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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, 2019, 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] = inptr[2]; /* RGB to BGR order */
106     outptr[1] = inptr[1];
107     outptr[2] = 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 
122   inptr = dest->pub.buffer[0];
123   outptr = dest->iobuffer;
124   MEMCOPY(outptr, inptr, cinfo->output_width);
125   (void)JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
126 }
127 
128 
129 /*
130  * Write some demapped pixel data when color quantization is in effect.
131  * For Targa, this is only applied to grayscale data.
132  */
133 
134 METHODDEF(void)
put_demapped_gray(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo,JDIMENSION rows_supplied)135 put_demapped_gray(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
136                   JDIMENSION rows_supplied)
137 {
138   tga_dest_ptr dest = (tga_dest_ptr)dinfo;
139   register JSAMPROW inptr;
140   register char *outptr;
141   register JSAMPROW color_map0 = cinfo->colormap[0];
142   register JDIMENSION col;
143 
144   inptr = dest->pub.buffer[0];
145   outptr = dest->iobuffer;
146   for (col = cinfo->output_width; col > 0; col--) {
147     *outptr++ = color_map0[*inptr++];
148   }
149   (void)JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
150 }
151 
152 
153 /*
154  * Startup: write the file header.
155  */
156 
157 METHODDEF(void)
start_output_tga(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo)158 start_output_tga(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
159 {
160   tga_dest_ptr dest = (tga_dest_ptr)dinfo;
161   int num_colors, i;
162   FILE *outfile;
163 
164   if (cinfo->out_color_space == JCS_GRAYSCALE) {
165     /* Targa doesn't have a mapped grayscale format, so we will */
166     /* demap quantized gray output.  Never emit a colormap. */
167     write_header(cinfo, dinfo, 0);
168     if (cinfo->quantize_colors)
169       dest->pub.put_pixel_rows = put_demapped_gray;
170     else
171       dest->pub.put_pixel_rows = put_gray_rows;
172   } else if (cinfo->out_color_space == JCS_RGB) {
173     if (cinfo->quantize_colors) {
174       /* We only support 8-bit colormap indexes, so only 256 colors */
175       num_colors = cinfo->actual_number_of_colors;
176       if (num_colors > 256)
177         ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, num_colors);
178       write_header(cinfo, dinfo, num_colors);
179       /* Write the colormap.  Note Targa uses BGR byte order */
180       outfile = dest->pub.output_file;
181       for (i = 0; i < num_colors; i++) {
182         putc(cinfo->colormap[2][i], outfile);
183         putc(cinfo->colormap[1][i], outfile);
184         putc(cinfo->colormap[0][i], outfile);
185       }
186       dest->pub.put_pixel_rows = put_gray_rows;
187     } else {
188       write_header(cinfo, dinfo, 0);
189       dest->pub.put_pixel_rows = put_pixel_rows;
190     }
191   } else {
192     ERREXIT(cinfo, JERR_TGA_COLORSPACE);
193   }
194 }
195 
196 
197 /*
198  * Finish up at the end of the file.
199  */
200 
201 METHODDEF(void)
finish_output_tga(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo)202 finish_output_tga(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
203 {
204   /* Make sure we wrote the output file OK */
205   fflush(dinfo->output_file);
206   if (ferror(dinfo->output_file))
207     ERREXIT(cinfo, JERR_FILE_WRITE);
208 }
209 
210 
211 /*
212  * Re-calculate buffer dimensions based on output dimensions.
213  */
214 
215 METHODDEF(void)
calc_buffer_dimensions_tga(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo)216 calc_buffer_dimensions_tga(j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
217 {
218   tga_dest_ptr dest = (tga_dest_ptr)dinfo;
219 
220   dest->buffer_width = cinfo->output_width * cinfo->output_components;
221 }
222 
223 
224 /*
225  * The module selection routine for Targa format output.
226  */
227 
228 GLOBAL(djpeg_dest_ptr)
jinit_write_targa(j_decompress_ptr cinfo)229 jinit_write_targa(j_decompress_ptr cinfo)
230 {
231   tga_dest_ptr dest;
232 
233   /* Create module interface object, fill in method pointers */
234   dest = (tga_dest_ptr)
235     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
236                                 sizeof(tga_dest_struct));
237   dest->pub.start_output = start_output_tga;
238   dest->pub.finish_output = finish_output_tga;
239   dest->pub.calc_buffer_dimensions = calc_buffer_dimensions_tga;
240 
241   /* Calculate output image dimensions so we can allocate space */
242   jpeg_calc_output_dimensions(cinfo);
243 
244   /* Create I/O buffer. */
245   dest->pub.calc_buffer_dimensions(cinfo, (djpeg_dest_ptr)dest);
246   dest->iobuffer = (char *)
247     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
248                                 (size_t)(dest->buffer_width * sizeof(char)));
249 
250   /* Create decompressor output buffer. */
251   dest->pub.buffer = (*cinfo->mem->alloc_sarray)
252     ((j_common_ptr)cinfo, JPOOL_IMAGE, dest->buffer_width, (JDIMENSION)1);
253   dest->pub.buffer_height = 1;
254 
255   return (djpeg_dest_ptr)dest;
256 }
257 
258 #endif /* TARGA_SUPPORTED */
259