2 * General DV muxer/demuxer
3 * Copyright (c) 2003 Roman Shaposhnik
5 * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth
6 * of DV technical info.
9 * Copyright (c) 2002 Fabrice Bellard.
11 * 50 Mbps (DVCPRO50) support
12 * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
14 * This library is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU Lesser General Public
16 * License as published by the Free Software Foundation; either
17 * version 2 of the License, or (at your option) any later version.
19 * This library is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * Lesser General Public License for more details.
24 * You should have received a copy of the GNU Lesser General Public
25 * License along with this library; if not, write to the Free Software
26 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
33 struct DVDemuxContext {
34 const DVprofile* sys; /* Current DV profile. E.g.: 525/60, 625/50 */
35 AVFormatContext* fctx;
38 AVPacket audio_pkt[2];
39 uint8_t audio_buf[2][8192];
46 const DVprofile* sys; /* Current DV profile. E.g.: 525/60, 625/50 */
47 int n_ast; /* Number of stereo audio streams (up to 2) */
48 AVStream *ast[2]; /* Stereo audio streams */
49 FifoBuffer audio_data[2]; /* Fifo for storing excessive amounts of PCM */
50 int frames; /* Number of a current frame */
51 time_t start_time; /* Start time of recording */
52 int has_audio; /* frame under contruction has audio */
53 int has_video; /* frame under contruction has video */
54 uint8_t frame_buf[DV_MAX_FRAME_SIZE]; /* frame under contruction */
57 static const int dv_aaux_packs_dist[12][9] = {
58 { 0xff, 0xff, 0xff, 0x50, 0x51, 0x52, 0x53, 0xff, 0xff },
59 { 0x50, 0x51, 0x52, 0x53, 0xff, 0xff, 0xff, 0xff, 0xff },
60 { 0xff, 0xff, 0xff, 0x50, 0x51, 0x52, 0x53, 0xff, 0xff },
61 { 0x50, 0x51, 0x52, 0x53, 0xff, 0xff, 0xff, 0xff, 0xff },
62 { 0xff, 0xff, 0xff, 0x50, 0x51, 0x52, 0x53, 0xff, 0xff },
63 { 0x50, 0x51, 0x52, 0x53, 0xff, 0xff, 0xff, 0xff, 0xff },
64 { 0xff, 0xff, 0xff, 0x50, 0x51, 0x52, 0x53, 0xff, 0xff },
65 { 0x50, 0x51, 0x52, 0x53, 0xff, 0xff, 0xff, 0xff, 0xff },
66 { 0xff, 0xff, 0xff, 0x50, 0x51, 0x52, 0x53, 0xff, 0xff },
67 { 0x50, 0x51, 0x52, 0x53, 0xff, 0xff, 0xff, 0xff, 0xff },
68 { 0xff, 0xff, 0xff, 0x50, 0x51, 0x52, 0x53, 0xff, 0xff },
69 { 0x50, 0x51, 0x52, 0x53, 0xff, 0xff, 0xff, 0xff, 0xff },
72 static inline uint16_t dv_audio_12to16(uint16_t sample)
74 uint16_t shift, result;
76 sample = (sample < 0x800) ? sample : sample | 0xf000;
77 shift = (sample & 0xf00) >> 8;
79 if (shift < 0x2 || shift > 0xd) {
81 } else if (shift < 0x8) {
83 result = (sample - (256 * shift)) << shift;
86 result = ((sample + ((256 * shift) + 1)) << shift) - 1;
92 static int dv_audio_frame_size(const DVprofile* sys, int frame)
94 return sys->audio_samples_dist[frame % (sizeof(sys->audio_samples_dist)/
95 sizeof(sys->audio_samples_dist[0]))];
98 static int dv_write_pack(enum dv_pack_type pack_id, DVMuxContext *c, uint8_t* buf)
104 /* Its hard to tell what SMPTE requires w.r.t. APT, but Quicktime needs it.
