vrshoot
diff libs/libjpeg/jcparam.c @ 0:b2f14e535253
initial commit
author | John Tsiombikas <nuclear@member.fsf.org> |
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date | Sat, 01 Feb 2014 19:58:19 +0200 |
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1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/libs/libjpeg/jcparam.c Sat Feb 01 19:58:19 2014 +0200 1.3 @@ -0,0 +1,610 @@ 1.4 +/* 1.5 + * jcparam.c 1.6 + * 1.7 + * Copyright (C) 1991-1998, Thomas G. Lane. 1.8 + * This file is part of the Independent JPEG Group's software. 1.9 + * For conditions of distribution and use, see the accompanying README file. 1.10 + * 1.11 + * This file contains optional default-setting code for the JPEG compressor. 1.12 + * Applications do not have to use this file, but those that don't use it 1.13 + * must know a lot more about the innards of the JPEG code. 1.14 + */ 1.15 + 1.16 +#define JPEG_INTERNALS 1.17 +#include "jinclude.h" 1.18 +#include "jpeglib.h" 1.19 + 1.20 + 1.21 +/* 1.22 + * Quantization table setup routines 1.23 + */ 1.24 + 1.25 +GLOBAL(void) 1.26 +jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl, 1.27 + const unsigned int *basic_table, 1.28 + int scale_factor, boolean force_baseline) 1.29 +/* Define a quantization table equal to the basic_table times 1.30 + * a scale factor (given as a percentage). 1.31 + * If force_baseline is TRUE, the computed quantization table entries 1.32 + * are limited to 1..255 for JPEG baseline compatibility. 1.33 + */ 1.34 +{ 1.35 + JQUANT_TBL ** qtblptr; 1.36 + int i; 1.37 + long temp; 1.38 + 1.39 + /* Safety check to ensure start_compress not called yet. */ 1.40 + if (cinfo->global_state != CSTATE_START) 1.41 + ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 1.42 + 1.43 + if (which_tbl < 0 || which_tbl >= NUM_QUANT_TBLS) 1.44 + ERREXIT1(cinfo, JERR_DQT_INDEX, which_tbl); 1.45 + 1.46 + qtblptr = & cinfo->quant_tbl_ptrs[which_tbl]; 1.47 + 1.48 + if (*qtblptr == NULL) 1.49 + *qtblptr = jpeg_alloc_quant_table((j_common_ptr) cinfo); 1.50 + 1.51 + for (i = 0; i < DCTSIZE2; i++) { 1.52 + temp = ((long) basic_table[i] * scale_factor + 50L) / 100L; 1.53 + /* limit the values to the valid range */ 1.54 + if (temp <= 0L) temp = 1L; 1.55 + if (temp > 32767L) temp = 32767L; /* max quantizer needed for 12 bits */ 1.56 + if (force_baseline && temp > 255L) 1.57 + temp = 255L; /* limit to baseline range if requested */ 1.58 + (*qtblptr)->quantval[i] = (UINT16) temp; 1.59 + } 1.60 + 1.61 + /* Initialize sent_table FALSE so table will be written to JPEG file. */ 1.62 + (*qtblptr)->sent_table = FALSE; 1.63 +} 1.64 + 1.65 + 1.66 +GLOBAL(void) 1.67 +jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor, 1.68 + boolean force_baseline) 1.69 +/* Set or change the 'quality' (quantization) setting, using default tables 1.70 + * and a straight percentage-scaling quality scale. In most cases it's better 1.71 + * to use jpeg_set_quality (below); this entry point is provided for 1.72 + * applications that insist on a linear percentage scaling. 1.73 + */ 1.74 +{ 1.75 + /* These are the sample quantization tables given in JPEG spec section K.1. 1.76 + * The spec says that the values given produce "good" quality, and 1.77 + * when divided by 2, "very good" quality. 