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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 "targa.h"
27 
28 typedef struct TargaContext {
30 
31  int width, height;
32  int bpp;
35 } TargaContext;
36 
37 #define CHECK_BUFFER_SIZE(buf, buf_end, needed, where) \
38  if(needed > buf_end - buf){ \
39  av_log(avctx, AV_LOG_ERROR, "Problem: unexpected end of data while reading " where "\n"); \
40  return -1; \
41  } \
42 
43 static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s, const uint8_t *src, int src_size, uint8_t *dst, int w, int h, int stride, int bpp)
44 {
45  int i, x, y;
46  int depth = (bpp + 1) >> 3;
47  int type, count;
48  int diff;
49  const uint8_t *src_end = src + src_size;
50 
51  diff = stride - w * depth;
52  x = y = 0;
53  while(y < h){
54  CHECK_BUFFER_SIZE(src, src_end, 1, "image type");
55  type = *src++;
56  count = (type & 0x7F) + 1;
57  type &= 0x80;
58  if((x + count > w) && (x + count + 1 > (h - y) * w)){
59  av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds: position (%i,%i) size %i\n", x, y, count);
60  return -1;
61  }
62  if(type){
63  CHECK_BUFFER_SIZE(src, src_end, depth, "image data");
64  }else{
65  CHECK_BUFFER_SIZE(src, src_end, count * depth, "image data");
66  }
67  for(i = 0; i < count; i++){
68  switch(depth){
69  case 1:
70  *dst = *src;
71  break;
72  case 2:
73  *((uint16_t*)dst) = AV_RL16(src);
74  break;
75  case 3:
76  dst[0] = src[0];
77  dst[1] = src[1];
78  dst[2] = src[2];
79  break;
80  case 4:
81  *((uint32_t*)dst) = AV_RL32(src);
82  break;
83  }
84  dst += depth;
85  if(!type)
86  src += depth;
87 
88  x++;
89  if(x == w){
90  x = 0;
91  y++;
92  dst += diff;
93  }
94  }
95  if(type)
96  src += depth;
97  }
98  return src_size;
99 }
100 
101 static int decode_frame(AVCodecContext *avctx,
102  void *data, int *data_size,
103  AVPacket *avpkt)
104 {
105  const uint8_t *buf = avpkt->data;
106  const uint8_t *buf_end = avpkt->data + avpkt->size;
107  TargaContext * const s = avctx->priv_data;
108  AVFrame *picture = data;
109  AVFrame * const p= (AVFrame*)&s->picture;
110  uint8_t *dst;
111  int stride;
112  int idlen, compr, y, w, h, bpp, flags;
113  int first_clr, colors, csize;
114 
115  /* parse image header */
116  CHECK_BUFFER_SIZE(buf, buf_end, 18, "header");
117  idlen = *buf++;
118  buf++; /* pal */
119  compr = *buf++;
120  first_clr = AV_RL16(buf); buf += 2;
121  colors = AV_RL16(buf); buf += 2;
122  csize = *buf++;
123  buf += 2; /* x */
124  y = AV_RL16(buf); buf += 2;
125  w = AV_RL16(buf); buf += 2;
126  h = AV_RL16(buf); buf += 2;
127  bpp = *buf++;
128  flags = *buf++;
129  //skip identifier if any
130  CHECK_BUFFER_SIZE(buf, buf_end, idlen, "identifiers");
131  buf += idlen;
132  s->bpp = bpp;
133  s->width = w;
134  s->height = h;
135  switch(s->bpp){
136  case 8:
137  avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? PIX_FMT_GRAY8 : PIX_FMT_PAL8;
138  break;
139  case 15:
140  avctx->pix_fmt = PIX_FMT_RGB555;
141  break;
142  case 16:
143  avctx->pix_fmt = PIX_FMT_RGB555;
144  break;
145  case 24:
146  avctx->pix_fmt = PIX_FMT_BGR24;
147  break;
148  case 32:
149  avctx->pix_fmt = PIX_FMT_RGB32;
150  break;
151  default:
152  av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", s->bpp);
153  return -1;
154  }
155 
156  if(s->picture.data[0])
157  avctx->release_buffer(avctx, &s->picture);
158 
159  if(av_image_check_size(w, h, 0, avctx))
