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targa.c
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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 {
31 } TargaContext;
32 
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 
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 
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  if (bytestream2_get_bytes_left(&s->gb) <= idlen) {
136  av_log(avctx, AV_LOG_ERROR,
137  "Not enough data to read header\n");
138  return AVERROR_INVALIDDATA;
139  }
140 
141  flags = bytestream2_get_byte(&s->gb);
142 
143  if (!pal && (first_clr || colors || csize)) {
144  av_log(avctx, AV_LOG_WARNING, "File without colormap has colormap information set.\n");
145  // specification says we should ignore those value in this case
146  first_clr = colors = csize = 0;
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 = av_image_check_size(w, h, 0, avctx)) < 0)
177  return ret;
178  if (w != avctx->width || h != avctx->height)
179  avcodec_set_dimensions(avctx, w, h);
180  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
181  return ret;
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 
270  if (flags & TGA_RIGHTTOLEFT) { // right-to-left, needs horizontal flip
271  int x;
272  for (y = 0; y < h; y++) {
273  void *line = &p->data[0][y * p->linesize[0]];
274  for (x = 0; x < w >> 1; x++) {
275  switch (bpp) {
276  case 32:
277  FFSWAP(uint32_t, ((uint32_t *)line)[x], ((uint32_t *)line)[w - x - 1]);
278  break;
279  case 24:
280  FFSWAP(uint8_t, ((uint8_t *)line)[3 * x ], ((uint8_t *)line)[3 * w - 3 * x - 3]);
281  FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 1], ((uint8_t *)line)[3 * w - 3 * x - 2]);
282  FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 2], ((uint8_t *)line)[3 * w - 3 * x - 1]);
283  break;
284  case 16:
285  FFSWAP(uint16_t, ((uint16_t *)line)[x], ((uint16_t *)line)[w - x - 1]);
286  break;
287  case 8:
288  FFSWAP(uint8_t, ((uint8_t *)line)[x], ((uint8_t *)line)[w - x - 1]);
289  }
290  }
291  }
292  }
293 
294  *got_frame = 1;
295 
296  return avpkt->size;
297 }
298 
300  .name = "targa",
301  .type = AVMEDIA_TYPE_VIDEO,
302  .id = AV_CODEC_ID_TARGA,
303  .priv_data_size = sizeof(TargaContext),
304  .decode = decode_frame,
305  .capabilities = CODEC_CAP_DR1,
306  .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
307 };