1.78 + */ 1.79 + static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = { 1.80 + 16, 11, 10, 16, 24, 40, 51, 61, 1.81 + 12, 12, 14, 19, 26, 58, 60, 55, 1.82 + 14, 13, 16, 24, 40, 57, 69, 56, 1.83 + 14, 17, 22, 29, 51, 87, 80, 62, 1.84 + 18, 22, 37, 56, 68, 109, 103, 77, 1.85 + 24, 35, 55, 64, 81, 104, 113, 92, 1.86 + 49, 64, 78, 87, 103, 121, 120, 101, 1.87 + 72, 92, 95, 98, 112, 100, 103, 99 1.88 + }; 1.89 + static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = { 1.90 + 17, 18, 24, 47, 99, 99, 99, 99, 1.91 + 18, 21, 26, 66, 99, 99, 99, 99, 1.92 + 24, 26, 56, 99, 99, 99, 99, 99, 1.93 + 47, 66, 99, 99, 99, 99, 99, 99, 1.94 + 99, 99, 99, 99, 99, 99, 99, 99, 1.95 + 99, 99, 99, 99, 99, 99, 99, 99, 1.96 + 99, 99, 99, 99, 99, 99, 99, 99, 1.97 + 99, 99, 99, 99, 99, 99, 99, 99 1.98 + }; 1.99 + 1.100 + /* Set up two quantization tables using the specified scaling */ 1.101 + jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl, 1.102 + scale_factor, force_baseline); 1.103 + jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl, 1.104 + scale_factor, force_baseline); 1.105 +} 1.106 + 1.107 + 1.108 +GLOBAL(int) 1.109 +jpeg_quality_scaling (int quality) 1.110 +/* Convert a user-specified quality rating to a percentage scaling factor 1.111 + * for an underlying quantization table, using our recommended scaling curve. 1.112 + * The input 'quality' factor should be 0 (terrible) to 100 (very good). 1.113 + */ 1.114 +{ 1.115 + /* Safety limit on quality factor. Convert 0 to 1 to avoid zero divide. */ 1.116 + if (quality <= 0) quality = 1; 1.117 + if (quality > 100) quality = 100; 1.118 + 1.119 + /* The basic table is used as-is (scaling 100) for a quality of 50. 1.120 + * Qualities 50..100 are converted to scaling percentage 200 - 2*Q; 1.121 + * note that at Q=100 the scaling is 0, which will cause jpeg_add_quant_table 1.122 + * to make all the table entries 1 (hence, minimum quantization loss). 1.123 + * Qualities 1..50 are converted to scaling percentage 5000/Q. 1.124 + */ 1.125 + if (quality < 50) 1.126 + quality = 5000 / quality; 1.127 + else 1.128 + quality = 200 - quality*2; 1.129 + 1.130 + return quality; 1.131 +} 1.132 + 1.133 + 1.134 +GLOBAL(void) 1.135 +jpeg_set_quality (j_compress_ptr cinfo, int quality, boolean force_baseline) 1.136 +/* Set or change the 'quality' (quantization) setting, using default tables. 1.137 + * This is the standard quality-adjusting entry point for typical user 1.138 + * interfaces; only those who want detailed control over quantization tables 1.139 + * would use the preceding three routines directly. 1.140 + */ 1.141 +{ 1.142 + /* Convert user 0-100 rating to percentage scaling */ 1.143 + quality = jpeg_quality_scaling(quality); 1.144 + 1.145 + /* Set up standard quality tables */ 1.146 + jpeg_set_linear_quality(cinfo, quality, force_baseline); 1.147 +} 1.148 + 1.149 + 1.150 +/* 1.151 + * Huffman table setup routines 1.152 + */ 1.153 + 1.154 +LOCAL(void) 1.155 +add_huff_table (j_compress_ptr cinfo, 1.156 + JHUFF_TBL **htblptr, const UINT8 *bits, const UINT8 *val) 1.157 +/* Define a Huffman table */ 1.158 +{ 1.159 + int nsymbols, len; 1.160 + 1.161 + if (*htblptr == NULL) 1.162 + *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo); 1.163 + 1.164 + /* Copy the number-of-symbols-of-each-code-length counts */ 1.165 + MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits)); 1.166 + 1.167 + /* Validate the counts. We do this here mainly so we can copy the right 1.168 + * number of symbols from the val[] array, without risking marching off 1.169 + * the end of memory. jchuff.c will do a more thorough test later. 