Synchronized video playback on different Android devices

[Nicolas Dufresne]

Le 2014-08-29 05:22, Jeppe Ledet-Pedersen a écrit :
> I assume this is because the pipeline latencies of the two devices are
> not the same? Can I somehow read back the latency and adjust the
> rtpjitterbuffer latency to get a identical total latency of all the
> devices? Or is there a better solution?

I would guess the difference is in the display latency, an information 
that I don't think can be programmatically determined on Android (please 
correct me if I'm wrong, I'd love to know). You can tweak this using 
"render-delay" on the sink element. You need to align to the worst 
delay. So far I have been able to manually meansure the delay with 
counting generated stream, that playback at the screen refresh rate of 
the device. Then I record from a good quality camera, ideally with 
higher or equal rate to your display, and watch the result 
frame-by-frame, to average the delay (jitter is possible). I think if 
one could manage to finish zero-copy on Android, we'd get better result 
for such use case.

hope this helps,
Nicolas