[MEncoder-users] Deinterlacing or iVTC and "best settings"

[Justin Randall]

> These filter chains are utterly wrong...
>
> > # for pure interleaved NTSC @ 29.97 fps
> > mencoder -oac copy -ovc xvid -xvidencopts
> > fixed_quant=4:chroma_opt:vhq=4:bvhq=1:quant_type=mpeg -vf
> > hqdn3d=3:2:3:3,yadif=3:1,mcdeint=2:1:10,framestep=2,filmdint=dint_thr
> > es=256,crop=704:480:0:0,scale=640:480 -ofps 24000/1001 -o test.avi
> > capture000.mpg
>
> hqdn3d isn't going to work properly while the video is still interlaced.
>  hqdn3d takes 3 options, not 4.  Running deinterlacing BEFORE IVTC
> (filmdint) is utterly wrong.
>
> Basically, you're destroying the video, JUST deinterlacing (no IVTC at
> all), and then dropping every 5th frame for no reason.

Thanks for the response. So I'm now running hqdn3d after the
deinterlacing filters but before the crop and resize. I've also
switched to 2 pass at a fairly substantial bitrate. If the video is
pure interlaced then I should be keeping all 29.97 fps? I've just seen
so many encodes out there that are 23.97 fps so I just assumed that
this is what you're supposed to do for NTSC no matter the format. I
guess I was just wrong ;-) thank you for clearing that up. From the
feedback I got I am now using these commands:

# full deinterlacing (2-pass) copy audio ac3 performance ~1 FPS
mencoder -oac copy -vf
yadif=3:1,mcdeint=2:1:10,framestep=2,hqdn3d=3:2:3:3,crop=704:480:0:0,scale=640:480
-sws 9 -ovc xvid -xvidencopts
bitrate=2600:nopacked:me_quality=6:vhq=4:closed_gop:qpel:trellis:bvhq=1:bquant_ratio=100:bquant_offset=0:pass=1
-ofps 29000/1001 -o /dev/null ds000.mpg

mencoder -oac copy -vf
yadif=3:1,mcdeint=2:1:10,framestep=2,hqdn3d=3:2:3:3,crop=704:480:0:0,scale=640:480
-sws 9 -ovc xvid -xvidencopts
bitrate=2600:nopacked:me_quality=6:vhq=4:closed_gop:qpel:trellis:bvhq=1:bquant_ratio=100:bquant_offset=0:pass=2
-ofps 29000/1001 -o movie.avi ds000.mpg

# iVTC (2-pass) copy audio ac3 performance ~15 FPS
mencoder -oac copy -vf
pullup,softskip,pp=lb,hqdn3d=3:2:3:3,crop=704:480:0:0,scale=640:480
-sws 9 -ovc xvid -xvidencopts
bitrate=2600:nopacked:me_quality=6:vhq=4:closed_gop:qpel:trellis:bvhq=1:bquant_ratio=100:bquant_offset=0:pass=1
-ofps 24000/1001 -o /dev/null ds000.mpg

mencoder -oac copy -vf
pullup,softskip,pp=lb,hqdn3d=3:2:3:3,crop=704:480:0:0,scale=640:480
-sws 9 -ovc xvid -xvidencopts
bitrate=2600:nopacked:me_quality=6:vhq=4:closed_gop:qpel:trellis:bvhq=1:bquant_ratio=100:bquant_offset=0:pass=2
-ofps 24000/1001 -o movie.avi ds000.mpg


Hopefully these look more sane to people on this list ;-) Again please
let me know if you disagree with anything. Thanks a lot for your
feedback everyone.  I would still like to know if there is a way for
mplayer or mencoder to detect the video format after sampling several
frames, then choose the appropriate commands to run the encode with on
that stream. (Perhaps in an automated way with a script.)

Justin