mxpegdec.c
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1 /*
2  * MxPEG decoder
3  * Copyright (c) 2011 Anatoly Nenashev
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 
28 #include "mjpeg.h"
29 #include "mjpegdec.h"
30 
31 typedef struct MXpegDecodeContext {
33  AVFrame picture[2]; /* pictures array */
34  int picture_index; /* index of current picture */
35  int got_sof_data; /* true if SOF data successfully parsed */
36  int got_mxm_bitmask; /* true if MXM bitmask available */
37  uint8_t *mxm_bitmask; /* bitmask buffer */
38  unsigned bitmask_size; /* size of bitmask */
39  int has_complete_frame; /* true if has complete frame */
40  uint8_t *completion_bitmask; /* completion bitmask of macroblocks */
41  unsigned mb_width, mb_height; /* size of picture in MB's from MXM header */
43 
45 {
46  MXpegDecodeContext *s = avctx->priv_data;
47 
48  s->picture[0].reference = s->picture[1].reference = 3;
49  s->jpg.picture_ptr = &s->picture[0];
50  return ff_mjpeg_decode_init(avctx);
51 }
52 
54  const uint8_t *buf_ptr, int buf_size)
55 {
56  int len;
57  if (buf_size < 2)
58  return 0;
59  len = AV_RB16(buf_ptr);
60  skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
61 
62  return 0;
63 }
64 
66  const uint8_t *buf_ptr, int buf_size)
67 {
68  unsigned bitmask_size, mb_count;
69  int i;
70 
71  s->mb_width = AV_RL16(buf_ptr+4);
72  s->mb_height = AV_RL16(buf_ptr+6);
73  mb_count = s->mb_width * s->mb_height;
74 
75  bitmask_size = (mb_count + 7) >> 3;
76  if (bitmask_size > buf_size - 12) {
78  "MXM bitmask is not complete\n");
79  return AVERROR(EINVAL);
80  }
81 
82  if (s->bitmask_size != bitmask_size) {
83  av_freep(&s->mxm_bitmask);
84  s->mxm_bitmask = av_malloc(bitmask_size);
85  if (!s->mxm_bitmask) {
87  "MXM bitmask memory allocation error\n");
88  return AVERROR(ENOMEM);
89  }
90 
92  s->completion_bitmask = av_mallocz(bitmask_size);
93  if (!s->completion_bitmask) {
95  "Completion bitmask memory allocation error\n");
96  return AVERROR(ENOMEM);
97  }
98 
99  s->bitmask_size = bitmask_size;
100  }
101 
102  memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size);
103  s->got_mxm_bitmask = 1;
104 
105  if (!s->has_complete_frame) {
106  uint8_t completion_check = 0xFF;
107  for (i = 0; i < bitmask_size; ++i) {
108  s->completion_bitmask[i] |= s->mxm_bitmask[i];
109  completion_check &= s->completion_bitmask[i];
110  }
111  s->has_complete_frame = !(completion_check ^ 0xFF);
112  }
113 
114  return 0;
115 }
116 
118  const uint8_t *buf_ptr, int buf_size)
119 {
120  int len, ret = 0;
121  if (buf_size < 2)
122  return 0;
123  len = AV_RB16(buf_ptr);
124  if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) {
125  ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2);
126  }
127  skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
128 
129  return ret;
130 }
131 
133  AVFrame *reference_ptr)
134 {
135  if ((jpg->width + 0x0F)>>4 != s->mb_width ||
136  (jpg->height + 0x0F)>>4 != s->mb_height) {
137  av_log(jpg->avctx, AV_LOG_ERROR,
138  "Picture dimensions stored in SOF and MXM mismatch\n");
139  return AVERROR(EINVAL);
140  }
141 
142  if (reference_ptr->data[0]) {
143  int i;
144  for (i = 0; i < MAX_COMPONENTS; ++i) {
145  if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) ||
146  reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) {
147  av_log(jpg->avctx, AV_LOG_ERROR,
148  "Dimensions of current and reference picture mismatch\n");
149  return AVERROR(EINVAL);
150  }
151  }
152  }
153 
154  return 0;
155 }
156 
158  void *data, int *data_size,
159  AVPacket *avpkt)
160 {
161  const uint8_t *buf = avpkt->data;
162  int buf_size = avpkt->size;
163  MXpegDecodeContext *s = avctx->priv_data;
164  MJpegDecodeContext *jpg = &s->jpg;
165  const uint8_t *buf_end, *buf_ptr;
166  const uint8_t *unescaped_buf_ptr;
167  int unescaped_buf_size;
168  int start_code;
169  AVFrame *picture = data;
170  int ret;
171 
172  buf_ptr = buf;
173  buf_end = buf + buf_size;
174  jpg->got_picture = 0;
175  s->got_mxm_bitmask = 0;
176  while (buf_ptr < buf_end) {
177  start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
