1/* 2 * jctrans.c 3 * 4 * Copyright (C) 1995-1998, 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 library routines for transcoding compression, 9 * that is, writing raw DCT coefficient arrays to an output JPEG file. 10 * The routines in jcapimin.c will also be needed by a transcoder. 11 */ 12 13#define JPEG_INTERNALS 14#include "jinclude.h" 15#include "jpeglib.h" 16 17 18/* Forward declarations */ 19LOCAL(void) transencode_master_selection 20 JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)); 21LOCAL(void) transencode_coef_controller 22 JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)); 23 24#if defined(__VISAGECPP__) 25/* Visual Age fixups for multiple declarations */ 26# define start_pass_coef start_pass_coef2 /* already in jccoeft.c */ 27# define compress_output compress_output2 /* already in jccoeft.c */ 28#endif 29 30 31/* 32 * Compression initialization for writing raw-coefficient data. 33 * Before calling this, all parameters and a data destination must be set up. 34 * Call jpeg_finish_compress() to actually write the data. 35 * 36 * The number of passed virtual arrays must match cinfo->num_components. 37 * Note that the virtual arrays need not be filled or even realized at 38 * the time write_coefficients is called; indeed, if the virtual arrays 39 * were requested from this compression object's memory manager, they 40 * typically will be realized during this routine and filled afterwards. 41 */ 42 43GLOBAL(void) 44jpeg_write_coefficients (j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays) 45{ 46 if (cinfo->global_state != CSTATE_START) 47 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 48 /* Mark all tables to be written */ 49 jpeg_suppress_tables(cinfo, FALSE); 50 /* (Re)initialize error mgr and destination modules */ 51 (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo); 52 (*cinfo->dest->init_destination) (cinfo); 53 /* Perform master selection of active modules */ 54 transencode_master_selection(cinfo, coef_arrays); 55 /* Wait for jpeg_finish_compress() call */ 56 cinfo->next_scanline = 0; /* so jpeg_write_marker works */ 57 cinfo->global_state = CSTATE_WRCOEFS; 58} 59 60 61/* 62 * Initialize the compression object with default parameters, 63 * then copy from the source object all parameters needed for lossless 64 * transcoding. Parameters that can be varied without loss (such as 65 * scan script and Huffman optimization) are left in their default states. 66 */ 67 68GLOBAL(void) 69jpeg_copy_critical_parameters (j_decompress_ptr srcinfo, 70 j_compress_ptr dstinfo) 71{ 72 JQUANT_TBL ** qtblptr; 73 jpeg_component_info *incomp, *outcomp; 74 JQUANT_TBL *c_quant, *slot_quant; 75 int tblno, ci, coefi; 76 77 /* Safety check to ensure start_compress not called yet. */ 78 if (dstinfo->global_state != CSTATE_START) 79 ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state); 80 /* Copy fundamental image dimensions */ 81 dstinfo->image_width = srcinfo->image_width; 82 dstinfo->image_height = srcinfo->image_height; 83 dstinfo->input_components = srcinfo->num_components; 84 dstinfo->in_color_space = srcinfo->jpeg_color_space; 85 /* Initialize all parameters to default values */ 86 jpeg_set_defaults(dstinfo); 87 /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB. 88 * Fix it to get the right header markers for the image colorspace. 89 */ 90 jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space); 91 dstinfo->data_precision = srcinfo->data_precision; 92 dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling; 93 /* Copy the source's quantization tables. */ 94 for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) { 95 if (srcinfo->quant_tbl_ptrs[tblno] != NULL) { 96 qtblptr = & dstinfo->quant_tbl_ptrs[tblno]; 97 if (*qtblptr == NULL) 98 *qtblptr = jpeg_alloc_quant_table((j_common_ptr) dstinfo); 99 MEMCOPY((*qtblptr)->quantval, 100 srcinfo->quant_tbl_ptrs[tblno]->quantval, 101 SIZEOF((*qtblptr)->quantval)); 102 (*qtblptr)->sent_table = FALSE; 103 } 104 } 105 /* Copy the source's per-component info. 106 * Note we assume jpeg_set_defaults has allocated the dest comp_info array. 107 */ 108 dstinfo->num_components = srcinfo->num_components; 109 if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS) 110 ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components, 111 MAX_COMPONENTS); 112 for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info; 113 ci < dstinfo->num_components; ci++, incomp++, outcomp++) { 114 outcomp->component_id = incomp->component_id; 115 outcomp->h_samp_factor = incomp->h_samp_factor; 116 outcomp->v_samp_factor = incomp->v_samp_factor; 117 outcomp->quant_tbl_no = incomp->quant_tbl_no; 118 /* Make sure saved quantization table for component matches the qtable 119 * slot. If not, the input file re-used this qtable slot. 120 * IJG encoder currently cannot duplicate this. 121 */ 122 tblno = outcomp->quant_tbl_no; 123 if (tblno < 0 || tblno >= NUM_QUANT_TBLS || 124 srcinfo->quant_tbl_ptrs[tblno] == NULL) 125 ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno); 126 slot_quant = srcinfo->quant_tbl_ptrs[tblno]; 127 c_quant = incomp->quant_table; 128 if (c_quant != NULL) { 129 for (coefi = 0; coefi < DCTSIZE2; coefi++) { 130 if (c_quant->quantval[coefi] != slot_quant->quantval[coefi]) 131 ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno); 132 } 133 } 134 /* Note: we do not copy the source's Huffman table assignments; 135 * instead we rely on jpeg_set_colorspace to have made a suitable choice. 