1.170 + */ 1.171 + nsymbols = 0; 1.172 + for (len = 1; len <= 16; len++) 1.173 + nsymbols += bits[len]; 1.174 + if (nsymbols < 1 || nsymbols > 256) 1.175 + ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 1.176 + 1.177 + MEMCOPY((*htblptr)->huffval, val, nsymbols * SIZEOF(UINT8)); 1.178 + 1.179 + /* Initialize sent_table FALSE so table will be written to JPEG file. */ 1.180 + (*htblptr)->sent_table = FALSE; 1.181 +} 1.182 + 1.183 + 1.184 +LOCAL(void) 1.185 +std_huff_tables (j_compress_ptr cinfo) 1.186 +/* Set up the standard Huffman tables (cf. JPEG standard section K.3) */ 1.187 +/* IMPORTANT: these are only valid for 8-bit data precision! */ 1.188 +{ 1.189 + static const UINT8 bits_dc_luminance[17] = 1.190 + { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 }; 1.191 + static const UINT8 val_dc_luminance[] = 1.192 + { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 }; 1.193 + 1.194 + static const UINT8 bits_dc_chrominance[17] = 1.195 + { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 }; 1.196 + static const UINT8 val_dc_chrominance[] = 1.197 + { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 }; 1.198 + 1.199 + static const UINT8 bits_ac_luminance[17] = 1.200 + { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d }; 1.201 + static const UINT8 val_ac_luminance[] = 1.202 + { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, 1.203 + 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, 1.204 + 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08, 1.205 + 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0, 1.206 + 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16, 1.207 + 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28, 1.208 + 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 1.209 + 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 1.210 + 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 1.211 + 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 1.212 + 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 1.213 + 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 1.214 + 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 1.215 + 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 1.216 + 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 1.217 + 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, 1.218 + 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, 1.219 + 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2, 1.220 + 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 1.221 + 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 1.222 + 0xf9, 0xfa }; 1.223 + 1.224 + static const UINT8 bits_ac_chrominance[17] = 1.225 + { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 }; 1.226 + static const UINT8 val_ac_chrominance[] = 1.227 + { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, 1.228 + 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, 1.229 + 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, 1.230 + 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, 1.231 + 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, 1.232 + 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, 1.233 + 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, 1.234 + 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 1.235 + 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 1.236 + 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 1.237 + 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 1.238 + 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 1.239 + 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 1.240 + 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 1.241 + 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 1.242 + 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 1.243 + 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 1.244 + 