105 * We set it based on pix_fmt value but it really should be per DV profile */
106 int apt = (c->sys->pix_fmt == PIX_FMT_YUV422P ? 1 : 0);
108 buf[0] = (uint8_t)pack_id;
111 ct = (time_t)(c->frames / ((float)c->sys->frame_rate /
112 (float)c->sys->frame_rate_base));
115 * LTC drop-frame frame counter drops two frames (0 and 1) every
116 * minute, unless it is exactly divisible by 10
118 ltc_frame = (c->frames + 2*ct/60 - 2*ct/600) % c->sys->ltc_divisor;
119 buf[1] = (0 << 7) | /* Color fame: 0 - unsync; 1 - sync mode */
120 (1 << 6) | /* Drop frame timecode: 0 - nondrop; 1 - drop */
121 ((ltc_frame / 10) << 4) | /* Tens of frames */
122 (ltc_frame % 10); /* Units of frames */
123 buf[2] = (1 << 7) | /* Biphase mark polarity correction: 0 - even; 1 - odd */
124 ((tc.tm_sec / 10) << 4) | /* Tens of seconds */
125 (tc.tm_sec % 10); /* Units of seconds */
126 buf[3] = (1 << 7) | /* Binary group flag BGF0 */
127 ((tc.tm_min / 10) << 4) | /* Tens of minutes */
128 (tc.tm_min % 10); /* Units of minutes */
129 buf[4] = (1 << 7) | /* Binary group flag BGF2 */
130 (1 << 6) | /* Binary group flag BGF1 */
131 ((tc.tm_hour / 10) << 4) | /* Tens of hours */
132 (tc.tm_hour % 10); /* Units of hours */
134 case dv_audio_source: /* AAUX source pack */
135 buf[1] = (0 << 7) | /* locked mode */
136 (1 << 6) | /* reserved -- always 1 */
137 (dv_audio_frame_size(c->sys, c->frames) -
138 c->sys->audio_min_samples[0]);
140 buf[2] = (0 << 7) | /* multi-stereo */
141 (0 << 5) | /* #of audio channels per block: 0 -- 1 channel */
142 (0 << 4) | /* pair bit: 0 -- one pair of channels */
144 buf[3] = (1 << 7) | /* res */
145 (1 << 6) | /* multi-language flag */
146 (c->sys->dsf << 5) | /* system: 60fields/50fields */
147 (apt << 1);/* definition: 0 -- 25Mbps, 2 -- 50Mbps */
148 buf[4] = (1 << 7) | /* emphasis: 1 -- off */
149 (0 << 6) | /* emphasis time constant: 0 -- reserved */
150 (0 << 3) | /* frequency: 0 -- 48Khz, 1 -- 44,1Khz, 2 -- 32Khz */
151 0; /* quantization: 0 -- 16bit linear, 1 -- 12bit nonlinear */
153 case dv_audio_control:
154 buf[1] = (0 << 6) | /* copy protection: 0 -- unrestricted */
155 (1 << 4) | /* input source: 1 -- digital input */
156 (3 << 2) | /* compression: 3 -- no information */
157 0; /* misc. info/SMPTE emphasis off */
158 buf[2] = (1 << 7) | /* recording start point: 1 -- no */
159 (1 << 6) | /* recording end point: 1 -- no */
160 (1 << 3) | /* recording mode: 1 -- original */
162 buf[3] = (1 << 7) | /* direction: 1 -- forward */
164 buf[4] = (1 << 7) | /* reserved -- always 1 */
165 0x7f; /* genre category */
167 case dv_audio_recdate:
168 case dv_video_recdate: /* VAUX recording date */
169 ct = c->start_time + (time_t)(c->frames /
170 ((float)c->sys->frame_rate / (float)c->sys->frame_rate_base));
172 buf[1] = 0xff; /* ds, tm, tens of time zone, units of time zone */
173 /* 0xff is very likely to be "unknown" */
174 buf[2] = (3 << 6) | /* reserved -- always 1 */
175 ((tc.tm_mday / 10) << 4) | /* Tens of day */
176 (tc.tm_mday % 10); /* Units of day */
