[MPlayer-dev-eng]

[D Richard Felker III]

On Sun, Feb 16, 2003 at 01:41:27PM +0100, Arpi wrote:
> Hi,
> 
> > after using mencoder for awhile I came across movies with (real)
> > 29.97 fps which were created from a 24 fps source by inserting a
> > duplicate frame after every 4th frame. When (re)encoding these movies it
> > would be clever to drop these duplicated frames to save bandwidth and to
> > eliminate the jerky motion artefacts.
> > 
> > But to only use the option '-ofps 23.976' is not satisfactory because
> > mencoder bluntly drops every 5th frame regardless of being duplicates
> > or not; or missed I something?
> 
> isn't -vop dint the same? afair it was written for the same purpose.

AFAIK, -vop dint does not work at all. I've never been able to succeed
in getting it to drop frames.

> > Some implementation details; how I see this problem; things I would like
> > to discuss:
> > - To detect the duplicated frames it is necessary to buffer at least 6
> >   frames (you cannot display/encode the frames and decide afterwards
> >   'Oh, I wanted to skip that frame'). But buffering (at least of this
> >   amount) is not supported by the vf-API (am I right?). So I had to
> >   expand it by introducing a new image-type MP_IMGTYPE_BUF.
> 
> ehh
> why do you need 6 frames for detecting duplicated frame?
> keep only the previous one (IMGTYPE_IP) and comtare teh current one with
> the previous, if the same, drop it.

Agree!

Rich