1 /*
2 * DHAV demuxer
3 *
4 * Copyright (c) 2018 Paul B Mahol
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "libavutil/parseutils.h"
24 #include "avio_internal.h"
25 #include "avformat.h"
26 #include "internal.h"
27
28 typedef struct DHAVContext {
29 unsigned type;
30 unsigned subtype;
31 unsigned channel;
32 unsigned frame_subnumber;
33 unsigned frame_number;
34 unsigned date;
35 unsigned timestamp;
36 int width, height;
37 int video_codec;
38 int frame_rate;
39 int audio_channels;
40 int audio_codec;
41 int sample_rate;
42 int64_t last_good_pos;
43 int64_t duration;
44
45 int video_stream_index;
46 int audio_stream_index;
47 } DHAVContext;
48
49 typedef struct DHAVStream {
50 int64_t last_timestamp;
51 int64_t last_time;
52 int64_t pts;
53 } DHAVStream;
54
dhav_probe(const AVProbeData * p)55 static int dhav_probe(const AVProbeData *p)
56 {
57 if (!memcmp(p->buf, "DAHUA", 5))
58 return AVPROBE_SCORE_MAX;
59
60 if (memcmp(p->buf, "DHAV", 4))
61 return 0;
62
63 if (p->buf[4] == 0xf0 ||
64 p->buf[4] == 0xf1 ||
65 p->buf[4] == 0xfc ||
66 p->buf[4] == 0xfd)
67 return AVPROBE_SCORE_MAX;
68 return 0;
69 }
70
71 static const uint32_t sample_rates[] = {
72 8000, 4000, 8000, 11025, 16000,
73 20000, 22050, 32000, 44100, 48000,
74 96000, 192000, 64000,
75 };
76
parse_ext(AVFormatContext * s,int length)77 static int parse_ext(AVFormatContext *s, int length)
78 {
79 DHAVContext *dhav = s->priv_data;
80 int index, ret = 0;
81
82 while (length > 0) {
83 int type = avio_r8(s->pb);
84
85 switch (type) {
86 case 0x80:
87 ret = avio_skip(s->pb, 1);
88 dhav->width = 8 * avio_r8(s->pb);
89 dhav->height = 8 * avio_r8(s->pb);
90 length -= 4;
91 break;
92 case 0x81:
93 ret = avio_skip(s->pb, 1);
94 dhav->video_codec = avio_r8(s->pb);
95 dhav->frame_rate = avio_r8(s->pb);
96 length -= 4;
97 break;
98 case 0x82:
99 ret = avio_skip(s->pb, 3);
100 dhav->width = avio_rl16(s->pb);
101 dhav->height = avio_rl16(s->pb);
102 length -= 8;
103 break;
104 case 0x83:
105 dhav->audio_channels = avio_r8(s->pb);
106 dhav->audio_codec = avio_r8(s->pb);
107 index = avio_r8(s->pb);
108 if (index < FF_ARRAY_ELEMS(sample_rates)) {
109 dhav->sample_rate = sample_rates[index];
110 } else {
111 dhav->sample_rate = 8000;
112 }
113 length -= 4;
114 break;
115 case 0x88:
116 ret = avio_skip(s->pb, 7);
117 length -= 8;
118 break;
119 case 0x8c:
120 ret = avio_skip(s->pb, 1);
121 dhav->audio_channels = avio_r8(s->pb);
122 dhav->audio_codec = avio_r8(s->pb);
123 index = avio_r8(s->pb);
124 if (index < FF_ARRAY_ELEMS(sample_rates)) {
125 dhav->sample_rate = sample_rates[index];
126 } else {
127 dhav->sample_rate = 8000;
128 }
129 ret = avio_skip(s->pb, 3);
130 length -= 8;
131 break;
132 case 0x91:
133 case 0x92:
134 case 0x93:
135 case 0x95:
136 case 0x9a:
137 case 0x9b: // sample aspect ratio
138 case 0xb3:
139 ret = avio_skip(s->pb, 7);
140 length -= 8;
141 break;
142 case 0x84:
143 case 0x85:
144 case 0x8b:
145 case 0x94:
146 case 0x96:
147 case 0xa0:
148 case 0xb2:
149 case 0xb4:
150 ret = avio_skip(s->pb, 3);
151 length -= 4;
152 break;
153 default:
154 av_log(s, AV_LOG_INFO, "Unknown type: %X, skipping rest of header.\n", type);
155 ret = avio_skip(s->pb, length - 1);
