[FFmpeg-user] Best way to scale interlaced video

[Andrey Aleksandrovich]

On 2/25/14, Massimo Battistel <battistel at gmail.com> wrote:
> hello,
> I have to scale 16:9 interlaced 1080i video down to PAL 576i 4:3 with black
> bars.

Do you really need 4:3 aspect?

If so, you can do something like that chain:
1920x1080 at 50i -> (lossless codec) 1920x540 at 50p -> (lossless codec)
720x576 at 50p -> 720x576 at 50i
It is the best way to save time resolution (frame fields - fine motion
scenes), while the static scenes will be little worse, cause of
upscale fields from 540 to 576. However, you can to do not upscale and
replace those 36 lines with black borders. Aspect ratio will be lost
corrupt.