178  &unescaped_buf_ptr, &unescaped_buf_size);
179  if (start_code < 0)
180  goto the_end;
181  {
182  init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8);
183 
184  if (start_code >= APP0 && start_code <= APP15) {
185  mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size);
186  }
187 
188  switch (start_code) {
189  case SOI:
190  if (jpg->got_picture) //emulating EOI
191  goto the_end;
192  break;
193  case EOI:
194  goto the_end;
195  case DQT:
196  ret = ff_mjpeg_decode_dqt(jpg);
197  if (ret < 0) {
198  av_log(avctx, AV_LOG_ERROR,
199  "quantization table decode error\n");
200  return ret;
201  }
202  break;
203  case DHT:
204  ret = ff_mjpeg_decode_dht(jpg);
205  if (ret < 0) {
206  av_log(avctx, AV_LOG_ERROR,
207  "huffman table decode error\n");
208  return ret;
209  }
210  break;
211  case COM:
212  ret = mxpeg_decode_com(s, unescaped_buf_ptr,
213  unescaped_buf_size);
214  if (ret < 0)
215  return ret;
216  break;
217  case SOF0:
218  s->got_sof_data = 0;
219  ret = ff_mjpeg_decode_sof(jpg);
220  if (ret < 0) {
221  av_log(avctx, AV_LOG_ERROR,
222  "SOF data decode error\n");
223  return ret;
224  }
225  if (jpg->interlaced) {
226  av_log(avctx, AV_LOG_ERROR,
227  "Interlaced mode not supported in MxPEG\n");
228  return AVERROR(EINVAL);
229  }
230  s->got_sof_data = 1;
231  break;
232  case SOS:
233  if (!s->got_sof_data) {
234  av_log(avctx, AV_LOG_WARNING,
235  "Can not process SOS without SOF data, skipping\n");
236  break;
237  }
238  if (!jpg->got_picture) {
239  if (jpg->first_picture) {
240  av_log(avctx, AV_LOG_WARNING,
241  "First picture has no SOF, skipping\n");
242  break;
243  }
244  if (!s->got_mxm_bitmask){
245  av_log(avctx, AV_LOG_WARNING,
246  "Non-key frame has no MXM, skipping\n");
247  break;
248  }
249  /* use stored SOF data to allocate current picture */
250  if (jpg->picture_ptr->data[0])
251  avctx->release_buffer(avctx, jpg->picture_ptr);
252  if (avctx->get_buffer(avctx, jpg->picture_ptr) < 0) {
253  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
254  return AVERROR(ENOMEM);
255  }
257  jpg->picture_ptr->key_frame = 0;
258  jpg->got_picture = 1;
259  } else {
261  jpg->picture_ptr->key_frame = 1;
262  }
263 
264  if (s->got_mxm_bitmask) {
265  AVFrame *reference_ptr = &s->picture[s->picture_index ^ 1];
266  if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0)
267  break;
268 
269  /* allocate dummy reference picture if needed */
270  if (!reference_ptr->data[0] &&
271  avctx->get_buffer(avctx, reference_ptr) < 0) {
272  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
273  return AVERROR(ENOMEM);
274  }
275 
276  ret = ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, reference_ptr);
277  if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
278  return ret;
279  } else {
280  ret = ff_mjpeg_decode_sos(jpg, NULL, NULL);
281  if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
282  return ret;
283  }
284 
285  break;
286  }
287 
288  buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3;
289  }
290 
291  }
292 
293 the_end:
294  if (jpg->got_picture) {
295  *data_size = sizeof(AVFrame);
296  *picture = *jpg->picture_ptr;
297  s->picture_index ^= 1;
298  jpg->picture_ptr = &s->picture[s->picture_index];
299 
300  if (!s->has_complete_frame) {
301  if (!s->got_mxm_bitmask)
302  s->has_complete_frame = 1;
303  else
304  *data_size = 0;
305  }
306  }
307 
308  return buf_ptr - buf;
309 }
310 
312 {
313  MXpegDecodeContext *s = avctx->priv_data;
314  MJpegDecodeContext *jpg = &s->jpg;
315  int i;
316 
317  jpg->picture_ptr = NULL;
318  ff_mjpeg_decode_end(avctx);
319 
320  for (i = 0; i < 2; ++i) {
321  if (s->picture[i].data[0])
322  avctx->release_buffer(avctx, &s->picture[i]);
323  }
324 
325  av_freep(&s->mxm_bitmask);
327 
328  return 0;
329 }
330 
332  .name = "mxpeg",
333  .long_name = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"),
334  .type = AVMEDIA_TYPE_VIDEO,
335  .id = CODEC_ID_MXPEG,
336  .priv_data_size = sizeof(MXpegDecodeContext),
340  .capabilities = CODEC_CAP_DR1,
341  .max_lowres = 3
342 };