[MPlayer-users] mencoder doesn't honor bitrate

[Michael Halcrow]

I've been trying to use mencoder on a .vob to convert it to mpeg4, but
so far I have only been able to get the resulting file to either be
900MB or 2.6GB. I have tried 5 times so far. My most recent attempt went
something like this:

cat *vob | mencoder -ovc lavc -lavcopts
vcodec=mpeg4:vpass=1:vbitrate=1200:vhq -oac mp3lame -vop scale=640:427
-ofps 23.98 -o movie.avi -

cat *vob | mencoder -ovc lavc -lavcopts
vcodec=mpeg4:vpass=2:vbitrate=1200:vhq -oac mp3lame -vop scale=640:427
-ofps 23.98 -o movie.avi -

I had previously run:

cat *vob | mencoder -ovc frameno -o frameno.avi

In my last attempt, I deleted frameno.avi immediately afterwards. Only
the .vob files were in the directory.

And it told me that I needed 637kbps in order to result in a 700MB file.
I wanted a 1400MB file, so I roughly doubled that. The result:

...
Pos:6567.0s 157439f ( 0%)  11fps Trem:   0min   0mb  A-V:-0.032
[866:163]
duplicate 1 frame(s)!!!    
Pos:6823.5s 163591f ( 0%)  11fps Trem:   0min   0mb  A-V:-0.034
[860:163]
duplicate 1 frame(s)!!!    
Pos:7080.1s 169743f ( 0%)  11fps Trem:   0min   0mb  A-V:-0.035
[874:163]
duplicate 1 frame(s)!!!    
Pos:7219.8s 173091f ( 0%)  11fps Trem:   0min   0mb  A-V:-0.050
[875:162]
Writing AVI index...
Fixup AVI header...

Video stream:  875.231 kbit/s  (109403 bps)  size: 789873775 bytes 
7219.796 secs  173091 frames

Audio stream:  162.923 kbit/s  (20365 bps)  size: 147044208 bytes 
7220.304 secs

Is vbitrate the (v)ideo bitrate, or the combined bitrate of the video
and the audio? I assume it's the combined bitrate of the video and
audio.

That's a total of 1037 kbit/s instead of 1200 kbit/s (14% lower than I
asked). I specifically told the codec vbitrate=1200! The resulting file
is 948MB... too big for one CD-R, and too small to take advantage of all
the space of 2 CD-R's. Of course, if the file were 16% larger, it would
only be 1097MB, and I really want 1400MB (indicating that the estimation
given in the frameno run was a little off, or I can't just simply
multiply the bitrate to get multiple of the base amount; well, I should
have technically done 1274 kbit/s, but this has nothing to do with the
problem I'm experiencing here). Some insight would be appreciated here.
I'd use transcode, but it still won't keep A/V syncronized in my NTSC
video; mencoder succeeds at doing that.

Thanks,
Mike