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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 {
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         return AVERROR(ENOMEM);
72 
73     s->jpg.picture_ptr      = s->picture[0];
74     return ff_mjpeg_decode_init(avctx);
75 }
76 
mxpeg_decode_app(MXpegDecodeContext * s,const uint8_t * buf_ptr,int buf_size)77 static int mxpeg_decode_app(MXpegDecodeContext *s,
78                             const uint8_t *buf_ptr, int buf_size)
79 {
80     int len;
81     if (buf_size < 2)
82         return 0;
83     len = AV_RB16(buf_ptr);
84     skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
85 
86     return 0;
87 }
88 
mxpeg_decode_mxm(MXpegDecodeContext * s,const uint8_t * buf_ptr,int buf_size)89 static int mxpeg_decode_mxm(MXpegDecodeContext *s,
90                             const uint8_t *buf_ptr, int buf_size)
91 {
92     unsigned bitmask_size, mb_count;
93     int i;
94 
95     s->mb_width  = AV_RL16(buf_ptr+4);
96     s->mb_height = AV_RL16(buf_ptr+6);
97     mb_count = s->mb_width * s->mb_height;
98 
99     bitmask_size = (mb_count + 7) >> 3;
100     if (bitmask_size > buf_size - 12) {
101         av_log(s->jpg.avctx, AV_LOG_ERROR,
102                "MXM bitmask is not complete\n");
103         return AVERROR(EINVAL);
104     }
105 
106     if (s->bitmask_size != bitmask_size) {
107         s->bitmask_size = 0;
108         av_freep(&s->mxm_bitmask);
109         s->mxm_bitmask = av_malloc(bitmask_size);
110         if (!s->mxm_bitmask) {
111             av_log(s->jpg.avctx, AV_LOG_ERROR,
112                    "MXM bitmask memory allocation error\n");
113             return AVERROR(ENOMEM);
114         }
115 
116         av_freep(&s->completion_bitmask);
117         s->completion_bitmask = av_mallocz(bitmask_size);
118         if (!s->completion_bitmask) {
119             av_log(s->jpg.avctx, AV_LOG_ERROR,
120                    "Completion bitmask memory allocation error\n");
121             return AVERROR(ENOMEM);
122         }
123 
124         s->bitmask_size = bitmask_size;
125     }
126 
127     memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size);
128     s->got_mxm_bitmask = 1;
129 
130     if (!s->has_complete_frame) {
131         uint8_t completion_check = 0xFF;
132         for (i = 0; i < bitmask_size; ++i) {
133             s->completion_bitmask[i] |= s->mxm_bitmask[i];
134             completion_check &= s->completion_bitmask[i];
135         }
136         s->has_complete_frame = !(completion_check ^ 0xFF);
137     }
138 
139     return 0;
140 }
141 
mxpeg_decode_com(MXpegDecodeContext * s,const uint8_t * buf_ptr,int buf_size)142 static int mxpeg_decode_com(MXpegDecodeContext *s,
143                             const uint8_t *buf_ptr, int buf_size)
144 {
145     int len, ret = 0;
146     if (buf_size < 2)
147         return 0;
148     len = AV_RB16(buf_ptr);
149     if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) {
150         ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2);
151     }
152     skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
153 
154     return ret;
155 }
156 
mxpeg_check_dimensions(MXpegDecodeContext * s,MJpegDecodeContext * jpg,AVFrame * reference_ptr)157 static int mxpeg_check_dimensions(MXpegDecodeContext *s, MJpegDecodeContext *jpg,
158                                   AVFrame *reference_ptr)
159 {
160     if ((jpg->width + 0x0F)>>4 != s->mb_width ||
161         (jpg->height + 0x0F)>>4 != s->mb_height) {
162         av_log(jpg->avctx, AV_LOG_ERROR,
163                "Picture dimensions stored in SOF and MXM mismatch\n");
164         return AVERROR(EINVAL);
165     }
166 
167     if (reference_ptr->data[0]) {
168         int i;
169         for (i = 0; i < MAX_COMPONENTS; ++i) {
170             if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) ||
171                  reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) {
172                 av_log(jpg->avctx, AV_LOG_ERROR,
173                        "Dimensions of current and reference picture mismatch\n");
174                 return AVERROR(EINVAL);
175             }
176         }
177     }
178 
179     return 0;
180 }
181 
mxpeg_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)182 static int mxpeg_decode_frame(AVCodecContext *avctx,
183                           void *data, int *got_frame,
184                           AVPacket *avpkt)
185 {
186     const uint8_t *buf = avpkt->data;
187     int buf_size = avpkt->size;
188     MXpegDecodeContext *s = avctx->priv_data;
189     MJpegDecodeContext *jpg = &s->jpg;
190     const uint8_t *buf_end, *buf_ptr;
191     const uint8_t *unescaped_buf_ptr;
192     int unescaped_buf_size;
193     int start_code;
194     int ret;
195 
196     if (avctx->skip_frame == AVDISCARD_ALL)
197         return AVERROR_PATCHWELCOME;
198 
199     buf_ptr = buf;
200     buf_end = buf + buf_size;
201     jpg->got_picture = 0;
202     s->got_mxm_bitmask = 0;
203     s->got_sof_data = !!s->got_sof_data;
204     while (buf_ptr < buf_end) {
205         start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
206                                           &unescaped_buf_ptr, &unescaped_buf_size);
207         if (start_code < 0)
208             goto the_end;
209         {
210             init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8);
211 
212             if (start_code >= APP0 && start_code <= APP15) {
213                 mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size);
214             }
215 
216             switch (start_code) {
217             case SOI:
218                 if (jpg->got_picture) //emulating EOI
219                     goto the_end;
220                 break;
