dbf-halloween2015

annotate libs/libjpeg/jdpostct.c @ 3:c37fe5d8a4ed

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windows port
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 01 Nov 2015 06:04:28 +0200
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nuclear@1 1 /*
nuclear@1 2 * jdpostct.c
nuclear@1 3 *
nuclear@1 4 * Copyright (C) 1994-1996, Thomas G. Lane.
nuclear@1 5 * This file is part of the Independent JPEG Group's software.
nuclear@1 6 * For conditions of distribution and use, see the accompanying README file.
nuclear@1 7 *
nuclear@1 8 * This file contains the decompression postprocessing controller.
nuclear@1 9 * This controller manages the upsampling, color conversion, and color
nuclear@1 10 * quantization/reduction steps; specifically, it controls the buffering
nuclear@1 11 * between upsample/color conversion and color quantization/reduction.
nuclear@1 12 *
nuclear@1 13 * If no color quantization/reduction is required, then this module has no
nuclear@1 14 * work to do, and it just hands off to the upsample/color conversion code.
nuclear@1 15 * An integrated upsample/convert/quantize process would replace this module
nuclear@1 16 * entirely.
nuclear@1 17 */
nuclear@1 18
nuclear@1 19 #define JPEG_INTERNALS
nuclear@1 20 #include "jinclude.h"
nuclear@1 21 #include "jpeglib.h"
nuclear@1 22
nuclear@1 23
nuclear@1 24 /* Private buffer controller object */
nuclear@1 25
nuclear@1 26 typedef struct {
nuclear@1 27 struct jpeg_d_post_controller pub; /* public fields */
nuclear@1 28
nuclear@1 29 /* Color quantization source buffer: this holds output data from
nuclear@1 30 * the upsample/color conversion step to be passed to the quantizer.
nuclear@1 31 * For two-pass color quantization, we need a full-image buffer;
nuclear@1 32 * for one-pass operation, a strip buffer is sufficient.
nuclear@1 33 */
nuclear@1 34 jvirt_sarray_ptr whole_image; /* virtual array, or NULL if one-pass */
nuclear@1 35 JSAMPARRAY buffer; /* strip buffer, or current strip of virtual */
nuclear@1 36 JDIMENSION strip_height; /* buffer size in rows */
nuclear@1 37 /* for two-pass mode only: */
nuclear@1 38 JDIMENSION starting_row; /* row # of first row in current strip */
nuclear@1 39 JDIMENSION next_row; /* index of next row to fill/empty in strip */
nuclear@1 40 } my_post_controller;
nuclear@1 41
nuclear@1 42 typedef my_post_controller * my_post_ptr;
nuclear@1 43
nuclear@1 44
nuclear@1 45 /* Forward declarations */
nuclear@1 46 METHODDEF(void) post_process_1pass
nuclear@1 47 JPP((j_decompress_ptr cinfo,
nuclear@1 48 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
nuclear@1 49 JDIMENSION in_row_groups_avail,
nuclear@1 50 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
nuclear@1 51 JDIMENSION out_rows_avail));
nuclear@1 52 #ifdef QUANT_2PASS_SUPPORTED
nuclear@1 53 METHODDEF(void) post_process_prepass
nuclear@1 54 JPP((j_decompress_ptr cinfo,
nuclear@1 55 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
nuclear@1 56 JDIMENSION in_row_groups_avail,
nuclear@1 57 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
nuclear@1 58 JDIMENSION out_rows_avail));
nuclear@1 59 METHODDEF(void) post_process_2pass
nuclear@1 60 JPP((j_decompress_ptr cinfo,
nuclear@1 61 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
nuclear@1 62 JDIMENSION in_row_groups_avail,
nuclear@1 63 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
nuclear@1 64 JDIMENSION out_rows_avail));
nuclear@1 65 #endif
nuclear@1 66
nuclear@1 67
nuclear@1 68 /*
nuclear@1 69 * Initialize for a processing pass.
