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 "internal.h"
27 #include "targa.h"
28
29 typedef struct TargaContext {
30 GetByteContext gb;
31 } TargaContext;
32
advance_line(uint8_t * start,uint8_t * line,int stride,int * y,int h,int interleave)33 static uint8_t *advance_line(uint8_t *start, uint8_t *line,
34 int stride, int *y, int h, int interleave)
35 {
36 *y += interleave;
37
38 if (*y < h) {
39 return line + interleave * stride;
40 } else {
41 *y = (*y + 1) & (interleave - 1);
42 if (*y && *y < h) {
43 return start + *y * stride;
44 } else {
45 return NULL;
46 }
47 }
48 }
49
targa_decode_rle(AVCodecContext * avctx,TargaContext * s,uint8_t * start,int w,int h,int stride,int bpp,int interleave)50 static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s,
51 uint8_t *start, int w, int h, int stride,
52 int bpp, int interleave)
53 {
54 int x, y;
55 int depth = (bpp + 1) >> 3;
56 int type, count;
57 uint8_t *line = start;
58 uint8_t *dst = line;
59
60 x = y = count = 0;
61 while (dst) {
62 if (bytestream2_get_bytes_left(&s->gb) <= 0) {
63 av_log(avctx, AV_LOG_ERROR,
64 "Ran ouf of data before end-of-image\n");
65 return AVERROR_INVALIDDATA;
66 }
67 type = bytestream2_get_byteu(&s->gb);
68 count = (type & 0x7F) + 1;
69 type &= 0x80;
70 if (!type) {
71 do {
72 int n = FFMIN(count, w - x);
73 bytestream2_get_buffer(&s->gb, dst, n * depth);
74 count -= n;
75 dst += n * depth;
76 x += n;
77 if (x == w) {
78 x = 0;
79 dst = line = advance_line(start, line, stride, &y, h, interleave);
80 }
81 } while (dst && count > 0);
82 } else {
83 uint8_t tmp[4];
84 bytestream2_get_buffer(&s->gb, tmp, depth);
85 do {
86 int n = FFMIN(count, w - x);
87 count -= n;
88 x += n;
89 do {
90 memcpy(dst, tmp, depth);
91 dst += depth;
92 } while (--n);
93 if (x == w) {
94 x = 0;
95 dst = line = advance_line(start, line, stride, &y, h, interleave);
96 }
97 } while (dst && count > 0);
98 }
99 }
100
101 if (count) {
102 av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds\n");
103 return AVERROR_INVALIDDATA;
104 }
105
106 return 0;
107 }
108
decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)109 static int decode_frame(AVCodecContext *avctx,
110 void *data, int *got_frame,
111 AVPacket *avpkt)
112 {
113 TargaContext * const s = avctx->priv_data;
114 AVFrame * const p = data;
115 uint8_t *dst;
116 int stride;
117 int idlen, pal, compr, y, w, h, bpp, flags, ret;
118 int first_clr, colors, csize;
119 int interleave;
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 ((ret = ff_get_buffer(avctx, p, 0)) < 0)
180 return ret;
181 p->pict_type = AV_PICTURE_TYPE_I;
182
183 if (flags & TGA_TOPTOBOTTOM) {
184 dst = p->data[0];
185 stride = p->linesize[0];
186 } else { //image is upside-down
187 dst = p->data[0] + p->linesize[0] * (h - 1);
188 stride = -p->linesize[0];
189 }
190
191 interleave = flags & TGA_INTERLEAVE2 ? 2 :
192 flags & TGA_INTERLEAVE4 ? 4 : 1;
193
194 if (colors) {
195 int pal_size, pal_sample_size;
196
197 switch (csize) {
198 case 32: pal_sample_size = 4; break;
199 case 24: pal_sample_size = 3; break;
200 case 16:
