1 #if !defined(_FX_JPEG_TURBO_) 2 /* 3 * jctrans.c 4 * 5 * Copyright (C) 1995-1998, Thomas G. Lane. 6 * This file is part of the Independent JPEG Group's software. 7 * For conditions of distribution and use, see the accompanying README file. 8 * 9 * This file contains library routines for transcoding compression, 10 * that is, writing raw DCT coefficient arrays to an output JPEG file. 11 * The routines in jcapimin.c will also be needed by a transcoder. 12 */ 13 14 #define JPEG_INTERNALS 15 #include "jinclude.h" 16 #include "jpeglib.h" 17 18 19 /* Forward declarations */ 20 LOCAL(void) transencode_master_selection 21 JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)); 22 LOCAL(void) transencode_coef_controller 23 JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)); 24 25 26 /* 27 * Compression initialization for writing raw-coefficient data. 28 * Before calling this, all parameters and a data destination must be set up. 29 * Call jpeg_finish_compress() to actually write the data. 30 * 31 * The number of passed virtual arrays must match cinfo->num_components. 32 * Note that the virtual arrays need not be filled or even realized at 33 * the time write_coefficients is called; indeed, if the virtual arrays 34 * were requested from this compression object's memory manager, they 35 * typically will be realized during this routine and filled afterwards. 36 */ 37 38 GLOBAL(void) 39 jpeg_write_coefficients (j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays) 40 { 41 if (cinfo->global_state != CSTATE_START) 42 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 43 /* Mark all tables to be written */ 44 jpeg_suppress_tables(cinfo, FALSE); 45 /* (Re)initialize error mgr and destination modules */ 46 (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo); 47 (*cinfo->dest->init_destination) (cinfo); 48 /* Perform master selection of active modules */ 49 transencode_master_selection(cinfo, coef_arrays); 50 /* Wait for jpeg_finish_compress() call */ 51 cinfo->next_scanline = 0; /* so jpeg_write_marker works */ 52 cinfo->global_state = CSTATE_WRCOEFS; 53 } 54 55 56 /* 57 * Initialize the compression object with default parameters, 58 * then copy from the source object all parameters needed for lossless 59 * transcoding. Parameters that can be varied without loss (such as 60 * scan script and Huffman optimization) are left in their default states. 61 */ 62 63 GLOBAL(void) 64 jpeg_copy_critical_parameters (j_decompress_ptr srcinfo, 65 j_compress_ptr dstinfo) 66 { 67 JQUANT_TBL ** qtblptr; 68 jpeg_component_info *incomp, *outcomp; 69 JQUANT_TBL *c_quant, *slot_quant; 70 int tblno, ci, coefi; 71 72 /* Safety check to ensure start_compress not called yet. */ 73 if (dstinfo->global_state != CSTATE_START) 74 ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state); 75 /* Copy fundamental image dimensions */ 76 dstinfo->image_width = srcinfo->image_width; 77 dstinfo->image_height = srcinfo->image_height; 78 dstinfo->input_components = srcinfo->num_components; 79 dstinfo->in_color_space = srcinfo->jpeg_color_space; 80 /* Initialize all parameters to default values */ 81 jpeg_set_defaults(dstinfo); 82 /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB. 83 * Fix it to get the right header markers for the image colorspace. 84 */ 85 jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space); 86 dstinfo->data_precision = srcinfo->data_precision; 87 dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling; 88 /* Copy the source's quantization tables. */ 89 for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) { 90 if (srcinfo->quant_tbl_ptrs[tblno] != NULL) { 91 qtblptr = & dstinfo->quant_tbl_ptrs[tblno]; 92 if (*qtblptr == NULL) 93 *qtblptr = jpeg_alloc_quant_table((j_common_ptr) dstinfo); 94 MEMCOPY((*qtblptr)->quantval, 95 srcinfo->quant_tbl_ptrs[tblno]->quantval, 96 SIZEOF((*qtblptr)->quantval)); 97 (*qtblptr)->sent_table = FALSE; 98 } 99 } 100 /* Copy the source's per-component info. 101 * Note we assume jpeg_set_defaults has allocated the dest comp_info array. 102 */ 103 dstinfo->num_components = srcinfo->num_components; 104 if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS) 105 ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components, 106 MAX_COMPONENTS); 107 for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info; 108 ci < dstinfo->num_components; ci++, incomp++, outcomp++) { 109 outcomp->component_id = incomp->component_id; 110 outcomp->h_samp_factor = incomp->h_samp_factor; 111 outcomp->v_samp_factor = incomp->v_samp_factor; 112 outcomp->quant_tbl_no = incomp->quant_tbl_no; 113 /* Make sure saved quantization table for component matches the qtable 114 * slot. If not, the input file re-used this qtable slot. 115 * IJG encoder currently cannot duplicate this. 116 */ 117 tblno = outcomp->quant_tbl_no; 118 if (tblno < 0 || tblno >= NUM_QUANT_TBLS || 119 srcinfo->quant_tbl_ptrs[tblno] == NULL) 120 ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno); 121 slot_quant = srcinfo->quant_tbl_ptrs[tblno]; 122 c_quant = incomp->quant_table; 123 if (c_quant != NULL) { 124 for (coefi = 0; coefi < DCTSIZE2; coefi++) { 125 if (c_quant->quantval[coefi] != slot_quant->quantval[coefi]) 126 ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno); 127 } 128 } 129 /* Note: we do not copy the source's Huffman table assignments; 130 * instead we rely on jpeg_set_colorspace to have made a suitable choice. 