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 1.245 + 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 1.246 + 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 1.247 + 0xf9, 0xfa }; 1.248 + 1.249 + add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[0], 1.250 + bits_dc_luminance, val_dc_luminance); 1.251 + add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[0], 1.252 + bits_ac_luminance, val_ac_luminance); 1.253 + add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[1], 1.254 + bits_dc_chrominance, val_dc_chrominance); 1.255 + add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[1], 1.256 + bits_ac_chrominance, val_ac_chrominance); 1.257 +} 1.258 + 1.259 + 1.260 +/* 1.261 + * Default parameter setup for compression. 1.262 + * 1.263 + * Applications that don't choose to use this routine must do their 1.264 + * own setup of all these parameters. Alternately, you can call this 1.265 + * to establish defaults and then alter parameters selectively. This 1.266 + * is the recommended approach since, if we add any new parameters, 1.267 + * your code will still work (they'll be set to reasonable defaults). 1.268 + */ 1.269 + 1.270 +GLOBAL(void) 1.271 +jpeg_set_defaults (j_compress_ptr cinfo) 1.272 +{ 1.273 + int i; 1.274 + 1.275 + /* Safety check to ensure start_compress not called yet. */ 1.276 + if (cinfo->global_state != CSTATE_START) 1.277 + ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 1.278 + 1.279 + /* Allocate comp_info array large enough for maximum component count. 1.280 + * Array is made permanent in case application wants to compress 1.281 + * multiple images at same param settings. 1.282 + */ 1.283 + if (cinfo->comp_info == NULL) 1.284 + cinfo->comp_info = (jpeg_component_info *) 1.285 + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, 1.286 + MAX_COMPONENTS * SIZEOF(jpeg_component_info)); 1.287 + 1.288 + /* Initialize everything not dependent on the color space */ 1.289 + 1.290 + cinfo->data_precision = BITS_IN_JSAMPLE; 1.291 + /* Set up two quantization tables using default quality of 75 */ 1.292 + jpeg_set_quality(cinfo, 75, TRUE); 1.293 + /* Set up two Huffman tables */ 1.294 + std_huff_tables(cinfo); 1.295 + 1.296 + /* Initialize default arithmetic coding conditioning */ 1.297 + for (i = 0; i < NUM_ARITH_TBLS; i++) { 1.298 + cinfo->arith_dc_L[i] = 0; 1.299 + cinfo->arith_dc_U[i] = 1; 1.300 + cinfo->arith_ac_K[i] = 5; 1.301 + } 1.302 + 1.303 + /* Default is no multiple-scan output */ 1.304 + cinfo->scan_info = NULL; 1.305 + cinfo->num_scans = 0; 1.306 + 1.307 + /* Expect normal source image, not raw downsampled data */ 1.308 + cinfo->raw_data_in = FALSE; 1.309 + 1.310 + /* Use Huffman coding, not arithmetic coding, by default */ 1.311 + cinfo->arith_code = FALSE; 1.312 + 1.313 + /* By default, don't do extra passes to optimize entropy coding */ 1.314 + cinfo->optimize_coding = FALSE; 1.315 + /* The standard Huffman tables are only valid for 8-bit data precision. 1.316 + * If the precision is higher, force optimization on so that usable 1.317 + * tables will be computed. This test can be removed if default tables 1.318 + * are supplied that are valid for the desired precision. 1.319 + */ 1.320 + if (cinfo->data_precision > 8) 1.321 + cinfo->optimize_coding = TRUE; 1.322 + 1.323 + /* By default, use the simpler non-cosited sampling alignment */ 1.324 + cinfo->CCIR601_sampling = FALSE; 1.325 + 1.326 + /* No input smoothing */ 1.327 + cinfo->smoothing_factor = 0; 1.328 + 1.329 + /* DCT algorithm preference */ 1.330 + cinfo->dct_method = JDCT_DEFAULT; 1.331 + 1.332 + /* No restart markers */ 1.333 + cinfo->restart_interval = 0; 1.334 + cinfo->restart_in_rows = 0; 1.335 + 1.336 + /* Fill in default JFIF marker parameters. Note that whether the marker 1.337 + * will actually be written is determined by jpeg_set_colorspace. 