side (jdinput.c) saves away the appropriate
1.35 + * quantization table for each component at the start of the first scan
1.36 + * involving that component. (This is necessary in order to correctly
1.37 + * decode files that reuse Q-table slots.)
1.38 + * When we are ready to make an output pass, the saved Q-table is converted
1.39 + * to a multiplier table that will actually be used by the IDCT routine.
1.40 + * The multiplier table contents are IDCT-method-dependent. To support
1.41 + * application changes in IDCT method between scans, we can remake the
1.42 + * multiplier tables if necessary.
1.43 + * In buffered-image mode, the first output pass may occur before any data
1.44 + * has been seen for some components, and thus before their Q-tables have
1.45 + * been saved away. To handle this case, multiplier tables are preset
1.46 + * to zeroes; the result of the IDCT will be a neutral gray level.
1.47 + */
1.48 +
1.49 +
1.50 +/* Private subobject for this module */
1.51 +
1.52 +typedef struct {
1.53 + struct jpeg_inverse_dct pub; /* public fields */
1.54 +
1.55 + /* This array contains the IDCT method code that each multiplier table
1.56 + * is currently set up for, or -1 if it's not yet set up.
1.57 + * The actual multiplier tables are pointed to by dct_table in the
1.58 + * per-component comp_info structures.
1.59 + */
1.60 + int cur_method[MAX_COMPONENTS];
1.61 +} my_idct_controller;
1.62 +
1.63 +typedef my_idct_controller * my_idct_ptr;
1.64 +
1.65 +
1.66 +/* Allocated multiplier tables: big enough for any supported variant */
1.67 +
1.68 +typedef union {
1.69 + ISLOW_MULT_TYPE islow_array[DCTSIZE2];
1.70 +#ifdef DCT_IFAST_SUPPORTED
1.71 + IFAST_MULT_TYPE ifast_array[DCTSIZE2];
1.72 +#endif
1.73 +#ifdef DCT_FLOAT_SUPPORTED
1.74 + FLOAT_MULT_TYPE float_array[DCTSIZE2];
1.75 +#endif
1.76 +} multiplier_table;
1.77 +
1.78 +
1.79 +/* The current scaled-IDCT routines require ISLOW-style multiplier tables,
1.80 + * so be sure to compile that code if either ISLOW or SCALING is requested.
1.81 + */
1.82 +#ifdef DCT_ISLOW_SUPPORTED
1.83 +#define PROVIDE_ISLOW_TABLES
1.84 +#else
1.85 +#ifdef IDCT_SCALING_SUPPORTED
1.86 +#define PROVIDE_ISLOW_TABLES
1.87 +#endif
1.88 +#endif
1.89 +
1.90 +
1.91 +/*
1.92 + * Prepare for an output pass.
1.93 + * Here we select the proper IDCT routine for each component and build
1.94 + * a matching multiplier table.
1.95 + */
1.96 +
1.97 +METHODDEF(void)
1.98 +start_pass (j_decompress_ptr cinfo)
1.99 +{
1.100 + my_idct_ptr idct = (my_idct_ptr) cinfo->idct;
1.101 + int ci, i;
1.102 + jpeg_component_info *compptr;
1.103 + int method = 0;
1.104 + inverse_DCT_method_ptr method_ptr = NULL;
1.105 + JQUANT_TBL * qtbl;
1.106 +
1.107 + for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
1.108 + ci++, compptr++) {
1.109 + /* Select the proper IDCT routine for this component's scaling */
1.110 + switch (compptr->_DCT_scaled_size) {
1.111 +#ifdef IDCT_SCALING_SUPPORTED
1.112 + case 1:
1.113 + method_ptr = jpeg_idct_1x1;
1.114 + method = JDCT_ISLOW; /* jidctred uses islow-style table */
1.115 + break;
1.116 + case 2:
1.117 + if (jsimd_can_idct_2x2())
1.118 + method_ptr = jsimd_idct_2x2;
1.119 + else
1.120 + method_ptr = jpeg_idct_2x2;
1.121 + method = JDCT_ISLOW; /* jidctred uses islow-style table */
1.122 + break;
1.123 + case 3:
1.124 + method_ptr = jpeg_idct_3x3;
1.125 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.126 + break;
1.127 + case 4:
1.128 + if (jsimd_can_idct_4x4())
1.129 + method_ptr = jsimd_idct_4x4;
