[FFmpeg-user] -vf tinterlace=6 not behaving as expected

[Andy Furniss]

Andy Furniss wrote:

> https://www.ffmpeg.org/ffmpeg-filters.html#tinterlace
>
> describes what the filter should do, the trouble is when I test it as
> below with eg the scrolling letters burosch1.mpg (available in ffmpeg
> or mplayer samples IIRC). I don't see what I expect when frame
> stepping the result in that both fields move each frame rather than
> one being the same.

After looking at the code I still can't work out why both frames move
each frame rather than one, but it doesn't seem to matter anyway. If I
hook up to my TV and put it into an interlaced mode, I do get an always
field synced deinterlace.

Of course the command I was testing with is useless for chroma as I need
to use mpv + vdpau to play at refresh rate and vdpau doesn't do
interlaced yuv->rgb, but (possibly because I don't have amd uvd) my
vdpau has advertised working 422, so this is what's needed with ffmpeg,
I don't know yet if it's possible to do this directly with mpv.

ffmpeg -i in-420.xyz -pix_fmt yuv422p -vf 
scale=interl=1,tinterlace=interlacex2 -an -sn -vcodec rawvideo out-422.nut