[Linphone-developers] About the audio-video sync(lip-sync) in linphone

[Weikai Xie]

Folks,
    I'm wondering whether Linphone has any logic to ensure the
synchronized playout of the received audio and video stream (i.e.
lip-sync).
   As I read from the source code (v3.3.1), the audio filter graph and
the video filter graph are totally separated from each other. It seems
to me that the audio and video stream will just be played out in a
pace without referring to each other's progress.
  Although both audio and video rtp recv filter has an internal jitter
buffer to make sure the audio and video packets are played out in a
smooth way, but I think they can only ensure the intra-stream
synchronization of the audio and video respectively, but not for the
inter-stream synchronization between them.
  Please share your idea if my analysis is wrong. Thanks.

Regards.

Weikai Xie