136 */ 137 } 138 /* Also copy JFIF version and resolution information, if available. 139 * Strictly speaking this isn't "critical" info, but it's nearly 140 * always appropriate to copy it if available. In particular, 141 * if the application chooses to copy JFIF 1.02 extension markers from 142 * the source file, we need to copy the version to make sure we don't 143 * emit a file that has 1.02 extensions but a claimed version of 1.01. 144 * We will *not*, however, copy version info from mislabeled "2.01" files. 145 */ 146 if (srcinfo->saw_JFIF_marker) { 147 if (srcinfo->JFIF_major_version == 1) { 148 dstinfo->JFIF_major_version = srcinfo->JFIF_major_version; 149 dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version; 150 } 151 dstinfo->density_unit = srcinfo->density_unit; 152 dstinfo->X_density = srcinfo->X_density; 153 dstinfo->Y_density = srcinfo->Y_density; 154 } 155} 156 157 158/* 159 * Master selection of compression modules for transcoding. 160 * This substitutes for jcinit.c's initialization of the full compressor. 161 */ 162 163LOCAL(void) 164transencode_master_selection (j_compress_ptr cinfo, 165 jvirt_barray_ptr * coef_arrays) 166{ 167 /* Although we don't actually use input_components for transcoding, 168 * jcmaster.c's initial_setup will complain if input_components is 0. 169 */ 170 cinfo->input_components = 1; 171 /* Initialize master control (includes parameter checking/processing) */ 172 jinit_c_master_control(cinfo, TRUE /* transcode only */); 173 174 /* Entropy encoding: either Huffman or arithmetic coding. */ 175 if (cinfo->arith_code) { 176 ERREXIT(cinfo, JERR_ARITH_NOTIMPL); 177 } else { 178 if (cinfo->progressive_mode) { 179#ifdef C_PROGRESSIVE_SUPPORTED 180 jinit_phuff_encoder(cinfo); 181#else 182 ERREXIT(cinfo, JERR_NOT_COMPILED); 183#endif 184 } else 185 jinit_huff_encoder(cinfo); 186 } 187 188 /* We need a special coefficient buffer controller. */ 189 transencode_coef_controller(cinfo, coef_arrays); 190 191 jinit_marker_writer(cinfo); 192 193 /* We can now tell the memory manager to allocate virtual arrays. */ 194 (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo); 195 196 /* Write the datastream header (SOI, JFIF) immediately. 197 * Frame and scan headers are postponed till later. 198 * This lets application insert special markers after the SOI. 199 */ 200 (*cinfo->marker->write_file_header) (cinfo); 201} 202 203 204/* 205 * The rest of this file is a special implementation of the coefficient 206 * buffer controller. This is similar to jccoefct.c, but it handles only 207 * output from presupplied virtual arrays. Furthermore, we generate any 208 * dummy padding blocks on-the-fly rather than expecting them to be present 209 * in the arrays. 210 */ 211 212/* Private buffer controller object */ 213 214typedef struct { 215 struct jpeg_c_coef_controller pub; /* public fields */ 216 217 JDIMENSION iMCU_row_num; /* iMCU row # within image */ 218 JDIMENSION mcu_ctr; /* counts MCUs processed in current row */ 219 int MCU_vert_offset; /* counts MCU rows within iMCU row */ 220 int MCU_rows_per_iMCU_row; /* number of such rows needed */ 221 222 /* Virtual block array for each component. */ 223 jvirt_barray_ptr * whole_image; 224 225 /* Workspace for constructing dummy blocks at right/bottom edges. */ 226 JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU]; 227} my_coef_controller; 228 229typedef my_coef_controller * my_coef_ptr; 230 231 232LOCAL(void) 233start_iMCU_row (j_compress_ptr cinfo) 234/* Reset within-iMCU-row counters for a new row */ 235{ 236 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; 237 238 /* In an interleaved scan, an MCU row is the same as an iMCU row. 239 * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows. 240 * But at the bottom of the image, process only what's left. 241 */ 242 if (cinfo->comps_in_scan > 1) { 243 coef->MCU_rows_per_iMCU_row = 1; 244 } else { 245 if (coef->iMCU_row_num < (cinfo->total_iMCU_rows-1)) 246 coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor; 247 else 248 coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height; 249 } 250 251 coef->mcu_ctr = 0; 252 coef->MCU_vert_offset = 0; 253} 254 255/* 256 * Initialize for a processing pass. 257 */ 258 259METHODDEF(void) 260start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode) 261{ 262 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; 263 264 if (pass_mode != JBUF_CRANK_DEST) 265 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); 266 267 coef->iMCU_row_num = 0; 268 start_iMCU_row(cinfo); 269} 270 271 272/* 273 * Process some data. 274 * We process the equivalent of one fully interleaved MCU row ("iMCU" row) 275 * per call, ie, v_samp_factor block rows for each component in the scan. 276 * The data is obtained from the virtual arrays and fed to the entropy coder. 