FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
bmp.c
Go to the documentation of this file.
1 /*
2  * BMP image format decoder
3  * Copyright (c) 2005 Mans Rullgard
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 <inttypes.h>
23 
24 #include "avcodec.h"
25 #include "bytestream.h"
26 #include "bmp.h"
27 #include "internal.h"
28 #include "msrledec.h"
29 
30 static int bmp_decode_frame(AVCodecContext *avctx,
31  void *data, int *got_frame,
32  AVPacket *avpkt)
33 {
34  const uint8_t *buf = avpkt->data;
35  int buf_size = avpkt->size;
36  AVFrame *p = data;
37  unsigned int fsize, hsize;
38  int width, height;
39  unsigned int depth;
40  BiCompression comp;
41  unsigned int ihsize;
42  int i, j, n, linesize, ret;
43  uint32_t rgb[3] = {0};
44  uint32_t alpha = 0;
45  uint8_t *ptr;
46  int dsize;
47  const uint8_t *buf0 = buf;
48  GetByteContext gb;
49 
50  if (buf_size < 14) {
51  av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
52  return AVERROR_INVALIDDATA;
53  }
54 
55  if (bytestream_get_byte(&buf) != 'B' ||
56  bytestream_get_byte(&buf) != 'M') {
57  av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
58  return AVERROR_INVALIDDATA;
59  }
60 
61  fsize = bytestream_get_le32(&buf);
62  if (buf_size < fsize) {
63  av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %u), trying to decode anyway\n",
64  buf_size, fsize);
65  fsize = buf_size;
66  }
67 
68  buf += 2; /* reserved1 */
69  buf += 2; /* reserved2 */
70 
71  hsize = bytestream_get_le32(&buf); /* header size */
72  ihsize = bytestream_get_le32(&buf); /* more header size */
73  if (ihsize + 14LL > hsize) {
74  av_log(avctx, AV_LOG_ERROR, "invalid header size %u\n", hsize);
75  return AVERROR_INVALIDDATA;
76  }
77 
78  /* sometimes file size is set to some headers size, set a real size in that case */
79  if (fsize == 14 || fsize == ihsize + 14)
80  fsize = buf_size - 2;
81 
82  if (fsize <= hsize) {
83  av_log(avctx, AV_LOG_ERROR,
84  "Declared file size is less than header size (%u < %u)\n",
85  fsize, hsize);
86  return AVERROR_INVALIDDATA;
87  }
88 
89  switch (ihsize) {
90  case 40: // windib
91  case 56: // windib v3
92  case 64: // OS/2 v2
93  case 108: // windib v4
94  case 124: // windib v5
95  width = bytestream_get_le32(&buf);
96  height = bytestream_get_le32(&buf);
97  break;
98  case 12: // OS/2 v1
99  width = bytestream_get_le16(&buf);
100  height = bytestream_get_le16(&buf);
101  break;
102  default:
103  av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n");
104  return AVERROR_PATCHWELCOME;
105  }
106 
107  /* planes */
108  if (bytestream_get_le16(&buf) != 1) {
109  av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
110  return AVERROR_INVALIDDATA;
111  }
112 
113  depth = bytestream_get_le16(&buf);
114 
115  if (ihsize >= 40)
116  comp = bytestream_get_le32(&buf);
117  else
118  comp = BMP_RGB;
119 
120  if (comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 &&
121  comp != BMP_RLE8) {
122  av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
123  return AVERROR_INVALIDDATA;
124  }
125 
126  if (comp == BMP_BITFIELDS) {
127  buf += 20;
128  rgb[0] = bytestream_get_le32(&buf);
129  rgb[1] = bytestream_get_le32(&buf);
130  rgb[2] = bytestream_get_le32(&buf);
131  if (ihsize > 40)
