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