[FFmpeg-user] ntsc-dvd doesn't default to interlaced.

[Andy Furniss]

Andy Civil wrote:
> *never mind*
>
> Sorry, I think I found the answer by trial and error.
>
> c:\ffmpeg\bin\ffmpeg -i E:\temp\2013-06-06-hdp.mp4 -vf
> scale=720:480,tinterlace=interleave_bottom -flags ildct+ilme -target
> ntsc-dvd -acodec mp2 -ac 2 -b:a 128000 2013-06-06-i.mpg
>
> This LOOKS right in VLC. It seems that if I put the filter definition
> first, and scale before interleaving, I get a good output.

It may be perfect, I don't know, but I do know that playing with 
interlaced can be a pain.

Even if something looks OK in VLC there could be hidden issues - eg if 
VLC is deinterlacing to frame rate you may miss field order being wrong.

The content also plays a role, try getting a shot with something bright 
red moving fast horizontally, or do a fast pan past similar.

After making the ntsc, just as a test, recode the sample to field rate 
progressive like -

ffmpeg -i ntsc.mpg -an -sn -vf yadif=1 -vcodec libx264 -crf 22 -r 60 
test.mkv

(maybe -r should be 59.94)

Play back and frame step the fast horizontal chroma motion/pan to check 
that it doesn't skip back and forward and also that the chroma is 
planted on the luma!