177 buf[3] = /* we set high 4 bits to 0, shouldn't we set them to week? */
178 ((tc.tm_mon / 10) << 4) | /* Tens of month */
179 (tc.tm_mon % 10); /* Units of month */
180 buf[4] = (((tc.tm_year % 100) / 10) << 4) | /* Tens of year */
181 (tc.tm_year % 10); /* Units of year */
183 case dv_audio_rectime: /* AAUX recording time */
184 case dv_video_rectime: /* VAUX recording time */
185 ct = c->start_time + (time_t)(c->frames /
186 ((float)c->sys->frame_rate / (float)c->sys->frame_rate_base));
188 buf[1] = (3 << 6) | /* reserved -- always 1 */
189 0x3f; /* tens of frame, units of frame: 0x3f - "unknown" ? */
190 buf[2] = (1 << 7) | /* reserved -- always 1 */
191 ((tc.tm_sec / 10) << 4) | /* Tens of seconds */
192 (tc.tm_sec % 10); /* Units of seconds */
193 buf[3] = (1 << 7) | /* reserved -- always 1 */
194 ((tc.tm_min / 10) << 4) | /* Tens of minutes */
195 (tc.tm_min % 10); /* Units of minutes */
196 buf[4] = (3 << 6) | /* reserved -- always 1 */
197 ((tc.tm_hour / 10) << 4) | /* Tens of hours */
198 (tc.tm_hour % 10); /* Units of hours */
201 buf[1] = buf[2] = buf[3] = buf[4] = 0xff;
206 static void dv_inject_audio(DVMuxContext *c, int channel, uint8_t* frame_ptr)
208 int i, j, d, of, size;
209 size = 4 * dv_audio_frame_size(c->sys, c->frames);
210 frame_ptr += channel * c->sys->difseg_size * 150 * 80;
211 for (i = 0; i < c->sys->difseg_size; i++) {
212 frame_ptr += 6 * 80; /* skip DIF segment header */
213 for (j = 0; j < 9; j++) {
214 dv_write_pack(dv_aaux_packs_dist[i][j], c, &frame_ptr[3]);
215 for (d = 8; d < 80; d+=2) {
216 of = c->sys->audio_shuffle[i][j] + (d - 8)/2 * c->sys->audio_stride;
220 frame_ptr[d] = fifo_peek(&c->audio_data[channel], of*2+1); // FIXME: may be we have to admit
221 frame_ptr[d+1] = fifo_peek(&c->audio_data[channel], of*2); // that DV is a big endian PCM
223 frame_ptr += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
228 static void dv_inject_metadata(DVMuxContext *c, uint8_t* frame)
233 for (buf = frame; buf < frame + c->sys->frame_size; buf += 150 * 80) {
234 /* DV subcode: 2nd and 3d DIFs */
235 for (j = 80; j < 80 * 3; j += 80) {
236 for (k = 6; k < 6 * 8; k += 8)
237 dv_write_pack(dv_timecode, c, &buf[j+k]);
239 if (((long)(buf-frame)/(c->sys->frame_size/(c->sys->difseg_size*c->sys->n_difchan))%c->sys->difseg_size) > 5) { /* FIXME: is this really needed ? */
240 dv_write_pack(dv_video_recdate, c, &buf[j+14]);
241 dv_write_pack(dv_video_rectime, c, &buf[j+22]);
242 dv_write_pack(dv_video_recdate, c, &buf[j+38]);
243 dv_write_pack(dv_video_rectime, c, &buf[j+46]);
247 /* DV VAUX: 4th, 5th and 6th 3DIFs */
248 for (j = 80*3 + 3; j < 80*6; j += 80) {
249 dv_write_pack(dv_video_recdate, c, &buf[j+5*2]);
250 dv_write_pack(dv_video_rectime, c, &buf[j+5*3]);
251 dv_write_pack(dv_video_recdate, c, &buf[j+5*11]);
252 dv_write_pack(dv_video_rectime, c, &buf[j+5*12]);
258 * This is the dumbest implementation of all -- it simply looks at
259 * a fixed offset and if pack isn't there -- fails. We might want
260 * to have a fallback mechanism for complete search of missing packs.
