[FFmpeg-user] Assumefps() equivalent in FFMPEG

[Reuben Martin]

On Tuesday, July 29, 2014 02:54:40 PM Eugene Gekhter wrote:
> I have a 50fps progressive scan file that I need to playback at 18fps - no
> dropped frames.

> I try and accomplish the same result of 18 fps, 18 tbr, 18 tbn, and 18 tbc
> directly in ffmpeg with:
> -r 18 -i "<SourceFileName>" -y -vcodec copy  -acodec copy
>  "<OutputPath><OutputFileName>.mov"
> 
> but the output is  Stream #0:0(eng): Video: v210 (v210 / 0x30313276),
> yuv422p1
> 1, 995328 kb/s, 50 fps, 18432 tbn, 18 tbc (default)
> 

You can't use stream-copy. The timestamps for the video frames have to be re-
written and codec metadata has to be changed in order for this to work 
correctly. Stream-copy will not accomplish that.

Also ditch the audio or it will get quite messy.

ffmpeg -r 18 -i <Source.ext> -r 18 -c:v v210 -an -f mov <Output.mov>