nuclear@1 70 */
nuclear@1 71
nuclear@1 72 METHODDEF(void)
nuclear@1 73 start_pass_dpost (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
nuclear@1 74 {
nuclear@1 75 my_post_ptr post = (my_post_ptr) cinfo->post;
nuclear@1 76
nuclear@1 77 switch (pass_mode) {
nuclear@1 78 case JBUF_PASS_THRU:
nuclear@1 79 if (cinfo->quantize_colors) {
nuclear@1 80 /* Single-pass processing with color quantization. */
nuclear@1 81 post->pub.post_process_data = post_process_1pass;
nuclear@1 82 /* We could be doing buffered-image output before starting a 2-pass
nuclear@1 83 * color quantization; in that case, jinit_d_post_controller did not
nuclear@1 84 * allocate a strip buffer. Use the virtual-array buffer as workspace.
nuclear@1 85 */
nuclear@1 86 if (post->buffer == NULL) {
nuclear@1 87 post->buffer = (*cinfo->mem->access_virt_sarray)
nuclear@1 88 ((j_common_ptr) cinfo, post->whole_image,
nuclear@1 89 (JDIMENSION) 0, post->strip_height, TRUE);
nuclear@1 90 }
nuclear@1 91 } else {
nuclear@1 92 /* For single-pass processing without color quantization,
nuclear@1 93 * I have no work to do; just call the upsampler directly.
nuclear@1 94 */
nuclear@1 95 post->pub.post_process_data = cinfo->upsample->upsample;
nuclear@1 96 }
nuclear@1 97 break;
nuclear@1 98 #ifdef QUANT_2PASS_SUPPORTED
nuclear@1 99 case JBUF_SAVE_AND_PASS:
nuclear@1 100 /* First pass of 2-pass quantization */
nuclear@1 101 if (post->whole_image == NULL)
nuclear@1 102 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
nuclear@1 103 post->pub.post_process_data = post_process_prepass;
nuclear@1 104 break;
nuclear@1 105 case JBUF_CRANK_DEST:
nuclear@1 106 /* Second pass of 2-pass quantization */
nuclear@1 107 if (post->whole_image == NULL)
nuclear@1 108 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
nuclear@1 109 post->pub.post_process_data = post_process_2pass;
nuclear@1 110 break;
nuclear@1 111 #endif /* QUANT_2PASS_SUPPORTED */
nuclear@1 112 default:
nuclear@1 113 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
nuclear@1 114 break;
nuclear@1 115 }
nuclear@1 116 post->starting_row = post->next_row = 0;
nuclear@1 117 }
nuclear@1 118
nuclear@1 119
nuclear@1 120 /*
nuclear@1 121 * Process some data in the one-pass (strip buffer) case.
nuclear@1 122 * This is used for color precision reduction as well as one-pass quantization.
nuclear@1 123 */
nuclear@1 124
nuclear@1 125 METHODDEF(void)
nuclear@1 126 post_process_1pass (j_decompress_ptr cinfo,
nuclear@1 127 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
nuclear@1 128 JDIMENSION in_row_groups_avail,
nuclear@1 129 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
nuclear@1 130 JDIMENSION out_rows_avail)
nuclear@1 131 {
nuclear@1 132 my_post_ptr post = (my_post_ptr) cinfo->post;
nuclear@1 133 JDIMENSION num_rows, max_rows;
nuclear@1 134
nuclear@1 135 /* Fill the buffer, but not more than what we can dump out in one go. */
nuclear@1 136 /* Note we rely on the upsampler to detect bottom of image. */
nuclear@1 137 max_rows = out_rows_avail - *out_row_ctr;
nuclear@1 138 if (max_rows > post->strip_height)
nuclear@1 139 max_rows = post->strip_height;
nuclear@1 140 num_rows = 0;
nuclear@1 141 (*cinfo->upsample->upsample) (cinfo,
nuclear@1 142 input_buf, in_row_group_ctr, in_row_groups_avail,
nuclear@1 143 post->buffer, &num_rows, max_rows);
nuclear@1 144 /* Quantize and emit data. */
nuclear@1 145 (*cinfo->cquantize->color_quantize) (cinfo,
nuclear@1 146 post->buffer, output_buf + *out_row_ctr, (int) num_rows);
nuclear@1 147 *out_row_ctr += num_rows;
nuclear@1 148 }
nuclear@1 149
nuclear@1 150
nuclear@1 151 #ifdef QUANT_2PASS_SUPPORTED
nuclear@1 152
nuclear@1 153 /*
nuclear@1 154 * Process some data in the first pass of 2-pass quantization.
