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mxpegdec.c
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1 /*
2  * MxPEG decoder
3  * Copyright (c) 2011 Anatoly Nenashev
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 
23 /**
24  * @file
25  * MxPEG decoder
26  */
27 
28 #include "internal.h"
29 #include "mjpeg.h"
30 #include "mjpegdec.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  s->bitmask_size = 0;
85  av_freep(&s->mxm_bitmask);
86  s->mxm_bitmask = av_malloc(bitmask_size);
87  if (!s->mxm_bitmask) {
89  "MXM bitmask memory allocation error\n");
90  return AVERROR(ENOMEM);
91  }
92 
94  s->completion_bitmask = av_mallocz(bitmask_size);
95  if (!s->completion_bitmask) {
97  "Completion bitmask memory allocation error\n");
98  return AVERROR(ENOMEM);
99  }
100 
101  s->bitmask_size = bitmask_size;
102  }
103 
104  memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size);
105  s->got_mxm_bitmask = 1;
106 
107  if (!s->has_complete_frame) {
108  uint8_t completion_check = 0xFF;
109  for (i = 0; i < bitmask_size; ++i) {
110  s->completion_bitmask[i] |= s->mxm_bitmask[i];
111  completion_check &= s->completion_bitmask[i];
112  }
113  s->has_complete_frame = !(completion_check ^ 0xFF);
114  }
115 
116  return 0;
117 }
118 
120  const uint8_t *buf_ptr, int buf_size)
121 {
122  int len, ret = 0;
123  if (buf_size < 2)
124  return 0;
125  len = AV_RB16(buf_ptr);
126  if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) {
127  ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2);
128  }
129  skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
130 
131  return ret;
132 }
133 
135  AVFrame *reference_ptr)
136 {
137  if ((jpg->width + 0x0F)>>4 != s->mb_width ||
138  (jpg->height + 0x0F)>>4 != s->mb_height) {
139  av_log(jpg->avctx, AV_LOG_ERROR,
140  "Picture dimensions stored in SOF and MXM mismatch\n");
141  return AVERROR(EINVAL);
142  }
143 
144  if (reference_ptr->data[0]) {
145  int i;
146  for (i = 0; i < MAX_COMPONENTS; ++i) {
147  if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) ||
148  reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) {
149  av_log(jpg->avctx, AV_LOG_ERROR,
150  "Dimensions of current and reference picture mismatch\n");
151  return AVERROR(EINVAL);
152  }
153  }
154  }
155 
156  return 0;
157 }
158 
160  void *data, int *got_frame,
161  AVPacket *avpkt)
162 {
163  const uint8_t *buf = avpkt->data;
164  int buf_size = avpkt->size;
165  MXpegDecodeContext *s = avctx->priv_data;
166  MJpegDecodeContext *jpg = &s->jpg;
167  const uint8_t *buf_end, *buf_ptr;
168  const uint8_t *unescaped_buf_ptr;
169  int unescaped_buf_size;
170  int start_code;
171  AVFrame *picture = data;
172  int ret;
173 
174  buf_ptr = buf;
175  buf_end = buf + buf_size;
176  jpg->got_picture = 0;
177  s->got_mxm_bitmask = 0;
178  while (buf_ptr < buf_end) {
179  start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
180  &unescaped_buf_ptr, &unescaped_buf_size);
181  if (start_code < 0)
182  goto the_end;
183  {
184  init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8);
185 
186  if (start_code >= APP0 && start_code <= APP15) {
187  mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size);
188  }
189 
190  switch (start_code) {
191  case SOI:
192  if (jpg->got_picture) //emulating EOI
193  goto the_end;
194  break;
195  case EOI:
196  goto the_end;
197  case DQT:
198  ret = ff_mjpeg_decode_dqt(jpg);
199  if (ret < 0) {
200  av_log(avctx, AV_LOG_ERROR,