131 */ 132 } 133 /* Also copy JFIF version and resolution information, if available. 134 * Strictly speaking this isn't "critical" info, but it's nearly 135 * always appropriate to copy it if available. In particular, 136 * if the application chooses to copy JFIF 1.02 extension markers from 137 * the source file, we need to copy the version to make sure we don't 138 * emit a file that has 1.02 extensions but a claimed version of 1.01. 139 * We will *not*, however, copy version info from mislabeled "2.01" files. 140 */ 141 if (srcinfo->saw_JFIF_marker) { 142 if (srcinfo->JFIF_major_version == 1) { 143 dstinfo->JFIF_major_version = srcinfo->JFIF_major_version; 144 dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version; 145 } 146 dstinfo->density_unit = srcinfo->density_unit; 147 dstinfo->X_density = srcinfo->X_density; 148 dstinfo->Y_density = srcinfo->Y_density; 149 } 150 } 151 152 153 /* 154 * Master selection of compression modules for transcoding. 155 * This substitutes for jcinit.c's initialization of the full compressor. 156 */ 157 158 LOCAL(void) 159 transencode_master_selection (j_compress_ptr cinfo, 160 jvirt_barray_ptr * coef_arrays) 161 { 162 /* Although we don't actually use input_components for transcoding, 163 * jcmaster.c's initial_setup will complain if input_components is 0. 164 */ 165 cinfo->input_components = 1; 166 /* Initialize master control (includes parameter checking/processing) */ 167 jinit_c_master_control(cinfo, TRUE /* transcode only */); 168 169 /* Entropy encoding: either Huffman or arithmetic coding. */ 170 if (cinfo->arith_code) { 171 ERREXIT(cinfo, JERR_ARITH_NOTIMPL); 172 } else { 173 if (cinfo->progressive_mode) { 174 #ifdef C_PROGRESSIVE_SUPPORTED 175 jinit_phuff_encoder(cinfo); 176 #else 177 ERREXIT(cinfo, JERR_NOT_COMPILED); 178 #endif 179 } else 180 jinit_huff_encoder(cinfo); 181 } 182 183 /* We need a special coefficient buffer controller. */ 184 transencode_coef_controller(cinfo, coef_arrays); 185 186 jinit_marker_writer(cinfo); 187 188 /* We can now tell the memory manager to allocate virtual arrays. */ 189 (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo); 190 191 /* Write the datastream header (SOI, JFIF) immediately. 192 * Frame and scan headers are postponed till later. 193 * This lets application insert special markers after the SOI. 194 */ 195 (*cinfo->marker->write_file_header) (cinfo); 196 } 197 198 199 /* 200 * The rest of this file is a special implementation of the coefficient 201 * buffer controller. This is similar to jccoefct.c, but it handles only 202 * output from presupplied virtual arrays. Furthermore, we generate any 203 * dummy padding blocks on-the-fly rather than expecting them to be present 204 * in the arrays. 205 */ 206 207 /* Private buffer controller object */ 208 209 typedef struct { 210 struct jpeg_c_coef_controller pub; /* public fields */ 211 212 JDIMENSION iMCU_row_num; /* iMCU row # within image */ 213 JDIMENSION mcu_ctr; /* counts MCUs processed in current row */ 214 int MCU_vert_offset; /* counts MCU rows within iMCU row */ 215 int MCU_rows_per_iMCU_row; /* number of such rows needed */ 216 217 /* Virtual block array for each component. */ 218 jvirt_barray_ptr * whole_image; 219 220 /* Workspace for constructing dummy blocks at right/bottom edges. */ 221 JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU]; 222 } my_coef_controller; 223 224 typedef my_coef_controller * my_coef_ptr; 225 226 227 LOCAL(void) 228 start_iMCU_row (j_compress_ptr cinfo) 229 /* Reset within-iMCU-row counters for a new row */ 230 { 231 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; 232 233 /* In an interleaved scan, an MCU row is the same as an iMCU row. 234 * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows. 235 * But at the bottom of the image, process only what's left. 236 */ 237 if (cinfo->comps_in_scan > 1) { 238 coef->MCU_rows_per_iMCU_row = 1; 239 } else { 240 if (coef->iMCU_row_num < (cinfo->total_iMCU_rows-1)) 241 coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor; 242 else 243 coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height; 244 } 245 246 coef->mcu_ctr = 0; 247 coef->MCU_vert_offset = 0; 248 } 249 250 251 /* 252 * Initialize for a processing pass. 253 */ 254 255 METHODDEF(void) 256 start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode) 257 { 258 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; 259 260 if (pass_mode != JBUF_CRANK_DEST) 261 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); 262 263 coef->iMCU_row_num = 0; 264 start_iMCU_row(cinfo); 265 } 266 267 268 /* 269 * Process some data. 270 * We process the equivalent of one fully interleaved MCU row ("iMCU" row) 271 * per call, ie, v_samp_factor block rows for each component in the scan. 272 * The data is obtained from the virtual arrays and fed to the entropy coder. 