1 /* 2 * wrtarga.c 3 * 4 * This file was part of the Independent JPEG Group's software: 5 * Copyright (C) 1991-1996, Thomas G. Lane. 6 * libjpeg-turbo Modifications: 7 * Copyright (C) 2017, D. R. Commander. 8 * For conditions of distribution and use, see the accompanying README.ijg 9 * file. 10 * 11 * This file contains routines to write output images in Targa format. 12 * 13 * These routines may need modification for non-Unix environments or 14 * specialized applications. As they stand, they assume output to 15 * an ordinary stdio stream. 16 * 17 * Based on code contributed by Lee Daniel Crocker. 18 */ 19 20 #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ 21 22 #ifdef TARGA_SUPPORTED 23 24 25 /* 26 * To support 12-bit JPEG data, we'd have to scale output down to 8 bits. 27 * This is not yet implemented. 28 */ 29 30 #if BITS_IN_JSAMPLE != 8 31 Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */ 32 #endif 33 34 35 /* Private version of data destination object */ 36 37 typedef struct { 38 struct djpeg_dest_struct pub; /* public fields */ 39 40 char *iobuffer; /* physical I/O buffer */ 41 JDIMENSION buffer_width; /* width of one row */ 42 } tga_dest_struct; 43 44 typedef tga_dest_struct *tga_dest_ptr; 45 46 47 LOCAL(void) 48 write_header (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, int num_colors) 49 /* Create and write a Targa header */ 50 { 51 char targaheader[18]; 52 53 /* Set unused fields of header to 0 */ 54 MEMZERO(targaheader, sizeof(targaheader)); 55 56 if (num_colors > 0) { 57 targaheader[1] = 1; /* color map type 1 */ 58 targaheader[5] = (char) (num_colors & 0xFF); 59 targaheader[6] = (char) (num_colors >> 8); 60 targaheader[7] = 24; /* 24 bits per cmap entry */ 61 } 62 63 targaheader[12] = (char) (cinfo->output_width & 0xFF); 64 targaheader[13] = (char) (cinfo->output_width >> 8); 65 targaheader[14] = (char) (cinfo->output_height & 0xFF); 66 targaheader[15] = (char) (cinfo->output_height >> 8); 67 targaheader[17] = 0x20; /* Top-down, non-interlaced */ 68 69 if (cinfo->out_color_space == JCS_GRAYSCALE) { 70 targaheader[2] = 3; /* image type = uncompressed grayscale */ 71 targaheader[16] = 8; /* bits per pixel */ 72 } else { /* must be RGB */ 73 if (num_colors > 0) { 74 targaheader[2] = 1; /* image type = colormapped RGB */ 75 targaheader[16] = 8; 76 } else { 77 targaheader[2] = 2; /* image type = uncompressed RGB */ 78 targaheader[16] = 24; 79 } 80 } 81 82 if (JFWRITE(dinfo->output_file, targaheader, 18) != (size_t) 18) 83 ERREXIT(cinfo, JERR_FILE_WRITE); 84 } 85 86 87 /* 88 * Write some pixel data. 89 * In this module rows_supplied will always be 1. 90 */ 91 92 METHODDEF(void) 93 put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, 94 JDIMENSION rows_supplied) 95 /* used for unquantized full-color output */ 96 { 97 tga_dest_ptr dest = (tga_dest_ptr) dinfo; 98 register JSAMPROW inptr; 99 register char *outptr; 100 register JDIMENSION col; 101 102 inptr = dest->pub.buffer[0]; 103 outptr = dest->iobuffer; 104 for (col = cinfo->output_width; col > 0; col--) { 105 outptr[0] = (char) GETJSAMPLE(inptr[2]); /* RGB to BGR order */ 106 outptr[1] = (char) GETJSAMPLE(inptr[1]); 107 outptr[2] = (char) GETJSAMPLE(inptr[0]); 108 inptr += 3, outptr += 3; 109 } 110 (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); 111 } 112 113 METHODDEF(void) 114 put_gray_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, 115 JDIMENSION rows_supplied) 116 /* used for grayscale OR quantized color output */ 117 { 118 tga_dest_ptr dest = (tga_dest_ptr) dinfo; 119 register JSAMPROW inptr; 120 register char *outptr; 121 register JDIMENSION col; 122 123 inptr = dest->pub.buffer[0]; 124 outptr = dest->iobuffer; 125 for (col = cinfo->output_width; col > 0; col--) { 126 *outptr++ = (char) GETJSAMPLE(*inptr++); 127 } 128 (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); 129 } 130 131 132 /* 133 * Write some demapped pixel data when color quantization is in effect. 