| 1 | /* |
| 2 | * jcparam.c |
| 3 | * |
| 4 | * Copyright (C) 1991-1998, Thomas G. Lane. |
| 5 | * This file is part of the Independent JPEG Group's software. |
| 6 | * For conditions of distribution and use, see the accompanying README file. |
| 7 | * |
| 8 | * This file contains optional default-setting code for the JPEG compressor. |
| 9 | * Applications do not have to use this file, but those that don't use it |
| 10 | * must know a lot more about the innards of the JPEG code. |
| 11 | */ |
| 12 | |
| 13 | #define JPEG_INTERNALS |
| 14 | #include "jinclude.h" |
| 15 | #include "jpeglib.h" |
| 16 | |
| 17 | |
| 18 | /* |
| 19 | * Quantization table setup routines |
| 20 | */ |
| 21 | |
| 22 | GLOBAL(void) |
| 23 | jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl, |
| 24 | const unsigned int *basic_table, |
| 25 | int scale_factor, boolean force_baseline) |
| 26 | /* Define a quantization table equal to the basic_table times |
| 27 | * a scale factor (given as a percentage). |
| 28 | * If force_baseline is TRUE, the computed quantization table entries |
| 29 | * are limited to 1..255 for JPEG baseline compatibility. |
| 30 | */ |
| 31 | { |
| 32 | JQUANT_TBL ** qtblptr; |
| 33 | int i; |
| 34 | long temp; |
| 35 | |
| 36 | /* Safety check to ensure start_compress not called yet. */ |
| 37 | if (cinfo->global_state != CSTATE_START) |
| 38 | ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
| 39 | |
| 40 | if (which_tbl < 0 || which_tbl >= NUM_QUANT_TBLS) |
| 41 | ERREXIT1(cinfo, JERR_DQT_INDEX, which_tbl); |
| 42 | |
| 43 | qtblptr = & cinfo->quant_tbl_ptrs[which_tbl]; |
| 44 | |
| 45 | if (*qtblptr == NULL) |
| 46 | *qtblptr = jpeg_alloc_quant_table((j_common_ptr) cinfo); |
| 47 | |
| 48 | for (i = 0; i < DCTSIZE2; i++) { |
| 49 | temp = ((long) basic_table[i] * scale_factor + 50L) / 100L; |
| 50 | /* limit the values to the valid range */ |
| 51 | if (temp <= 0L) temp = 1L; |
| 52 | if (temp > 32767L) temp = 32767L; /* max quantizer needed for 12 bits */ |
| 53 | if (force_baseline && temp > 255L) |
| 54 | temp = 255L; /* limit to baseline range if requested */ |
| 55 | (*qtblptr)->quantval[i] = (UINT16) temp; |
| 56 | } |
| 57 | |
| 58 | /* Initialize sent_table FALSE so table will be written to JPEG file. */ |
| 59 | (*qtblptr)->sent_table = FALSE; |
| 60 | } |
| 61 | |
| 62 | |
| 63 | GLOBAL(void) |
| 64 | jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor, |
| 65 | boolean force_baseline) |
| 66 | /* Set or change the 'quality' (quantization) setting, using default tables |
| 67 | * and a straight percentage-scaling quality scale. In most cases it's better |
| 68 | * to use jpeg_set_quality (below); this entry point is provided for |
| 69 | * applications that insist on a linear percentage scaling. |
| 70 | */ |
| 71 | { |
| 72 | /* These are the sample quantization tables given in JPEG spec section K.1. |
| 73 | * The spec says that the values given produce "good" quality, and |
| 74 | * when divided by 2, "very good" quality. |
| 75 | */ |
| 76 | static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = { |
| 77 | 16, 11, 10, 16, 24, 40, 51, 61, |
| 78 | 12, 12, 14, 19, 26, 58, 60, 55, |
| 79 | 14, 13, 16, 24, 40, 57, 69, 56, |
| 80 | 14, 17, 22, 29, 51, 87, 80, 62, |
| 81 | 18, 22, 37, 56, 68, 109, 103, 77, |
| 82 | 24, 35, 55, 64, 81, 104, 113, 92, |
| 83 | 49, 64, 78, 87, 103, 121, 120, 101, |
| 84 | 72, 92, 95, 98, 112, 100, 103, 99 |
| 85 | }; |
| 86 | static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = { |
| 87 | 17, 18, 24, 47, 99, 99, 99, 99, |
| 88 | 18, 21, 26, 66, 99, 99, 99, 99, |
| 89 | 24, 26, 56, 99, 99, 99, 99, 99, |
| 90 | 47, 66, 99, 99, 99, 99, 99, 99, |
| 91 | 99, 99, 99, 99, 99, 99, 99, 99, |
