[MEncoder-users] resize movie

[Corey Hickey]

David Rault wrote:
>>I want to downsize my movie from 352x288 to 176x144 with mencoder.
>>mencoder -xy 176 -o tmp.avi -oac copy -ovc copy <file>

You can't use -ovc copy when you are altering the video in any way --
you have to re-encode the video. I'm not going to tell you exactly how
to do it because that depends on what you need. I suggest you read at
least these parts of the documentation:

http://www1.mplayerhq.hu/DOCS/HTML/en/menc-feat-dvd-mpeg4.html#menc-feat-dvd-mpeg4-codec
http://www1.mplayerhq.hu/DOCS/HTML/en/menc-feat-enc-libavcodec.html
http://www1.mplayerhq.hu/DOCS/HTML/en/menc-feat-xvid.html
http://www1.mplayerhq.hu/DOCS/HTML/en/menc-feat-x264.html

Also, when you're encoding you need to use -vf scale instead of -xy.
Thus, your command is going to look something like this:

mencoder -o tmp.avi -oac copy -vf scale=176:144 \
-ovc <encoder> -<encoderopts> <encoderoptions>

where:
<encoder> is the video encoder you choose: libavcodec, xvid, or x264
<encoderopts> corresponds to the video encoder; -lavcopts, -xvidencopts,
  or -x264encopts
<encoderoptions> are the parameters to your <encoderopts>, like bitrate,
  pass, etc.

I could tell you a lot more, but it's mostly in the documentation.

>>It does not work and I get the message:
>>ODML: Aspect information not (yet?) available or unspecified, not writing vprp h
>>eader.

That's unrelated.

>>I use a Windows version of mencoder/mplayer I didn't compiled myself.

Depending on where you got it, your version might or might not support
some of the encoders I mentioned above.

-Corey