Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * wrgif.c |
| 3 | * |
| 4 | * Copyright (C) 1991-1994, 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 | * |
Thomas G. Lane | a8b67c4 | 1995-03-15 00:00:00 +0000 | [diff] [blame^] | 8 | ************************************************************************** |
| 9 | * WARNING: You will need an LZW patent license from Unisys in order to * |
| 10 | * use this file legally in any commercial or shareware application. * |
| 11 | ************************************************************************** |
| 12 | * |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 13 | * This file contains routines to write output images in GIF format. |
| 14 | * |
| 15 | * These routines may need modification for non-Unix environments or |
| 16 | * specialized applications. As they stand, they assume output to |
| 17 | * an ordinary stdio stream. |
| 18 | */ |
| 19 | |
| 20 | /* |
| 21 | * This code is loosely based on ppmtogif from the PBMPLUS distribution |
| 22 | * of Feb. 1991. That file contains the following copyright notice: |
| 23 | * Based on GIFENCODE by David Rowley <mgardi@watdscu.waterloo.edu>. |
| 24 | * Lempel-Ziv compression based on "compress" by Spencer W. Thomas et al. |
| 25 | * Copyright (C) 1989 by Jef Poskanzer. |
| 26 | * Permission to use, copy, modify, and distribute this software and its |
| 27 | * documentation for any purpose and without fee is hereby granted, provided |
| 28 | * that the above copyright notice appear in all copies and that both that |
| 29 | * copyright notice and this permission notice appear in supporting |
| 30 | * documentation. This software is provided "as is" without express or |
| 31 | * implied warranty. |
| 32 | * |
| 33 | * We are also required to state that |
| 34 | * "The Graphics Interchange Format(c) is the Copyright property of |
| 35 | * CompuServe Incorporated. GIF(sm) is a Service Mark property of |
| 36 | * CompuServe Incorporated." |
| 37 | */ |
| 38 | |
| 39 | #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ |
| 40 | |
| 41 | #ifdef GIF_SUPPORTED |
| 42 | |
| 43 | |
| 44 | #define MAX_LZW_BITS 12 /* maximum LZW code size (4096 symbols) */ |
| 45 | |
| 46 | typedef INT16 code_int; /* must hold -1 .. 2**MAX_LZW_BITS */ |
| 47 | |
| 48 | #define LZW_TABLE_SIZE ((code_int) 1 << MAX_LZW_BITS) |
| 49 | |
| 50 | #define HSIZE 5003 /* hash table size for 80% occupancy */ |
| 51 | |
| 52 | typedef int hash_int; /* must hold -2*HSIZE..2*HSIZE */ |
| 53 | |
| 54 | #define MAXCODE(n_bits) (((code_int) 1 << (n_bits)) - 1) |
| 55 | |
| 56 | |
| 57 | /* |
| 58 | * The LZW hash table consists of two parallel arrays: |
| 59 | * hash_code[i] code of symbol in slot i, or 0 if empty slot |
| 60 | * hash_value[i] symbol's value; undefined if empty slot |
| 61 | * where slot values (i) range from 0 to HSIZE-1. The symbol value is |
| 62 | * its prefix symbol's code concatenated with its suffix character. |
| 63 | * |
| 64 | * Algorithm: use open addressing double hashing (no chaining) on the |
| 65 | * prefix code / suffix character combination. We do a variant of Knuth's |
| 66 | * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime |
| 67 | * secondary probe. |
| 68 | * |
| 69 | * The hash_value[] table is allocated from FAR heap space since it would |
