On Mon, Jun 22, 2009 at 2:32 PM, Arthur <[email protected]> wrote:
> Hello, > > Based on audio output I synchronize my video output. I noticed that some > files do not exactly start with audio/video at the same time. > I have a WMV file that has pAudioStream->start_time = 8000. I assume I can > sync audio and video with the right use of this number, but I don't know > what to do with this value. > Does anyone know how to calculate the delay in for instance milliseconds > (so > I can calculate the correct video frame pts out of this value for instance) > from this value? > > Best regards, > Arthur > _______________________________________________ > libav-user mailing list > [email protected] > https://lists.mplayerhq.hu/mailman/listinfo/libav-user > Ya I'm having the same problem. I'll repost a question I asked on a forum here since I got no answer there. For example: The Video stream has a start_time of 64194, with a timebase of 1/90000 The Audio stream has a start_time of 56994, with a timebase of 1/90000. The format context has a start_time of 633267. So should I start playing the audio 64194 - 56994 = 7200 timebase units (0.08 seconds) before the video? Where does the format context's start_time come into play here? What do I do if the first audio packet has a pts thats bigger than the audio stream's start_time? Do I just play silence for the first little bit? Or should the first decoded audio packet match up with the first decoded video packet? Thanks for any help. _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
