ts_delay += res;
pkt->pts = timestamp.tv_sec * 1000000LL
+ (timestamp.tv_nsec * st->codec->sample_rate
- - ts_delay * 1000000000LL + st->codec->sample_rate * 500LL)
+ - (int64_t)ts_delay * 1000000000LL + st->codec->sample_rate * 500LL)
/ (st->codec->sample_rate * 1000LL);
pkt->size = res * s->frame_size;