132  alpha = bytestream_get_le32(&buf);
133  }
134 
135  avctx->width = width;
136  avctx->height = height > 0 ? height : -height;
137 
138  avctx->pix_fmt = AV_PIX_FMT_NONE;
139 
140  switch (depth) {
141  case 32:
142  if (comp == BMP_BITFIELDS) {
143  if (rgb[0] == 0xFF000000 && rgb[1] == 0x00FF0000 && rgb[2] == 0x0000FF00)
144  avctx->pix_fmt = alpha ? AV_PIX_FMT_ABGR : AV_PIX_FMT_0BGR;
145  else if (rgb[0] == 0x00FF0000 && rgb[1] == 0x0000FF00 && rgb[2] == 0x000000FF)
146  avctx->pix_fmt = alpha ? AV_PIX_FMT_BGRA : AV_PIX_FMT_BGR0;
147  else if (rgb[0] == 0x0000FF00 && rgb[1] == 0x00FF0000 && rgb[2] == 0xFF000000)
148  avctx->pix_fmt = alpha ? AV_PIX_FMT_ARGB : AV_PIX_FMT_0RGB;
149  else if (rgb[0] == 0x000000FF && rgb[1] == 0x0000FF00 && rgb[2] == 0x00FF0000)
150  avctx->pix_fmt = alpha ? AV_PIX_FMT_RGBA : AV_PIX_FMT_RGB0;
151  else {
152  av_log(avctx, AV_LOG_ERROR, "Unknown bitfields %0X %0X %0X\n", rgb[0], rgb[1], rgb[2]);
153  return AVERROR(EINVAL);
154  }
155  } else {
156  avctx->pix_fmt = AV_PIX_FMT_BGRA;
157  }
158  break;
159  case 24:
160  avctx->pix_fmt = AV_PIX_FMT_BGR24;
161  break;
162  case 16:
163  if (comp == BMP_RGB)
164  avctx->pix_fmt = AV_PIX_FMT_RGB555;
165  else if (comp == BMP_BITFIELDS) {
166  if (rgb[0] == 0xF800 && rgb[1] == 0x07E0 && rgb[2] == 0x001F)
167  avctx->pix_fmt = AV_PIX_FMT_RGB565;
168  else if (rgb[0] == 0x7C00 && rgb[1] == 0x03E0 && rgb[2] == 0x001F)
169  avctx->pix_fmt = AV_PIX_FMT_RGB555;
170  else if (rgb[0] == 0x0F00 && rgb[1] == 0x00F0 && rgb[2] == 0x000F)
171  avctx->pix_fmt = AV_PIX_FMT_RGB444;
172  else {
173  av_log(avctx, AV_LOG_ERROR,
174  "Unknown bitfields %0"PRIX32" %0"PRIX32" %0"PRIX32"\n",
175  rgb[0], rgb[1], rgb[2]);
176  return AVERROR(EINVAL);
177  }
178  }
179  break;
180  case 8:
181  if (hsize - ihsize - 14 > 0)
182  avctx->pix_fmt = AV_PIX_FMT_PAL8;
183  else
184  avctx->pix_fmt = AV_PIX_FMT_GRAY8;
185  break;
186  case 1:
187  case 4:
188  if (hsize - ihsize - 14 > 0) {
189  avctx->pix_fmt = AV_PIX_FMT_PAL8;
190  } else {
191  av_log(avctx, AV_LOG_ERROR, "Unknown palette for %u-colour BMP\n",
192  1 << depth);
193  return AVERROR_INVALIDDATA;
194  }
195  break;
196  default:
197  av_log(avctx, AV_LOG_ERROR, "depth %u not supported\n", depth);
198  return AVERROR_INVALIDDATA;
199  }
200 
201  if (avctx->pix_fmt == AV_PIX_FMT_NONE) {
202  av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
203  return AVERROR_INVALIDDATA;
204  }
205 
206  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
207  return ret;
208  p->pict_type = AV_PICTURE_TYPE_I;
209  p->key_frame = 1;
210 
211  buf = buf0 + hsize;
212  dsize = buf_size - hsize;
213 
214  /* Line size in file multiple of 4 */
215  n = ((avctx->width * depth + 31) / 8) & ~3;
216 
217  if (n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8) {
218  av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
219  dsize, n * avctx->height);
220  return AVERROR_INVALIDDATA;
221  }
222 
223  // RLE may skip decoding some picture areas, so blank picture before decoding
224  if (comp == BMP_RLE4 || comp == BMP_RLE8)
225  memset(p->data[0], 0, avctx->height * p->linesize[0]);
226 
227  if (height > 0) {
228  ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
