[MEncoder-users] Problems with some videos

[Pete Davis]

I have a lot of videos that I've recoded using mencoder. The originals might
be in DIVX3, 5, or XVID, and audio is usually AC3, sometimes MP3. I
re-encode them so that they'll play back (if they don't play at all) or play
back better, on my DLink DSM 320 media player.

I reencode them all to be MP3 and I use lavc and force the 4CC to DIVX. Now,
this works with probably 95% of the videos. It works with 100% of my TV
captures (which are all mpeg2) and 100% of my DVD transcodings (though the
params for my DVD transcoding varies depending on DVD, of course)

But a small number of the videos I download, even after re-encoding, won't
playback on the DSM 320. They vary in original video and audio codecs. So my
question is, why is it that after re-encoding might these videos still
refuse to play? I would think that they would be completely new files after
re-encoding. I use the same parameters for all of the re-encodings, so what
could it be about these 5% that make them not want to play back on the DSM
320?

They play just fine in mplayer and in Windows Media Player (both originals
and the re-encodings).

The parameters I use are ($1 is the parameter to the script):

mencoder "$1" -o /dev/null -ovc lavc -lavcopts
vcodec=mpeg4:vbitrate=1100:mbd=2:vpass=1:vqmin=2:vqmax=31:keyint=30:turbo
-ffourcc DIVX -oac copy

mencoder "$1" -o newfile.avi -ovc lavc -lavcopts
vcodec=mpeg4:vbitrate=1100:mbd=2:vpass=2:vqmin=2:vqmax=31:keyint=30 -ffourcc
DIVX -oac mp3lame -lameopts cbr:br=128

If anyone has any ideas, I'd appreciate it. God knows the people at D-Link
aren't very helpful on this. Unfortunately, they won't release specifics
about what sorts of encoding parameters they support, so I've kind of
figured it out by trial and error and hence the re-use of the same script.

I'm not expecting you guys to necessarily know about the DSM 320's
specifics, but I guess I'm asking, what could it be about the files that
would survive re-encoding that would make them continue to fail.

Pete