On Sun, Dec 13, 2020 at 2:05 AM Anton Khirnov <an...@khirnov.net> wrote:
> Quoting mindm...@gmail.com (2020-11-29 05:08:38) > > From: Mark Reid <mindm...@gmail.com> > > > > The current behaviour ends up squaring the avg_frame_rate if the conter > mode flag is set. > > This messes up the timecode calculation, and looks to me as a regression > that > > seems to have been introduced 428b4aac. > > > > The new behaviour is use the "Number of frames" field for avg_frame_rate > from the timecode atom as describe here: > > > https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap3/qtff3.html#//apple_ref/doc/uid/TP40000939-CH205-69831 > > > > Number of frames > > An 8-bit integer that contains the number of frames per second for > the timecode format. > > If the time is a counter, this is the number of frames for each > counter tick. > > I'm no expert on mov, but this looks suspicious. avg_frame_rate is > supposed to be per seconds, not per counter ticks, whatever those are. > Looking at your sample, frame duration is 1001/24k, while the 'number of > frames' field is just 24, which seems like it's losing precision. > > Then wouldn't it be better to just stop squaring the number without any > other changes? Or am I misunderstanding this? > I'm not entirely clear on what "counter ticks" are either. I think what your saying sounds better, I'll submit a new patch. thanks for reviewing. > > -- > Anton Khirnov > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