229  linesize = -p->linesize[0];
230  } else {
231  ptr = p->data[0];
232  linesize = p->linesize[0];
233  }
234 
235  if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
236  int colors = 1 << depth;
237 
238  memset(p->data[1], 0, 1024);
239 
240  if (ihsize >= 36) {
241  int t;
242  buf = buf0 + 46;
243  t = bytestream_get_le32(&buf);
244  if (t < 0 || t > (1 << depth)) {
245  av_log(avctx, AV_LOG_ERROR,
246  "Incorrect number of colors - %X for bitdepth %u\n",
247  t, depth);
248  } else if (t) {
249  colors = t;
250  }
251  } else {
252  colors = FFMIN(256, (hsize-ihsize-14) / 3);
253  }
254  buf = buf0 + 14 + ihsize; //palette location
255  // OS/2 bitmap, 3 bytes per palette entry
256  if ((hsize-ihsize-14) < (colors << 2)) {
257  if ((hsize-ihsize-14) < colors * 3) {
258  av_log(avctx, AV_LOG_ERROR, "palette doesn't fit in packet\n");
259  return AVERROR_INVALIDDATA;
260  }
261  for (i = 0; i < colors; i++)
262  ((uint32_t*)p->data[1])[i] = (0xFFU<<24) | bytestream_get_le24(&buf);
263  } else {
264  for (i = 0; i < colors; i++)
265  ((uint32_t*)p->data[1])[i] = 0xFFU << 24 | bytestream_get_le32(&buf);
266  }
267  buf = buf0 + hsize;
268  }
269  if (comp == BMP_RLE4 || comp == BMP_RLE8) {
270  if (comp == BMP_RLE8 && height < 0) {
271  p->data[0] += p->linesize[0] * (avctx->height - 1);
272  p->linesize[0] = -p->linesize[0];
273  }
274  bytestream2_init(&gb, buf, dsize);
275  ff_msrle_decode(avctx, (AVPicture*)p, depth, &gb);
276  if (height < 0) {
277  p->data[0] += p->linesize[0] * (avctx->height - 1);
278  p->linesize[0] = -p->linesize[0];
279  }
280  } else {
281  switch (depth) {
282  case 1:
283  for (i = 0; i < avctx->height; i++) {
284  int j;
285  for (j = 0; j < n; j++) {
286  ptr[j*8+0] = buf[j] >> 7;
287  ptr[j*8+1] = (buf[j] >> 6) & 1;
288  ptr[j*8+2] = (buf[j] >> 5) & 1;
289  ptr[j*8+3] = (buf[j] >> 4) & 1;
290  ptr[j*8+4] = (buf[j] >> 3) & 1;
291  ptr[j*8+5] = (buf[j] >> 2) & 1;
292  ptr[j*8+6] = (buf[j] >> 1) & 1;
293  ptr[j*8+7] = buf[j] & 1;
294  }
295  buf += n;
296  ptr += linesize;
297  }
298  break;
299  case 8:
300  case 24:
301  case 32:
302  for (i = 0; i < avctx->height; i++) {
303  memcpy(ptr, buf, n);
304  buf += n;
305  ptr += linesize;
306  }
307  break;
308  case 4:
309  for (i = 0; i < avctx->height; i++) {
310  int j;
311  for (j = 0; j < n; j++) {
312  ptr[j*2+0] = (buf[j] >> 4) & 0xF;
313  ptr[j*2+1] = buf[j] & 0xF;
314  }
315  buf += n;
316  ptr += linesize;
317  }
318  break;
319  case 16:
320  for (i = 0; i < avctx->height; i++) {
321  const uint16_t *src = (const uint16_t *) buf;
322  uint16_t *dst = (uint16_t *) ptr;
323 
324  for (j = 0; j < avctx->width; j++)
325  *dst++ = av_le2ne16(*src++);
326 
327  buf += n;
328  ptr += linesize;
329  }
330  break;
331  default:
332  av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
333  return AVERROR_INVALIDDATA;
334  }
335  }
336 
337  *got_frame = 1;
338 
339  return buf_size;
340 }
341 
342 AVCodec ff_bmp_decoder = {
343  .name = "bmp",
344  .long_name = NULL_IF_CONFIG_SMALL("BMP (Windows and OS/2 bitmap)"),
345  .type = AVMEDIA_TYPE_VIDEO,
346  .id = AV_CODEC_ID_BMP,
347  .decode = bmp_decode_frame,
348  .capabilities = CODEC_CAP_DR1,
349 };
Generated on Wed Jul 30 2014 19:21:11 for FFmpeg by   doxygen 1.8.2