Stereo to mono problem with mencoder

[kyroii]

Hi all,

I want to re-encode a video with mencoder (let's say stereo.avi [xvid+mp3]) so that sound becomes mono.

That's what I do:

mencoder stereo.avi -ovc copy -oac mp3lame -lameopts cbr:br=128:mode=3 -o mono.avi

Ok, this doesn't work, this still has 2 channels.

I've also tried the following:

mencoder stereo.avi -ovc copy -oac mp3lame -lameopts cbr:br=128:mode=3 -af pan=1:0.5:0.5 -channels 1 -o mono.avi

That also doesn't work

What am I doing wrong?

Any help is appreciated, thx a lot.

[lpn1160]

Try ffmpeg instead, a little easier imho:

ffmpeg -i stereo.avi -vcodec copy -acodec mp3 -ac 1 -ab 128 mono.avi

[kyroii]

Hi, thx for your answer.

Does ffmpeg use lame for encoding mp3?

Anyway, I'd like to do it with mencoder so if anyone knows how to do it i'll be very happy if u post.

Thank you.

[richip]

The mencoder option that worked for me was:

mencoder -af channels=2:2:0:0:0:1 ...
or
mencoder -af channels=2:2:1:0:1:1 ...

The difference between the two is the channel that I'm selecting as the audio source (left vs. right). Useful for hardcoding videoke files.