| 92 | 99, 99, 99, 99, 99, 99, 99, 99, |
| 93 | 99, 99, 99, 99, 99, 99, 99, 99, |
| 94 | 99, 99, 99, 99, 99, 99, 99, 99 |
| 95 | }; |
| 96 | |
| 97 | /* Set up two quantization tables using the specified scaling */ |
| 98 | jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl, |
| 99 | scale_factor, force_baseline); |
| 100 | jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl, |
| 101 | scale_factor, force_baseline); |
| 102 | } |
| 103 | |
| 104 | |
| 105 | GLOBAL(int) |
| 106 | jpeg_quality_scaling (int quality) |
| 107 | /* Convert a user-specified quality rating to a percentage scaling factor |
| 108 | * for an underlying quantization table, using our recommended scaling curve. |
| 109 | * The input 'quality' factor should be 0 (terrible) to 100 (very good). |
| 110 | */ |
| 111 | { |
| 112 | /* Safety limit on quality factor. Convert 0 to 1 to avoid zero divide. */ |
| 113 | if (quality <= 0) quality = 1; |
| 114 | if (quality > 100) quality = 100; |
| 115 | |
| 116 | /* The basic table is used as-is (scaling 100) for a quality of 50. |
| 117 | * Qualities 50..100 are converted to scaling percentage 200 - 2*Q; |
| 118 | * note that at Q=100 the scaling is 0, which will cause jpeg_add_quant_table |
| 119 | * to make all the table entries 1 (hence, minimum quantization loss). |
| 120 | * Qualities 1..50 are converted to scaling percentage 5000/Q. |
| 121 | */ |
| 122 | if (quality < 50) |
| 123 | quality = 5000 / quality; |
| 124 | else |
| 125 | quality = 200 - quality*2; |
| 126 | |
| 127 | return quality; |
| 128 | } |
| 129 | |
| 130 | |
| 131 | GLOBAL(void) |
| 132 | jpeg_set_quality (j_compress_ptr cinfo, int quality, boolean force_baseline) |
| 133 | /* Set or change the 'quality' (quantization) setting, using default tables. |
| 134 | * This is the standard quality-adjusting entry point for typical user |
| 135 | * interfaces; only those who want detailed control over quantization tables |
| 136 | * would use the preceding three routines directly. |
| 137 | */ |
| 138 | { |
| 139 | /* Convert user 0-100 rating to percentage scaling */ |
| 140 | quality = jpeg_quality_scaling(quality); |
| 141 | |
| 142 | /* Set up standard quality tables */ |
| 143 | jpeg_set_linear_quality(cinfo, quality, force_baseline); |
| 144 | } |
| 145 | |
| 146 | |
| 147 | /* |
| 148 | * Huffman table setup routines |
| 149 | */ |
| 150 | |
| 151 | LOCAL(void) |
| 152 | add_huff_table (j_compress_ptr cinfo, |
| 153 | JHUFF_TBL **htblptr, const UINT8 *bits, const UINT8 *val) |
| 154 | /* Define a Huffman table */ |
| 155 | { |
| 156 | int nsymbols, len; |
| 157 | |
| 158 | if (*htblptr == NULL) |
| 159 | *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo); |
| 160 | |
| 161 | /* Copy the number-of-symbols-of-each-code-length counts */ |
| 162 | MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits)); |
| 163 | |
| 164 | /* Validate the counts. We do this here mainly so we can copy the right |
| 165 | * number of symbols from the val[] array, without risking marching off |
| 166 | * the end of memory. jchuff.c will do a more thorough test later. |
| 167 | */ |
| 168 | nsymbols = 0; |
| 169 | for (len = 1; len <= 16; len++) |
| 170 | nsymbols += bits[len]; |
| 171 | if (nsymbols < 1 || nsymbols > 256) |
| 172 | ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
| 173 | |
| 174 | MEMCOPY((*htblptr)->huffval, val, nsymbols * SIZEOF(UINT8)); |
| 175 | |
| 176 | /* Initialize sent_table FALSE so table will be written to JPEG file. */ |
| 177 | (*htblptr)->sent_table = FALSE; |
| 178 | } |
| 179 | |
| 180 | |
| 181 | LOCAL(void) |
| 182 | std_huff_tables (j_compress_ptr cinfo) |
