On Tue, Feb 16, 2021 at 11:09 AM Nicolas George <geo...@nsup.org> wrote:
> Livio Tenze (12021-02-16): > > At the moment I have only one thread (the main one, as in doc/examples). > > The process I implemented is the following: > > 0) Initialize PTS output frame (one PTS for video and another for audio) > > 1) check PTS difference between PTS video and audio > > 2) if ptsvideo>ptsaudio then decode one video frame, and encode it in the > > output stream > > otherwise decode audio frame, and it in the output stream. > > 3) go to point 1 > > That should work, provided you checked that your timestamps relate to > the same origin. If some timestamps relate to the system boot and some > to 1970-01-01, you will get a desync. > The timestamp I am currently using is related to the pts obtained from the AVPacket packets: I use the first PTS packet as reference. Is it a right approach for syncing? > Plus, if the capture did not start at the same time, you will get extra > frames at the beginning of a stream, and it is possible that some > players will not catch up or catch up slowly. It would probably be more > reliable to discard frames captured before the first frame of the other > stream. > I haven't found info about this issue: does the av_read_frame call return always the latest acquired packet or does it return a buffered packet? I haven't found this info. The question is related to real-time acquisition. > > > > Do you think that this behaviour is due to missing multithread? I found > the > > Yes. Without parallelism for the capture, the codec initialization could > take so much time as to cause a buffer overrun in one of the capture > drivers. > > Ok, thank you for this suggestion. Do you suggest to use one thread for every source and one thread for encoding? Is it a good approach in your opinion? > > Regards, > > Thanks a lot! Livius > > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
