I've found a way to synchronize the A/V streams with usleep() but I don't think that's the best way to do this. Is there a switch_core.... function to perform a similar task (and maybe allow other tasks to run)? Here's the current version of the playback loop (that takes into consideration multiple RTP packets per video frame) : u_int64_t videoNext = 0, audioNext = 0; u_int64_t ts = 0; bool videoSent = true, audioSent = true; while (switch_channel_ready(channel)) { bool vOk, aOk; if(videoSent) { vid_frame.packetlen = vid_frame.buflen; vOk = vc.getVideoPacket(vid_frame.packet, vid_frame.packetlen); if (vOk) { switch_rtp_hdr_t *hdr = reinterpret_cast<switch_rtp_hdr_t *>(vid_frame.packet); videoNext = vc.videoTrack().track.get90KTimestamp(ntohl(hdr->ts)); hdr->ts = htonl(videoNext); if (pt) hdr->pt = pt; } videoSent = false; } if(audioSent) { write_frame.datalen = write_frame.buflen; aOk = vc.getAudioPacket(write_frame.data, write_frame.datalen); audioSent = false; } if (!vOk && !aOk) break; int64_t wait = min(audioNext, videoNext) - ts; if(wait > 0) { /* wait the time for the next A/V frame */ usleep(wait * 1000 / 90); //switch_core_timer_next(&timer); ts += wait; } if (switch_channel_test_flag(channel, CF_VIDEO) && ts >= videoNext) { switch_byte_t *data = (switch_byte_t *) vid_frame.packet; vid_frame.data = data + 12; vid_frame.datalen = vid_frame.packetlen - 12; switch_core_session_write_video_frame(session, &vid_frame, SWITCH_IO_FLAG_NONE, 0); videoSent = true; } if(aOk && ts >= audioNext) { if (write_frame.datalen > (int) write_frame.buflen) write_frame.datalen = write_frame.buflen; switch_core_session_write_frame(session, &write_frame, SWITCH_IO_FLAG_NONE, 0); audioSent = true; audioNext += 90000 / 50; // 20ms } } Btw, thanks for the tip. I'll keep the separate thread to store video for the record function. Regards, Paulo On 13/07/10 15:39, Anthony Minessale wrote:
we need to get nonblocking reads to the rtp working so the
read_video_frame(); read_audio_frame();
don't block when there is no data.