| 183 | /* Set up the standard Huffman tables (cf. JPEG standard section K.3) */ |
| 184 | /* IMPORTANT: these are only valid for 8-bit data precision! */ |
| 185 | { |
| 186 | static const UINT8 bits_dc_luminance[17] = |
| 187 | { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 }; |
| 188 | static const UINT8 val_dc_luminance[] = |
| 189 | { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 }; |
| 190 | |
| 191 | static const UINT8 bits_dc_chrominance[17] = |
| 192 | { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 }; |
| 193 | static const UINT8 val_dc_chrominance[] = |
| 194 | { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 }; |
| 195 | |
| 196 | static const UINT8 bits_ac_luminance[17] = |
| 197 | { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d }; |
| 198 | static const UINT8 val_ac_luminance[] = |
| 199 | { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, |
| 200 | 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, |
| 201 | 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08, |
| 202 | 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0, |
| 203 | 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16, |
| 204 | 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28, |
| 205 | 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, |
| 206 | 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, |
| 207 | 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, |
| 208 | 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, |
| 209 | 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, |
| 210 | 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, |
| 211 | 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, |
| 212 | 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, |
| 213 | 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, |
| 214 | 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, |
| 215 | 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, |
| 216 | 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2, |
| 217 | 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, |
| 218 | 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, |
| 219 | 0xf9, 0xfa }; |
| 220 | |
| 221 | static const UINT8 bits_ac_chrominance[17] = |
| 222 | { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 }; |
| 223 | static const UINT8 val_ac_chrominance[] = |
| 224 | { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, |
| 225 | 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, |
| 226 | 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, |
| 227 | 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, |
| 228 | 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, |
| 229 | 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, |
| 230 | 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, |
| 231 | 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, |
| 232 | 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, |
| 233 | 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, |
| 234 | 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, |
| 235 | 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, |
| 236 | 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, |
| 237 | 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, |
| 238 | 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, |
| 239 | 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, |
| 240 | 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, |
| 241 | 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, |
| 242 | 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, |
| 243 | 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, |
| 244 | 0xf9, 0xfa }; |
| 245 | |
| 246 | add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[0], |