1.130 + else
1.131 + method_ptr = jpeg_idct_4x4;
1.132 + method = JDCT_ISLOW; /* jidctred uses islow-style table */
1.133 + break;
1.134 + case 5:
1.135 + method_ptr = jpeg_idct_5x5;
1.136 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.137 + break;
1.138 + case 6:
1.139 + method_ptr = jpeg_idct_6x6;
1.140 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.141 + break;
1.142 + case 7:
1.143 + method_ptr = jpeg_idct_7x7;
1.144 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.145 + break;
1.146 +#endif
1.147 + case DCTSIZE:
1.148 + switch (cinfo->dct_method) {
1.149 +#ifdef DCT_ISLOW_SUPPORTED
1.150 + case JDCT_ISLOW:
1.151 + if (jsimd_can_idct_islow())
1.152 + method_ptr = jsimd_idct_islow;
1.153 + else
1.154 + method_ptr = jpeg_idct_islow;
1.155 + method = JDCT_ISLOW;
1.156 + break;
1.157 +#endif
1.158 +#ifdef DCT_IFAST_SUPPORTED
1.159 + case JDCT_IFAST:
1.160 + if (jsimd_can_idct_ifast())
1.161 + method_ptr = jsimd_idct_ifast;
1.162 + else
1.163 + method_ptr = jpeg_idct_ifast;
1.164 + method = JDCT_IFAST;
1.165 + break;
1.166 +#endif
1.167 +#ifdef DCT_FLOAT_SUPPORTED
1.168 + case JDCT_FLOAT:
1.169 + if (jsimd_can_idct_float())
1.170 + method_ptr = jsimd_idct_float;
1.171 + else
1.172 + method_ptr = jpeg_idct_float;
1.173 + method = JDCT_FLOAT;
1.174 + break;
1.175 +#endif
1.176 + default:
1.177 + ERREXIT(cinfo, JERR_NOT_COMPILED);
1.178 + break;
1.179 + }
1.180 + break;
1.181 + case 9:
1.182 + method_ptr = jpeg_idct_9x9;
1.183 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.184 + break;
1.185 + case 10:
1.186 + method_ptr = jpeg_idct_10x10;
1.187 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.188 + break;
1.189 + case 11:
1.190 + method_ptr = jpeg_idct_11x11;
1.191 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.192 + break;
1.193 + case 12:
1.194 + method_ptr = jpeg_idct_12x12;
1.195 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.196 + break;
1.197 + case 13:
1.198 + method_ptr = jpeg_idct_13x13;
1.199 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.200 + break;
1.201 + case 14:
1.202 + method_ptr = jpeg_idct_14x14;
1.203 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.204 + break;
1.205 + case 15:
1.206 + method_ptr = jpeg_idct_15x15;
1.207 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.208 + break;
1.209 + case 16:
1.210 + method_ptr = jpeg_idct_16x16;
1.211 + method = JDCT_ISLOW; /* jidctint uses islow-style table */
1.212 + break;
1.213 + default:
1.214 + ERREXIT1(cinfo, JERR_BAD_DCTSIZE, compptr->_DCT_scaled_size);
1.215 + break;
1.216 + }
1.217 + idct->pub.inverse_DCT[ci] = method_ptr;
1.218 + /* Create multiplier table from quant table.
1.219 + * However, we can skip this if the component is uninteresting
1.220 + * or if we already built the table. Also, if no quant table
1.221 + * has yet been saved for the component, we leave the
1.222 + * multiplier table all-zero; we'll be reading zeroes from the
1.223 + * coefficient controller's buffer anyway.
1.224 + */
1.225 + if (! compptr->component_needed || idct->cur_method[ci] == method)
1.226 + continue;
1.227 + qtbl = compptr->quant_table;
1.228 + if (qtbl == NULL) /* happens if no data yet for component */
1.229 + continue;
1.230 + idct->cur_method[ci] = method;
1.231 + switch (method) {
1.232 +#ifdef PROVIDE_ISLOW_TABLES
1.233 + case JDCT_ISLOW:
1.234 + {
1.235 + /* For LL&M IDCT method, multipliers are equal to raw quantization
1.236 + * coefficients, but are stored as ints to ensure access efficiency.
