dts = av_gettime();
snd_pcm_delay(s->h, &delay);
dts -= av_rescale(delay + res, 1000000, s->sample_rate);
pkt->pts = ff_timefilter_update(s->timefilter, dts, s->last_period);
s->last_period = res;
dts = av_gettime();
snd_pcm_delay(s->h, &delay);
dts -= av_rescale(delay + res, 1000000, s->sample_rate);
pkt->pts = ff_timefilter_update(s->timefilter, dts, s->last_period);
s->last_period = res;