262 static const uint8_t* dv_extract_pack(uint8_t* frame, enum dv_pack_type t)
267 case dv_audio_source:
268 offs = (80*6 + 80*16*3 + 3);
270 case dv_audio_control:
271 offs = (80*6 + 80*16*4 + 3);
273 case dv_video_control:
274 offs = (80*5 + 48 + 5);
280 return (frame[offs] == t ? &frame[offs] : NULL);
284 * There's a couple of assumptions being made here:
285 * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples.
286 * We can pass them upwards when ffmpeg will be ready to deal with them.
287 * 2. We don't do software emphasis.
288 * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples
289 * are converted into 16bit linear ones.
291 static int dv_extract_audio(uint8_t* frame, uint8_t* pcm, uint8_t* pcm2,
292 const DVprofile *sys)
294 int size, chan, i, j, d, of, smpls, freq, quant, half_ch;
296 const uint8_t* as_pack;
298 as_pack = dv_extract_pack(frame, dv_audio_source);
299 if (!as_pack) /* No audio ? */
302 smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */
303 freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48KHz, 1 - 44,1kHz, 2 - 32 kHz */
304 quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */
307 return -1; /* Unsupported quantization */
309 size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */
310 half_ch = sys->difseg_size/2;
312 /* for each DIF channel */
313 for (chan = 0; chan < sys->n_difchan; chan++) {
314 /* for each DIF segment */
315 for (i = 0; i < sys->difseg_size; i++) {
316 frame += 6 * 80; /* skip DIF segment header */
317 if (quant == 1 && i == half_ch) {
318 /* next stereo channel (12bit mode only) */
325 /* for each AV sequence */
326 for (j = 0; j < 9; j++) {
327 for (d = 8; d < 80; d += 2) {
328 if (quant == 0) { /* 16bit quantization */
329 of = sys->audio_shuffle[i][j] + (d - 8)/2 * sys->audio_stride;
333 pcm[of*2] = frame[d+1]; // FIXME: may be we have to admit
334 pcm[of*2+1] = frame[d]; // that DV is a big endian PCM
335 if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00)
337 } else { /* 12bit quantization */
338 lc = ((uint16_t)frame[d] << 4) |
339 ((uint16_t)frame[d+2] >> 4);
340 rc = ((uint16_t)frame[d+1] << 4) |
341 ((uint16_t)frame[d+2] & 0x0f);
342 lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
343 rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
345 of = sys->audio_shuffle[i%half_ch][j] + (d - 8)/3 * sys->audio_stride;
349 pcm[of*2] = lc & 0xff; // FIXME: may be we have to admit
350 pcm[of*2+1] = lc >> 8; // that DV is a big endian PCM
351 of = sys->audio_shuffle[i%half_ch+half_ch][j] +
352 (d - 8)/3 * sys->audio_stride;
353 pcm[of*2] = rc & 0xff; // FIXME: may be we have to admit
354 pcm[of*2+1] = rc >> 8; // that DV is a big endian PCM
359 frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
363 /* next stereo channel (50Mbps only) */
372 static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame)
374 const uint8_t* as_pack;
375 int freq, stype, smpls, quant, i, ach;
377 as_pack = dv_extract_pack(frame, dv_audio_source);
378 if (!as_pack || !c->sys) { /* No audio ? */
383 smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */
384 freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48KHz, 1 - 44,1kHz, 2 - 32 kHz */
385 stype = (as_pack[3] & 0x1f); /* 0 - 2CH, 2 - 4CH */
386 quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */
