1 /* 2 * wrppm.c 3 * 4 * Copyright (C) 1991-1996, Thomas G. Lane. 5 * Modified 2009 by Guido Vollbeding. 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 routines to write output images in PPM/PGM format. 10 * The extended 2-byte-per-sample raw PPM/PGM formats are supported. 11 * The PBMPLUS library is NOT required to compile this software 12 * (but it is highly useful as a set of PPM image manipulation programs). 13 * 14 * These routines may need modification for non-Unix environments or 15 * specialized applications. As they stand, they assume output to 16 * an ordinary stdio stream. 17 */ 18 19 #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ 20 21 #ifdef PPM_SUPPORTED 22 23 24 /* 25 * For 12-bit JPEG data, we either downscale the values to 8 bits 26 * (to write standard byte-per-sample PPM/PGM files), or output 27 * nonstandard word-per-sample PPM/PGM files. Downscaling is done 28 * if PPM_NORAWWORD is defined (this can be done in the Makefile 29 * or in jconfig.h). 30 * (When the core library supports data precision reduction, a cleaner 31 * implementation will be to ask for that instead.) 32 */ 33 34 #if BITS_IN_JSAMPLE == 8 35 #define PUTPPMSAMPLE(ptr,v) *ptr++ = (char) (v) 36 #define BYTESPERSAMPLE 1 37 #define PPM_MAXVAL 255 38 #else 39 #ifdef PPM_NORAWWORD 40 #define PUTPPMSAMPLE(ptr,v) *ptr++ = (char) ((v) >> (BITS_IN_JSAMPLE-8)) 41 #define BYTESPERSAMPLE 1 42 #define PPM_MAXVAL 255 43 #else 44 /* The word-per-sample format always puts the MSB first. */ 45 #define PUTPPMSAMPLE(ptr,v) \ 46 { register int val_ = v; \ 47 *ptr++ = (char) ((val_ >> 8) & 0xFF); \ 48 *ptr++ = (char) (val_ & 0xFF); \ 49 } 50 #define BYTESPERSAMPLE 2 51 #define PPM_MAXVAL ((1<<BITS_IN_JSAMPLE)-1) 52 #endif 53 #endif 54 55 56 /* 57 * When JSAMPLE is the same size as char, we can just fwrite() the 58 * decompressed data to the PPM or PGM file. On PCs, in order to make this 59 * work the output buffer must be allocated in near data space, because we are 60 * assuming small-data memory model wherein fwrite() can't reach far memory. 61 * If you need to process very wide images on a PC, you might have to compile 62 * in large-memory model, or else replace fwrite() with a putc() loop --- 63 * which will be much slower. 64 */ 65 66 67 /* Private version of data destination object */ 68 69 typedef struct { 70 struct djpeg_dest_struct pub; /* public fields */ 71 72 /* Usually these two pointers point to the same place: */ 73 char *iobuffer; /* fwrite's I/O buffer */ 74 JSAMPROW pixrow; /* decompressor output buffer */ 75 size_t buffer_width; /* width of I/O buffer */ 76 JDIMENSION samples_per_row; /* JSAMPLEs per output row */ 77 } ppm_dest_struct; 78 79 typedef ppm_dest_struct * ppm_dest_ptr; 80 81 82 /* 83 * Write some pixel data. 84 * In this module rows_supplied will always be 1. 85 * 86 * put_pixel_rows handles the "normal" 8-bit case where the decompressor 87 * output buffer is physically the same as the fwrite buffer. 88 */ 89 90 METHODDEF(void) 91 put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, 92 JDIMENSION rows_supplied) 93 { 94 ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; 95 96 (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); 97 } 98 99 100 /* 101 * This code is used when we have to copy the data and apply a pixel 102 * format translation. Typically this only happens in 12-bit mode. 103 */ 104 105 METHODDEF(void) 106 copy_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, 107 JDIMENSION rows_supplied) 108 { 109 ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; 110 register char * bufferptr; 111 register JSAMPROW ptr; 112 register JDIMENSION col; 113 114 ptr = dest->pub.buffer[0]; 115 bufferptr = dest->iobuffer; 116 for (col = dest->samples_per_row; col > 0; col--) { 117 PUTPPMSAMPLE(bufferptr, GETJSAMPLE(*ptr++)); 118 } 119 (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); 120 } 121 122 123 /* 124 * Write some pixel data when color quantization is in effect. 