• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 {
33     MJpegDecodeContext jpg;
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 */
43 } MXpegDecodeContext;
44 
mxpeg_decode_end(AVCodecContext * avctx)45 static av_cold int mxpeg_decode_end(AVCodecContext *avctx)
46 {
47     MXpegDecodeContext *s = avctx->priv_data;
48     MJpegDecodeContext *jpg = &s->jpg;
49     int i;
50 
51     jpg->picture_ptr = NULL;
52     ff_mjpeg_decode_end(avctx);
53 
54     for (i = 0; i < 2; ++i)
55         av_frame_free(&s->picture[i]);
56 
57     s->bitmask_size = 0;
58     av_freep(&s->mxm_bitmask);
59     av_freep(&s->completion_bitmask);
60 
61     return 0;
62 }
63 
mxpeg_decode_init(AVCodecContext * avctx)64 static av_cold int mxpeg_decode_init(AVCodecContext *avctx)
65 {
66     MXpegDecodeContext *s = avctx->priv_data;
67 
68     s->picture[0] = av_frame_alloc();
69     s->picture[1] = av_frame_alloc();
70     if (!s->picture[0] || !s->picture[1]) {
71         mxpeg_decode_end(avctx);
72         return AVERROR(ENOMEM);
73     }
74 
75     s->jpg.picture_ptr      = s->picture[0];
76     return ff_mjpeg_decode_init(avctx);
77 }
78 
mxpeg_decode_app(MXpegDecodeContext * s,const uint8_t * buf_ptr,int buf_size)79 static int mxpeg_decode_app(MXpegDecodeContext *s,
80                             const uint8_t *buf_ptr, int buf_size)
81 {
82     int len;
83     if (buf_size < 2)
84         return 0;
85     len = AV_RB16(buf_ptr);
86     skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
87 
88     return 0;
89 }
90 
mxpeg_decode_mxm(MXpegDecodeContext * s,const uint8_t * buf_ptr,int buf_size)91 static int mxpeg_decode_mxm(MXpegDecodeContext *s,
92                             const uint8_t *buf_ptr, int buf_size)
93 {
94     unsigned bitmask_size, mb_count;
95     int i;
96 
97     s->mb_width  = AV_RL16(buf_ptr+4);
98     s->mb_height = AV_RL16(buf_ptr+6);
99     mb_count = s->mb_width * s->mb_height;
100 
101     bitmask_size = (mb_count + 7) >> 3;
102     if (bitmask_size > buf_size - 12) {
103         av_log(s->jpg.avctx, AV_LOG_ERROR,
104                "MXM bitmask is not complete\n");
105         return AVERROR(EINVAL);
106     }
107 
108     if (s->bitmask_size != bitmask_size) {
109         s->bitmask_size = 0;
110         av_freep(&s->mxm_bitmask);
111         s->mxm_bitmask = av_malloc(bitmask_size);
112         if (!s->mxm_bitmask) {
113             av_log(s->jpg.avctx, AV_LOG_ERROR,
114                    "MXM bitmask memory allocation error\n");
115             return AVERROR(ENOMEM);
116         }
117 
118         av_freep(&s->completion_bitmask);
119         s->completion_bitmask = av_mallocz(bitmask_size);
120         if (!s->completion_bitmask) {
121             av_log(s->jpg.avctx, AV_LOG_ERROR,
122                    "Completion bitmask memory allocation error\n");
123             return AVERROR(ENOMEM);
124         }
125 
126         s->bitmask_size = bitmask_size;
127     }
128 
129     memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size);
130     s->got_mxm_bitmask = 1;
131 
132     if (!s->has_complete_frame) {
133         uint8_t completion_check = 0xFF;
134         for (i = 0; i < bitmask_size; ++i) {
135             s->completion_bitmask[i] |= s->mxm_bitmask[i];
136             completion_check &= s->completion_bitmask[i];
137         }
138         s->has_complete_frame = !(completion_check ^ 0xFF);
139     }
140 
141     return 0;
142 }
143 
mxpeg_decode_com(MXpegDecodeContext * s,const uint8_t * buf_ptr,int buf_size)144 static int mxpeg_decode_com(MXpegDecodeContext *s,
145                             const uint8_t *buf_ptr, int buf_size)
146 {
147     int len, ret = 0;
148     if (buf_size < 2)
149         return 0;
150     len = AV_RB16(buf_ptr);
151     if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) {
152         ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2);
153     }
154     skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
155 
156     return ret;
157 }
158 
mxpeg_check_dimensions(MXpegDecodeContext * s,MJpegDecodeContext * jpg,AVFrame * reference_ptr)159 static int mxpeg_check_dimensions(MXpegDecodeContext *s, MJpegDecodeContext *jpg,
160                                   AVFrame *reference_ptr)
161 {
162     if ((jpg->width + 0x0F)>>4 != s->mb_width ||
163         (jpg->height + 0x0F)>>4 != s->mb_height) {
164         av_log(jpg->avctx, AV_LOG_ERROR,
165                "Picture dimensions stored in SOF and MXM mismatch\n");
166         return AVERROR(EINVAL);
167     }
168 
169     if (reference_ptr->data[0]) {
170         int i;
171         for (i = 0; i < MAX_COMPONENTS; ++i) {
172             if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) ||
173                  reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) {
174                 av_log(jpg->avctx, AV_LOG_ERROR,
175                        "Dimensions of current and reference picture mismatch\n");
176                 return AVERROR(EINVAL);
177             }
178         }
179     }
180 
181     return 0;
182 }
183 
mxpeg_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)184 static int mxpeg_decode_frame(AVCodecContext *avctx,
185                           void *data, int *got_frame,
186                           AVPacket *avpkt)
187 {
188     const uint8_t *buf = avpkt->data;
189     int buf_size = avpkt->size;
190     MXpegDecodeContext *s = avctx->priv_data;
191     MJpegDecodeContext *jpg = &s->jpg;
192     const uint8_t *buf_end, *buf_ptr;
193     const uint8_t *unescaped_buf_ptr;
194     int unescaped_buf_size;
195     int start_code;
196     int ret;
197 
198     buf_ptr = buf;
199     buf_end = buf + buf_size;
200     jpg->got_picture = 0;
201     s->got_mxm_bitmask = 0;
202     s->got_sof_data = !!s->got_sof_data;
203     while (buf_ptr < buf_end) {
204         start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
205                                           &unescaped_buf_ptr, &unescaped_buf_size);
206         if (start_code < 0)
207             goto the_end;
208         {
209             init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8);