| 70 | * use up rather a lot of the near data space in a PC. |
| 71 | */ |
| 72 | |
| 73 | typedef INT32 hash_entry; /* must hold (code_int<<8) | byte */ |
| 74 | |
| 75 | #define HASH_ENTRY(prefix,suffix) ((((hash_entry) (prefix)) << 8) | (suffix)) |
| 76 | |
| 77 | |
| 78 | /* Private version of data destination object */ |
| 79 | |
| 80 | typedef struct { |
| 81 | struct djpeg_dest_struct pub; /* public fields */ |
| 82 | |
| 83 | j_decompress_ptr cinfo; /* back link saves passing separate parm */ |
| 84 | |
| 85 | /* State for packing variable-width codes into a bitstream */ |
| 86 | int n_bits; /* current number of bits/code */ |
| 87 | code_int maxcode; /* maximum code, given n_bits */ |
| 88 | int init_bits; /* initial n_bits ... restored after clear */ |
| 89 | INT32 cur_accum; /* holds bits not yet output */ |
| 90 | int cur_bits; /* # of bits in cur_accum */ |
| 91 | |
| 92 | /* LZW string construction */ |
| 93 | code_int waiting_code; /* symbol not yet output; may be extendable */ |
| 94 | boolean first_byte; /* if TRUE, waiting_code is not valid */ |
| 95 | |
| 96 | /* State for LZW code assignment */ |
| 97 | code_int ClearCode; /* clear code (doesn't change) */ |
| 98 | code_int EOFCode; /* EOF code (ditto) */ |
| 99 | code_int free_code; /* first not-yet-used symbol code */ |
| 100 | |
| 101 | /* LZW hash table */ |
| 102 | code_int *hash_code; /* => hash table of symbol codes */ |
| 103 | hash_entry FAR *hash_value; /* => hash table of symbol values */ |
| 104 | |
| 105 | /* GIF data packet construction buffer */ |
| 106 | int bytesinpkt; /* # of bytes in current packet */ |
| 107 | char packetbuf[256]; /* workspace for accumulating packet */ |
| 108 | |
| 109 | } gif_dest_struct; |
| 110 | |
| 111 | typedef gif_dest_struct * gif_dest_ptr; |
| 112 | |
| 113 | |
| 114 | /* |
| 115 | * Routines to package compressed data bytes into GIF data blocks. |
| 116 | * A data block consists of a count byte (1..255) and that many data bytes. |
| 117 | */ |
| 118 | |
| 119 | LOCAL void |
| 120 | flush_packet (gif_dest_ptr dinfo) |
| 121 | /* flush any accumulated data */ |
| 122 | { |
| 123 | if (dinfo->bytesinpkt > 0) { /* never write zero-length packet */ |
| 124 | dinfo->packetbuf[0] = (char) dinfo->bytesinpkt++; |
| 125 | if (JFWRITE(dinfo->pub.output_file, dinfo->packetbuf, dinfo->bytesinpkt) |
| 126 | != (size_t) dinfo->bytesinpkt) |
| 127 | ERREXIT(dinfo->cinfo, JERR_FILE_WRITE); |
| 128 | dinfo->bytesinpkt = 0; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | |
| 133 | /* Add a character to current packet; flush to disk if necessary */ |
| 134 | #define CHAR_OUT(dinfo,c) \ |
| 135 | { (dinfo)->packetbuf[++(dinfo)->bytesinpkt] = (char) (c); \ |
| 136 | if ((dinfo)->bytesinpkt >= 255) \ |
| 137 | flush_packet(dinfo); \ |
| 138 | } |
| 139 | |
| 140 | |
| 141 | /* Routine to convert variable-width codes into a byte stream */ |
| 142 | |
| 143 | LOCAL void |
| 144 | output (gif_dest_ptr dinfo, code_int code) |
| 145 | /* Emit a code of n_bits bits */ |
| 146 | /* Uses cur_accum and cur_bits to reblock into 8-bit bytes */ |
| 147 | { |
| 148 | dinfo->cur_accum |= ((INT32) code) << dinfo->cur_bits; |
| 149 | dinfo->cur_bits += dinfo->n_bits; |
| 150 | |
| 151 | while (dinfo->cur_bits >= 8) { |