156 length = 0;
157 }
158
159 if (ret < 0)
160 return ret;
161 }
162
163 return 0;
164 }
165
read_chunk(AVFormatContext * s)166 static int read_chunk(AVFormatContext *s)
167 {
168 DHAVContext *dhav = s->priv_data;
169 int frame_length, ext_length;
170 int64_t start, end;
171 int ret;
172
173 if (avio_feof(s->pb))
174 return AVERROR_EOF;
175
176 if (avio_rl32(s->pb) != MKTAG('D','H','A','V') && dhav->last_good_pos < INT64_MAX - 0x8000) {
177 dhav->last_good_pos += 0x8000;
178 avio_seek(s->pb, dhav->last_good_pos, SEEK_SET);
179
180 while (avio_rl32(s->pb) != MKTAG('D','H','A','V')) {
181 if (avio_feof(s->pb) || dhav->last_good_pos >= INT64_MAX - 0x8000)
182 return AVERROR_EOF;
183 dhav->last_good_pos += 0x8000;
184 ret = avio_skip(s->pb, 0x8000 - 4);
185 if (ret < 0)
186 return ret;
187 }
188 }
189
190 start = avio_tell(s->pb) - 4;
191 dhav->last_good_pos = start;
192 dhav->type = avio_r8(s->pb);
193 dhav->subtype = avio_r8(s->pb);
194 dhav->channel = avio_r8(s->pb);
195 dhav->frame_subnumber = avio_r8(s->pb);
196 dhav->frame_number = avio_rl32(s->pb);
197 frame_length = avio_rl32(s->pb);
198 dhav->date = avio_rl32(s->pb);
199
200 if (frame_length < 24)
201 return AVERROR_INVALIDDATA;
202 if (dhav->type == 0xf1) {
203 ret = avio_skip(s->pb, frame_length - 20);
204 return ret < 0 ? ret : 0;
205 }
206
207 dhav->timestamp = avio_rl16(s->pb);
208 ext_length = avio_r8(s->pb);
209 avio_skip(s->pb, 1); // checksum
210
211 ret = parse_ext(s, ext_length);
212 if (ret < 0)
213 return ret;
214
215 end = avio_tell(s->pb);
216
217 return frame_length - 8 - (end - start);
218 }
219
get_timeinfo(unsigned date,struct tm * timeinfo)220 static void get_timeinfo(unsigned date, struct tm *timeinfo)
221 {
222 int year, month, day, hour, min, sec;
223
224 sec = date & 0x3F;
225 min = (date >> 6) & 0x3F;
226 hour = (date >> 12) & 0x1F;
227 day = (date >> 17) & 0x1F;
228 month = (date >> 22) & 0x0F;
229 year = ((date >> 26) & 0x3F) + 2000;
230
231 timeinfo->tm_year = year - 1900;
232 timeinfo->tm_mon = month - 1;
233 timeinfo->tm_mday = day;
234 timeinfo->tm_hour = hour;
235 timeinfo->tm_min = min;
236 timeinfo->tm_sec = sec;
237 }
238
get_duration(AVFormatContext * s)239 static int64_t get_duration(AVFormatContext *s)
240 {
241 DHAVContext *dhav = s->priv_data;
242 int64_t start_pos = avio_tell(s->pb);
243 int64_t start = 0, end = 0;
244 struct tm timeinfo;
245
246 if (!s->pb->seekable)
247 return 0;
248
249 avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
250 if (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
251 int seek_back = avio_rl32(s->pb);
252
253 avio_seek(s->pb, -seek_back, SEEK_CUR);
254 read_chunk(s);
255 get_timeinfo(dhav->date, &timeinfo);
256 end = av_timegm(&timeinfo) * 1000LL;
257 } else {
258 avio_seek(s->pb, start_pos, SEEK_SET);
259 return 0;
260 }
261
262 avio_seek(s->pb, start_pos, SEEK_SET);
263
264 read_chunk(s);
265 get_timeinfo(dhav->date, &timeinfo);
266 start = av_timegm(&timeinfo) * 1000LL;
267
268 avio_seek(s->pb, start_pos, SEEK_SET);
269
270 return end - start;
271 }
272
dhav_read_header(AVFormatContext * s)273 static int dhav_read_header(AVFormatContext *s)
274 {
275 DHAVContext *dhav = s->priv_data;