1.338 + * 1.339 + * By default, the library emits JFIF version code 1.01. 1.340 + * An application that wants to emit JFIF 1.02 extension markers should set 1.341 + * JFIF_minor_version to 2. We could probably get away with just defaulting 1.342 + * to 1.02, but there may still be some decoders in use that will complain 1.343 + * about that; saying 1.01 should minimize compatibility problems. 1.344 + */ 1.345 + cinfo->JFIF_major_version = 1; /* Default JFIF version = 1.01 */ 1.346 + cinfo->JFIF_minor_version = 1; 1.347 + cinfo->density_unit = 0; /* Pixel size is unknown by default */ 1.348 + cinfo->X_density = 1; /* Pixel aspect ratio is square by default */ 1.349 + cinfo->Y_density = 1; 1.350 + 1.351 + /* Choose JPEG colorspace based on input space, set defaults accordingly */ 1.352 + 1.353 + jpeg_default_colorspace(cinfo); 1.354 +} 1.355 + 1.356 + 1.357 +/* 1.358 + * Select an appropriate JPEG colorspace for in_color_space. 1.359 + */ 1.360 + 1.361 +GLOBAL(void) 1.362 +jpeg_default_colorspace (j_compress_ptr cinfo) 1.363 +{ 1.364 + switch (cinfo->in_color_space) { 1.365 + case JCS_GRAYSCALE: 1.366 + jpeg_set_colorspace(cinfo, JCS_GRAYSCALE); 1.367 + break; 1.368 + case JCS_RGB: 1.369 + jpeg_set_colorspace(cinfo, JCS_YCbCr); 1.370 + break; 1.371 + case JCS_YCbCr: 1.372 + jpeg_set_colorspace(cinfo, JCS_YCbCr); 1.373 + break; 1.374 + case JCS_CMYK: 1.375 + jpeg_set_colorspace(cinfo, JCS_CMYK); /* By default, no translation */ 1.376 + break; 1.377 + case JCS_YCCK: 1.378 + jpeg_set_colorspace(cinfo, JCS_YCCK); 1.379 + break; 1.380 + case JCS_UNKNOWN: 1.381 + jpeg_set_colorspace(cinfo, JCS_UNKNOWN); 1.382 + break; 1.383 + default: 1.384 + ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE); 1.385 + } 1.386 +} 1.387 + 1.388 + 1.389 +/* 1.390 + * Set the JPEG colorspace, and choose colorspace-dependent default values. 1.391 + */ 1.392 + 1.393 +GLOBAL(void) 1.394 +jpeg_set_colorspace (j_compress_ptr cinfo, J_COLOR_SPACE colorspace) 1.395 +{ 1.396 + jpeg_component_info * compptr; 1.397 + int ci; 1.398 + 1.399 +#define SET_COMP(index,id,hsamp,vsamp,quant,dctbl,actbl) \ 1.400 + (compptr = &cinfo->comp_info[index], \ 1.401 + compptr->component_id = (id), \ 1.402 + compptr->h_samp_factor = (hsamp), \ 1.403 + compptr->v_samp_factor = (vsamp), \ 1.404 + compptr->quant_tbl_no = (quant), \ 1.405 + compptr->dc_tbl_no = (dctbl), \ 1.406 + compptr->ac_tbl_no = (actbl) ) 1.407 + 1.408 + /* Safety check to ensure start_compress not called yet. */ 1.409 + if (cinfo->global_state != CSTATE_START) 1.410 + ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 1.411 + 1.412 + /* For all colorspaces, we use Q and Huff tables 0 for luminance components, 1.413 + * tables 1 for chrominance components. 1.414 + */ 1.415 + 1.416 + cinfo->jpeg_color_space = colorspace; 1.417 + 1.418 + cinfo->write_JFIF_header = FALSE; /* No marker for non-JFIF colorspaces */ 1.419 + cinfo->write_Adobe_marker = FALSE; /* write no Adobe marker by default */ 1.420 + 1.421 + switch (colorspace) { 1.422 + case JCS_GRAYSCALE: 1.423 + cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */ 1.424 + cinfo->num_components = 1; 1.425 + /* JFIF specifies component ID 1 */ 1.426 + SET_COMP(0, 1, 1,1, 0, 0,0); 1.427 + break; 1.428 + case JCS_RGB: 1.429 + cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag