Thank you, Nicolas. First of all, let me say a few more words about the camera. We are recording video by ourselves (using libav) and we only get a sequence of (bitmaps) from the camera (by the way, its GigE UI-5220SE). I know that in its API there are functions for getting timestamps but at first glance they have nothing to do with the video being recorded.
Speaking about the PTS I thought (after studying FFMpeg tutorial at dranger.com) that these are only sequence numbers needed to correctly display frames which should be decoded in a different order (B-frames). After looking at the Wikipedia page about PTS I figured out that PTS may be indeed linked with real time. Thank you for this particular clue. Could you please mention which libav-functions should I look at to use those arbitrary PTS? And am I right that this stuff is somehow related to variable framerate (VFR)? I am curious because at the moment we are using constant frame rate to record videos (we set it equal to camera framerate). This raised a tough question for us even when we used a single camera: small inaccuracies in from-camera frames timings would not be taken into account when recording constant frame rate video. So using custom timestamps would be a panacea. One last question is about the correct format for storing arbitrary timestamps. In fact the format we are using now is AVI, so I would like to ask you to suggest formats which are supported by libav* and are capable of storing those timestamps? Thanks a lot. Timour Khanipov. 2011/11/23 Nicolas George <[email protected]> > Le tridi 3 frimaire, an CCXX, Timour Khanipov a écrit : > > In our application we are recording several video streams from different > > cameras and we need to synchronize them at replay stage. Besides that we > > have some events which should be linked with specific camera and specific > > time moment. So it would be very useful if there were some sort of > > functionality in libav for writing real timestamps for each frame. > > The PTS is almost exactly that. And, depending on the kind of camera you > are > recording from, it may be already set to the timestamp recorded by the > hardware or the driver. > > You just need to make sure you use a format that correctly stores arbitrary > timestamps, unlike AVI for example. > > Regards, > > -- > Nicolas George > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.11 (GNU/Linux) > > iEYEARECAAYFAk7NNewACgkQsGPZlzblTJPqSgCgqHLCgjRy0/vpq80vKC54WZ0n > CYsAoI9gMc1zSlruu770BTB6OPYvkCzV > =bZMy > -----END PGP SIGNATURE----- > > _______________________________________________ > Libav-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/libav-user > >
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