RTSP latency issues, effect of sync=false

[Nicolas Dufresne]

Le vendredi 24 juillet 2020 à 14:33 +0200, Guillermo Rodriguez Garcia a
écrit :
> > The sink element have no queues, so it does know if there is some late
> > frame already there. So I believe the answer is no.
> 
> Uhm.. but then for the same reason, I would expect the "speedup
> effect" to be rather limited.
> I mean, since the sink has no queues (and in fact I am not using
> queues anywhere else in the pipeline) there shouldn't be that too many
> "late" frames to play -- only the bunch of frames that were sent "more
> or less together" due to the network bursts you mentioned.
> 
> Anyway my problem seems to be that when the frames arrive, the sink
> discards them because of the timestamp (i.e. this is not a performance
> problem, but a latency problem). Using sync=false helps because the
> sink will not discard frames, but is subject to the speedup problems
> you describe.
> 
> Is there any way to configure the sink so that it does not drop late
> frames (or at least to be a bit more lenient) without using sync=false
> ?

Sinks have a max-lateness property, if you set it to -1, then it will
behave like udpsink, which is it will send the data on sync, or late
and won't drop. If you PC is too slow, it will never catch up.

Nicolas