160  return -1;
161  if(w != avctx->width || h != avctx->height)
162  avcodec_set_dimensions(avctx, w, h);
163  if(avctx->get_buffer(avctx, p) < 0){
164  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
165  return -1;
166  }
167  if(flags & 0x20){
168  dst = p->data[0];
169  stride = p->linesize[0];
170  }else{ //image is upside-down
171  dst = p->data[0] + p->linesize[0] * (h - 1);
172  stride = -p->linesize[0];
173  }
174 
175  if(colors){
176  int pal_size, pal_sample_size;
177  if((colors + first_clr) > 256){
178  av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);
179  return -1;
180  }
181  switch (csize) {
182  case 24: pal_sample_size = 3; break;
183  case 16:
184  case 15: pal_sample_size = 2; break;
185  default:
186  av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);
187  return -1;
188  }
189  pal_size = colors * pal_sample_size;
190  CHECK_BUFFER_SIZE(buf, buf_end, pal_size, "color table");
191  if(avctx->pix_fmt != PIX_FMT_PAL8)//should not occur but skip palette anyway
192  buf += pal_size;
193  else{
194  int t;
195  uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;
196 
197  switch (pal_sample_size) {
198  case 3:
199  /* RGB24 */
200  for (t = 0; t < colors; t++)
201  *pal++ = bytestream_get_le24(&buf);
202  break;
203  case 2:
204  /* RGB555 */
205  for (t = 0; t < colors; t++) {
206  uint32_t v = bytestream_get_le16(&buf);
207  v = ((v & 0x7C00) << 9) |
208  ((v & 0x03E0) << 6) |
209  ((v & 0x001F) << 3);
210  /* left bit replication */
211  v |= (v & 0xE0E0E0U) >> 5;
212  *pal++ = v;
213  }
214  break;
215  }
216  p->palette_has_changed = 1;
217  }
218  }
219  if((compr & (~TGA_RLE)) == TGA_NODATA)
220  memset(p->data[0], 0, p->linesize[0] * s->height);
221  else{
222  if(compr & TGA_RLE){
223  int res = targa_decode_rle(avctx, s, buf, buf_end - buf, dst, avctx->width, avctx->height, stride, bpp);
224  if (res < 0)
225  return -1;
226  buf += res;
227  }else{
228  size_t img_size = s->width * ((s->bpp + 1) >> 3);
229  CHECK_BUFFER_SIZE(buf, buf_end, img_size, "image data");
230  for(y = 0; y < s->height; y++){
231 #if HAVE_BIGENDIAN
232  int x;
233  if((s->bpp + 1) >> 3 == 2){
234  uint16_t *dst16 = (uint16_t*)dst;
235  for(x = 0; x < s->width; x++)
236  dst16[x] = AV_RL16(buf + x * 2);
237  }else if((s->bpp + 1) >> 3 == 4){
238  uint32_t *dst32 = (uint32_t*)dst;
239  for(x = 0; x < s->width; x++)
240  dst32[x] = AV_RL32(buf + x * 4);
241  }else
242 #endif
243  memcpy(dst, buf, img_size);
244 
245  dst += stride;
246  buf += img_size;
247  }
248  }
249  }
250 
251  *picture= *(AVFrame*)&s->picture;
252  *data_size = sizeof(AVPicture);
253 
254  return avpkt->size;
255 }
256 
257 static av_cold int targa_init(AVCodecContext *avctx){
258  TargaContext *s = avctx->priv_data;
259 
261  avctx->coded_frame= (AVFrame*)&s->picture;
262 
263  return 0;
264 }
265 
266 static av_cold int targa_end(AVCodecContext *avctx){
267  TargaContext *s = avctx->priv_data;
268 
269  if(s->picture.data[0])
270  avctx->release_buffer(avctx, &s->picture);
271 
272  return 0;
273 }
274 
276  .name = "targa",
277  .type = AVMEDIA_TYPE_VIDEO,
278  .id = CODEC_ID_TARGA,
279  .priv_data_size = sizeof(TargaContext),
280  .init = targa_init,
281  .close = targa_end,
282  .decode = decode_frame,
283  .capabilities = CODEC_CAP_DR1,
284  .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
285 };