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| 1 /* | |
| 2 * jdpostct.c | |
| 3 * | |
| 4 * Copyright (C) 1994-1996, 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 the decompression postprocessing controller. | |
| 9 * This controller manages the upsampling, color conversion, and color | |
| 10 * quantization/reduction steps; specifically, it controls the buffering | |
| 11 * between upsample/color conversion and color quantization/reduction. | |
| 12 * | |
| 13 * If no color quantization/reduction is required, then this module has no | |
| 14 * work to do, and it just hands off to the upsample/color conversion code. | |
| 15 * An integrated upsample/convert/quantize process would replace this module | |
| 16 * entirely. | |
| 17 */ | |
| 18 | |
| 19 #define JPEG_INTERNALS | |
| 20 #include "jinclude.h" | |
| 21 #include "jpeglib.h" | |
| 22 | |
| 23 | |
| 24 /* Private buffer controller object */ | |
| 25 | |
| 26 typedef struct { | |
| 27 struct jpeg_d_post_controller pub; /* public fields */ | |
| 28 | |
| 29 /* Color quantization source buffer: this holds output data from | |
| 30 * the upsample/color conversion step to be passed to the quantizer. | |
| 31 * For two-pass color quantization, we need a full-image buffer; | |
| 32 * for one-pass operation, a strip buffer is sufficient. | |
| 33 */ | |
| 34 jvirt_sarray_ptr whole_image; /* virtual array, or NULL if one-pass */ | |
| 35 JSAMPARRAY buffer; /* strip buffer, or current strip of virtual */ | |
| 36 JDIMENSION strip_height; /* buffer size in rows */ | |
| 37 /* for two-pass mode only: */ | |
| 38 JDIMENSION starting_row; /* row # of first row in current strip */ | |
| 39 JDIMENSION next_row; /* index of next row to fill/empty in strip */ | |
| 40 } my_post_controller; | |
| 41 | |
| 42 typedef my_post_controller * my_post_ptr; | |
| 43 | |
| 44 | |
| 45 /* Forward declarations */ | |
| 46 METHODDEF(void) post_process_1pass | |
| 47 JPP((j_decompress_ptr cinfo, | |
| 48 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
| 49 JDIMENSION in_row_groups_avail, | |
| 50 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 51 JDIMENSION out_rows_avail)); | |
| 52 #ifdef QUANT_2PASS_SUPPORTED | |
| 53 METHODDEF(void) post_process_prepass | |
| 54 JPP((j_decompress_ptr cinfo, | |
| 55 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
| 56 JDIMENSION in_row_groups_avail, | |
| 57 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 58 JDIMENSION out_rows_avail)); | |
| 59 METHODDEF(void) post_process_2pass | |
| 60 JPP((j_decompress_ptr cinfo, | |
| 61 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
| 62 JDIMENSION in_row_groups_avail, | |
| 63 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 64 JDIMENSION out_rows_avail)); | |
| 65 #endif | |
| 66 | |
| 67 | |
| 68 /* | |
| 69 * Initialize for a processing pass. | |
| 70 */ | |
| 71 | |
| 72 METHODDEF(void) | |
| 73 start_pass_dpost (j_decompress_ptr cinfo, J_BUF_MODE pass_mode) | |
| 74 { | |
| 75 my_post_ptr post = (my_post_ptr) cinfo->post; | |
| 76 | |
| 77 switch (pass_mode) { | |
| 78 case JBUF_PASS_THRU: | |
| 79 if (cinfo->quantize_colors) { | |
| 80 /* Single-pass processing with color quantization. */ | |
| 81 post->pub.post_process_data = post_process_1pass; | |
| 82 /* We could be doing buffered-image output before starting a 2-pass | |
| 83 * color quantization; in that case, jinit_d_post_controller did not | |
| 84 * allocate a strip buffer. Use the virtual-array buffer as workspace. | |
| 85 */ | |
| 86 if (post->buffer == NULL) { | |
| 87 post->buffer = (*cinfo->mem->access_virt_sarray) | |
| 88 ((j_common_ptr) cinfo, post->whole_image, | |
| 89 (JDIMENSION) 0, post->strip_height, TRUE); | |
| 90 } | |
| 91 } else { | |
| 92 /* For single-pass processing without color quantization, | |
| 93 * I have no work to do; just call the upsampler directly. | |
| 94 */ | |
| 95 post->pub.post_process_data = cinfo->upsample->upsample; | |
| 96 } | |
| 97 break; | |
