[FFmpeg-user] Frame dropping

Carl Eugen Hoyos ceffmpeg at gmail.com
Wed May 9 20:51:51 EEST 2018

2018-05-09 17:53 GMT+02:00, mohammed bey ahmed khernache:
> Thank you for your reply.
> The input video is encoded with hevc at 25 fps.
> I tries this command:
> ffmpeg -threads 1 -vsync drop -i <input_video> -f null /dev/null
> I got this message in yellow:
> Encoder did not produce proper pts, making some up
> Unfortunately, I can not reach 25 fps while decoding, even
> with dropping frames.
> So I think that the option for "frame dropping" is not working !!

The option vsync allows to duplicate / drop decoded frames to
maintain A/V sync, it is not related to the decoding speed.
Use "-skip_loop_filter all" to get some speed-up without
noticeable visual effect, use "-skip_frame noref" in addition to
get significant speed-up for some videos, feel free to also try
"-skip_frame bidir" (can cause artefacts iirc) and
"-skip_frame nokey" (which skips nearly all frames).

Please remember not to top-post here, Carl Eugen

PS: vsync is neither an input nor an output option, it is a
global option.

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