| 247 | bits_dc_luminance, val_dc_luminance); |
| 248 | add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[0], |
| 249 | bits_ac_luminance, val_ac_luminance); |
| 250 | add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[1], |
| 251 | bits_dc_chrominance, val_dc_chrominance); |
| 252 | add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[1], |
| 253 | bits_ac_chrominance, val_ac_chrominance); |
| 254 | } |
| 255 | |
| 256 | |
| 257 | /* |
| 258 | * Default parameter setup for compression. |
| 259 | * |
| 260 | * Applications that don't choose to use this routine must do their |
| 261 | * own setup of all these parameters. Alternately, you can call this |
| 262 | * to establish defaults and then alter parameters selectively. This |
| 263 | * is the recommended approach since, if we add any new parameters, |
| 264 | * your code will still work (they'll be set to reasonable defaults). |
| 265 | */ |
| 266 | |
| 267 | GLOBAL(void) |
| 268 | jpeg_set_defaults (j_compress_ptr cinfo) |
| 269 | { |
| 270 | int i; |
| 271 | |
| 272 | /* Safety check to ensure start_compress not called yet. */ |
| 273 | if (cinfo->global_state != CSTATE_START) |
| 274 | ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
| 275 | |
| 276 | /* Allocate comp_info array large enough for maximum component count. |
| 277 | * Array is made permanent in case application wants to compress |
| 278 | * multiple images at same param settings. |
| 279 | */ |
| 280 | if (cinfo->comp_info == NULL) |
| 281 | cinfo->comp_info = (jpeg_component_info *) |
| 282 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, |
| 283 | MAX_COMPONENTS * SIZEOF(jpeg_component_info)); |
| 284 | |
| 285 | /* Initialize everything not dependent on the color space */ |
| 286 | |
| 287 | cinfo->data_precision = BITS_IN_JSAMPLE; |
| 288 | /* Set up two quantization tables using default quality of 75 */ |
| 289 | jpeg_set_quality(cinfo, 75, TRUE); |
| 290 | /* Set up two Huffman tables */ |
| 291 | std_huff_tables(cinfo); |
| 292 | |
| 293 | /* Initialize default arithmetic coding conditioning */ |
| 294 | for (i = 0; i < NUM_ARITH_TBLS; i++) { |
| 295 | cinfo->arith_dc_L[i] = 0; |
| 296 | cinfo->arith_dc_U[i] = 1; |
| 297 | cinfo->arith_ac_K[i] = 5; |
| 298 | } |
| 299 | |
| 300 | /* Default is no multiple-scan output */ |
| 301 | cinfo->scan_info = NULL; |
| 302 | cinfo->num_scans = 0; |
| 303 | |
| 304 | /* Expect normal source image, not raw downsampled data */ |
| 305 | cinfo->raw_data_in = FALSE; |
| 306 | |
| 307 | /* Use Huffman coding, not arithmetic coding, by default */ |
| 308 | cinfo->arith_code = FALSE; |
| 309 | |
| 310 | /* By default, don't do extra passes to optimize entropy coding */ |
| 311 | cinfo->optimize_coding = FALSE; |
| 312 | /* The standard Huffman tables are only valid for 8-bit data precision. |
| 313 | * If the precision is higher, force optimization on so that usable |
| 314 | * tables will be computed. This test can be removed if default tables |
| 315 | * are supplied that are valid for the desired precision. |
| 316 | */ |
| 317 | if (cinfo->data_precision > 8) |
| 318 | cinfo->optimize_coding = TRUE; |
| 319 | |
| 320 | /* By default, use the simpler non-cosited sampling alignment */ |
| 321 | cinfo->CCIR601_sampling = FALSE; |
| 322 | |
| 323 | /* No input smoothing */ |
| 324 | cinfo->smoothing_factor = 0; |
| 325 | |
| 326 | /* DCT algorithm preference */ |
| 327 | cinfo->dct_method = JDCT_DEFAULT; |
| 328 | |
| 329 | /* No restart markers */ |
| 330 | cinfo->restart_interval = 0; |
| 331 | cinfo->restart_in_rows = 0; |
| 332 | |
| 333 | /* Fill in default JFIF marker parameters. Note that whether the marker |
