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

[James Hastings-Trew]

Martijn van Beurden wrote:
> 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?
I'm a little confused as to why your material is in an .mkv container to 
begin with. Why wouldn't you directly capture the Hi8 video into an 
MPEG2 file?