[FFmpeg-user] Best way to scale interlaced video

Carl Eugen Hoyos cehoyos at ag.or.at
Tue Mar 4 23:25:25 CET 2014

Massimo Battistel <battistel <at> gmail.com> writes:

> I've removed padding filter and audio track. The issue 
> is still reproducible.
> You can download HD reference sample from here:
> http://www.datafilehost.com/d/f8185302
> This is the command line for solution #1:
> ffmpeg -i sample1080i.mp4 -vcodec rawvideo 
> -vf scale=w=720:h=432:interl=1 -an out_interl.avi

The artefacts you see are the direct effect of 
using "scale=interl=1". In theory, the following 
command would be a workaround (detecting if a 
frame is interlaced or not), but the detection 
apparently does not detect still frames as 
"progressive" but as "undetermined".
Changing the behaviour of idet might be possible, 
I don't know for sure.
$ ffmpeg -i sample1080i.mp4 -vf idet,scale=720:432:interl=-1 
-qscale 2 out.avi

Carl Eugen

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