388 /* note: ach counts PAIRS of channels (i.e. stereo channels) */
389 ach = (stype == 2 || (quant && (freq == 2))) ? 2 : 1;
391 /* Dynamic handling of the audio streams in DV */
392 for (i=0; i<ach; i++) {
394 c->ast[i] = av_new_stream(c->fctx, 0);
397 av_set_pts_info(c->ast[i], 64, 1, 30000);
398 c->ast[i]->codec->codec_type = CODEC_TYPE_AUDIO;
399 c->ast[i]->codec->codec_id = CODEC_ID_PCM_S16LE;
401 av_init_packet(&c->audio_pkt[i]);
402 c->audio_pkt[i].size = 0;
403 c->audio_pkt[i].data = c->audio_buf[i];
404 c->audio_pkt[i].stream_index = c->ast[i]->index;
405 c->audio_pkt[i].flags |= PKT_FLAG_KEY;
407 c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];
408 c->ast[i]->codec->channels = 2;
409 c->ast[i]->codec->bit_rate = 2 * dv_audio_frequency[freq] * 16;
410 c->ast[i]->start_time = 0;
414 return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */;
417 static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame)
419 const uint8_t* vsc_pack;
420 AVCodecContext* avctx;
425 avctx = c->vst->codec;
427 av_set_pts_info(c->vst, 64, c->sys->frame_rate_base, c->sys->frame_rate);
428 avctx->time_base= (AVRational){c->sys->frame_rate_base, c->sys->frame_rate};
430 avctx->width = c->sys->width;
431 avctx->height = c->sys->height;
433 avctx->pix_fmt = c->sys->pix_fmt;
435 /* finding out SAR is a little bit messy */
436 vsc_pack = dv_extract_pack(frame, dv_video_control);
437 apt = frame[4] & 0x07;
438 is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
439 (!apt && (vsc_pack[2] & 0x07) == 0x07)));
440 avctx->sample_aspect_ratio = c->sys->sar[is16_9];
441 avctx->bit_rate = av_rescale(c->sys->frame_size * 8,
443 c->sys->frame_rate_base);
444 size = c->sys->frame_size;
450 * The following 6 functions constitute our interface to the world
453 int dv_assemble_frame(DVMuxContext *c, AVStream* st,
454 const uint8_t* data, int data_size, uint8_t** frame)
458 *frame = &c->frame_buf[0];
459 reqasize = 4 * dv_audio_frame_size(c->sys, c->frames);
461 switch (st->codec->codec_type) {
462 case CODEC_TYPE_VIDEO:
463 /* FIXME: we have to have more sensible approach than this one */
465 av_log(st->codec, AV_LOG_ERROR, "Can't process DV frame #%d. Insufficient audio data or severe sync problem.\n", c->frames);
467 memcpy(*frame, data, c->sys->frame_size);
470 case CODEC_TYPE_AUDIO:
471 for (i = 0; i < c->n_ast && st != c->ast[i]; i++);
473 /* FIXME: we have to have more sensible approach than this one */
474 if (fifo_size(&c->audio_data[i], c->audio_data[i].rptr) + data_size >= 100*AVCODEC_MAX_AUDIO_FRAME_SIZE)
475 av_log(st->codec, AV_LOG_ERROR, "Can't process DV frame #%d. Insufficient video data or severe sync problem.\n", c->frames);
476 fifo_write(&c->audio_data[i], data, data_size, &c->audio_data[i].wptr);
478 /* Lets see if we've got enough audio for one DV frame */
479 c->has_audio |= ((reqasize <= fifo_size(&c->audio_data[i], c->audio_data[i].rptr)) << i);
486 /* Lets see if we have enough data to construct one DV frame */
487 if (c->has_video == 1 && c->has_audio + 1 == 1<<c->n_ast) {
488 dv_inject_metadata(c, *frame);
489 for (i=0; i<c->n_ast; i++) {
490 dv_inject_audio(c, i, *frame);
491 fifo_drain(&c->audio_data[i], reqasize);
498 return c->sys->frame_size;
504 DVMuxContext* dv_init_mux(AVFormatContext* s)