| 98 #ifdef QUANT_2PASS_SUPPORTED | |
| 99 case JBUF_SAVE_AND_PASS: | |
| 100 /* First pass of 2-pass quantization */ | |
| 101 if (post->whole_image == NULL) | |
| 102 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
| 103 post->pub.post_process_data = post_process_prepass; | |
| 104 break; | |
| 105 case JBUF_CRANK_DEST: | |
| 106 /* Second pass of 2-pass quantization */ | |
| 107 if (post->whole_image == NULL) | |
| 108 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
| 109 post->pub.post_process_data = post_process_2pass; | |
| 110 break; | |
| 111 #endif /* QUANT_2PASS_SUPPORTED */ | |
| 112 default: | |
| 113 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
| 114 break; | |
| 115 } | |
| 116 post->starting_row = post->next_row = 0; | |
| 117 } | |
| 118 | |
| 119 | |
| 120 /* | |
| 121 * Process some data in the one-pass (strip buffer) case. | |
| 122 * This is used for color precision reduction as well as one-pass quantization. | |
| 123 */ | |
| 124 | |
| 125 METHODDEF(void) | |
| 126 post_process_1pass (j_decompress_ptr cinfo, | |
| 127 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
| 128 JDIMENSION in_row_groups_avail, | |
| 129 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 130 JDIMENSION out_rows_avail) | |
| 131 { | |
| 132 my_post_ptr post = (my_post_ptr) cinfo->post; | |
| 133 JDIMENSION num_rows, max_rows; | |
| 134 | |
| 135 /* Fill the buffer, but not more than what we can dump out in one go. */ | |
| 136 /* Note we rely on the upsampler to detect bottom of image. */ | |
| 137 max_rows = out_rows_avail - *out_row_ctr; | |
| 138 if (max_rows > post->strip_height) | |
| 139 max_rows = post->strip_height; | |
| 140 num_rows = 0; | |
| 141 (*cinfo->upsample->upsample) (cinfo, | |
| 142 input_buf, in_row_group_ctr, in_row_groups_avail, | |
| 143 post->buffer, &num_rows, max_rows); | |
| 144 /* Quantize and emit data. */ | |
| 145 (*cinfo->cquantize->color_quantize) (cinfo, | |
| 146 post->buffer, output_buf + *out_row_ctr, (int) num_rows); | |
| 147 *out_row_ctr += num_rows; | |
| 148 } | |
| 149 | |
| 150 | |
| 151 #ifdef QUANT_2PASS_SUPPORTED | |
| 152 | |
| 153 /* | |
| 154 * Process some data in the first pass of 2-pass quantization. | |
| 155 */ | |
| 156 | |
| 157 METHODDEF(void) | |
| 158 post_process_prepass (j_decompress_ptr cinfo, | |
| 159 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
| 160 JDIMENSION in_row_groups_avail, | |
| 161 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 162 JDIMENSION out_rows_avail) | |
| 163 { | |
| 164 my_post_ptr post = (my_post_ptr) cinfo->post; | |
| 165 JDIMENSION old_next_row, num_rows; | |
| 166 | |
| 167 /* Reposition virtual buffer if at start of strip. */ | |
| 168 if (post->next_row == 0) { | |
| 169 post->buffer = (*cinfo->mem->access_virt_sarray) | |
| 170 ((j_common_ptr) cinfo, post->whole_image, | |
| 171 post->starting_row, post->strip_height, TRUE); | |
| 172 } | |
| 173 | |
| 174 /* Upsample some data (up to a strip height's worth). */ | |
| 175 old_next_row = post->next_row; | |
| 176 (*cinfo->upsample->upsample) (cinfo, | |
| 177 input_buf, in_row_group_ctr, in_row_groups_avail, | |
| 178 post->buffer, &post->next_row, post->strip_height); | |
| 179 | |
| 180 /* Allow quantizer to scan new data. No data is emitted, */ | |
| 181 /* but we advance out_row_ctr so outer loop can tell when we're done. */ | |
| 182 if (post->next_row > old_next_row) { | |
| 183 num_rows = post->next_row - old_next_row; | |
| 184 (*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row, | |
| 185 (JSAMPARRAY) NULL, (int) num_rows); | |
| 186 *out_row_ctr += num_rows; | |
| 187 } | |
| 188 | |
| 189 /* Advance if we filled the strip. */ | |
| 190 if (post->next_row >= post->strip_height) { | |
| 191 post->starting_row += post->strip_height; | |
| 192 post->next_row = 0; | |
| 193 } | |
| 194 } | |
| 195 | |
| 196 | |
| 197 /* | |
| 198 * Process some data in the second pass of 2-pass quantization. | |
| 199 */ | |
