Video to mp3 using mencoder?

[naynay]

Is there any way to convert a video file of mp4 or flv format to an mp3 file without any problems?

I've tried the following command but the results aren't satisfactory:

mencoder in.mp4 -ovc frameno -oac mp3lame -o out.mp3

I'm getting an mp3 file of about half size of the video file, but it doesn't play in Window Media Player and in MPlayer the durations is not consistent (very long, like 40:00 or 1h+).

There doesn't seem to be a -novideo, so does that mean mencoder is only capable of converting videos properly? Does anybody know the command for properly extracting the audio out of a video file in mp3 format? Thanks.

[Baldrick]

I'm pretty sure it can not output audio only like mp3. Use instead ffmpeg, see for example https://www.videohelp.com/forum/archive/any-audio-to-mp3-with-mencoder-t343226.html

[naynay]

Thanks. Do you know if it can do FLVs too?

[Baldrick]

Yep.