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 #include "internal.h"
31 
32 typedef struct MXpegDecodeContext {
34  AVFrame picture[2]; /* pictures array */
35  int picture_index; /* index of current picture */
36  int got_sof_data; /* true if SOF data successfully parsed */
37  int got_mxm_bitmask; /* true if MXM bitmask available */
38  uint8_t *mxm_bitmask; /* bitmask buffer */
39  unsigned bitmask_size; /* size of bitmask */
40  int has_complete_frame; /* true if has complete frame */
41  uint8_t *completion_bitmask; /* completion bitmask of macroblocks */
42  unsigned mb_width, mb_height; /* size of picture in MB's from MXM header */
44 
46 {
47  MXpegDecodeContext *s = avctx->priv_data;
48 
49  s->picture[0].reference = s->picture[1].reference = 3;
50  s->jpg.picture_ptr = &s->picture[0];
51  return ff_mjpeg_decode_init(avctx);
52 }
53 
55  const uint8_t *buf_ptr, int buf_size)
56 {
57  int len;
58  if (buf_size < 2)
59  return 0;
60  len = AV_RB16(buf_ptr);
61  skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
62 
63  return 0;
64 }
65 
67  const uint8_t *buf_ptr, int buf_size)
68 {
69  unsigned bitmask_size, mb_count;
70  int i;
71 
72  s->mb_width = AV_RL16(buf_ptr+4);
73  s->mb_height = AV_RL16(buf_ptr+6);
74  mb_count = s->mb_width * s->mb_height;
75 
76  bitmask_size = (mb_count + 7) >> 3;
77  if (bitmask_size > buf_size - 12) {
79  "MXM bitmask is not complete\n");
80  return AVERROR(EINVAL);
81  }
82 
83  if (s->bitmask_size != bitmask_size) {
84  av_freep(&s->mxm_bitmask);
85  s->mxm_bitmask = av_malloc(bitmask_size);
86  if (!s->mxm_bitmask) {
88  "MXM bitmask memory allocation error\n");
89  return AVERROR(ENOMEM);
90  }
91 
93  s->completion_bitmask = av_mallocz(bitmask_size);
94  if (!s->completion_bitmask) {
96  "Completion bitmask memory allocation error\n");
97  return AVERROR(ENOMEM);
98  }
99 
100  s->bitmask_size = bitmask_size;
101  }
102 
103  memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size);
104  s->got_mxm_bitmask = 1;
105 
106  if (!s->has_complete_frame) {
107  uint8_t completion_check = 0xFF;
108  for (i = 0; i < bitmask_size; ++i) {
109  s->completion_bitmask[i] |= s->mxm_bitmask[i];
110  completion_check &= s->completion_bitmask[i];
111  }
112  s->has_complete_frame = !(completion_check ^ 0xFF);
113  }
114 
115  return 0;
116 }
117 
119  const uint8_t *buf_ptr, int buf_size)
120 {
121  int len, ret = 0;
122  if (buf_size < 2)
123  return 0;
124  len = AV_RB16(buf_ptr);
125  if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) {
126  ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2);
127  }
128  skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
129 
130  return ret;
131 }
132 
134  AVFrame *reference_ptr)
135 {
136  if ((jpg->width + 0x0F)>>4 != s->mb_width ||
137  (jpg->height + 0x0F)>>4 != s->mb_height) {
138  av_log(jpg->avctx, AV_LOG_ERROR,
139  "Picture dimensions stored in SOF and MXM mismatch\n");
140  return AVERROR(EINVAL);
141  }
142 
143  if (reference_ptr->data[0]) {
144  int i;
145  for (i = 0; i < MAX_COMPONENTS; ++i) {
146  if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) ||
147  reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) {
148  av_log(jpg->avctx, AV_LOG_ERROR,
149  "Dimensions of current and reference picture mismatch\n");
150  return AVERROR(EINVAL);
151  }
152  }
153  }
154 
155  return 0;
156 }
157 
159  void *data, int *data_size,
160  AVPacket *avpkt)
161 {
162  const uint8_t *buf = avpkt->data;
163  int buf_size = avpkt->size;
164  MXpegDecodeContext *s = avctx->priv_data;
165  MJpegDecodeContext *jpg = &s->jpg;
166  const uint8_t *buf_end, *buf_ptr;
167  const uint8_t *unescaped_buf_ptr;
168  int unescaped_buf_size;
169  int start_code;
170  AVFrame *picture = data;
171  int ret;
172 
173  buf_ptr = buf;
174  buf_end = buf + buf_size;
175  jpg->got_picture = 0;
176  s->got_mxm_bitmask = 0;
177  while (buf_ptr < buf_end) {
178  start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
179  &unescaped_buf_ptr, &unescaped_buf_size);