276 uint8_t signature[5];
277
278 ffio_ensure_seekback(s->pb, 5);
279 avio_read(s->pb, signature, sizeof(signature));
280 if (!memcmp(signature, "DAHUA", 5)) {
281 avio_skip(s->pb, 0x400 - 5);
282 dhav->last_good_pos = avio_tell(s->pb);
283 } else {
284 if (!memcmp(signature, "DHAV", 4)) {
285 avio_seek(s->pb, -5, SEEK_CUR);
286 dhav->last_good_pos = avio_tell(s->pb);
287 } else if (s->pb->seekable) {
288 avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
289 while (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
290 int seek_back;
291
292 seek_back = avio_rl32(s->pb) + 8;
293 if (seek_back < 9)
294 break;
295 dhav->last_good_pos = avio_tell(s->pb);
296 avio_seek(s->pb, -seek_back, SEEK_CUR);
297 }
298 avio_seek(s->pb, dhav->last_good_pos, SEEK_SET);
299 }
300 }
301
302 dhav->duration = get_duration(s);
303 dhav->last_good_pos = avio_tell(s->pb);
304 s->ctx_flags |= AVFMTCTX_NOHEADER;
305 dhav->video_stream_index = -1;
306 dhav->audio_stream_index = -1;
307
308 return 0;
309 }
310
get_pts(AVFormatContext * s,int stream_index)311 static int64_t get_pts(AVFormatContext *s, int stream_index)
312 {
313 DHAVStream *dst = s->streams[stream_index]->priv_data;
314 DHAVContext *dhav = s->priv_data;
315 struct tm timeinfo;
316 time_t t;
317
318 get_timeinfo(dhav->date, &timeinfo);
319
320 t = av_timegm(&timeinfo);
321 if (dst->last_time == t) {
322 int64_t diff = dhav->timestamp - dst->last_timestamp;
323
324 if (diff < 0)
325 diff += 65535;
326 dst->pts += diff;
327 } else {
328 dst->pts = t * 1000LL;
329 }
330
331 dst->last_time = t;
332 dst->last_timestamp = dhav->timestamp;
333
334 return dst->pts;
335 }
336
dhav_read_packet(AVFormatContext * s,AVPacket * pkt)337 static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
338 {
339 DHAVContext *dhav = s->priv_data;
340 int size, ret, stream_index;
341
342 retry:
343 while ((ret = read_chunk(s)) == 0)
344 ;
345
346 if (ret < 0)
347 return ret;
348
349 if (dhav->type == 0xfd && dhav->video_stream_index == -1) {
350 AVStream *st = avformat_new_stream(s, NULL);
351 DHAVStream *dst;
352
353 if (!st)
354 return AVERROR(ENOMEM);
355
356 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
357 switch (dhav->video_codec) {
358 case 0x1: st->codecpar->codec_id = AV_CODEC_ID_MPEG4; break;
359 case 0x3: st->codecpar->codec_id = AV_CODEC_ID_MJPEG; break;
360 case 0x2:
361 case 0x4:
362 case 0x8: st->codecpar->codec_id = AV_CODEC_ID_H264; break;
363 case 0xc: st->codecpar->codec_id = AV_CODEC_ID_HEVC; break;
364 default: avpriv_request_sample(s, "Unknown video codec %X\n", dhav->video_codec);
365 }
366 st->duration = dhav->duration;
367 st->codecpar->width = dhav->width;
368 st->codecpar->height = dhav->height;
369 st->avg_frame_rate.num = dhav->frame_rate;
370 st->avg_frame_rate.den = 1;
371 st->priv_data = dst = av_mallocz(sizeof(DHAVStream));
372 if (!st->priv_data)
373 return AVERROR(ENOMEM);
374 dst->last_time = AV_NOPTS_VALUE;
375 dhav->video_stream_index = st->index;
376
377 avpriv_set_pts_info(st, 64, 1, 1000);
378 } else if (dhav->type == 0xf0 && dhav->audio_stream_index == -1) {
379 AVStream *st = avformat_new_stream(s, NULL);
380 DHAVStream *dst;
381
382 if (!st)