| 152 | CHAR_OUT(dinfo, dinfo->cur_accum & 0xFF); |
| 153 | dinfo->cur_accum >>= 8; |
| 154 | dinfo->cur_bits -= 8; |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * If the next entry is going to be too big for the code size, |
| 159 | * then increase it, if possible. We do this here to ensure |
| 160 | * that it's done in sync with the decoder's codesize increases. |
| 161 | */ |
| 162 | if (dinfo->free_code > dinfo->maxcode) { |
| 163 | dinfo->n_bits++; |
| 164 | if (dinfo->n_bits == MAX_LZW_BITS) |
| 165 | dinfo->maxcode = LZW_TABLE_SIZE; /* free_code will never exceed this */ |
| 166 | else |
| 167 | dinfo->maxcode = MAXCODE(dinfo->n_bits); |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | |
| 172 | /* The LZW algorithm proper */ |
| 173 | |
| 174 | |
| 175 | LOCAL void |
| 176 | clear_hash (gif_dest_ptr dinfo) |
| 177 | /* Fill the hash table with empty entries */ |
| 178 | { |
| 179 | /* It's sufficient to zero hash_code[] */ |
| 180 | MEMZERO(dinfo->hash_code, HSIZE * SIZEOF(code_int)); |
| 181 | } |
| 182 | |
| 183 | |
| 184 | LOCAL void |
| 185 | clear_block (gif_dest_ptr dinfo) |
| 186 | /* Reset compressor and issue a Clear code */ |
| 187 | { |
| 188 | clear_hash(dinfo); /* delete all the symbols */ |
| 189 | dinfo->free_code = dinfo->ClearCode + 2; |
| 190 | output(dinfo, dinfo->ClearCode); /* inform decoder */ |
| 191 | dinfo->n_bits = dinfo->init_bits; /* reset code size */ |
| 192 | dinfo->maxcode = MAXCODE(dinfo->n_bits); |
| 193 | } |
| 194 | |
| 195 | |
| 196 | LOCAL void |
| 197 | compress_init (gif_dest_ptr dinfo, int i_bits) |
| 198 | /* Initialize LZW compressor */ |
| 199 | { |
| 200 | /* init all the state variables */ |
| 201 | dinfo->n_bits = dinfo->init_bits = i_bits; |
| 202 | dinfo->maxcode = MAXCODE(dinfo->n_bits); |
| 203 | dinfo->ClearCode = ((code_int) 1 << (i_bits - 1)); |
| 204 | dinfo->EOFCode = dinfo->ClearCode + 1; |
| 205 | dinfo->free_code = dinfo->ClearCode + 2; |
| 206 | dinfo->first_byte = TRUE; /* no waiting symbol yet */ |
| 207 | /* init output buffering vars */ |
| 208 | dinfo->bytesinpkt = 0; |
| 209 | dinfo->cur_accum = 0; |
| 210 | dinfo->cur_bits = 0; |
| 211 | /* clear hash table */ |
| 212 | clear_hash(dinfo); |
| 213 | /* GIF specifies an initial Clear code */ |
| 214 | output(dinfo, dinfo->ClearCode); |
| 215 | } |
| 216 | |
| 217 | |
| 218 | LOCAL void |
| 219 | compress_byte (gif_dest_ptr dinfo, int c) |
| 220 | /* Accept and compress one 8-bit byte */ |
| 221 | { |
| 222 | register hash_int i; |
| 223 | register hash_int disp; |
| 224 | register hash_entry probe_value; |
| 225 | |
| 226 | if (dinfo->first_byte) { /* need to initialize waiting_code */ |
| 227 | dinfo->waiting_code = c; |
| 228 | dinfo->first_byte = FALSE; |
| 229 | return; |
| 230 | } |
| 231 | |
| 232 | /* Probe hash table to see if a symbol exists for |
| 233 | * waiting_code followed by c. |
| 234 | * If so, replace waiting_code by that symbol and return. |
| 235 | */ |
| 236 | i = ((hash_int) c << (MAX_LZW_BITS-8)) + dinfo->waiting_code; |
| 237 | /* i is less than twice 2**MAX_LZW_BITS, therefore less than twice HSIZE */ |
| 238 | if (i >= HSIZE) |
| 239 | i -= HSIZE; |
| 240 | |
| 241 | probe_value = HASH_ENTRY(dinfo->waiting_code, c); |
| 242 | |
| 243 | if (dinfo->hash_code[i] != 0) { /* is first probed slot empty? */ |