nuclear@1 155 */
nuclear@1 156
nuclear@1 157 METHODDEF(void)
nuclear@1 158 post_process_prepass (j_decompress_ptr cinfo,
nuclear@1 159 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
nuclear@1 160 JDIMENSION in_row_groups_avail,
nuclear@1 161 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
nuclear@1 162 JDIMENSION out_rows_avail)
nuclear@1 163 {
nuclear@1 164 my_post_ptr post = (my_post_ptr) cinfo->post;
nuclear@1 165 JDIMENSION old_next_row, num_rows;
nuclear@1 166
nuclear@1 167 /* Reposition virtual buffer if at start of strip. */
nuclear@1 168 if (post->next_row == 0) {
nuclear@1 169 post->buffer = (*cinfo->mem->access_virt_sarray)
nuclear@1 170 ((j_common_ptr) cinfo, post->whole_image,
nuclear@1 171 post->starting_row, post->strip_height, TRUE);
nuclear@1 172 }
nuclear@1 173
nuclear@1 174 /* Upsample some data (up to a strip height's worth). */
nuclear@1 175 old_next_row = post->next_row;
nuclear@1 176 (*cinfo->upsample->upsample) (cinfo,
nuclear@1 177 input_buf, in_row_group_ctr, in_row_groups_avail,
nuclear@1 178 post->buffer, &post->next_row, post->strip_height);
nuclear@1 179
nuclear@1 180 /* Allow quantizer to scan new data. No data is emitted, */
nuclear@1 181 /* but we advance out_row_ctr so outer loop can tell when we're done. */
nuclear@1 182 if (post->next_row > old_next_row) {
nuclear@1 183 num_rows = post->next_row - old_next_row;
nuclear@1 184 (*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row,
nuclear@1 185 (JSAMPARRAY) NULL, (int) num_rows);
nuclear@1 186 *out_row_ctr += num_rows;
nuclear@1 187 }
nuclear@1 188
nuclear@1 189 /* Advance if we filled the strip. */
nuclear@1 190 if (post->next_row >= post->strip_height) {
nuclear@1 191 post->starting_row += post->strip_height;
nuclear@1 192 post->next_row = 0;
nuclear@1 193 }
nuclear@1 194 }
nuclear@1 195
nuclear@1 196
nuclear@1 197 /*
nuclear@1 198 * Process some data in the second pass of 2-pass quantization.
