Gstreamer custom sink renderer takes too long time !

[Duchassin Frederic]

> Well, that's a pretty bad design, but you can workaround with a thread.

Of course after your last answer, I try to implement a new thread with a queue (protected by mutex) and it nearly gives the same behavior.

> Well, then you cannot do framerate adaptation. Your rendered must be as fast as your video rate, otherwise it will break.

My renderer give me the possibility to output a stream at 90Mb/s whereas when I connect it to gstreamer, the bitrate has a limitation at about 40 Mb/s.
It's a very strange behavior because when I increase the bitrate of my souce, the sink bitrate can increase until 40Mb/s and after the bitrate decrease. (more and more packets are lost)

The pipeline used is :

gst-launch-1.0 udpsrc address=239.0.0.1 port=1234 buffer-size=30000000 ! queue ! eimsink sync=false async=true

> That will require an unlimited amount of RAM, also it will eliminate the possibility to use a HW decoder (pretty much all the HW decoder we have limits the number of output buffers).

No because my renderer bitrate could reach 90Mb/s.



-----Message d'origine-----
De : gstreamer-devel [mailto:gstreamer-devel-bounces at lists.freedesktop.org] De la part de Nicolas Dufresne
Envoyé : mercredi 5 septembre 2018 16:33
À : Discussion of the development of and with GStreamer
Objet : Re: Gstreamer custom sink renderer takes too long time !

Le mercredi 05 septembre 2018 à 15:07 +0200, Duchassin Frederic a écrit :
> Hello Nicolas,
> 
> My renderer is locked by mutex so it makes it synchronous. There is no 
> way for me to make different.

Well, that's a pretty bad design, but you can workaround with a thread.


> 
> And I can't lose any frame (or data).

Well, then you cannot do framerate adaptation. Your rendered must be as fast as your video rate, otherwise it will break.

> 
> But because I have a queue in the upstream, I probably could ask for 
> buffering during my renderer isn'it ?

That will require an unlimited amount of RAM, also it will eliminate the possibility to use a HW decoder (pretty much all the HW decoder we have limits the number of output buffers).

regards,
Nicolas

> 
> 
> -----Message d'origine-----
> De : gstreamer-devel [mailto:
> gstreamer-devel-bounces at lists.freedesktop.org] De la part de Nicolas 
> Dufresne Envoyé : mercredi 5 septembre 2018 14:52 À : Discussion of 
> the development of and with GStreamer Objet : Re: Gstreamer custom 
> sink renderer takes too long time !
> 
> Le mercredi 05 septembre 2018 à 12:41 +0000, Duchassin Frédéric a 
> écrit :
> > Hello All !
> >  
> > I try to make my own sink.
> > My main problem is that my renderer is quite slow (about 50000ns to 
> > get out render() function) and give poor performance with high input 
> > bitrate. (packet lost !)
> >  
> > For example a case which doesn’t work :
> > This is the interval between each time I feed my sink (without
> > renderer):
> > dt=127654ns
> > dt=138320ns
> > dt=51995
> > dt=55661
> > dt=75326
> > dt=139319
> > dt=76660
> > dt=91991
> > dt=159318
> > dt=91991
> > dt=21664
> > dt=54995
> > dt=88324
> > dt=135986
> > dt=88324
> > dt=18665
> > dt=81326
> > dt=51995
> > dt=77659
> > dt=100990
> > dt=17665
> > dt=78659
> >  
> > As you can see, sometimes I feed my sink every 21 µs and as my 
> > renderer take 50µs, I can lose packet.
> >  
> > Can you advice me about a way to stop feeding my sink during 
> > renderer ???
> > Or if there is another way….
> 
> What we usually do is to make the renderer asynchronous. This way, you 
> don't wait for the renderer to finish, and can receive the following 
> frame immediately. Then, whenever a frame is submitted while another 
> is being rendered, you can skip it (ideally sending a QoS message to 
> tell the app you have done so).
> 
> You should also check that max-lateness/deadline-timeout and other 
> sink properties are configured correctly. That QoS is enabled also, 
> since some element can decide a head of time to drop a buffer is it's 
> safe to do so and that this buffer isn't going to make it.
> 
> >  
> > Thanks in for your help.
> >  
> > Frederic
> >  
> >  
> > _______________________________________________
> > gstreamer-devel mailing list
> > gstreamer-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
> 
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