507 AVStream *vst = NULL;
510 /* we support at most 1 video and 2 audio streams */
511 if (s->nb_streams > 3)
514 c = av_mallocz(sizeof(DVMuxContext));
519 c->ast[0] = c->ast[1] = NULL;
521 /* We have to sort out where audio and where video stream is */
522 for (i=0; i<s->nb_streams; i++) {
523 switch (s->streams[i]->codec->codec_type) {
524 case CODEC_TYPE_VIDEO:
527 case CODEC_TYPE_AUDIO:
528 c->ast[c->n_ast++] = s->streams[i];
535 /* Some checks -- DV format is very picky about its incoming streams */
536 if (!vst || vst->codec->codec_id != CODEC_ID_DVVIDEO)
538 for (i=0; i<c->n_ast; i++) {
539 if (c->ast[i] && (c->ast[i]->codec->codec_id != CODEC_ID_PCM_S16LE ||
540 c->ast[i]->codec->sample_rate != 48000 ||
541 c->ast[i]->codec->channels != 2))
544 c->sys = dv_codec_profile(vst->codec);
548 if((c->n_ast > 1) && (c->sys->n_difchan < 2)) {
549 /* only 1 stereo pair is allowed in 25Mbps mode */
553 /* Ok, everything seems to be in working order */
557 c->start_time = (time_t)s->timestamp;
559 for (i=0; i<c->n_ast; i++) {
560 if (c->ast[i] && fifo_init(&c->audio_data[i], 100*AVCODEC_MAX_AUDIO_FRAME_SIZE) < 0) {
563 fifo_free(&c->audio_data[i]);
576 void dv_delete_mux(DVMuxContext *c)
579 for (i=0; i < c->n_ast; i++)
580 fifo_free(&c->audio_data[i]);
583 DVDemuxContext* dv_init_demux(AVFormatContext *s)
587 c = av_mallocz(sizeof(DVDemuxContext));
591 c->vst = av_new_stream(s, 0);
599 c->ast[0] = c->ast[1] = NULL;
604 c->vst->codec->codec_type = CODEC_TYPE_VIDEO;
605 c->vst->codec->codec_id = CODEC_ID_DVVIDEO;
606 c->vst->codec->bit_rate = 25000000;
607 c->vst->start_time = 0;
612 int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
617 for (i=0; i<c->ach; i++) {
618 if (c->ast[i] && c->audio_pkt[i].size) {
619 *pkt = c->audio_pkt[i];
620 c->audio_pkt[i].size = 0;
629 int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
630 uint8_t* buf, int buf_size)
634 if (buf_size < DV_PROFILE_BYTES ||
635 !(c->sys = dv_frame_profile(buf)) ||
636 buf_size < c->sys->frame_size) {
637 return -1; /* Broken frame, or not enough data */
640 /* Queueing audio packet */
641 /* FIXME: in case of no audio/bad audio we have to do something */
642 size = dv_extract_audio_info(c, buf);
643 for (i=0; i<c->ach; i++) {
644 c->audio_pkt[i].size = size;
645 c->audio_pkt[i].pts = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
647 dv_extract_audio(buf, c->audio_buf[0], c->audio_buf[1], c->sys);
650 /* Now it's time to return video packet */
651 size = dv_extract_video_info(c, buf);
655 pkt->flags |= PKT_FLAG_KEY;
656 pkt->stream_index = c->vst->id;
657 pkt->pts = c->frames;
664 static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
665 int64_t timestamp, int flags)
667 // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
668 const DVprofile* sys = dv_codec_profile(c->vst->codec);
670 int64_t size = url_fsize(&s->pb);
671 int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
673 offset = sys->frame_size * timestamp;
675 if (offset > max_offset) offset = max_offset;
676 else if (offset < 0) offset = 0;
681 void dv_flush_audio_packets(DVDemuxContext *c)
683 c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
686 /************************************************************
687 * Implementation of the easiest DV storage of all -- raw DV.
