Yet another Mplayer Question (looked it up. honest!)

I have several mplayer setups but in one I get the error "can't find codec "mpeg4" in libavcodec.

It;'s unusually that the amazingly powerful libavcodec does _not_ have an mpeg4 decoder. Am I naive? Or is it just a configuration setting I'm getting wrong?

what is the output of

ffmpeg -formats | grep mpeg4

thanks for the heads-up.

I don't have ffmpeg on that installation. Hmmm... now I thought mplayer uses ffmpeg, so mplayer shouldn't really work at all really.

On second thoughts, I suppose I have only being using it for listening to mp3's ... I'd better install it and look up formats on it then so.

What should I be looking for? It says mpeg4, mpeg4aac,msmpeg4,msmpeg4v1 and v2.

That mustn't be enough ...

ffmpeg consists of the libs (libavcodec/-format/-util ...), which are the main part of the project, and the "demonstration programs" ffmpeg and ffplay. These are usually in separate packages, so you can have the libs installed without the binaries. mplayer/mencoder only needs the libs.

I'd still install ffmpeg because you can see the capabilities of your libs with 'ffmpeg -formats'. Most distributions have crippled versions because of license issues.
You should look for a line like this

DEVSDT mpeg4 MPEG-4 part 2

This means you can decode and encode mpeg4, at least decoding should be possible for use with mplayer.

Thanks.

Ok what it says is:

DEVSDT mpeg4
D A mpeg4aac
DEVSD msmpeg4
DEVSD msmpeg4v1
DEVSD msmpeg4v2

there's no part 2.

However, now armed with ffmpeg, ffplay does work on my file.

So it seems to be the interaction between mplayer and ffmpeg on my system.

Uninstall mplayer and re-install it (now that I have ffmpeg installed).
That sort of behaviour is a sure sign of somebody who doesn't know what he's doing. Bah, did it anyway, and gues what? Now it works.

It's hard to work out an explanation for this. But anyhow, the lesson of the tail is, that it's nice to have ffmpeg installed before you install mplayer.

Maybe it's not required, but it would seem to be A Good Idea (c).