| 334 | * will actually be written is determined by jpeg_set_colorspace. |
| 335 | * |
| 336 | * By default, the library emits JFIF version code 1.01. |
| 337 | * An application that wants to emit JFIF 1.02 extension markers should set |
| 338 | * JFIF_minor_version to 2. We could probably get away with just defaulting |
| 339 | * to 1.02, but there may still be some decoders in use that will complain |
| 340 | * about that; saying 1.01 should minimize compatibility problems. |
| 341 | */ |
| 342 | cinfo->JFIF_major_version = 1; /* Default JFIF version = 1.01 */ |
| 343 | cinfo->JFIF_minor_version = 1; |
| 344 | cinfo->density_unit = 0; /* Pixel size is unknown by default */ |
| 345 | cinfo->X_density = 1; /* Pixel aspect ratio is square by default */ |
| 346 | cinfo->Y_density = 1; |
| 347 | |
| 348 | /* Choose JPEG colorspace based on input space, set defaults accordingly */ |
| 349 | |
| 350 | jpeg_default_colorspace(cinfo); |
| 351 | } |
| 352 | |
| 353 | |
| 354 | /* |
| 355 | * Select an appropriate JPEG colorspace for in_color_space. |
| 356 | */ |
| 357 | |
| 358 | GLOBAL(void) |
| 359 | jpeg_default_colorspace (j_compress_ptr cinfo) |
| 360 | { |
| 361 | switch (cinfo->in_color_space) { |
| 362 | case JCS_GRAYSCALE: |
| 363 | jpeg_set_colorspace(cinfo, JCS_GRAYSCALE); |
| 364 | break; |
| 365 | case JCS_RGB: |
| 366 | jpeg_set_colorspace(cinfo, JCS_YCbCr); |
| 367 | break; |
| 368 | case JCS_YCbCr: |
| 369 | jpeg_set_colorspace(cinfo, JCS_YCbCr); |
| 370 | break; |
| 371 | case JCS_CMYK: |
| 372 | jpeg_set_colorspace(cinfo, JCS_CMYK); /* By default, no translation */ |
| 373 | break; |
| 374 | case JCS_YCCK: |
| 375 | jpeg_set_colorspace(cinfo, JCS_YCCK); |
| 376 | break; |
| 377 | case JCS_UNKNOWN: |
| 378 | jpeg_set_colorspace(cinfo, JCS_UNKNOWN); |
| 379 | break; |
| 380 | default: |
| 381 | ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE); |
| 382 | } |
| 383 | } |
| 384 | |
| 385 | |
| 386 | /* |
| 387 | * Set the JPEG colorspace, and choose colorspace-dependent default values. |
| 388 | */ |
| 389 | |
| 390 | GLOBAL(void) |
| 391 | jpeg_set_colorspace (j_compress_ptr cinfo, J_COLOR_SPACE colorspace) |
| 392 | { |
| 393 | jpeg_component_info * compptr; |
| 394 | int ci; |
| 395 | |
| 396 | #define SET_COMP(index,id,hsamp,vsamp,quant,dctbl,actbl) \ |
| 397 | (compptr = &cinfo->comp_info[index], \ |
| 398 | compptr->component_id = (id), \ |
| 399 | compptr->h_samp_factor = (hsamp), \ |
| 400 | compptr->v_samp_factor = (vsamp), \ |
| 401 | compptr->quant_tbl_no = (quant), \ |
| 402 | compptr->dc_tbl_no = (dctbl), \ |
| 403 | compptr->ac_tbl_no = (actbl) ) |
| 404 | |
| 405 | /* Safety check to ensure start_compress not called yet. */ |
| 406 | if (cinfo->global_state != CSTATE_START) |
| 407 | ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
| 408 | |
| 409 | /* For all colorspaces, we use Q and Huff tables 0 for luminance components, |
| 410 | * tables 1 for chrominance components. |
| 411 | */ |
| 412 | |
| 413 | cinfo->jpeg_color_space = colorspace; |
| 414 | |
| 415 | cinfo->write_JFIF_header = FALSE; /* No marker for non-JFIF colorspaces */ |
| 416 | cinfo->write_Adobe_marker = FALSE; /* write no Adobe marker by default */ |
| 417 | |
| 418 | switch (colorspace) { |
| 419 | case JCS_GRAYSCALE: |
| 420 | cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */ |
| 421 | cinfo->num_components = 1; |
| 422 | /* JFIF specifies component ID 1 */ |
| 423 | SET_COMP(0, 1, 1,1, 0, 0,0); |
| 424 | break; |
| 425 | case JCS_RGB: |
| 426 | cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag RGB */ |
| 427 | cinfo->num_components = 3; |
| 428 | SET_COMP(0, 0x52 /* 'R' */, 1,1, 0, 0,0); |