273 * Returns TRUE if the iMCU row is completed, FALSE if suspended. 274 * 275 * NB: input_buf is ignored; it is likely to be a NULL pointer. 276 */ 277 278 METHODDEF(boolean) 279 compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf) 280 { 281 my_coef_ptr coef = (my_coef_ptr) cinfo->coef; 282 JDIMENSION MCU_col_num; /* index of current MCU within row */ 283 JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1; 284 JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1; 285 int blkn, ci, xindex, yindex, yoffset, blockcnt; 286 JDIMENSION start_col; 287 JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN]; 288 JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU]; 289 JBLOCKROW buffer_ptr; 290 jpeg_component_info *compptr; 291 292 /* Align the virtual buffers for the components used in this scan. */ 293 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 294 compptr = cinfo->cur_comp_info[ci]; 295 buffer[ci] = (*cinfo->mem->access_virt_barray) 296 ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index], 297 coef->iMCU_row_num * compptr->v_samp_factor, 298 (JDIMENSION) compptr->v_samp_factor, FALSE); 299 } 300 301 /* Loop to process one whole iMCU row */ 302 for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row; 303 yoffset++) { 304 for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row; 305 MCU_col_num++) { 306 /* Construct list of pointers to DCT blocks belonging to this MCU */ 307 blkn = 0; /* index of current DCT block within MCU */ 308 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 309 compptr = cinfo->cur_comp_info[ci]; 310 start_col = MCU_col_num * compptr->MCU_width; 311 blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width 312 : compptr->last_col_width; 313 for (yindex = 0; yindex < compptr->MCU_height; yindex++) { 314 if (coef->iMCU_row_num < last_iMCU_row || 315 yindex+yoffset < compptr->last_row_height) { 316 /* Fill in pointers to real blocks in this row */ 317 buffer_ptr = buffer[ci][yindex+yoffset] + start_col; 318 for (xindex = 0; xindex < blockcnt; xindex++) 319 MCU_buffer[blkn++] = buffer_ptr++; 320 } else { 321 /* At bottom of image, need a whole row of dummy blocks */ 322 xindex = 0; 323 } 324 /* Fill in any dummy blocks needed in this row. 325 * Dummy blocks are filled in the same way as in jccoefct.c: 326 * all zeroes in the AC entries, DC entries equal to previous 327 * block's DC value. The init routine has already zeroed the 328 * AC entries, so we need only set the DC entries correctly. 329 */ 330 for (; xindex < compptr->MCU_width; xindex++) { 331 MCU_buffer[blkn] = coef->dummy_buffer[blkn]; 332 MCU_buffer[blkn][0][0] = MCU_buffer[blkn-1][0][0]; 333 blkn++; 334 } 335 } 336 } 337 /* Try to write the MCU. */ 338 if (! (*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) { 339 /* Suspension forced; update state counters and exit */ 340 coef->MCU_vert_offset = yoffset; 341 coef->mcu_ctr = MCU_col_num; 342 return FALSE; 343 } 344 } 345 /* Completed an MCU row, but perhaps not an iMCU row */ 346 coef->mcu_ctr = 0; 347 } 348 /* Completed the iMCU row, advance counters for next one */ 349 coef->iMCU_row_num++; 350 start_iMCU_row(cinfo); 351 return TRUE; 352 } 353 354 355 /* 356 * Initialize coefficient buffer controller. 357 * 358 * Each passed coefficient array must be the right size for that 359 * coefficient: width_in_blocks wide and height_in_blocks high, 360 * with unitheight at least v_samp_factor. 361 */ 362 363 LOCAL(void) 364 transencode_coef_controller (j_compress_ptr cinfo, 365 jvirt_barray_ptr * coef_arrays) 366 { 367 my_coef_ptr coef; 368 JBLOCKROW buffer; 369 int i; 370 371 coef = (my_coef_ptr) 372 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 373 SIZEOF(my_coef_controller)); 374 cinfo->coef = (struct jpeg_c_coef_controller *) coef; 375 coef->pub.start_pass = start_pass_coef; 376 coef->pub.compress_data = compress_output; 377 378 /* Save pointer to virtual arrays */ 379 coef->whole_image = coef_arrays; 380 381 /* Allocate and pre-zero space for dummy DCT blocks. */ 382 buffer = (JBLOCKROW) 383 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE, 384 C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK)); 385 jzero_far((void FAR *) buffer, C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK)); 386 for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) { 387 coef->dummy_buffer[i] = buffer + i; 388 } 389 } 390 391 #endif //_FX_JPEG_TURBO_ 392
