[MEncoder-users] Encoding interlaced content: what am I doing wrong?

[Martijn van Beurden]

Good afternoon,

Currently I'm busy transcoding Hi8 video to DVDs. I've already done 2
tapes, using pp=fd as deinterlacer, but very recently I discovered what
interlacing is exactly, and I'm convinced I should try keep the
interlacing, so I'm adjusting my toolchain.

First I capture the video with mencoder piped to x264 (just for --preset
and --tune setting convenience) and arecord to capture sound in 24-bit
format, then amplify it, turn it to 16-bit and merge it into a .mkv
file. So far so good, this is quite easy to keep interlaced, just pass
--interlaced to x264.

I'm looking which settings to use to encode interlaced material, but
some of my tests seem to fail. I used this command to generate a file
test.mpg
mencoder -edl tape3.edl -hr-edl-seek tape3.mkv -vf
crop=686:560:16:4,scale,expand=720:576:16:0 -nosound -ovc lavc -lavcopts
vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:turbo:vpass=1:ilme:ildct:vstrict=0:threads=2:vbitrate=5800:keyint=15 

-of mpeg -mpegopts format=dvd:tsaf -o test.mpg

So, as you can see, I'm messing around getting the first pass right.
(Second pass shouldn't be a problem) The resulting video is clearly
interlaced, it works when played with mplayer with -vf pp=fd, but when
using -vf tfields=0:0,scale the framerate doesn't double (or, when
played at 0.25x, motion isn't that smooth) while it does when I try at
tape3.mkv, the original capture. What am I doing wrong? I suspect
there's something wrong with the container, the video not being marked
as deinterlaced or something...? Or is my test method wrong and is this
encode fine?

Thanks in advance!

Kind regards, Martijn van Beurden