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