| 429 | SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0); |
| 430 | SET_COMP(2, 0x42 /* 'B' */, 1,1, 0, 0,0); |
| 431 | break; |
| 432 | case JCS_YCbCr: |
| 433 | cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */ |
| 434 | cinfo->num_components = 3; |
| 435 | /* JFIF specifies component IDs 1,2,3 */ |
| 436 | /* We default to 2x2 subsamples of chrominance */ |
| 437 | SET_COMP(0, 1, 2,2, 0, 0,0); |
| 438 | SET_COMP(1, 2, 1,1, 1, 1,1); |
| 439 | SET_COMP(2, 3, 1,1, 1, 1,1); |
| 440 | break; |
| 441 | case JCS_CMYK: |
| 442 | cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag CMYK */ |
| 443 | cinfo->num_components = 4; |
| 444 | SET_COMP(0, 0x43 /* 'C' */, 1,1, 0, 0,0); |
| 445 | SET_COMP(1, 0x4D /* 'M' */, 1,1, 0, 0,0); |
| 446 | SET_COMP(2, 0x59 /* 'Y' */, 1,1, 0, 0,0); |
| 447 | SET_COMP(3, 0x4B /* 'K' */, 1,1, 0, 0,0); |
| 448 | break; |
| 449 | case JCS_YCCK: |
| 450 | cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag YCCK */ |
| 451 | cinfo->num_components = 4; |
| 452 | SET_COMP(0, 1, 2,2, 0, 0,0); |
| 453 | SET_COMP(1, 2, 1,1, 1, 1,1); |
| 454 | SET_COMP(2, 3, 1,1, 1, 1,1); |
| 455 | SET_COMP(3, 4, 2,2, 0, 0,0); |
| 456 | break; |
| 457 | case JCS_UNKNOWN: |
| 458 | cinfo->num_components = cinfo->input_components; |
| 459 | if (cinfo->num_components < 1 || cinfo->num_components > MAX_COMPONENTS) |
| 460 | ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, |
| 461 | MAX_COMPONENTS); |
| 462 | for (ci = 0; ci < cinfo->num_components; ci++) { |
| 463 | SET_COMP(ci, ci, 1,1, 0, 0,0); |
| 464 | } |
| 465 | break; |
| 466 | default: |
| 467 | ERREXIT(cinfo, JERR_BAD_J_COLORSPACE); |
| 468 | } |
| 469 | } |
| 470 | |
| 471 | |
| 472 | #ifdef C_PROGRESSIVE_SUPPORTED |
| 473 | |
| 474 | LOCAL(jpeg_scan_info *) |
| 475 | fill_a_scan (jpeg_scan_info * scanptr, int ci, |
| 476 | int Ss, int Se, int Ah, int Al) |
| 477 | /* Support routine: generate one scan for specified component */ |
| 478 | { |
| 479 | scanptr->comps_in_scan = 1; |
| 480 | scanptr->component_index[0] = ci; |
| 481 | scanptr->Ss = Ss; |
| 482 | scanptr->Se = Se; |
| 483 | scanptr->Ah = Ah; |
| 484 | scanptr->Al = Al; |
| 485 | scanptr++; |
| 486 | return scanptr; |
| 487 | } |
| 488 | |
| 489 | LOCAL(jpeg_scan_info *) |
| 490 | fill_scans (jpeg_scan_info * scanptr, int ncomps, |
| 491 | int Ss, int Se, int Ah, int Al) |
| 492 | /* Support routine: generate one scan for each component */ |
| 493 | { |
| 494 | int ci; |
| 495 | |
| 496 | for (ci = 0; ci < ncomps; ci++) { |
| 497 | scanptr->comps_in_scan = 1; |
| 498 | scanptr->component_index[0] = ci; |
| 499 | scanptr->Ss = Ss; |
| 500 | scanptr->Se = Se; |
| 501 | scanptr->Ah = Ah; |
| 502 | scanptr->Al = Al; |
| 503 | scanptr++; |
| 504 | } |
| 505 | return scanptr; |
| 506 | } |
| 507 | |
| 508 | LOCAL(jpeg_scan_info *) |
| 509 | fill_dc_scans (jpeg_scan_info * scanptr, int ncomps, int Ah, int Al) |
| 510 | /* Support routine: generate interleaved DC scan if possible, else N scans */ |
| 511 | { |
| 512 | int ci; |
| 513 | |
| 514 | if (ncomps <= MAX_COMPS_IN_SCAN) { |
| 515 | /* Single interleaved DC scan */ |
| 516 | scanptr->comps_in_scan = ncomps; |
| 517 | for (ci = 0; ci < ncomps; ci++) |
| 518 | scanptr->component_index[ci] = ci; |
| 519 | scanptr->Ss = scanptr->Se = 0; |
| 520 | scanptr->Ah = Ah; |
| 521 | scanptr->Al = Al; |
| 522 | scanptr++; |
| 523 | } else { |
| 524 | /* Noninterleaved DC scan for each component */ |
| 525 | scanptr = fill_scans(scanptr, ncomps, 0, 0, Ah, Al); |
| 526 | } |
| 527 | return scanptr; |
| 528 | } |
| 529 | |
| 530 | |
| 531 | /* |
| 532 | * Create a recommended progressive-JPEG script. |
| 533 | * cinfo->num_components and cinfo->jpeg_color_space must be correct. |
| 534 | */ |
