A/V sync issue with appsrc, pulsesrc

[Dušan Poizl]

Hello. I am trying to play multiple video sequentially. For each file I
construct pipeline with decodebin which output to pulsesink and appsink
for video frames. Video frames goes to OpenGL where I draw some graphics
over them.

After I render it in OpenGL I push the result video frame to appsrc and
audio is recaptured with pulsesrc. Video from appsrc and audio from
pulsesrc goes to decklinksink. Problem is that after some while it goes
out of sync. Most strange is that it seems like switching between files
introduces desync because if I play single long video it stay in sync.

I also show rendered frames from OpenGL and listen to sound card output
which keep in sync.