[MPlayer-users] mencoder -ofps 23.98

[D Richard Felker III]

On Fri, Jan 10, 2003 at 09:11:03AM +0100, Moritz Bunkus wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> Hi.
> 
> > What about re-encoding vcd/mpeg1 encoded at 29.97 to mpeg4 without 
> > specifying -ofps at all, should that print out skip frame now and then 
> > too? Or am I missing something about how 29.97 mpeg tvcap streams are 
> > made?
> 
> Reencoding mpeg1s that were made from tv with 29.97 can have
> dropped/duplicated frames (I always get some), but that's because the
> stream itself is missing some frames. If you don't get those dropped
> frames continuously then you have the right FPS and the stream is just
> a bit f**** up.

Its not necessarily bad to have a few duplicated frames anyway... For
example frames with no change may be skipped. I seem to recall seeing
several DVDs where 4 or 5 dup frames occur at scene changes,
presumably because the encoder used decided not to waste bits
repeating the black frame over and over. :)

On the other hand, sometimes mencoder alternates between skipping and
duplicating a frame every 15-30 minutes or so. I imagine this is a bug
due to floating point imprecision and should probably be fixed
someday...


Rich