RGB */ 1.430 + cinfo->num_components = 3; 1.431 + SET_COMP(0, 0x52 /* 'R' */, 1,1, 0, 0,0); 1.432 + SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0); 1.433 + SET_COMP(2, 0x42 /* 'B' */, 1,1, 0, 0,0); 1.434 + break; 1.435 + case JCS_YCbCr: 1.436 + cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */ 1.437 + cinfo->num_components = 3; 1.438 + /* JFIF specifies component IDs 1,2,3 */ 1.439 + /* We default to 2x2 subsamples of chrominance */ 1.440 + SET_COMP(0, 1, 2,2, 0, 0,0); 1.441 + SET_COMP(1, 2, 1,1, 1, 1,1); 1.442 + SET_COMP(2, 3, 1,1, 1, 1,1); 1.443 + break; 1.444 + case JCS_CMYK: 1.445 + cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag CMYK */ 1.446 + cinfo->num_components = 4; 1.447 + SET_COMP(0, 0x43 /* 'C' */, 1,1, 0, 0,0); 1.448 + SET_COMP(1, 0x4D /* 'M' */, 1,1, 0, 0,0); 1.449 + SET_COMP(2, 0x59 /* 'Y' */, 1,1, 0, 0,0); 1.450 + SET_COMP(3, 0x4B /* 'K' */, 1,1, 0, 0,0); 1.451 + break; 1.452 + case JCS_YCCK: 1.453 + cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag YCCK */ 1.454 + cinfo->num_components = 4; 1.455 + SET_COMP(0, 1, 2,2, 0, 0,0); 1.456 + SET_COMP(1, 2, 1,1, 1, 1,1); 1.457 + SET_COMP(2, 3, 1,1, 1, 1,1); 1.458 + SET_COMP(3, 4, 2,2, 0, 0,0); 1.459 + break; 1.460 + case JCS_UNKNOWN: 1.461 + cinfo->num_components = cinfo->input_components; 1.462 + if (cinfo->num_components < 1 || cinfo->num_components > MAX_COMPONENTS) 1.463 + ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, 1.464 + MAX_COMPONENTS); 1.465 + for (ci = 0; ci < cinfo->num_components; ci++) { 1.466 + SET_COMP(ci, ci, 1,1, 0, 0,0); 1.467 + } 1.468 + break; 1.469 + default: 1.470 + ERREXIT(cinfo, JERR_BAD_J_COLORSPACE); 1.471 + } 1.472 +} 1.473 + 1.474 + 1.475 +#ifdef C_PROGRESSIVE_SUPPORTED 1.476 + 1.477 +LOCAL(jpeg_scan_info *) 1.478 +fill_a_scan (jpeg_scan_info * scanptr, int ci, 1.479 + int Ss, int Se, int Ah, int Al) 1.480 +/* Support routine: generate one scan for specified component */ 1.481 +{ 1.482 + scanptr->comps_in_scan = 1; 1.483 + scanptr->component_index[0] = ci; 1.484 + scanptr->Ss = Ss; 1.485 + scanptr->Se = Se; 1.486 + scanptr->Ah = Ah; 1.487 + scanptr->Al = Al; 1.488 + scanptr++; 1.489 + return scanptr; 1.490 +} 1.491 + 1.492 +LOCAL(jpeg_scan_info *) 1.493 +fill_scans (jpeg_scan_info * scanptr, int ncomps, 1.494 + int Ss, int Se, int Ah, int Al) 1.495 +/* Support routine: generate one scan for each component */ 1.496 +{ 1.497 + int ci; 1.498 + 1.499 + for (ci = 0; ci < ncomps; ci++) { 1.500 + scanptr->comps_in_scan = 1; 1.501 + scanptr->component_index[0] = ci; 1.502 + scanptr->Ss = Ss; 1.503 + scanptr->Se = Se; 1.504 + scanptr->Ah = Ah; 1.505 + scanptr->Al = Al; 1.506 + scanptr++; 1.507 + } 1.508 + return scanptr; 1.509 +} 1.510 + 1.511 +LOCAL(jpeg_scan_info *) 1.512 +fill_dc_scans (jpeg_scan_info * scanptr, int ncomps, int Ah, int Al) 1.513 +/* Support routine: generate interleaved DC scan if possible, else N scans */ 1.514 +{ 1.515 + int ci; 1.516 + 1.517 + if (ncomps <= MAX_COMPS_IN_SCAN) { 1.518 + /* Single interleaved DC scan */ 1.519 + scanptr->comps_in_scan = ncomps; 1.520 + for (ci = 0; ci < ncomps; ci++) 1.521 + scanptr->component_index[ci] = ci; 1.522 + scanptr->Ss = scanptr->Se = 0; 1.523 + scanptr->Ah = Ah; 1.524 + scanptr->Al = Al; 1.525 + scanptr++; 1.526 + } else { 1.527 + /* Noninterleaved DC scan for each component */ 1.528 + scanptr = fill_scans(scanptr, ncomps, 0, 0, Ah, Al); 1.529 + } 1.530 + return scanptr; 1.531 +} 1.532 + 1.533 + 1.534 +/* 1.535 + * Create a recommended progressive-JPEG script. 1.536 + * cinfo->num_components and cinfo->jpeg_color_space must be correct. 