| 535 | |
| 536 | GLOBAL(void) |
| 537 | jpeg_simple_progression (j_compress_ptr cinfo) |
| 538 | { |
| 539 | int ncomps = cinfo->num_components; |
| 540 | int nscans; |
| 541 | jpeg_scan_info * scanptr; |
| 542 | |
| 543 | /* Safety check to ensure start_compress not called yet. */ |
| 544 | if (cinfo->global_state != CSTATE_START) |
| 545 | ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
| 546 | |
| 547 | /* Figure space needed for script. Calculation must match code below! */ |
| 548 | if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) { |
| 549 | /* Custom script for YCbCr color images. */ |
| 550 | nscans = 10; |
| 551 | } else { |
| 552 | /* All-purpose script for other color spaces. */ |
| 553 | if (ncomps > MAX_COMPS_IN_SCAN) |
| 554 | nscans = 6 * ncomps; /* 2 DC + 4 AC scans per component */ |
| 555 | else |
| 556 | nscans = 2 + 4 * ncomps; /* 2 DC scans; 4 AC scans per component */ |
| 557 | } |
| 558 | |
| 559 | /* Allocate space for script. |
| 560 | * We need to put it in the permanent pool in case the application performs |
| 561 | * multiple compressions without changing the settings. To avoid a memory |
| 562 | * leak if jpeg_simple_progression is called repeatedly for the same JPEG |
| 563 | * object, we try to re-use previously allocated space, and we allocate |
| 564 | * enough space to handle YCbCr even if initially asked for grayscale. |
| 565 | */ |
| 566 | if (cinfo->script_space == NULL || cinfo->script_space_size < nscans) { |
| 567 | cinfo->script_space_size = MAX(nscans, 10); |
| 568 | cinfo->script_space = (jpeg_scan_info *) |
| 569 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, |
| 570 | cinfo->script_space_size * SIZEOF(jpeg_scan_info)); |
| 571 | } |
| 572 | scanptr = cinfo->script_space; |
| 573 | cinfo->scan_info = scanptr; |
| 574 | cinfo->num_scans = nscans; |
| 575 | |
| 576 | if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) { |
| 577 | /* Custom script for YCbCr color images. */ |
| 578 | /* Initial DC scan */ |
| 579 | scanptr = fill_dc_scans(scanptr, ncomps, 0, 1); |
| 580 | /* Initial AC scan: get some luma data out in a hurry */ |
| 581 | scanptr = fill_a_scan(scanptr, 0, 1, 5, 0, 2); |
| 582 | /* Chroma data is too small to be worth expending many scans on */ |
| 583 | scanptr = fill_a_scan(scanptr, 2, 1, 63, 0, 1); |
| 584 | scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 1); |
| 585 | /* Complete spectral selection for luma AC */ |
| 586 | scanptr = fill_a_scan(scanptr, 0, 6, 63, 0, 2); |
| 587 | /* Refine next bit of luma AC */ |
| 588 | scanptr = fill_a_scan(scanptr, 0, 1, 63, 2, 1); |
| 589 | /* Finish DC successive approximation */ |
| 590 | scanptr = fill_dc_scans(scanptr, ncomps, 1, 0); |
| 591 | /* Finish AC successive approximation */ |
| 592 | scanptr = fill_a_scan(scanptr, 2, 1, 63, 1, 0); |
| 593 | scanptr = fill_a_scan(scanptr, 1, 1, 63, 1, 0); |
| 594 | /* Luma bottom bit comes last since it's usually largest scan */ |
| 595 | scanptr = fill_a_scan(scanptr, 0, 1, 63, 1, 0); |
| 596 | } else { |
| 597 | /* All-purpose script for other color spaces. */ |
| 598 | /* Successive approximation first pass */ |
| 599 | scanptr = fill_dc_scans(scanptr, ncomps, 0, 1); |
| 600 | scanptr = fill_scans(scanptr, ncomps, 1, 5, 0, 2); |
| 601 | scanptr = fill_scans(scanptr, ncomps, 6, 63, 0, 2); |
| 602 | /* Successive approximation second pass */ |
| 603 | scanptr = fill_scans(scanptr, ncomps, 1, 63, 2, 1); |
| 604 | /* Successive approximation final pass */ |
| 605 | scanptr = fill_dc_scans(scanptr, ncomps, 1, 0); |
| 606 | scanptr = fill_scans(scanptr, ncomps, 1, 63, 1, 0); |
| 607 | } |
| 608 | } |
| 609 | |
| 610 | #endif /* C_PROGRESSIVE_SUPPORTED */ |