| 200 | |
| 201 METHODDEF(void) | |
| 202 post_process_2pass (j_decompress_ptr cinfo, | |
| 203 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
| 204 JDIMENSION in_row_groups_avail, | |
| 205 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
| 206 JDIMENSION out_rows_avail) | |
| 207 { | |
| 208 my_post_ptr post = (my_post_ptr) cinfo->post; | |
| 209 JDIMENSION num_rows, max_rows; | |
| 210 | |
| 211 /* Reposition virtual buffer if at start of strip. */ | |
| 212 if (post->next_row == 0) { | |
| 213 post->buffer = (*cinfo->mem->access_virt_sarray) | |
| 214 ((j_common_ptr) cinfo, post->whole_image, | |
| 215 post->starting_row, post->strip_height, FALSE); | |
| 216 } | |
| 217 | |
| 218 /* Determine number of rows to emit. */ | |
| 219 num_rows = post->strip_height - post->next_row; /* available in strip */ | |
| 220 max_rows = out_rows_avail - *out_row_ctr; /* available in output area */ | |
| 221 if (num_rows > max_rows) | |
| 222 num_rows = max_rows; | |
| 223 /* We have to check bottom of image here, can't depend on upsampler. */ | |
| 224 max_rows = cinfo->output_height - post->starting_row; | |
| 225 if (num_rows > max_rows) | |
| 226 num_rows = max_rows; | |
| 227 | |
| 228 /* Quantize and emit data. */ | |
| 229 (*cinfo->cquantize->color_quantize) (cinfo, | |
| 230 post->buffer + post->next_row, output_buf + *out_row_ctr, | |
| 231 (int) num_rows); | |
| 232 *out_row_ctr += num_rows; | |
| 233 | |
| 234 /* Advance if we filled the strip. */ | |
| 235 post->next_row += num_rows; | |
| 236 if (post->next_row >= post->strip_height) { | |
| 237 post->starting_row += post->strip_height; | |
| 238 post->next_row = 0; | |
| 239 } | |
| 240 } | |
| 241 | |
| 242 #endif /* QUANT_2PASS_SUPPORTED */ | |
| 243 | |
| 244 | |
| 245 /* | |
| 246 * Initialize postprocessing controller. | |
| 247 */ | |
| 248 | |
| 249 GLOBAL(void) | |
| 250 jinit_d_post_controller (j_decompress_ptr cinfo, boolean need_full_buffer) | |
| 251 { | |
| 252 my_post_ptr post; | |
| 253 | |
| 254 post = (my_post_ptr) | |
| 255 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 256 SIZEOF(my_post_controller)); | |
| 257 cinfo->post = (struct jpeg_d_post_controller *) post; | |
| 258 post->pub.start_pass = start_pass_dpost; | |
| 259 post->whole_image = NULL; /* flag for no virtual arrays */ | |
| 260 post->buffer = NULL; /* flag for no strip buffer */ | |
| 261 | |
| 262 /* Create the quantization buffer, if needed */ | |
| 263 if (cinfo->quantize_colors) { | |
| 264 /* The buffer strip height is max_v_samp_factor, which is typically | |
| 265 * an efficient number of rows for upsampling to return. | |
| 266 * (In the presence of output rescaling, we might want to be smarter?) | |
| 267 */ | |
| 268 post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor; | |
| 269 if (need_full_buffer) { | |
| 270 /* Two-pass color quantization: need full-image storage. */ | |
| 271 /* We round up the number of rows to a multiple of the strip height. */ | |
| 272 #ifdef QUANT_2PASS_SUPPORTED | |
| 273 post->whole_image = (*cinfo->mem->request_virt_sarray) | |
| 274 ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE, | |
| 275 cinfo->output_width * cinfo->out_color_components, | |
| 276 (JDIMENSION) jround_up((long) cinfo->output_height, | |
| 277 (long) post->strip_height), | |
| 278 post->strip_height); | |
| 279 #else | |
| 280 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
| 281 #endif /* QUANT_2PASS_SUPPORTED */ | |
| 282 } else { | |
| 283 /* One-pass color quantization: just make a strip buffer. */ | |
| 284 post->buffer = (*cinfo->mem->alloc_sarray) | |
| 285 ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 286 cinfo->output_width * cinfo->out_color_components, | |
| 287 post->strip_height); | |
| 288 } | |
| 289 } | |
| 290 } | |
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Chromium Code Reviews
Issue 1705523002:
Remove libjpeg and libjpeg_turbo. (Closed)
Base URL: https://github.com/domokit/mojo.git@master