277 * Returns TRUE if the iMCU row is completed, FALSE if suspended. 278 * 279 * NB: input_buf is ignored; it is likely to be a NULL pointer. 280 */ 281 282METHODDEF(wxjpeg_boolean) 283compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf) 284{ 285 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; 286 JDIMENSION MCU_col_num; /* index of current MCU within row */ 287 JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1; 288 JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1; 289 int blkn, ci, xindex, yindex, yoffset, blockcnt; 290 JDIMENSION start_col; 291 JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN]; 292 JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU]; 293 JBLOCKROW buffer_ptr; 294 jpeg_component_info *compptr; 295 296 /* Align the virtual buffers for the components used in this scan. */ 297 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 298 compptr = cinfo->cur_comp_info[ci]; 299 buffer[ci] = (*cinfo->mem->access_virt_barray) 300 ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index], 301 coef->iMCU_row_num * compptr->v_samp_factor, 302 (JDIMENSION) compptr->v_samp_factor, FALSE); 303 } 304 305 /* Loop to process one whole iMCU row */ 306 for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row; 307 yoffset++) { 308 for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row; 309 MCU_col_num++) { 310 /* Construct list of pointers to DCT blocks belonging to this MCU */ 311 blkn = 0; /* index of current DCT block within MCU */ 312 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 313 compptr = cinfo->cur_comp_info[ci]; 314 start_col = MCU_col_num * compptr->MCU_width; 315 blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width 316 : compptr->last_col_width; 317 for (yindex = 0; yindex < compptr->MCU_height; yindex++) { 318 if (coef->iMCU_row_num < last_iMCU_row || 319 yindex+yoffset < compptr->last_row_height) { 320 /* Fill in pointers to real blocks in this row */ 321 buffer_ptr = buffer[ci][yindex+yoffset] + start_col; 322 for (xindex = 0; xindex < blockcnt; xindex++) 323 MCU_buffer[blkn++] = buffer_ptr++; 324 } else { 325 /* At bottom of image, need a whole row of dummy blocks */ 326 xindex = 0; 327 } 328 /* Fill in any dummy blocks needed in this row. 329 * Dummy blocks are filled in the same way as in jccoefct.c: 330 * all zeroes in the AC entries, DC entries equal to previous 331 * block's DC value. The init routine has already zeroed the 332 * AC entries, so we need only set the DC entries correctly. 333 */ 334 for (; xindex < compptr->MCU_width; xindex++) { 335 MCU_buffer[blkn] = coef->dummy_buffer[blkn]; 336 MCU_buffer[blkn][0][0] = MCU_buffer[blkn-1][0][0]; 337 blkn++; 338 } 339 } 340 } 341 /* Try to write the MCU. */ 342 if (! (*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) { 343 /* Suspension forced; update state counters and exit */ 344 coef->MCU_vert_offset = yoffset; 345 coef->mcu_ctr = MCU_col_num; 346 return FALSE; 347 } 348 } 349 /* Completed an MCU row, but perhaps not an iMCU row */ 350 coef->mcu_ctr = 0; 351 } 352 /* Completed the iMCU row, advance counters for next one */ 353 coef->iMCU_row_num++; 354 start_iMCU_row(cinfo); 355 return TRUE; 356} 357 358 359/* 360 * Initialize coefficient buffer controller. 361 * 362 * Each passed coefficient array must be the right size for that 363 * coefficient: width_in_blocks wide and height_in_blocks high, 364 * with unitheight at least v_samp_factor. 365 */ 366 367LOCAL(void) 368transencode_coef_controller (j_compress_ptr cinfo, 369 jvirt_barray_ptr * coef_arrays) 370{ 371 my_coef_ptr coef; 372 JBLOCKROW buffer; 373 int i; 374 375 coef = (my_coef_ptr) 376 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 377 SIZEOF(my_coef_controller)); 378 cinfo->coef = (struct jpeg_c_coef_controller *) coef; 379 coef->pub.start_pass = start_pass_coef; 380 coef->pub.compress_data = compress_output; 381 382 /* Save pointer to virtual arrays */ 383 coef->whole_image = coef_arrays; 384 385 /* Allocate and pre-zero space for dummy DCT blocks. */ 386 buffer = (JBLOCKROW) 387 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE, 388 C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK)); 389 jzero_far((void FAR *) buffer, C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK)); 390 for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) { 391 coef->dummy_buffer[i] = buffer + i; 392 } 393} 394 395#if defined(__VISAGECPP__) 396# ifdef start_pass_coef2 397# undef start_pass_coef2 398# endif 399# ifdef compress_output2 400# undef compress_output2 401# endif 402#endif 403