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