Re: [Linphone-developers] rtp timestamp for video

[Simon Morlat]

Hi,

Usually cameras have approximate frames per second values. Incrementing the 
timestamp by 90000/30 is not reliable.
You should instead do a gettimeofday each time the camera gives you a frame, 
and then send the packet with a timestamp derived from the gettimeofday time.
uint32_t ts=(uint32_t) (current_time_in_milliseconds*90);

Simon


Le Monday 10 December 2007 13:44:37 Pramod Bhagwat, vous avez écrit :
> Hi,
> I am using oRTP to stream the video data from the camera on Linux. I am
> using H.263 codec  for sending the video data. I am using custom H.263
> codec and added the H.263 header packetization  routines using
> rtp_session_create_packet() function and then sending the data using
> rtp_session_sendm_with_ts() function.
> Here I am incrementing "user_ts" value by 3000 Since the Camera outputs 30
> frames per second.
> i.e. 90000/30 = 3000.
> But when i profiled the rtp_session_sendm_with_ts() function using
> gettimeofday it is taking 400 millisecond which is very large value.
>
> Is there any thing wrong in my timestamp calculation. Please let me know.
>
> Warm Regards,
> pramod