1.237 + */
1.238 + ISLOW_MULT_TYPE * ismtbl = (ISLOW_MULT_TYPE *) compptr->dct_table;
1.239 + for (i = 0; i < DCTSIZE2; i++) {
1.240 + ismtbl[i] = (ISLOW_MULT_TYPE) qtbl->quantval[i];
1.241 + }
1.242 + }
1.243 + break;
1.244 +#endif
1.245 +#ifdef DCT_IFAST_SUPPORTED
1.246 + case JDCT_IFAST:
1.247 + {
1.248 + /* For AA&N IDCT method, multipliers are equal to quantization
1.249 + * coefficients scaled by scalefactor[row]*scalefactor[col], where
1.250 + * scalefactor[0] = 1
1.251 + * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
1.252 + * For integer operation, the multiplier table is to be scaled by
1.253 + * IFAST_SCALE_BITS.
1.254 + */
1.255 + IFAST_MULT_TYPE * ifmtbl = (IFAST_MULT_TYPE *) compptr->dct_table;
1.256 +#define CONST_BITS 14
1.257 + static const INT16 aanscales[DCTSIZE2] = {
1.258 + /* precomputed values scaled up by 14 bits */
1.259 + 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520,
1.260 + 22725, 31521, 29692, 26722, 22725, 17855, 12299, 6270,
1.261 + 21407, 29692, 27969, 25172, 21407, 16819, 11585, 5906,
1.262 + 19266, 26722, 25172, 22654, 19266, 15137, 10426, 5315,
1.263 + 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520,
1.264 + 12873, 17855, 16819, 15137, 12873, 10114, 6967, 3552,
1.265 + 8867, 12299, 11585, 10426, 8867, 6967, 4799, 2446,
1.266 + 4520, 6270, 5906, 5315, 4520, 3552, 2446, 1247
1.267 + };
1.268 + SHIFT_TEMPS
1.269 +
1.270 + for (i = 0; i < DCTSIZE2; i++) {
1.271 + ifmtbl[i] = (IFAST_MULT_TYPE)
1.272 + DESCALE(MULTIPLY16V16((INT32) qtbl->quantval[i],
1.273 + (INT32) aanscales[i]),
1.274 + CONST_BITS-IFAST_SCALE_BITS);
1.275 + }
1.276 + }
1.277 + break;
1.278 +#endif
1.279 +#ifdef DCT_FLOAT_SUPPORTED
1.280 + case JDCT_FLOAT:
1.281 + {
1.282 + /* For float AA&N IDCT method, multipliers are equal to quantization
1.283 + * coefficients scaled by scalefactor[row]*scalefactor[col], where
1.284 + * scalefactor[0] = 1
1.285 + * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
1.286 + */
1.287 + FLOAT_MULT_TYPE * fmtbl = (FLOAT_MULT_TYPE *) compptr->dct_table;
1.288 + int row, col;
1.289 + static const double aanscalefactor[DCTSIZE] = {
1.290 + 1.0, 1.387039845, 1.306562965, 1.175875602,
1.291 + 1.0, 0.785694958, 0.541196100, 0.275899379
1.292 + };
1.293 +
1.294 + i = 0;
1.295 + for (row = 0; row < DCTSIZE; row++) {
1.296 + for (col = 0; col < DCTSIZE; col++) {
1.297 + fmtbl[i] = (FLOAT_MULT_TYPE)
1.298 + ((double) qtbl->quantval[i] *
1.299 + aanscalefactor[row] * aanscalefactor[col]);
1.300 + i++;
1.301 + }
1.302 + }
1.303 + }
1.304 + break;
1.305 +#endif
1.306 + default:
1.307 + ERREXIT(cinfo, JERR_NOT_COMPILED);
1.308 + break;
1.309 + }
1.310 + }
1.311 +}
1.312 +
1.313 +
1.314 +/*
1.315 + * Initialize IDCT manager.
1.316 + */
1.317 +
1.318 +GLOBAL(void)
1.319 +jinit_inverse_dct (j_decompress_ptr cinfo)
1.320 +{
1.321 + my_idct_ptr idct;
1.322 + int ci;
1.323 + jpeg_component_info *compptr;
1.324 +
1.325 + idct = (my_idct_ptr)
1.326 + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
1.327 + SIZEOF(my_idct_controller));
1.328 + cinfo->idct = (struct jpeg_inverse_dct *) idct;
1.329 + idct->pub.start_pass = start_pass;
1.330 +
1.331 + for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
1.332 + ci++, compptr++) {
1.333 + /* Allocate and pre-zero a multiplier table for each component */
1.334 + compptr->dct_table =
1.335 + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
1.336 + SIZEOF(multiplier_table));
1.337 + MEMZERO(compptr->dct_table, SIZEOF(multiplier_table));
1.338 + /* Mark multiplier table not yet set up for any method */
1.339 + idct->cur_method[ci] = -1;
1.340 + }
1.341 +}