383 return AVERROR(ENOMEM);
384
385 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
386 switch (dhav->audio_codec) {
387 case 0x07: st->codecpar->codec_id = AV_CODEC_ID_PCM_S8; break;
388 case 0x0c: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE; break;
389 case 0x10: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE; break;
390 case 0x0a: st->codecpar->codec_id = AV_CODEC_ID_PCM_MULAW; break;
391 case 0x16: st->codecpar->codec_id = AV_CODEC_ID_PCM_MULAW; break;
392 case 0x0e: st->codecpar->codec_id = AV_CODEC_ID_PCM_ALAW; break;
393 case 0x1a: st->codecpar->codec_id = AV_CODEC_ID_AAC; break;
394 case 0x1f: st->codecpar->codec_id = AV_CODEC_ID_MP2; break;
395 case 0x21: st->codecpar->codec_id = AV_CODEC_ID_MP3; break;
396 case 0x0d: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_MS; break;
397 default: avpriv_request_sample(s, "Unknown audio codec %X\n", dhav->audio_codec);
398 }
399 st->duration = dhav->duration;
400 st->codecpar->channels = dhav->audio_channels;
401 st->codecpar->sample_rate = dhav->sample_rate;
402 st->priv_data = dst = av_mallocz(sizeof(DHAVStream));
403 if (!st->priv_data)
404 return AVERROR(ENOMEM);
405 dst->last_time = AV_NOPTS_VALUE;
406 dhav->audio_stream_index = st->index;
407
408 avpriv_set_pts_info(st, 64, 1, 1000);
409 }
410
411 stream_index = dhav->type == 0xf0 ? dhav->audio_stream_index : dhav->video_stream_index;
412 if (stream_index < 0) {
413 avio_skip(s->pb, ret);
414 if (avio_rl32(s->pb) == MKTAG('d','h','a','v'))
415 avio_skip(s->pb, 4);
416 goto retry;
417 }
418
419 size = ret;
420 ret = av_get_packet(s->pb, pkt, size);
421 if (ret < 0)
422 return ret;
423 pkt->stream_index = stream_index;
424 if (dhav->type != 0xfc)
425 pkt->flags |= AV_PKT_FLAG_KEY;
426 pkt->duration = 1;
427 if (pkt->stream_index >= 0)
428 pkt->pts = get_pts(s, pkt->stream_index);
429 pkt->pos = dhav->last_good_pos;
430 if (avio_rl32(s->pb) == MKTAG('d','h','a','v'))
431 avio_skip(s->pb, 4);
432
433 return ret;
434 }
435
dhav_read_seek(AVFormatContext * s,int stream_index,int64_t timestamp,int flags)436 static int dhav_read_seek(AVFormatContext *s, int stream_index,
437 int64_t timestamp, int flags)
438 {
439 DHAVContext *dhav = s->priv_data;
440 AVStream *st = s->streams[stream_index];
441 int index = av_index_search_timestamp(st, timestamp, flags);
442 int64_t pts;
443
444 if (index < 0)
445 return -1;
446 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
447 return -1;
448
449 pts = st->index_entries[index].timestamp;
450
451 for (int n = 0; n < s->nb_streams; n++) {
452 AVStream *st = s->streams[n];
453 DHAVStream *dst = st->priv_data;
454
455 dst->pts = pts;
456 dst->last_time = AV_NOPTS_VALUE;
457 }
458 dhav->last_good_pos = avio_tell(s->pb);
459
460 return 0;
461 }
462
463 AVInputFormat ff_dhav_demuxer = {
464 .name = "dhav",
465 .long_name = NULL_IF_CONFIG_SMALL("Video DAV"),
466 .priv_data_size = sizeof(DHAVContext),
467 .read_probe = dhav_probe,
468 .read_header = dhav_read_header,
469 .read_packet = dhav_read_packet,
470 .read_seek = dhav_read_seek,
471 .extensions = "dav",
472 .flags = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK | AVFMT_TS_DISCONT | AVFMT_TS_NONSTRICT,
473 };
474