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.