On Sun, Apr 28, 2019 at 5:30 PM Gyan <ffm...@gyani.pro> wrote: > > > > On 28-04-2019 07:19 AM, myp...@gmail.com wrote: > > On Sat, Apr 27, 2019 at 8:22 PM Gyan <ffm...@gyani.pro> wrote: > >> > >> > >> On 27-04-2019 05:25 PM, Carl Eugen Hoyos wrote: > >>> 2019-04-27 13:17 GMT+02:00, Jun Zhao <mypopy...@gmail.com>: > >>>> perfer avctx->framerate first than use avctx->time_base when > >>>> setting the frame rate to encoder. 1/time_base is not the > >>>> average frame rate if the frame rate is not constant. > >>> But why would the average framerate be a good choice to set > >>> the encoder timebase? > >>> > >> Also, note that x264/5 RC looks at the framerate. > >> See > >> https://code.videolan.org/videolan/x264/commit/c583687fab832ba7eaf8626048f05ad1f861a855 > >> > >> I can generate a difference with x264 by setting -enc_time_base to > >> different values (with vsync vfr). > >> Maybe check that this change does not lead to a significant change in > >> output. Although I think this would be still an improvement for those > >> cases where r_frame_rate >> avg_frame_rate > >> > >> Gyan > > Yes, framerate and time_base is not close correlation in vfr case, > > e,g, I can setting the framerate = 60fps, but time_base = 1/1000 s, > > then setting pts like: > > > > time_base = 1/1000 s = 1 millisecond > > framerate = 60 fps per second > > PTS 0----16----33----50----66----83----100 ... > > > > PTS delta 16 17 17 16 17 17 ... > > > > we will get 16ms * 20 frames + 17 ms * 40 frames = 1000ms > > I'm aware of the relationship between TB and PTS. My point is x264's RC > adjusts its quantizer based on fps. You're changing that value so the > output bitrate will change for the same input with the same encoder > config if (avg_frame_rate) != (ticks * 1/TB). > > Gyan in fact，this is the purpose of this patch, we used FFmpeg API to setting the time_base/pts/framerate like above to tuning the PTS. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
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