1 /*
2 * Targa (.tga) image decoder
3 * Copyright (c) 2006 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "libavutil/intreadwrite.h"
23 #include "libavutil/imgutils.h"
24 #include "avcodec.h"
25 #include "bytestream.h"
26 #include "codec_internal.h"
27 #include "internal.h"
28 #include "targa.h"
29
30 typedef struct TargaContext {
31 GetByteContext gb;
32 } TargaContext;
33
advance_line(uint8_t *start, uint8_t *line, int stride, int *y, int h, int interleave)34 static uint8_t *advance_line(uint8_t *start, uint8_t *line,
35 int stride, int *y, int h, int interleave)
36 {
37 *y += interleave;
38
39 if (*y < h) {
40 return line + interleave * stride;
41 } else {
42 *y = (*y + 1) & (interleave - 1);
43 if (*y && *y < h) {
44 return start + *y * stride;
45 } else {
46 return NULL;
47 }
48 }
49 }
50
targa_decode_rle(AVCodecContext *avctx, TargaContext *s, uint8_t *start, int w, int h, int stride, int bpp, int interleave)51 static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s,
52 uint8_t *start, int w, int h, int stride,
53 int bpp, int interleave)
54 {
55 int x, y;
56 int depth = (bpp + 1) >> 3;
57 int type, count;
58 uint8_t *line = start;
59 uint8_t *dst = line;
60
61 x = y = count = 0;
62 while (dst) {
63 if (bytestream2_get_bytes_left(&s->gb) <= 0) {
64 av_log(avctx, AV_LOG_ERROR,
65 "Ran ouf of data before end-of-image\n");
66 return AVERROR_INVALIDDATA;
67 }
68 type = bytestream2_get_byteu(&s->gb);
69 count = (type & 0x7F) + 1;
70 type &= 0x80;
71 if (!type) {
72 do {
73 int n = FFMIN(count, w - x);
74 bytestream2_get_buffer(&s->gb, dst, n * depth);
75 count -= n;
76 dst += n * depth;
77 x += n;
78 if (x == w) {
79 x = 0;
80 dst = line = advance_line(start, line, stride, &y, h, interleave);
81 }
82 } while (dst && count > 0);
83 } else {
84 uint8_t tmp[4];
85 bytestream2_get_buffer(&s->gb, tmp, depth);
86 do {
87 int n = FFMIN(count, w - x);
88 count -= n;
89 x += n;
90 do {
91 memcpy(dst, tmp, depth);
92 dst += depth;
93 } while (--n);
94 if (x == w) {
95 x = 0;
96 dst = line = advance_line(start, line, stride, &y, h, interleave);
97 }
98 } while (dst && count > 0);
99 }
100 }
101
102 if (count) {
103 av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds\n");
104 return AVERROR_INVALIDDATA;
105 }
106
107 return 0;
108 }
109
decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, AVPacket *avpkt)110 static int decode_frame(AVCodecContext *avctx, AVFrame *p,
111 int *got_frame, AVPacket *avpkt)
112 {
113 TargaContext * const s = avctx->priv_data;
114 uint8_t *dst;
115 int stride;
116 int idlen, pal, compr, y, w, h, bpp, flags, ret;
117 int first_clr, colors, csize;
118 int interleave;
119 size_t img_size;
120
121 bytestream2_init(&s->gb, avpkt->data, avpkt->size);
122
123 /* parse image header */
124 idlen = bytestream2_get_byte(&s->gb);
125 pal = bytestream2_get_byte(&s->gb);
126 compr = bytestream2_get_byte(&s->gb);
127 first_clr = bytestream2_get_le16(&s->gb);
128 colors = bytestream2_get_le16(&s->gb);
129 csize = bytestream2_get_byte(&s->gb);
130 bytestream2_skip(&s->gb, 4); /* 2: x, 2: y */
131 w = bytestream2_get_le16(&s->gb);
132 h = bytestream2_get_le16(&s->gb);
133 bpp = bytestream2_get_byte(&s->gb);
134
135 flags = bytestream2_get_byte(&s->gb);
136
137 if (!pal && (first_clr || colors || csize)) {
138 av_log(avctx, AV_LOG_WARNING, "File without colormap has colormap information set.\n");
139 // specification says we should ignore those value in this case
140 first_clr = colors = csize = 0;
141 }
142
143 if (bytestream2_get_bytes_left(&s->gb) < idlen + 2*colors) {
144 av_log(avctx, AV_LOG_ERROR,
145 "Not enough data to read header\n");
146 return AVERROR_INVALIDDATA;
147 }
148
149 // skip identifier if any
150 bytestream2_skip(&s->gb, idlen);
151
152 switch (bpp) {
153 case 8:
154 avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? AV_PIX_FMT_GRAY8 : AV_PIX_FMT_PAL8;
155 break;
156 case 15:
157 case 16:
158 avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
159 break;
160 case 24:
161 avctx->pix_fmt = AV_PIX_FMT_BGR24;
162 break;
163 case 32:
164 avctx->pix_fmt = AV_PIX_FMT_BGRA;
165 break;
166 default:
167 av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", bpp);