nuclear@1 199 */
nuclear@1 200
nuclear@1 201 METHODDEF(void)
nuclear@1 202 post_process_2pass (j_decompress_ptr cinfo,
nuclear@1 203 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
nuclear@1 204 JDIMENSION in_row_groups_avail,
nuclear@1 205 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
nuclear@1 206 JDIMENSION out_rows_avail)
nuclear@1 207 {
nuclear@1 208 my_post_ptr post = (my_post_ptr) cinfo->post;
nuclear@1 209 JDIMENSION num_rows, max_rows;
nuclear@1 210
nuclear@1 211 /* Reposition virtual buffer if at start of strip. */
nuclear@1 212 if (post->next_row == 0) {
nuclear@1 213 post->buffer = (*cinfo->mem->access_virt_sarray)
nuclear@1 214 ((j_common_ptr) cinfo, post->whole_image,
nuclear@1 215 post->starting_row, post->strip_height, FALSE);
nuclear@1 216 }
nuclear@1 217
nuclear@1 218 /* Determine number of rows to emit. */
nuclear@1 219 num_rows = post->strip_height - post->next_row; /* available in strip */
nuclear@1 220 max_rows = out_rows_avail - *out_row_ctr; /* available in output area */
nuclear@1 221 if (num_rows > max_rows)
nuclear@1 222 num_rows = max_rows;
nuclear@1 223 /* We have to check bottom of image here, can't depend on upsampler. */
nuclear@1 224 max_rows = cinfo->output_height - post->starting_row;
nuclear@1 225 if (num_rows > max_rows)
nuclear@1 226 num_rows = max_rows;
nuclear@1 227
nuclear@1 228 /* Quantize and emit data. */
nuclear@1 229 (*cinfo->cquantize->color_quantize) (cinfo,
nuclear@1 230 post->buffer + post->next_row, output_buf + *out_row_ctr,
nuclear@1 231 (int) num_rows);
nuclear@1 232 *out_row_ctr += num_rows;
nuclear@1 233
nuclear@1 234 /* Advance if we filled the strip. */
nuclear@1 235 post->next_row += num_rows;
nuclear@1 236 if (post->next_row >= post->strip_height) {
nuclear@1 237 post->starting_row += post->strip_height;
nuclear@1 238 post->next_row = 0;
nuclear@1 239 }
nuclear@1 240 }
nuclear@1 241
nuclear@1 242 #endif /* QUANT_2PASS_SUPPORTED */
nuclear@1 243
nuclear@1 244
nuclear@1 245 /*
nuclear@1 246 * Initialize postprocessing controller.
nuclear@1 247 */
nuclear@1 248
nuclear@1 249 GLOBAL(void)
nuclear@1 250 jinit_d_post_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
nuclear@1 251 {
nuclear@1 252 my_post_ptr post;
nuclear@1 253
nuclear@1 254 post = (my_post_ptr)
nuclear@1 255 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@1 256 SIZEOF(my_post_controller));
nuclear@1 257 cinfo->post = (struct jpeg_d_post_controller *) post;
nuclear@1 258 post->pub.start_pass = start_pass_dpost;
nuclear@1 259 post->whole_image = NULL; /* flag for no virtual arrays */
nuclear@1 260 post->buffer = NULL; /* flag for no strip buffer */
nuclear@1 261
nuclear@1 262 /* Create the quantization buffer, if needed */
nuclear@1 263 if (cinfo->quantize_colors) {
nuclear@1 264 /* The buffer strip height is max_v_samp_factor, which is typically
nuclear@1 265 * an efficient number of rows for upsampling to return.
nuclear@1 266 * (In the presence of output rescaling, we might want to be smarter?)
nuclear@1 267 */
nuclear@1 268 post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor;
nuclear@1 269 if (need_full_buffer) {
nuclear@1 270 /* Two-pass color quantization: need full-image storage. */
nuclear@1 271 /* We round up the number of rows to a multiple of the strip height. */
nuclear@1 272 #ifdef QUANT_2PASS_SUPPORTED
nuclear@1 273 post->whole_image = (*cinfo->mem->request_virt_sarray)
nuclear@1 274 ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
nuclear@1 275 cinfo->output_width * cinfo->out_color_components,
nuclear@1 276 (JDIMENSION) jround_up((long) cinfo->output_height,
nuclear@1 277 (long) post->strip_height),
nuclear@1 278 post->strip_height);
nuclear@1 279 #else
nuclear@1 280 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
nuclear@1 281 #endif /* QUANT_2PASS_SUPPORTED */
nuclear@1 282 } else {
nuclear@1 283 /* One-pass color quantization: just make a strip buffer. */
nuclear@1 284 post->buffer = (*cinfo->mem->alloc_sarray)
nuclear@1 285 ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@1 286 cinfo->output_width * cinfo->out_color_components,
nuclear@1 287 post->strip_height);
nuclear@1 288 }
nuclear@1 289 }
nuclear@1 290 }