Re: [Linphone-developers] Disable jittercompensation

[Simon Morlat]

Hi,

Sorry for the late answer.

> The first thing is easily accomplished by using
> rtp_session_set_scheduling_mode(NO), rtp_session_set_blocking_mode(NO) and
> rtp_session_send_with_ts(). As far as I can understand the packets will be
> sent immediately when the send function is called with these settings.
This is true.

>
> But this makes it impossible to have rtp_session_recv_with_ts() block and
> return when a packet arrives. The only way to accomplish this is to enable
> blocking, but then the send function will block as well and scheduling will
> be enabled implicitly.
>
> I don't want oRTP to schedule sending nor receiving and not buffer packets
> within the stack. My current approach is to disable jitter compensation by
> calling rtp_session_enable_jitter_buffer(NO),
> rtp_session_enable_adaptive_jitter_compensation(NO) and to poll with
> rtp_session_recvm_with_ts() using the same approach as in Linphone.
> However, it seems to me like there is some jitter compensation or buffering
> being done in this case as well since if I poll with 10ms intervals I get a
> packet every second time (timestamp is increased by 160) although I can see
> in wireshark that there is sometimes 80ms between packets.
rtp_session_enable_adaptive_jitter_compensation() just disables the "adaptive" 
behaviour of the jitter buffer.
With rtp_session_enable_jitter_buffer(_session,false); you disable it globally 
and rtp packets are returned immediately as they are availlable on the udp 
socket.
If timestamp is incremented by 160 you have one packet every 20 ms so it is 
normal that half of the rtp_session_recvm_with_ts() return NULL.


>
> I'd really appreciate if someone could tell me if I am on the right track
> and how I can receive RTP packets as they arrive from the network and still
> have packets being sent at the rate I want.
You are in the right track.

Simon