1.537 + */ 1.538 + 1.539 +GLOBAL(void) 1.540 +jpeg_simple_progression (j_compress_ptr cinfo) 1.541 +{ 1.542 + int ncomps = cinfo->num_components; 1.543 + int nscans; 1.544 + jpeg_scan_info * scanptr; 1.545 + 1.546 + /* Safety check to ensure start_compress not called yet. */ 1.547 + if (cinfo->global_state != CSTATE_START) 1.548 + ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 1.549 + 1.550 + /* Figure space needed for script. Calculation must match code below! */ 1.551 + if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) { 1.552 + /* Custom script for YCbCr color images. */ 1.553 + nscans = 10; 1.554 + } else { 1.555 + /* All-purpose script for other color spaces. */ 1.556 + if (ncomps > MAX_COMPS_IN_SCAN) 1.557 + nscans = 6 * ncomps; /* 2 DC + 4 AC scans per component */ 1.558 + else 1.559 + nscans = 2 + 4 * ncomps; /* 2 DC scans; 4 AC scans per component */ 1.560 + } 1.561 + 1.562 + /* Allocate space for script. 1.563 + * We need to put it in the permanent pool in case the application performs 1.564 + * multiple compressions without changing the settings. To avoid a memory 1.565 + * leak if jpeg_simple_progression is called repeatedly for the same JPEG 1.566 + * object, we try to re-use previously allocated space, and we allocate 1.567 + * enough space to handle YCbCr even if initially asked for grayscale. 1.568 + */ 1.569 + if (cinfo->script_space == NULL || cinfo->script_space_size < nscans) { 1.570 + cinfo->script_space_size = MAX(nscans, 10); 1.571 + cinfo->script_space = (jpeg_scan_info *) 1.572 + (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, 1.573 + cinfo->script_space_size * SIZEOF(jpeg_scan_info)); 1.574 + } 1.575 + scanptr = cinfo->script_space; 1.576 + cinfo->scan_info = scanptr; 1.577 + cinfo->num_scans = nscans; 1.578 + 1.579 + if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) { 1.580 + /* Custom script for YCbCr color images. */ 1.581 + /* Initial DC scan */ 1.582 + scanptr = fill_dc_scans(scanptr, ncomps, 0, 1); 1.583 + /* Initial AC scan: get some luma data out in a hurry */ 1.584 + scanptr = fill_a_scan(scanptr, 0, 1, 5, 0, 2); 1.585 + /* Chroma data is too small to be worth expending many scans on */ 1.586 + scanptr = fill_a_scan(scanptr, 2, 1, 63, 0, 1); 1.587 + scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 1); 1.588 + /* Complete spectral selection for luma AC */ 1.589 + scanptr = fill_a_scan(scanptr, 0, 6, 63, 0, 2); 1.590 + /* Refine next bit of luma AC */ 1.591 + scanptr = fill_a_scan(scanptr, 0, 1, 63, 2, 1); 1.592 + /* Finish DC successive approximation */ 1.593 + scanptr = fill_dc_scans(scanptr, ncomps, 1, 0); 1.594 + /* Finish AC successive approximation */ 1.595 + scanptr = fill_a_scan(scanptr, 2, 1, 63, 1, 0); 1.596 + scanptr = fill_a_scan(scanptr, 1, 1, 63, 1, 0); 1.597 + /* Luma bottom bit comes last since it's usually largest scan */ 1.598 + scanptr = fill_a_scan(scanptr, 0, 1, 63, 1, 0); 1.599 + } else { 1.600 + /* All-purpose script for other color spaces. */ 1.601 + /* Successive approximation first pass */ 1.602 + scanptr = fill_dc_scans(scanptr, ncomps, 0, 1); 1.603 + scanptr = fill_scans(scanptr, ncomps, 1, 5, 0, 2); 1.604 + scanptr = fill_scans(scanptr, ncomps, 6, 63, 0, 2); 1.605 + /* Successive approximation second pass */ 1.606 + scanptr = fill_scans(scanptr, ncomps, 1, 63, 2, 1); 1.607 + /* Successive approximation final pass */ 1.608 + scanptr = fill_dc_scans(scanptr, ncomps, 1, 0); 1.609 + scanptr = fill_scans(scanptr, ncomps, 1, 63, 1, 0); 1.610 + } 1.611 +} 1.612 + 1.613 +#endif /* C_PROGRESSIVE_SUPPORTED */