180  if (start_code < 0)
181  goto the_end;
182  {
183  init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8);
184 
185  if (start_code >= APP0 && start_code <= APP15) {
186  mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size);
187  }
188 
189  switch (start_code) {
190  case SOI:
191  if (jpg->got_picture) //emulating EOI
192  goto the_end;
193  break;
194  case EOI:
195  goto the_end;
196  case DQT:
197  ret = ff_mjpeg_decode_dqt(jpg);
198  if (ret < 0) {
199  av_log(avctx, AV_LOG_ERROR,
200  "quantization table decode error\n");
201  return ret;
202  }
203  break;
204  case DHT:
205  ret = ff_mjpeg_decode_dht(jpg);
206  if (ret < 0) {
207  av_log(avctx, AV_LOG_ERROR,
208  "huffman table decode error\n");
209  return ret;
210  }
211  break;
212  case COM:
213  ret = mxpeg_decode_com(s, unescaped_buf_ptr,
214  unescaped_buf_size);
215  if (ret < 0)
216  return ret;
217  break;
218  case SOF0:
219  s->got_sof_data = 0;
220  ret = ff_mjpeg_decode_sof(jpg);
221  if (ret < 0) {
222  av_log(avctx, AV_LOG_ERROR,
223  "SOF data decode error\n");
224  return ret;
225  }
226  if (jpg->interlaced) {
227  av_log(avctx, AV_LOG_ERROR,
228  "Interlaced mode not supported in MxPEG\n");
229  return AVERROR(EINVAL);
230  }
231  s->got_sof_data = 1;
232  break;
233  case SOS:
234  if (!s->got_sof_data) {
235  av_log(avctx, AV_LOG_WARNING,
236  "Can not process SOS without SOF data, skipping\n");
237  break;
238  }
239  if (!jpg->got_picture) {
240  if (jpg->first_picture) {
241  av_log(avctx, AV_LOG_WARNING,
242  "First picture has no SOF, skipping\n");
243  break;
244  }
245  if (!s->got_mxm_bitmask){
246  av_log(avctx, AV_LOG_WARNING,
247  "Non-key frame has no MXM, skipping\n");
248  break;
249  }
250  /* use stored SOF data to allocate current picture */
251  if (jpg->picture_ptr->data[0])
252  avctx->release_buffer(avctx, jpg->picture_ptr);
253  if (ff_get_buffer(avctx, jpg->picture_ptr) < 0) {
254  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
255  return AVERROR(ENOMEM);
256  }
258  jpg->picture_ptr->key_frame = 0;
259  jpg->got_picture = 1;
260  } else {
262  jpg->picture_ptr->key_frame = 1;
263  }
264 
265  if (s->got_mxm_bitmask) {
266  AVFrame *reference_ptr = &s->picture[s->picture_index ^ 1];
267  if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0)
268  break;
269 
270  /* allocate dummy reference picture if needed */
271  if (!reference_ptr->data[0] &&
272  ff_get_buffer(avctx, reference_ptr) < 0) {
273  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
274  return AVERROR(ENOMEM);
275  }
276 
277  ret = ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, reference_ptr);
278  if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
279  return ret;
280  } else {
281  ret = ff_mjpeg_decode_sos(jpg, NULL, NULL);
282  if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
283  return ret;
284  }
285 
286  break;
287  }
288 
289  buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3;
290  }
291 
292  }
293 
294 the_end:
295  if (jpg->got_picture) {
296  *data_size = sizeof(AVFrame);
297  *picture = *jpg->picture_ptr;
298  s->picture_index ^= 1;
299  jpg->picture_ptr = &s->picture[s->picture_index];
300 
301  if (!s->has_complete_frame) {
302  if (!s->got_mxm_bitmask)
303  s->has_complete_frame = 1;
304  else
305  *data_size = 0;
306  }
307  }
308 
309  return buf_ptr - buf;
310 }
311 
313 {
314  MXpegDecodeContext *s = avctx->priv_data;
315  MJpegDecodeContext *jpg = &s->jpg;
316  int i;
317 
318  jpg->picture_ptr = NULL;
319  ff_mjpeg_decode_end(avctx);
320 
321  for (i = 0; i < 2; ++i) {
322  if (s->picture[i].data[0])
323  avctx->release_buffer(avctx, &s->picture[i]);
324  }
325 
326  av_freep(&s->mxm_bitmask);
328 
329  return 0;
330 }
331 
333  .name = "mxpeg",
334  .long_name = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"),
335  .type = AVMEDIA_TYPE_VIDEO,
336  .id = CODEC_ID_MXPEG,
337  .priv_data_size = sizeof(MXpegDecodeContext),
341  .capabilities = CODEC_CAP_DR1,
342  .max_lowres = 3
343 };