[MPlayer-dev-eng] libmpcodecs - how to code video-filter which double (or quad) output frame rate

[D Richard Felker III]

On Wed, Jan 12, 2005 at 01:31:08PM +0100, Andreas Schulz wrote:
> Hi folks,
> 
> I want to give me a try to code a video-filter which controls
> LCD-shutter-glasses under linux for stereo-viewing of field-interleaced 
> video.
> 
> "incoming mpi" = odd lines -> [left] eye, even lines -> [right] eye
> 
> So I had to do:
> 
> "incoming mpi" -> odd lines -> first "outgoing mpi"
> "same incoming mpi" -> even lines -> second "outgoing mpi"
> (control of electronics for shutter-glasses is not the question)
> 
> i.e. after filtering I'll have 2x the number of incoming frames.
> 
> Question:
> 
> How is a filter to be build, which outputs double the frame rate / frame 
> numbers as it gets
> on input?

Actually it's not possible for MPlayer. If you don't mind reencoding
first though you can use such a filter with mencoder, but it's a huge
hack. Read vf_tfields.c for an example.

Rich