Scaling an interlaced DVCPRO25

[dariomartin at gmail.com (Darío Martín)]

Hi,

I'm trying to change the aspect ratio of a DVCPRO25 from anamorphic
16:9 to lettterbox. To do this, I have to scale it, and then expand
with black bands. As the source is interlaced I use the "il" filter (i
know that "scale" has an interlaced option, but by using it i don't
get better results). This is my best try:

mencoder original.dv -of lavf -lavfopts format=dv -ofps 25 -vf
il=d:d,scale=:432,il=i:i,expand=:576,harddup -oac pcm -ovc lavc
-lavcopts vcodec=dvvideo:format=411p:ildct -o converted.dv

However I get some strange artifacts when I play it in a interlaced display.

?Can anyone tell me if there is a better way to achieve this?.

Thank you.