134 * For Targa, this is only applied to grayscale data. 135 */ 136 137 METHODDEF(void) 138 put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, 139 JDIMENSION rows_supplied) 140 { 141 tga_dest_ptr dest = (tga_dest_ptr) dinfo; 142 register JSAMPROW inptr; 143 register char *outptr; 144 register JSAMPROW color_map0 = cinfo->colormap[0]; 145 register JDIMENSION col; 146 147 inptr = dest->pub.buffer[0]; 148 outptr = dest->iobuffer; 149 for (col = cinfo->output_width; col > 0; col--) { 150 *outptr++ = (char) GETJSAMPLE(color_map0[GETJSAMPLE(*inptr++)]); 151 } 152 (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width); 153 } 154 155 156 /* 157 * Startup: write the file header. 158 */ 159 160 METHODDEF(void) 161 start_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) 162 { 163 tga_dest_ptr dest = (tga_dest_ptr) dinfo; 164 int num_colors, i; 165 FILE *outfile; 166 167 if (cinfo->out_color_space == JCS_GRAYSCALE) { 168 /* Targa doesn't have a mapped grayscale format, so we will */ 169 /* demap quantized gray output. Never emit a colormap. */ 170 write_header(cinfo, dinfo, 0); 171 if (cinfo->quantize_colors) 172 dest->pub.put_pixel_rows = put_demapped_gray; 173 else 174 dest->pub.put_pixel_rows = put_gray_rows; 175 } else if (cinfo->out_color_space == JCS_RGB) { 176 if (cinfo->quantize_colors) { 177 /* We only support 8-bit colormap indexes, so only 256 colors */ 178 num_colors = cinfo->actual_number_of_colors; 179 if (num_colors > 256) 180 ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, num_colors); 181 write_header(cinfo, dinfo, num_colors); 182 /* Write the colormap. Note Targa uses BGR byte order */ 183 outfile = dest->pub.output_file; 184 for (i = 0; i < num_colors; i++) { 185 putc(GETJSAMPLE(cinfo->colormap[2][i]), outfile); 186 putc(GETJSAMPLE(cinfo->colormap[1][i]), outfile); 187 putc(GETJSAMPLE(cinfo->colormap[0][i]), outfile); 188 } 189 dest->pub.put_pixel_rows = put_gray_rows; 190 } else { 191 write_header(cinfo, dinfo, 0); 192 dest->pub.put_pixel_rows = put_pixel_rows; 193 } 194 } else { 195 ERREXIT(cinfo, JERR_TGA_COLORSPACE); 196 } 197 } 198 199 200 /* 201 * Finish up at the end of the file. 202 */ 203 204 METHODDEF(void) 205 finish_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) 206 { 207 /* Make sure we wrote the output file OK */ 208 fflush(dinfo->output_file); 209 if (ferror(dinfo->output_file)) 210 ERREXIT(cinfo, JERR_FILE_WRITE); 211 } 212 213 214 /* 215 * Re-calculate buffer dimensions based on output dimensions. 216 */ 217 218 METHODDEF(void) 219 calc_buffer_dimensions_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo) 220 { 221 tga_dest_ptr dest = (tga_dest_ptr) dinfo; 222 223 dest->buffer_width = cinfo->output_width * cinfo->output_components; 224 } 225 226 227 /* 228 * The module selection routine for Targa format output. 229 */ 230 231 GLOBAL(djpeg_dest_ptr) 232 jinit_write_targa (j_decompress_ptr cinfo) 233 { 234 tga_dest_ptr dest; 235 236 /* Create module interface object, fill in method pointers */ 237 dest = (tga_dest_ptr) 238 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 239 sizeof(tga_dest_struct)); 240 dest->pub.start_output = start_output_tga; 241 dest->pub.finish_output = finish_output_tga; 242 dest->pub.calc_buffer_dimensions = calc_buffer_dimensions_tga; 243 244 /* Calculate output image dimensions so we can allocate space */ 245 jpeg_calc_output_dimensions(cinfo); 246 247 /* Create I/O buffer. */ 248 dest->pub.calc_buffer_dimensions (cinfo, (djpeg_dest_ptr) dest); 249 dest->iobuffer = (char *) 250 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 251 (size_t) (dest->buffer_width * sizeof(char))); 252 253 /* Create decompressor output buffer. */ 254 dest->pub.buffer = (*cinfo->mem->alloc_sarray) 255 ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width, (JDIMENSION) 1); 256 dest->pub.buffer_height = 1; 257 258 return (djpeg_dest_ptr) dest; 259 } 260 261 #endif /* TARGA_SUPPORTED */ 262