221             case EOI:
222                 goto the_end;
223             case DQT:
224                 ret = ff_mjpeg_decode_dqt(jpg);
225                 if (ret < 0) {
226                     av_log(avctx, AV_LOG_ERROR,
227                            "quantization table decode error\n");
228                     return ret;
229                 }
230                 break;
231             case DHT:
232                 ret = ff_mjpeg_decode_dht(jpg);
233                 if (ret < 0) {
234                     av_log(avctx, AV_LOG_ERROR,
235                            "huffman table decode error\n");
236                     return ret;
237                 }
238                 break;
239             case COM:
240                 ret = mxpeg_decode_com(s, unescaped_buf_ptr,
241                                        unescaped_buf_size);
242                 if (ret < 0)
243                     return ret;
244                 break;
245             case SOF0:
246                 if (s->got_sof_data > 1) {
247                     av_log(avctx, AV_LOG_ERROR,
248                            "Multiple SOF in a frame\n");
249                     return AVERROR_INVALIDDATA;
250                 }
251                 ret = ff_mjpeg_decode_sof(jpg);
252                 if (ret < 0) {
253                     av_log(avctx, AV_LOG_ERROR,
254                            "SOF data decode error\n");
255                     s->got_sof_data = 0;
256                     return ret;
257                 }
258                 if (jpg->interlaced) {
259                     av_log(avctx, AV_LOG_ERROR,
260                            "Interlaced mode not supported in MxPEG\n");
261                     s->got_sof_data = 0;
262                     return AVERROR(EINVAL);
263                 }
264                 s->got_sof_data ++;
265                 break;
266             case SOS:
267                 if (!s->got_sof_data) {
268                     av_log(avctx, AV_LOG_WARNING,
269                            "Can not process SOS without SOF data, skipping\n");
270                     break;
271                 }
272                 if (!jpg->got_picture) {
273                     if (jpg->first_picture) {
274                         av_log(avctx, AV_LOG_WARNING,
275                                "First picture has no SOF, skipping\n");
276                         break;
277                     }
278                     if (!s->got_mxm_bitmask){
279                         av_log(avctx, AV_LOG_WARNING,
280                                "Non-key frame has no MXM, skipping\n");
281                         break;
282                     }
283                     /* use stored SOF data to allocate current picture */
284                     av_frame_unref(jpg->picture_ptr);
285                     if ((ret = ff_get_buffer(avctx, jpg->picture_ptr,
286                                              AV_GET_BUFFER_FLAG_REF)) < 0)
287                         return ret;
288                     jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_P;
289                     jpg->picture_ptr->key_frame = 0;
290                     jpg->got_picture = 1;
291                 } else {
292                     jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_I;
293                     jpg->picture_ptr->key_frame = 1;
294                 }
295 
296                 if (s->got_mxm_bitmask) {
297                     AVFrame *reference_ptr = s->picture[s->picture_index ^ 1];
298                     if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0)
299                         break;
300 
301                     /* allocate dummy reference picture if needed */
302                     if (!reference_ptr->data[0] &&
303                         (ret = ff_get_buffer(avctx, reference_ptr,
304                                              AV_GET_BUFFER_FLAG_REF)) < 0)
305                         return ret;
306 
307                     ret = ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, s->bitmask_size, reference_ptr);
308                     if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
309                         return ret;
310                 } else {
311                     ret = ff_mjpeg_decode_sos(jpg, NULL, 0, NULL);
312                     if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
313                         return ret;
314                 }
315 
316                 break;
317             }
318 
319             buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3;
320         }
321 
322     }
323 
324 the_end:
325     if (jpg->got_picture) {
326         int ret = av_frame_ref(data, jpg->picture_ptr);
327         if (ret < 0)
328             return ret;
329         *got_frame = 1;
330 
331         s->picture_index ^= 1;
332         jpg->picture_ptr = s->picture[s->picture_index];
333 
334         if (!s->has_complete_frame) {
335             if (!s->got_mxm_bitmask)
336                 s->has_complete_frame = 1;
337             else
338                 *got_frame = 0;
339         }
340     }
341 
342     return buf_ptr - buf;
343 }
344 
345 AVCodec ff_mxpeg_decoder = {
346     .name           = "mxpeg",
347     .long_name      = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"),
348     .type           = AVMEDIA_TYPE_VIDEO,
349     .id             = AV_CODEC_ID_MXPEG,
350     .priv_data_size = sizeof(MXpegDecodeContext),
351     .init           = mxpeg_decode_init,
352     .close          = mxpeg_decode_end,
353     .decode         = mxpeg_decode_frame,
354     .capabilities   = AV_CODEC_CAP_DR1,
355     .max_lowres     = 3,
356     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
357 };
358