[MPlayer-users] libavcodec mpeg error on framerate with pre8

[Rich Felker]

On Wed, Jun 21, 2006 at 03:52:15PM +0200, Jaap Struyk wrote:
> Op wo 21-06-2006, om 08:32 schreef Rich Felker:
> 
> > > it's a rounding error. append :vstrict=-2 to -lavcopts
> > 
> > This does not solve the problem, it just stores a nonstandard,
> > likely-incompatible framerate in the file. Instead you should fix the
> > framerate with something like -ofps 30000/1001 or 24000/1001 or
> > whatever the correct rate is.
> 
> I don't understand this completely, I extract the framerate from the avi
> with mplayer wich gives me 29.970.
> If I use -ofps 29.970 it bailes out but with -ofps 30000/1001 it works
> fine.
> But when I look at the resulting mpeg's both show ID_VIDEO_FPS=29.970

Because it's rounding to 3 decimal places and 30000/1001 rounds to
29.970 with just 3 decimal places. But 30000/1001 is not the closest
rational number (with small denom) to 29.970.

Rich