168 return AVERROR_INVALIDDATA;
169 }
170
171 if (colors && (colors + first_clr) > 256) {
172 av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
173 return AVERROR_INVALIDDATA;
174 }
175
176 if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
177 return ret;
178
179 if ((compr & (~TGA_RLE)) == TGA_NODATA) {
180 return avpkt->size;
181 }
182
183 if (!(compr & TGA_RLE)) {
184 img_size = w * ((bpp + 1) >> 3);
185 if (bytestream2_get_bytes_left(&s->gb) < img_size * h) {
186 av_log(avctx, AV_LOG_ERROR,
187 "Not enough data available for image\n");
188 return AVERROR_INVALIDDATA;
189 }
190 }
191
192 if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
193 return ret;
194 p->pict_type = AV_PICTURE_TYPE_I;
195
196 if (flags & TGA_TOPTOBOTTOM) {
197 dst = p->data[0];
198 stride = p->linesize[0];
199 } else { //image is upside-down
200 dst = p->data[0] + p->linesize[0] * (h - 1);
201 stride = -p->linesize[0];
202 }
203
204 interleave = flags & TGA_INTERLEAVE2 ? 2 :
205 flags & TGA_INTERLEAVE4 ? 4 : 1;
206
207 if (colors) {
208 int pal_size, pal_sample_size;
209
210 switch (csize) {
211 case 32: pal_sample_size = 4; break;
212 case 24: pal_sample_size = 3; break;
213 case 16:
214 case 15: pal_sample_size = 2; break;
215 default:
216 av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
217 return AVERROR_INVALIDDATA;
218 }
219 pal_size = colors * pal_sample_size;
220 if (avctx->pix_fmt != AV_PIX_FMT_PAL8) //should not occur but skip palette anyway
221 bytestream2_skip(&s->gb, pal_size);
222 else {
223 int t;
224 uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;
225
226 if (bytestream2_get_bytes_left(&s->gb) < pal_size) {
227 av_log(avctx, AV_LOG_ERROR,
228 "Not enough data to read palette\n");
229 return AVERROR_INVALIDDATA;
230 }
231 switch (pal_sample_size) {
232 case 4:
233 for (t = 0; t < colors; t++)
234 *pal++ = bytestream2_get_le32u(&s->gb);
235 break;
236 case 3:
237 /* RGB24 */
238 for (t = 0; t < colors; t++)
239 *pal++ = (0xffU<<24) | bytestream2_get_le24u(&s->gb);
240 break;
241 case 2:
242 /* RGB555 */
243 for (t = 0; t < colors; t++) {
244 uint32_t v = bytestream2_get_le16u(&s->gb);
245 v = ((v & 0x7C00) << 9) |
246 ((v & 0x03E0) << 6) |
247 ((v & 0x001F) << 3);
248 /* left bit replication */
249 v |= (v & 0xE0E0E0U) >> 5;
250 *pal++ = (0xffU<<24) | v;
251 }
252 break;
253 }
254 p->palette_has_changed = 1;
255 }
256 }
257
258 if (compr & TGA_RLE) {
259 int res = targa_decode_rle(avctx, s, dst, w, h, stride, bpp, interleave);
260 if (res < 0)
261 return res;
262 } else {
263 uint8_t *line;
264 if (bytestream2_get_bytes_left(&s->gb) < img_size * h) {
265 av_log(avctx, AV_LOG_ERROR,
266 "Not enough data available for image\n");
267 return AVERROR_INVALIDDATA;
268 }
269
270 line = dst;
271 y = 0;
272 do {
273 bytestream2_get_buffer(&s->gb, line, img_size);
274 line = advance_line(dst, line, stride, &y, h, interleave);
275 } while (line);
276 }
277
278 if (flags & TGA_RIGHTTOLEFT) { // right-to-left, needs horizontal flip
279 int x;
280 for (y = 0; y < h; y++) {
281 void *line = &p->data[0][y * p->linesize[0]];
282 for (x = 0; x < w >> 1; x++) {
283 switch (bpp) {
284 case 32:
285 FFSWAP(uint32_t, ((uint32_t *)line)[x], ((uint32_t *)line)[w - x - 1]);
286 break;
287 case 24:
288 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x ], ((uint8_t *)line)[3 * w - 3 * x - 3]);
289 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 1], ((uint8_t *)line)[3 * w - 3 * x - 2]);
290 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 2], ((uint8_t *)line)[3 * w - 3 * x - 1]);
291 break;
292 case 16:
293 FFSWAP(uint16_t, ((uint16_t *)line)[x], ((uint16_t *)line)[w - x - 1]);
294 break;
295 case 8:
296 FFSWAP(uint8_t, ((uint8_t *)line)[x], ((uint8_t *)line)[w - x - 1]);
297 }
298 }
299 }
300 }
301
302
303 *got_frame = 1;
304
305 return avpkt->size;
306 }
307
308 const FFCodec ff_targa_decoder = {
309 .p.name = "targa",
310 .p.long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
311 .p.type = AVMEDIA_TYPE_VIDEO,
312 .p.id = AV_CODEC_ID_TARGA,
313 .p.capabilities = AV_CODEC_CAP_DR1,
314 .priv_data_size = sizeof(TargaContext),
315 FF_CODEC_DECODE_CB(decode_frame),
316 };
317