| 244 | if (dinfo->hash_value[i] == probe_value) { |
| 245 | dinfo->waiting_code = dinfo->hash_code[i]; |
| 246 | return; |
| 247 | } |
| 248 | if (i == 0) /* secondary hash (after G. Knott) */ |
| 249 | disp = 1; |
| 250 | else |
| 251 | disp = HSIZE - i; |
| 252 | for (;;) { |
| 253 | i -= disp; |
| 254 | if (i < 0) |
| 255 | i += HSIZE; |
| 256 | if (dinfo->hash_code[i] == 0) |
| 257 | break; /* hit empty slot */ |
| 258 | if (dinfo->hash_value[i] == probe_value) { |
| 259 | dinfo->waiting_code = dinfo->hash_code[i]; |
| 260 | return; |
| 261 | } |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | /* here when hashtable[i] is an empty slot; desired symbol not in table */ |
| 266 | output(dinfo, dinfo->waiting_code); |
| 267 | if (dinfo->free_code < LZW_TABLE_SIZE) { |
| 268 | dinfo->hash_code[i] = dinfo->free_code++; /* add symbol to hashtable */ |
| 269 | dinfo->hash_value[i] = probe_value; |
| 270 | } else |
| 271 | clear_block(dinfo); |
| 272 | dinfo->waiting_code = c; |
| 273 | } |
| 274 | |
| 275 | |
| 276 | LOCAL void |
| 277 | compress_term (gif_dest_ptr dinfo) |
| 278 | /* Clean up at end */ |
| 279 | { |
| 280 | /* Flush out the buffered code */ |
| 281 | if (! dinfo->first_byte) |
| 282 | output(dinfo, dinfo->waiting_code); |
| 283 | /* Send an EOF code */ |
| 284 | output(dinfo, dinfo->EOFCode); |
| 285 | /* Flush the bit-packing buffer */ |
| 286 | if (dinfo->cur_bits > 0) { |
| 287 | CHAR_OUT(dinfo, dinfo->cur_accum & 0xFF); |
| 288 | } |
| 289 | /* Flush the packet buffer */ |
| 290 | flush_packet(dinfo); |
| 291 | } |
| 292 | |
| 293 | |
| 294 | /* GIF header construction */ |
| 295 | |
| 296 | |
| 297 | LOCAL void |
| 298 | put_word (gif_dest_ptr dinfo, unsigned int w) |
| 299 | /* Emit a 16-bit word, LSB first */ |
| 300 | { |
| 301 | putc(w & 0xFF, dinfo->pub.output_file); |
| 302 | putc((w >> 8) & 0xFF, dinfo->pub.output_file); |
| 303 | } |
| 304 | |
| 305 | |
| 306 | LOCAL void |
| 307 | put_3bytes (gif_dest_ptr dinfo, int val) |
| 308 | /* Emit 3 copies of same byte value --- handy subr for colormap construction */ |
| 309 | { |
| 310 | putc(val, dinfo->pub.output_file); |
| 311 | putc(val, dinfo->pub.output_file); |
| 312 | putc(val, dinfo->pub.output_file); |
| 313 | } |
| 314 | |
| 315 | |
| 316 | LOCAL void |
| 317 | emit_header (gif_dest_ptr dinfo, int num_colors, JSAMPARRAY colormap) |
| 318 | /* Output the GIF file header, including color map */ |
| 319 | /* If colormap==NULL, synthesize a gray-scale colormap */ |
| 320 | { |
| 321 | int BitsPerPixel, ColorMapSize, InitCodeSize, FlagByte; |
| 322 | int cshift = dinfo->cinfo->data_precision - 8; |
| 323 | int i; |
| 324 | |
| 325 | if (num_colors > 256) |
| 326 | ERREXIT1(dinfo->cinfo, JERR_TOO_MANY_COLORS, num_colors); |
| 327 | /* Compute bits/pixel and related values */ |
| 328 | BitsPerPixel = 1; |
| 329 | while (num_colors > (1 << BitsPerPixel)) |
| 330 | BitsPerPixel++; |
| 331 | ColorMapSize = 1 << BitsPerPixel; |
| 332 | if (BitsPerPixel <= 1) |
| 333 | InitCodeSize = 2; |
| 334 | else |
| 335 | InitCodeSize = BitsPerPixel; |
| 336 | /* |
| 337 | * Write the GIF header. |
| 338 | * Note that we generate a plain GIF87 header for maximum compatibility. |
| 339 | */ |
| 340 | putc('G', dinfo->pub.output_file); |