201  "quantization table decode error\n");
202  return ret;
203  }
204  break;
205  case DHT:
206  ret = ff_mjpeg_decode_dht(jpg);
207  if (ret < 0) {
208  av_log(avctx, AV_LOG_ERROR,
209  "huffman table decode error\n");
210  return ret;
211  }
212  break;
213  case COM:
214  ret = mxpeg_decode_com(s, unescaped_buf_ptr,
215  unescaped_buf_size);
216  if (ret < 0)
217  return ret;
218  break;
219  case SOF0:
220  s->got_sof_data = 0;
221  ret = ff_mjpeg_decode_sof(jpg);
222  if (ret < 0) {
223  av_log(avctx, AV_LOG_ERROR,
224  "SOF data decode error\n");
225  return ret;
226  }
227  if (jpg->interlaced) {
228  av_log(avctx, AV_LOG_ERROR,
229  "Interlaced mode not supported in MxPEG\n");
230  return AVERROR(EINVAL);
231  }
232  s->got_sof_data = 1;
233  break;
234  case SOS:
235  if (!s->got_sof_data) {
236  av_log(avctx, AV_LOG_WARNING,
237  "Can not process SOS without SOF data, skipping\n");
238  break;
239  }
240  if (!jpg->got_picture) {
241  if (jpg->first_picture) {
242  av_log(avctx, AV_LOG_WARNING,
243  "First picture has no SOF, skipping\n");
244  break;
245  }
246  if (!s->got_mxm_bitmask){
247  av_log(avctx, AV_LOG_WARNING,
248  "Non-key frame has no MXM, skipping\n");
249  break;
250  }
251  /* use stored SOF data to allocate current picture */
252  if (jpg->picture_ptr->data[0])
253  avctx->release_buffer(avctx, jpg->picture_ptr);
254  if (ff_get_buffer(avctx, jpg->picture_ptr) < 0) {
255  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
256  return AVERROR(ENOMEM);
257  }
259  jpg->picture_ptr->key_frame = 0;
260  jpg->got_picture = 1;
261  } else {
263  jpg->picture_ptr->key_frame = 1;
264  }
265 
266  if (s->got_mxm_bitmask) {
267  AVFrame *reference_ptr = &s->picture[s->picture_index ^ 1];
268  if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0)
269  break;
270 
271  /* allocate dummy reference picture if needed */
272  if (!reference_ptr->data[0] &&
273  ff_get_buffer(avctx, reference_ptr) < 0) {
274  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
275  return AVERROR(ENOMEM);
276  }
277 
278  ret = ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, reference_ptr);
279  if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
280  return ret;
281  } else {
282  ret = ff_mjpeg_decode_sos(jpg, NULL, NULL);
283  if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
284  return ret;
285  }
286 
287  break;
288  }
289 
290  buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3;
291  }
292 
293  }
294 
295 the_end:
296  if (jpg->got_picture) {
297  *got_frame = 1;
298  *picture = *jpg->picture_ptr;
299  s->picture_index ^= 1;
300  jpg->picture_ptr = &s->picture[s->picture_index];
301 
302  if (!s->has_complete_frame) {
303  if (!s->got_mxm_bitmask)
304  s->has_complete_frame = 1;
305  else
306  *got_frame = 0;
307  }
308  }
309 
310  return buf_ptr - buf;
311 }
312 
314 {
315  MXpegDecodeContext *s = avctx->priv_data;
316  MJpegDecodeContext *jpg = &s->jpg;
317  int i;
318 
319  jpg->picture_ptr = NULL;
320  ff_mjpeg_decode_end(avctx);
321 
322  for (i = 0; i < 2; ++i) {
323  if (s->picture[i].data[0])
324  avctx->release_buffer(avctx, &s->picture[i]);
325  }
326 
327  av_freep(&s->mxm_bitmask);
329 
330  return 0;
331 }
332 
334  .name = "mxpeg",
335  .long_name = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"),
336  .type = AVMEDIA_TYPE_VIDEO,
337  .id = AV_CODEC_ID_MXPEG,
338  .priv_data_size = sizeof(MXpegDecodeContext),
342  .capabilities = CODEC_CAP_DR1,
343  .max_lowres = 3,
344 };