201 case 15: pal_sample_size = 2; break;
202 default:
203 av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
204 return AVERROR_INVALIDDATA;
205 }
206 pal_size = colors * pal_sample_size;
207 if (avctx->pix_fmt != AV_PIX_FMT_PAL8) //should not occur but skip palette anyway
208 bytestream2_skip(&s->gb, pal_size);
209 else {
210 int t;
211 uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;
212
213 if (bytestream2_get_bytes_left(&s->gb) < pal_size) {
214 av_log(avctx, AV_LOG_ERROR,
215 "Not enough data to read palette\n");
216 return AVERROR_INVALIDDATA;
217 }
218 switch (pal_sample_size) {
219 case 4:
220 for (t = 0; t < colors; t++)
221 *pal++ = bytestream2_get_le32u(&s->gb);
222 break;
223 case 3:
224 /* RGB24 */
225 for (t = 0; t < colors; t++)
226 *pal++ = (0xffU<<24) | bytestream2_get_le24u(&s->gb);
227 break;
228 case 2:
229 /* RGB555 */
230 for (t = 0; t < colors; t++) {
231 uint32_t v = bytestream2_get_le16u(&s->gb);
232 v = ((v & 0x7C00) << 9) |
233 ((v & 0x03E0) << 6) |
234 ((v & 0x001F) << 3);
235 /* left bit replication */
236 v |= (v & 0xE0E0E0U) >> 5;
237 *pal++ = (0xffU<<24) | v;
238 }
239 break;
240 }
241 p->palette_has_changed = 1;
242 }
243 }
244
245 if ((compr & (~TGA_RLE)) == TGA_NODATA) {
246 memset(p->data[0], 0, p->linesize[0] * h);
247 } else {
248 if (compr & TGA_RLE) {
249 int res = targa_decode_rle(avctx, s, dst, w, h, stride, bpp, interleave);
250 if (res < 0)
251 return res;
252 } else {
253 size_t img_size = w * ((bpp + 1) >> 3);
254 uint8_t *line;
255 if (bytestream2_get_bytes_left(&s->gb) < img_size * h) {
256 av_log(avctx, AV_LOG_ERROR,
257 "Not enough data available for image\n");
258 return AVERROR_INVALIDDATA;
259 }
260
261 line = dst;
262 y = 0;
263 do {
264 bytestream2_get_buffer(&s->gb, line, img_size);
265 line = advance_line(dst, line, stride, &y, h, interleave);
266 } while (line);
267 }
268
269 if (flags & TGA_RIGHTTOLEFT) { // right-to-left, needs horizontal flip
270 int x;
271 for (y = 0; y < h; y++) {
272 void *line = &p->data[0][y * p->linesize[0]];
273 for (x = 0; x < w >> 1; x++) {
274 switch (bpp) {
275 case 32:
276 FFSWAP(uint32_t, ((uint32_t *)line)[x], ((uint32_t *)line)[w - x - 1]);
277 break;
278 case 24:
279 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x ], ((uint8_t *)line)[3 * w - 3 * x - 3]);
280 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 1], ((uint8_t *)line)[3 * w - 3 * x - 2]);
281 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 2], ((uint8_t *)line)[3 * w - 3 * x - 1]);
282 break;
283 case 16:
284 FFSWAP(uint16_t, ((uint16_t *)line)[x], ((uint16_t *)line)[w - x - 1]);
285 break;
286 case 8:
287 FFSWAP(uint8_t, ((uint8_t *)line)[x], ((uint8_t *)line)[w - x - 1]);
288 }
289 }
290 }
291 }
292 }
293
294
295 *got_frame = 1;
296
297 return avpkt->size;
298 }
299
300 AVCodec ff_targa_decoder = {
301 .name = "targa",
302 .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
303 .type = AVMEDIA_TYPE_VIDEO,
304 .id = AV_CODEC_ID_TARGA,
305 .priv_data_size = sizeof(TargaContext),
306 .decode = decode_frame,
307 .capabilities = AV_CODEC_CAP_DR1,
308 };
309