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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)
write_header(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo,int num_colors)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)
put_pixel_rows(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo,JDIMENSION rows_supplied)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)
put_gray_rows(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo,JDIMENSION rows_supplied)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)
put_demapped_gray(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo,JDIMENSION rows_supplied)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)
start_output_tga(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo)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)
finish_output_tga(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo)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)
calc_buffer_dimensions_tga(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo)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)
jinit_write_targa(j_decompress_ptr cinfo)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