688 ************************************************************/
690 typedef struct RawDVContext {
691 DVDemuxContext* dv_demux;
692 uint8_t buf[DV_MAX_FRAME_SIZE];
695 static int dv_read_header(AVFormatContext *s,
696 AVFormatParameters *ap)
698 RawDVContext *c = s->priv_data;
700 c->dv_demux = dv_init_demux(s);
704 if (get_buffer(&s->pb, c->buf, DV_PROFILE_BYTES) <= 0 ||
705 url_fseek(&s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
708 c->dv_demux->sys = dv_frame_profile(c->buf);
709 s->bit_rate = av_rescale(c->dv_demux->sys->frame_size * 8,
710 c->dv_demux->sys->frame_rate,
711 c->dv_demux->sys->frame_rate_base);
717 static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
720 RawDVContext *c = s->priv_data;
722 size = dv_get_packet(c->dv_demux, pkt);
725 size = c->dv_demux->sys->frame_size;
726 if (get_buffer(&s->pb, c->buf, size) <= 0)
729 size = dv_produce_packet(c->dv_demux, pkt, c->buf, size);
735 static int dv_read_seek(AVFormatContext *s, int stream_index,
736 int64_t timestamp, int flags)
738 RawDVContext *r = s->priv_data;
739 DVDemuxContext *c = r->dv_demux;
740 int64_t offset= dv_frame_offset(s, c, timestamp, flags);
742 c->frames= offset / c->sys->frame_size;
744 c->abytes= av_rescale(c->frames,
745 c->ast[0]->codec->bit_rate * (int64_t)c->sys->frame_rate_base,
746 8*c->sys->frame_rate);
748 dv_flush_audio_packets(c);
749 return url_fseek(&s->pb, offset, SEEK_SET);
752 static int dv_read_close(AVFormatContext *s)
754 RawDVContext *c = s->priv_data;
755 av_free(c->dv_demux);
760 static int dv_write_header(AVFormatContext *s)
762 s->priv_data = dv_init_mux(s);
764 av_log(s, AV_LOG_ERROR, "Can't initialize DV format!\n"
765 "Make sure that you supply exactly two streams:\n"
766 " video: 25fps or 29.97fps, audio: 2ch/48Khz/PCM\n"
767 " (50Mbps allows an optional second audio stream)\n");
773 static int dv_write_packet(struct AVFormatContext *s, AVPacket *pkt)
778 fsize = dv_assemble_frame((DVMuxContext *)s->priv_data, s->streams[pkt->stream_index],
779 pkt->data, pkt->size, &frame);
781 put_buffer(&s->pb, frame, fsize);
782 put_flush_packet(&s->pb);
788 * We might end up with some extra A/V data without matching counterpart.
789 * E.g. video data without enough audio to write the complete frame.
790 * Currently we simply drop the last frame. I don't know whether this
791 * is the best strategy of all
793 static int dv_write_trailer(struct AVFormatContext *s)
795 dv_delete_mux((DVMuxContext *)s->priv_data);
798 #endif /* CONFIG_MUXERS */
800 #ifdef CONFIG_DV_DEMUXER
801 AVInputFormat dv_demuxer = {
804 sizeof(RawDVContext),
810 .extensions = "dv,dif",
813 #ifdef CONFIG_DV_MUXER
814 AVOutputFormat dv_muxer = {
819 sizeof(DVMuxContext),