bmp.c
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1 /*
2  * BMP image format decoder
3  * Copyright (c) 2005 Mans Rullgard
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 "avcodec.h"
23 #include "bytestream.h"
24 #include "bmp.h"
25 #include "msrledec.h"
26 
28  BMPContext *s = avctx->priv_data;
29 
31  avctx->coded_frame = (AVFrame*)&s->picture;
32 
33  return 0;
34 }
35 
36 static int bmp_decode_frame(AVCodecContext *avctx,
37  void *data, int *data_size,
38  AVPacket *avpkt)
39 {
40  const uint8_t *buf = avpkt->data;
41  int buf_size = avpkt->size;
42  BMPContext *s = avctx->priv_data;
43  AVFrame *picture = data;
44  AVFrame *p = &s->picture;
45  unsigned int fsize, hsize;
46  int width, height;
47  unsigned int depth;
49  unsigned int ihsize;
50  int i, j, n, linesize;
51  uint32_t rgb[3];
52  uint8_t *ptr;
53  int dsize;
54  const uint8_t *buf0 = buf;
55  GetByteContext gb;
56 
57  if(buf_size < 14){
58  av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
59  return -1;
60  }
61 
62  if(bytestream_get_byte(&buf) != 'B' ||
63  bytestream_get_byte(&buf) != 'M') {
64  av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
65  return -1;
66  }
67 
68  fsize = bytestream_get_le32(&buf);
69  if(buf_size < fsize){
70  av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d), trying to decode anyway\n",
71  buf_size, fsize);
72  fsize = buf_size;
73  }
74 
75  buf += 2; /* reserved1 */
76  buf += 2; /* reserved2 */
77 
78  hsize = bytestream_get_le32(&buf); /* header size */
79  ihsize = bytestream_get_le32(&buf); /* more header size */
80  if(ihsize + 14 > hsize){
81  av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
82  return -1;
83  }
84 
85  /* sometimes file size is set to some headers size, set a real size in that case */
86  if(fsize == 14 || fsize == ihsize + 14)
87  fsize = buf_size - 2;
88 
89  if(fsize <= hsize){
90  av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n",
91  fsize, hsize);
92  return -1;
93  }
94 
95  switch(ihsize){
96  case 40: // windib v3
97  case 64: // OS/2 v2
98  case 108: // windib v4
99  case 124: // windib v5
100  width = bytestream_get_le32(&buf);
101  height = bytestream_get_le32(&buf);
102  break;
103  case 12: // OS/2 v1
104  width = bytestream_get_le16(&buf);
105  height = bytestream_get_le16(&buf);
106  break;
107  default:
108  av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n");
109  return -1;
110  }
111 
112  if(bytestream_get_le16(&buf) != 1){ /* planes */
113  av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
114  return -1;
115  }
116 
117  depth = bytestream_get_le16(&buf);
118 
119  if(ihsize == 40)
120  comp = bytestream_get_le32(&buf);
121  else
122  comp = BMP_RGB;
123 
124  if(comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 && comp != BMP_RLE8){
125  av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
126  return -1;
127  }
128 
129  if(comp == BMP_BITFIELDS){
130  buf += 20;
131  rgb[0] = bytestream_get_le32(&buf);
132  rgb[1] = bytestream_get_le32(&buf);
133  rgb[2] = bytestream_get_le32(&buf);
134  }
135 
136  avctx->width = width;
137  avctx->height = height > 0? height: -height;
138 
139  avctx->pix_fmt = PIX_FMT_NONE;
140 
141  switch(depth){
142  case 32:
143  if(comp == BMP_BITFIELDS){
144  rgb[0] = (rgb[0] >> 15) & 3;
145  rgb[1] = (rgb[1] >> 15) & 3;
146  rgb[2] = (rgb[2] >> 15) & 3;
147 
148  if(rgb[0] + rgb[1] + rgb[2] != 3 ||
149  rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){
150  break;
151  }
152  } else {
153  rgb[0] = 2;
154  rgb[1] = 1;
155  rgb[2] = 0;
156  }
157 
158  avctx->pix_fmt = PIX_FMT_BGR24;
159  break;
160  case 24:
161  avctx->pix_fmt = PIX_FMT_BGR24;
162  break;
163  case 16:
164  if(comp == BMP_RGB)
165  avctx->pix_fmt = PIX_FMT_RGB555;
166  else if (comp == BMP_BITFIELDS) {
167  if (rgb[0] == 0xF800 && rgb[1] == 0x07E0 && rgb[2] == 0x001F)
168  avctx->pix_fmt = PIX_FMT_RGB565;
169  else if (rgb[0] == 0x7C00 && rgb[1] == 0x03E0 && rgb[2] == 0x001F)
170  avctx->pix_fmt = PIX_FMT_RGB555;
171  else if (rgb[0] == 0x0F00 && rgb[1] == 0x00F0 && rgb[2] == 0x000F)
172  avctx->pix_fmt = PIX_FMT_RGB444;
173  else {
174  av_log(avctx, AV_LOG_ERROR, "Unknown bitfields %0X %0X %0X\n", rgb[0], rgb[1], rgb[2]);
175  return AVERROR(EINVAL);
176  }
177  }
178  break;
179  case 8:
180  if(hsize - ihsize - 14 > 0)
181  avctx->pix_fmt = PIX_FMT_PAL8;
182  else
183  avctx->pix_fmt = PIX_FMT_GRAY8;
184  break;
185  case 1:
186  case 4:
187  if(hsize - ihsize - 14 > 0){
188  avctx->pix_fmt = PIX_FMT_PAL8;
189  }else{