210 
211             if (start_code >= APP0 && start_code <= APP15) {
212                 mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size);
213             }
214 
215             switch (start_code) {
216             case SOI:
217                 if (jpg->got_picture) //emulating EOI
218                     goto the_end;
219                 break;
220             case EOI:
221                 goto the_end;
222             case DQT:
223                 ret = ff_mjpeg_decode_dqt(jpg);
224                 if (ret < 0) {
225                     av_log(avctx, AV_LOG_ERROR,
226                            "quantization table decode error\n");
227                     return ret;
228                 }
229                 break;
230             case DHT:
231                 ret = ff_mjpeg_decode_dht(jpg);
232                 if (ret < 0) {
233                     av_log(avctx, AV_LOG_ERROR,
234                            "huffman table decode error\n");
235                     return ret;
236                 }
237                 break;
238             case COM:
239                 ret = mxpeg_decode_com(s, unescaped_buf_ptr,
240                                        unescaped_buf_size);
241                 if (ret < 0)
242                     return ret;
243                 break;
244             case SOF0:
245                 if (s->got_sof_data > 1) {
246                     av_log(avctx, AV_LOG_ERROR,
247                            "Multiple SOF in a frame\n");
248                     return AVERROR_INVALIDDATA;
249                 }
250                 ret = ff_mjpeg_decode_sof(jpg);
251                 if (ret < 0) {
252                     av_log(avctx, AV_LOG_ERROR,
253                            "SOF data decode error\n");
254                     s->got_sof_data = 0;
255                     return ret;
256                 }
257                 if (jpg->interlaced) {
258                     av_log(avctx, AV_LOG_ERROR,
259                            "Interlaced mode not supported in MxPEG\n");
260                     s->got_sof_data = 0;
261                     return AVERROR(EINVAL);
262                 }
263                 s->got_sof_data ++;
264                 break;
265             case SOS:
266                 if (!s->got_sof_data) {
267                     av_log(avctx, AV_LOG_WARNING,
268                            "Can not process SOS without SOF data, skipping\n");
269                     break;
270                 }
271                 if (!jpg->got_picture) {
272                     if (jpg->first_picture) {
273                         av_log(avctx, AV_LOG_WARNING,
274                                "First picture has no SOF, skipping\n");
275                         break;
276                     }
277                     if (!s->got_mxm_bitmask){
278                         av_log(avctx, AV_LOG_WARNING,
279                                "Non-key frame has no MXM, skipping\n");
280                         break;
281                     }
282                     /* use stored SOF data to allocate current picture */
283                     av_frame_unref(jpg->picture_ptr);
284                     if ((ret = ff_get_buffer(avctx, jpg->picture_ptr,
285                                              AV_GET_BUFFER_FLAG_REF)) < 0)
286                         return ret;
287                     jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_P;
288                     jpg->picture_ptr->key_frame = 0;
289                     jpg->got_picture = 1;
290                 } else {
291                     jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_I;
292                     jpg->picture_ptr->key_frame = 1;
293                 }
294 
295                 if (s->got_mxm_bitmask) {
296                     AVFrame *reference_ptr = s->picture[s->picture_index ^ 1];
297                     if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0)
298                         break;
299 
300                     /* allocate dummy reference picture if needed */
301                     if (!reference_ptr->data[0] &&
302                         (ret = ff_get_buffer(avctx, reference_ptr,
303                                              AV_GET_BUFFER_FLAG_REF)) < 0)
304                         return ret;
305 
306                     ret = ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, s->bitmask_size, reference_ptr);
307                     if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
308                         return ret;
309                 } else {
310                     ret = ff_mjpeg_decode_sos(jpg, NULL, 0, NULL);
311                     if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
312                         return ret;
313                 }
314 
315                 break;
316             }
317 
318             buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3;
319         }
320 
321     }
322 
323 the_end:
324     if (jpg->got_picture) {
325         int ret = av_frame_ref(data, jpg->picture_ptr);
326         if (ret < 0)
327             return ret;
328         *got_frame = 1;
329 
330         s->picture_index ^= 1;
331         jpg->picture_ptr = s->picture[s->picture_index];
332 
333         if (!s->has_complete_frame) {
334             if (!s->got_mxm_bitmask)
335                 s->has_complete_frame = 1;
336             else
337                 *got_frame = 0;
338         }
339     }
340 
341     return buf_ptr - buf;
342 }
343 
344 AVCodec ff_mxpeg_decoder = {
345     .name           = "mxpeg",
346     .long_name      = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"),
347     .type           = AVMEDIA_TYPE_VIDEO,
348     .id             = AV_CODEC_ID_MXPEG,
349     .priv_data_size = sizeof(MXpegDecodeContext),
350     .init           = mxpeg_decode_init,
351     .close          = mxpeg_decode_end,
352     .decode         = mxpeg_decode_frame,
353     .capabilities   = AV_CODEC_CAP_DR1,
354     .max_lowres     = 3,
355     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
356 };
357