[Libav-user] ffmpeg and JM I_Frame nonconformity

[Alex Cohn]

On Thu, May 24, 2012 at 11:33 AM,  <amir.rouhi at rmit.edu.au> wrote:
> Oh, Thanks Alex, In the FFMPEG DOCUMENTATION says the format of usage should
> be:
> ‘-force_key_frames[:stream_specifier] time[,time...] (output,per-stream)
> so for example i should write:
>   ffmpeg -f image2 -r 0.1 -i C:\test%1d.bmp -an -vcodec libx264 -threads 0
>  -f  h264 -r 0.5 -force_key_frames time[0,5,10,15,20] -s 360x240
> C:\5frameTest.264
> Is that correct?

Looks reasonable.

> BTW, if the time stamps are long , i.e every 5 second from start of the
> video, is there any other simplified form to use in time stamp?

Not that I am aware of.

> and would you please let me know whats the difference of  -force_key_frames
> time  and -g ?

You should learn http://sites.google.com/site/linuxencoding/x264-ffmpeg-mapping

> Thanks
> Amir

BR,
Alex