[FFmpeg-user] Convert MPEG-PS progressive to Interlaced

[Rens Dijkshoorn]

> Hi All,
> I have been struggling with converting PS progressive stream to PS
> interlaced for my test app.
> 
> But all the conversion commands used by me are converting to Frame based
> interlaced stream but what I am looking for is I-P field based interlace(I
> frame having top filed and next frame having the bottom field) .

Maybe we are talking about different things

Interlaced = 2 fields one top one bottom together is 1 frame.
Changing a PS stream to interlaced would create a PSF frame
The 2 fields that make one frame don't have any temporal difference


ffmpeg has a few filter commands in this direction
have a look at a combination of framerate and tinterlace

    -vf framerate=50,tinterlace=4

I-frames or P-frames has more to do with mpeg encoding that
with the video being interlace.

For proper interlaced encoding the encoder needs to be
interlaced aware of this field structure and the possiblity
of temporal difference between fields in one video frame. 

Regards

Rens