| 341 | putc('I', dinfo->pub.output_file); |
| 342 | putc('F', dinfo->pub.output_file); |
| 343 | putc('8', dinfo->pub.output_file); |
| 344 | putc('7', dinfo->pub.output_file); |
| 345 | putc('a', dinfo->pub.output_file); |
| 346 | /* Write the Logical Screen Descriptor */ |
| 347 | put_word(dinfo, (unsigned int) dinfo->cinfo->output_width); |
| 348 | put_word(dinfo, (unsigned int) dinfo->cinfo->output_height); |
| 349 | FlagByte = 0x80; /* Yes, there is a global color table */ |
| 350 | FlagByte |= (BitsPerPixel-1) << 4; /* color resolution */ |
| 351 | FlagByte |= (BitsPerPixel-1); /* size of global color table */ |
| 352 | putc(FlagByte, dinfo->pub.output_file); |
| 353 | putc(0, dinfo->pub.output_file); /* Background color index */ |
| 354 | putc(0, dinfo->pub.output_file); /* Reserved (aspect ratio in GIF89) */ |
| 355 | /* Write the Global Color Map */ |
| 356 | /* If the color map is more than 8 bits precision, */ |
| 357 | /* we reduce it to 8 bits by shifting */ |
| 358 | for (i=0; i < ColorMapSize; i++) { |
| 359 | if (i < num_colors) { |
| 360 | if (colormap != NULL) { |
| 361 | if (dinfo->cinfo->out_color_space == JCS_RGB) { |
| 362 | /* Normal case: RGB color map */ |
| 363 | putc(GETJSAMPLE(colormap[0][i]) >> cshift, dinfo->pub.output_file); |
| 364 | putc(GETJSAMPLE(colormap[1][i]) >> cshift, dinfo->pub.output_file); |
| 365 | putc(GETJSAMPLE(colormap[2][i]) >> cshift, dinfo->pub.output_file); |
| 366 | } else { |
| 367 | /* Grayscale "color map": possible if quantizing grayscale image */ |
| 368 | put_3bytes(dinfo, GETJSAMPLE(colormap[0][i]) >> cshift); |
| 369 | } |
| 370 | } else { |
| 371 | /* Create a gray-scale map of num_colors values, range 0..255 */ |
| 372 | put_3bytes(dinfo, (i * 255 + (num_colors-1)/2) / (num_colors-1)); |
| 373 | } |
| 374 | } else { |
| 375 | /* fill out the map to a power of 2 */ |
| 376 | put_3bytes(dinfo, 0); |
| 377 | } |
| 378 | } |
| 379 | /* Write image separator and Image Descriptor */ |
| 380 | putc(',', dinfo->pub.output_file); /* separator */ |
| 381 | put_word(dinfo, 0); /* left/top offset */ |
| 382 | put_word(dinfo, 0); |
| 383 | put_word(dinfo, (unsigned int) dinfo->cinfo->output_width); /* image size */ |
| 384 | put_word(dinfo, (unsigned int) dinfo->cinfo->output_height); |
| 385 | /* flag byte: not interlaced, no local color map */ |
| 386 | putc(0x00, dinfo->pub.output_file); |
| 387 | /* Write Initial Code Size byte */ |
| 388 | putc(InitCodeSize, dinfo->pub.output_file); |
| 389 | |
| 390 | /* Initialize for LZW compression of image data */ |
| 391 | compress_init(dinfo, InitCodeSize+1); |
| 392 | } |
| 393 | |
| 394 | |
| 395 | /* |
| 396 | * Startup: write the file header. |
| 397 | */ |
| 398 | |
| 399 | METHODDEF void |
| 400 | start_output_gif (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) |
| 401 | { |
| 402 | gif_dest_ptr dest = (gif_dest_ptr) dinfo; |
| 403 | |
| 404 | if (cinfo->quantize_colors) |
| 405 | emit_header(dest, cinfo->actual_number_of_colors, cinfo->colormap); |
| 406 | else |
| 407 | emit_header(dest, 256, (JSAMPARRAY) NULL); |
| 408 | } |
| 409 | |
| 410 | |
| 411 | /* |
| 412 | * Write some pixel data. |
| 413 | * In this module rows_supplied will always be 1. |
| 414 | */ |
| 415 | |
| 416 | METHODDEF void |
| 417 | put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, |
