1 /* 2 * wrppm.c 3 * 4 * Copyright (C) 1991-1996, Thomas G. Lane. 5 * Modified 2009-2019 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 METHODDEF(void) 153 put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, 154 JDIMENSION rows_supplied) 155 { 156 ppm_dest_ptr dest = (ppm_dest_ptr) dinfo; 157 register char * bufferptr; 158 register JSAMPROW ptr; 159 register JSAMPROW color_map0 = cinfo->colormap[0]; 160 register JDIMENSION col; 161 162 ptr = dest->pub.buffer[0]; 163 bufferptr = dest->iobuffer; 164 for (col = cinfo->output_width; col > 0; col--) { 165 PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map0[GETJSAMPLE(*ptr++)])); 166 } 167 (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); 168 } 169 170 171 /* 172 * Startup: write the file header. 173 */ 174 175 METHODDEF(void) 176 start_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) 177 { 178 /* Emit file header */ 179 switch (cinfo->out_color_space) { 180 case JCS_GRAYSCALE: 181 /* emit header for raw PGM format */ 182 fprintf(dinfo->output_file, "P5\n%ld %ld\n%d\n", 183 (long) cinfo->output_width, (long) cinfo->output_height, 184 PPM_MAXVAL); 185 break; 186 case JCS_RGB: 187 /* emit header for raw PPM format */ 188 fprintf(dinfo->output_file, "P6\n%ld %ld\n%d\n", 189 (long) cinfo->output_width, (long) cinfo->output_height, 190 PPM_MAXVAL); 191 break; 192 default: 193 ERREXIT(cinfo, JERR_PPM_COLORSPACE); 194 } 195 } 196 197 198 /* 199 * Finish up at the end of the file. 200 */ 201 202 METHODDEF(void) 203 finish_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) 204 { 205 /* Make sure we wrote the output file OK */ 206 JFFLUSH(dinfo->output_file); 207 if (JFERROR(dinfo->output_file)) 208 ERREXIT(cinfo, JERR_FILE_WRITE); 209 } 210 211 212 /* 213 * The module selection routine for PPM format output. 214 */ 215 216 GLOBAL(djpeg_dest_ptr) 217 jinit_write_ppm (j_decompress_ptr cinfo) 218 { 219 ppm_dest_ptr dest; 220 221 /* Create module interface object, fill in method pointers */ 222 dest = (ppm_dest_ptr) (*cinfo->mem->alloc_small) 223 ((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(ppm_dest_struct)); 224 dest->pub.start_output = start_output_ppm; 225 dest->pub.finish_output = finish_output_ppm; 226 227 /* Calculate output image dimensions so we can allocate space */ 228 jpeg_calc_output_dimensions(cinfo); 229 230 /* Create physical I/O buffer. Note we make this near on a PC. */ 231 dest->samples_per_row = cinfo->output_width * cinfo->out_color_components; 232 dest->buffer_width = dest->samples_per_row * (BYTESPERSAMPLE * SIZEOF(char)); 233 dest->iobuffer = (char *) (*cinfo->mem->alloc_small) 234 ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width); 235 236 if (cinfo->quantize_colors || BITS_IN_JSAMPLE != 8 || 237 SIZEOF(JSAMPLE) != SIZEOF(char)) { 238 /* When quantizing, we need an output buffer for colormap indexes 239 * that's separate from the physical I/O buffer. We also need a 240 * separate buffer if pixel format translation must take place. 241 */ 242 dest->pub.buffer = (*cinfo->mem->alloc_sarray) 243 ((j_common_ptr) cinfo, JPOOL_IMAGE, 244 cinfo->output_width * cinfo->output_components, (JDIMENSION) 1); 245 dest->pub.buffer_height = 1; 246 if (! cinfo->quantize_colors) 247 dest->pub.put_pixel_rows = copy_pixel_rows; 248 else if (cinfo->out_color_space == JCS_GRAYSCALE) 249 dest->pub.put_pixel_rows = put_demapped_gray; 250 else 251 dest->pub.put_pixel_rows = put_demapped_rgb; 252 } else { 253 /* We will fwrite() directly from decompressor output buffer. */ 254 /* Synthesize a JSAMPARRAY pointer structure */ 255 /* Cast here implies near->far pointer conversion on PCs */ 256 dest->pixrow = (JSAMPROW) dest->iobuffer; 257 dest->pub.buffer = & dest->pixrow; 258 dest->pub.buffer_height = 1; 259 dest->pub.put_pixel_rows = put_pixel_rows; 260 } 261 262 return &dest->pub; 263 } 264 265 #endif /* PPM_SUPPORTED */ 266