Thanks again, Carl. >I may miss something but I believe now your pts are wrong, >I suspect a B-frame is shown first.
In my fictional model, I thought the I frame (frame-0) would come first and then the two B frames (frame-1,frame-2) and finally the P frame (frame-3) I hope this is now fixed, assuming we chose a timebase of 1/75 (with a timescale of 75). Given that our video runs at 25 FPS, therefore, we'll need to increase our PTS in 75/30 (timescale/FPS) = 3 PTS per frame. FRM 0 1 2 3 FRT I B B P PTS 0 1 2 3 DTS 0 3 2 2 PTT 0 0.04 0.08 0.12 (PTS * timebase) FRM=frames number FRT=frames types FTT=PTS time As far as I understood we could pick any time base to calculate the PTS_TIME, for instance, let's use the timebase 1/15360 (timescale of 15360) which gives 512 ticks per frame (on a 30 FPS video). Frame #0 PTS=0<but it could be any initial number> PTS_TIME=0 Frame #1 PTS=512 PTS_TIME= 512/15360 = 0.0333 Frame #2 PTS=1024 PTS_TIME= 1024/15360 = 0.066 Frame #2 PTS=1536 PTS_TIME=1536/15360 = 0.1 ... Frame #29 PTS=14848 PTS_TIME=14848/15360 = 0.966 When we look at MPEGTS we can see that they used 90K as timescale (or 1/90k) for some, apparently, hardware reasons but in all the other cases, can I just pick any number to be my timescale? Thanks On Mon, Nov 13, 2017 at 10:33 PM Carl Eugen Hoyos <[email protected]> wrote: > 2017-11-14 1:27 GMT+01:00 Leandro Moreira < > [email protected]>: > > > > Thanks, Carl!!! > > > >> PTS 0 1 2 3 (when it needs to be present, order) > >> DTS 0 3 1 1(when it needs to be decoded) > > > > Yes =(, you're right, it was supposed to be DTS 0 3 1 2 > > > (assuming 0 is an I-Frame, 1 and 2 were a B-Frames that > > depend on 3 and 3 is P-Frame). > > I may miss something but I believe now your pts are wrong, > I suspect a B-frame is shown first. > > I cannot really answer your other questions but I know that > H.264 streams exist for which FFmpeg is unable to produce > correct timestamps. > (The specification is apparently non-trivial.) > > Please fix your quoting, do not mix quoting-styles! > > Carl Eugen > _______________________________________________ > Libav-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/libav-user >
_______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user
