[FFmpeg-user] filter for changing frame rate

[Paul B Mahol]

On 5/13/19, Daniel Oberhoff via ffmpeg-user <ffmpeg-user at ffmpeg.org> wrote:
>
>>
>> You can not.
>
> I am curious what exactly the hindrance is. As I understand at least mp4
> there is not really a concept of frame rate in the file and in theory every
> frame can have a different „rate“, defined solely by pts. So in theory pts
> should be all you need. Where am I going wrong in my understanding, and what
> exactly are the problems in ffmpeg that would arise?

frame rate is only metadata number, pts defines real frame rate.