125 * We have to demap the color index values to straight data. 126 */ 127 128 METHODDEF(void) 129 put_demapped_rgb (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, 130 JDIMENSION rows_supplied) 131 { 132 ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; 133 register char * bufferptr; 134 register int pixval; 135 register JSAMPROW ptr; 136 register JSAMPROW color_map0 = cinfo->colormap[0]; 137 register JSAMPROW color_map1 = cinfo->colormap[1]; 138 register JSAMPROW color_map2 = cinfo->colormap[2]; 139 register JDIMENSION col; 140 141 ptr = dest->pub.buffer[0]; 142 bufferptr = dest->iobuffer; 143 for (col = cinfo->output_width; col > 0; col--) { 144 pixval = GETJSAMPLE(*ptr++); 145 PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map0[pixval])); 146 PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map1[pixval])); 147 PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map2[pixval])); 148 } 149 (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); 150 } 151 152 153 METHODDEF(void) 154 put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, 155 JDIMENSION rows_supplied) 156 { 157 ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; 158 register char * bufferptr; 159 register JSAMPROW ptr; 160 register JSAMPROW color_map = cinfo->colormap[0]; 161 register JDIMENSION col; 162 163 ptr = dest->pub.buffer[0]; 164 bufferptr = dest->iobuffer; 165 for (col = cinfo->output_width; col > 0; col--) { 166 PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)])); 167 } 168 (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); 169 } 170 171 172 /* 173 * Startup: write the file header. 174 */ 175 176 METHODDEF(void) 177 start_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) 178 { 179 ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; 180 181 /* Emit file header */ 182 switch (cinfo->out_color_space) { 183 case JCS_GRAYSCALE: 184 /* emit header for raw PGM format */ 185 fprintf(dest->pub.output_file, "P5\n%ld %ld\n%d\n", 186 (long) cinfo->output_width, (long) cinfo->output_height, 187 PPM_MAXVAL); 188 break; 189 case JCS_RGB: 190 /* emit header for raw PPM format */ 191 fprintf(dest->pub.output_file, "P6\n%ld %ld\n%d\n", 192 (long) cinfo->output_width, (long) cinfo->output_height, 193 PPM_MAXVAL); 194 break; 195 default: 196 ERREXIT(cinfo, JERR_PPM_COLORSPACE); 197 } 198 } 199 200 201 /* 202 * Finish up at the end of the file. 203 */ 204 205 METHODDEF(void) 206 finish_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) 207 { 208 /* Make sure we wrote the output file OK */ 209 fflush(dinfo->output_file); 210 if (ferror(dinfo->output_file)) 211 ERREXIT(cinfo, JERR_FILE_WRITE); 212 } 213 214 215 /* 216 * The module selection routine for PPM format output. 217 */ 218 219 GLOBAL(djpeg_dest_ptr) 220 jinit_write_ppm (j_decompress_ptr cinfo) 221 { 222 ppm_dest_ptr dest; 223 224 /* Create module interface object, fill in method pointers */ 225 dest = (ppm_dest_ptr) 226 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 227 SIZEOF(ppm_dest_struct)); 228 dest->pub.start_output = start_output_ppm; 229 dest->pub.finish_output = finish_output_ppm; 230 231 /* Calculate output image dimensions so we can allocate space */ 232 jpeg_calc_output_dimensions(cinfo); 233 234 /* Create physical I/O buffer. Note we make this near on a PC. */ 235 dest->samples_per_row = cinfo->output_width * cinfo->out_color_components; 236 dest->buffer_width = dest->samples_per_row * (BYTESPERSAMPLE * SIZEOF(char)); 237 dest->iobuffer = (char *) (*cinfo->mem->alloc_small) 238 ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width); 239 240 if (cinfo->quantize_colors || BITS_IN_JSAMPLE != 8 || 241 SIZEOF(JSAMPLE) != SIZEOF(char)) { 242 /* When quantizing, we need an output buffer for colormap indexes 243 * that's separate from the physical I/O buffer. We also need a 244 * separate buffer if pixel format translation must take place. 245 */ 246 dest->pub.buffer = (*cinfo->mem->alloc_sarray) 247 ((j_common_ptr) cinfo, JPOOL_IMAGE, 248 cinfo->output_width * cinfo->output_components, (JDIMENSION) 1); 249 dest->pub.buffer_height = 1; 250 if (! cinfo->quantize_colors) 251 dest->pub.put_pixel_rows = copy_pixel_rows; 252 else if (cinfo->out_color_space == JCS_GRAYSCALE) 253 dest->pub.put_pixel_rows = put_demapped_gray; 254 else 255 dest->pub.put_pixel_rows = put_demapped_rgb; 256 } else { 257 /* We will fwrite() directly from decompressor output buffer. */ 258 /* Synthesize a JSAMPARRAY pointer structure */ 259 /* Cast here implies near->far pointer conversion on PCs */ 260 dest->pixrow = (JSAMPROW) dest->iobuffer; 261 dest->pub.buffer = & dest->pixrow; 262 dest->pub.buffer_height = 1; 263 dest->pub.put_pixel_rows = put_pixel_rows; 264 } 265 266 return (djpeg_dest_ptr) dest; 267 } 268 269 #endif /* PPM_SUPPORTED */ 270