190  av_log(avctx, AV_LOG_ERROR, "Unknown palette for %d-colour BMP\n", 1<<depth);
191  return -1;
192  }
193  break;
194  default:
195  av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
196  return -1;
197  }
198 
199  if(avctx->pix_fmt == PIX_FMT_NONE){
200  av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
201  return -1;
202  }
203 
204  if(p->data[0])
205  avctx->release_buffer(avctx, p);
206 
207  p->reference = 0;
208  if(avctx->get_buffer(avctx, p) < 0){
209  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
210  return -1;
211  }
213  p->key_frame = 1;
214 
215  buf = buf0 + hsize;
216  dsize = buf_size - hsize;
217 
218  /* Line size in file multiple of 4 */
219  n = ((avctx->width * depth) / 8 + 3) & ~3;
220 
221  if(n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8){
222  av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
223  dsize, n * avctx->height);
224  return -1;
225  }
226 
227  // RLE may skip decoding some picture areas, so blank picture before decoding
228  if(comp == BMP_RLE4 || comp == BMP_RLE8)
229  memset(p->data[0], 0, avctx->height * p->linesize[0]);
230 
231  if(height > 0){
232  ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
233  linesize = -p->linesize[0];
234  } else {
235  ptr = p->data[0];
236  linesize = p->linesize[0];
237  }
238 
239  if(avctx->pix_fmt == PIX_FMT_PAL8){
240  int colors = 1 << depth;
241 
242  memset(p->data[1], 0, 1024);
243 
244  if(ihsize >= 36){
245  int t;
246  buf = buf0 + 46;
247  t = bytestream_get_le32(&buf);
248  if(t < 0 || t > (1 << depth)){
249  av_log(avctx, AV_LOG_ERROR, "Incorrect number of colors - %X for bitdepth %d\n", t, depth);
250  }else if(t){
251  colors = t;
252  }
253  }
254  buf = buf0 + 14 + ihsize; //palette location
255  if((hsize-ihsize-14) < (colors << 2)){ // OS/2 bitmap, 3 bytes per palette entry
256  for(i = 0; i < colors; i++)
257  ((uint32_t*)p->data[1])[i] = bytestream_get_le24(&buf);
258  }else{
259  for(i = 0; i < colors; i++)
260  ((uint32_t*)p->data[1])[i] = bytestream_get_le32(&buf);
261  }
262  buf = buf0 + hsize;
263  }
264  if(comp == BMP_RLE4 || comp == BMP_RLE8){
265  if(height < 0){
266  p->data[0] += p->linesize[0] * (avctx->height - 1);
267  p->linesize[0] = -p->linesize[0];
268  }
269  bytestream2_init(&gb, buf, dsize);
270  ff_msrle_decode(avctx, (AVPicture*)p, depth, &gb);
271  if(height < 0){
272  p->data[0] += p->linesize[0] * (avctx->height - 1);
273  p->linesize[0] = -p->linesize[0];
274  }
275  }else{
276  switch(depth){
277  case 1:
278  for (i = 0; i < avctx->height; i++) {
279  int j;
280  for (j = 0; j < n; j++) {
281  ptr[j*8+0] = buf[j] >> 7;
282  ptr[j*8+1] = (buf[j] >> 6) & 1;
283  ptr[j*8+2] = (buf[j] >> 5) & 1;
284  ptr[j*8+3] = (buf[j] >> 4) & 1;
285  ptr[j*8+4] = (buf[j] >> 3) & 1;
286  ptr[j*8+5] = (buf[j] >> 2) & 1;
287  ptr[j*8+6] = (buf[j] >> 1) & 1;
288  ptr[j*8+7] = buf[j] & 1;
289  }
290  buf += n;
291  ptr += linesize;
292  }
293  break;
294  case 8:
295  case 24:
296  for(i = 0; i < avctx->height; i++){
297  memcpy(ptr, buf, n);
298  buf += n;
299  ptr += linesize;
300  }
301  break;
302  case 4:
303  for(i = 0; i < avctx->height; i++){
304  int j;
305  for(j = 0; j < n; j++){
306  ptr[j*2+0] = (buf[j] >> 4) & 0xF;
307  ptr[j*2+1] = buf[j] & 0xF;
308  }
309  buf += n;
310  ptr += linesize;
311  }
312  break;
313  case 16:
314  for(i = 0; i < avctx->height; i++){
315  const uint16_t *src = (const uint16_t *) buf;
316  uint16_t *dst = (uint16_t *) ptr;
317 
318  for(j = 0; j < avctx->width; j++)
319  *dst++ = av_le2ne16(*src++);
320 
321  buf += n;
322  ptr += linesize;
323  }
324  break;
325  case 32:
326  for(i = 0; i < avctx->height; i++){
327  const uint8_t *src = buf;
328  uint8_t *dst = ptr;
329 
330  for(j = 0; j < avctx->width; j++){
331  dst[0] = src[rgb[2]];
332  dst[1] = src[rgb[1]];
333  dst[2] = src[rgb[0]];
334  dst += 3;
335  src += 4;
336  }
337 
338  buf += n;
339  ptr += linesize;
340  }
341  break;
342  default:
343  av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
344  return -1;
345  }
346  }
347 
348  *picture = s->picture;
349  *data_size = sizeof(AVPicture);
350 
351  return buf_size;
352 }
353 
355 {
356  BMPContext* c = avctx->priv_data;
357 
358  if (c->picture.data[0])
359  avctx->release_buffer(avctx, &c->picture);
360 
361  return 0;
362 }
363 
365  .name = "bmp",
366  .type = AVMEDIA_TYPE_VIDEO,
367  .id = CODEC_ID_BMP,
368  .priv_data_size = sizeof(BMPContext),
372  .capabilities = CODEC_CAP_DR1,
373  .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
374 };