| 418 | JDIMENSION rows_supplied) |
| 419 | { |
| 420 | gif_dest_ptr dest = (gif_dest_ptr) dinfo; |
| 421 | register JSAMPROW ptr; |
| 422 | register JDIMENSION col; |
| 423 | |
| 424 | ptr = dest->pub.buffer[0]; |
| 425 | for (col = cinfo->output_width; col > 0; col--) { |
| 426 | compress_byte(dest, GETJSAMPLE(*ptr++)); |
| 427 | } |
| 428 | } |
| 429 | |
| 430 | |
| 431 | /* |
| 432 | * Finish up at the end of the file. |
| 433 | */ |
| 434 | |
| 435 | METHODDEF void |
| 436 | finish_output_gif (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) |
| 437 | { |
| 438 | gif_dest_ptr dest = (gif_dest_ptr) dinfo; |
| 439 | |
| 440 | /* Flush LZW mechanism */ |
| 441 | compress_term(dest); |
| 442 | /* Write a zero-length data block to end the series */ |
| 443 | putc(0, dest->pub.output_file); |
| 444 | /* Write the GIF terminator mark */ |
| 445 | putc(';', dest->pub.output_file); |
| 446 | /* Make sure we wrote the output file OK */ |
| 447 | fflush(dest->pub.output_file); |
| 448 | if (ferror(dest->pub.output_file)) |
| 449 | ERREXIT(cinfo, JERR_FILE_WRITE); |
| 450 | } |
| 451 | |
| 452 | |
| 453 | /* |
| 454 | * The module selection routine for GIF format output. |
| 455 | */ |
| 456 | |
| 457 | GLOBAL djpeg_dest_ptr |
| 458 | jinit_write_gif (j_decompress_ptr cinfo) |
| 459 | { |
| 460 | gif_dest_ptr dest; |
| 461 | |
| 462 | /* Create module interface object, fill in method pointers */ |
| 463 | dest = (gif_dest_ptr) |
| 464 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| 465 | SIZEOF(gif_dest_struct)); |
| 466 | dest->cinfo = cinfo; /* make back link for subroutines */ |
| 467 | dest->pub.start_output = start_output_gif; |
| 468 | dest->pub.put_pixel_rows = put_pixel_rows; |
| 469 | dest->pub.finish_output = finish_output_gif; |
| 470 | |
| 471 | if (cinfo->out_color_space != JCS_GRAYSCALE && |
| 472 | cinfo->out_color_space != JCS_RGB) |
| 473 | ERREXIT(cinfo, JERR_GIF_COLORSPACE); |
| 474 | |
| 475 | /* Force quantization if color or if > 8 bits input */ |
| 476 | if (cinfo->out_color_space != JCS_GRAYSCALE || cinfo->data_precision > 8) { |
| 477 | /* Force quantization to at most 256 colors */ |
| 478 | cinfo->quantize_colors = TRUE; |
| 479 | if (cinfo->desired_number_of_colors > 256) |
| 480 | cinfo->desired_number_of_colors = 256; |
| 481 | } |
| 482 | |
| 483 | /* Calculate output image dimensions so we can allocate space */ |
| 484 | jpeg_calc_output_dimensions(cinfo); |
| 485 | |
| 486 | if (cinfo->output_components != 1) /* safety check: just one component? */ |
| 487 | ERREXIT(cinfo, JERR_GIF_BUG); |
| 488 | |
| 489 | /* Create decompressor output buffer. */ |
| 490 | dest->pub.buffer = (*cinfo->mem->alloc_sarray) |
| 491 | ((j_common_ptr) cinfo, JPOOL_IMAGE, cinfo->output_width, (JDIMENSION) 1); |
| 492 | dest->pub.buffer_height = 1; |
| 493 | |
| 494 | /* Allocate space for hash table */ |
| 495 | dest->hash_code = (code_int *) |
| 496 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| 497 | HSIZE * SIZEOF(code_int)); |
| 498 | dest->hash_value = (hash_entry FAR *) |
| 499 | (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| 500 | HSIZE * SIZEOF(hash_entry)); |
| 501 | |
| 502 | return (djpeg_dest_ptr) dest; |
| 503 | } |
| 504 | |
| 505 | #endif /* GIF_SUPPORTED */ |