Hi, I am a longtime linux user(gentoo usually) just trying out slackware 10.0 for the first time.
I am trying to get mplayer plugin workingcorrectly in firefox. I installed the plugin and went to quicktimes website to test it out. video streams play correctly but there is no audio. I am an alsa / kde user. I tried to make a mplayerplug-in.conf file in .mplayer and with the line eo=arts but that didn't seem to help either. My thinking is that I am missing some codecs. In gentoo I usually in add in some win32codecs but I can't seem to find a package like that for slack. Anyone know what I am missing and how I can get mplayerplug-in to play the audio?

Where did you get the MPlayer package? If it came from linuxpackages.net, there is no propietary codec support built in. You should go to mplayerhq.hu and grab the essential codec pack. Once you have it, extract it to either /usr/lib/codecs or /usr/lib/win32. Either will work but /usr/lib/codecs is the new default location.
I've quit using mplayerplug-in in favor of Plugger because Plugger covers a wider variety of media. I also build MPlayer and Plugger from source instead of using prebuilt packages. I tend to get better results that way.

I did download it from linuxpackages, I expected there to be a seperate codec package but didn't find it. I now see why. I will grab the codecs and give it a whirl. It seems strange to me that it could play the quicktime video without the codec package.
Thanks.

Thanks again, making a directory /usr/lib/codecs and untarring the codecs there fixed my problem. Plugger does sound interesting what does it support that mplayerplug-in doesn't?

Midi, soundtracker, atari sound, pdf, postscript, word, excel, most image formats(tiff, photoshop, bmp and the like) and some I'm not remebering right now.
You'll need to install the associated software but that's not much of a step. Plugger"s website tells you what you need and where to get it. Most can also be had linuxpackages.net.
Plugger will use MPlayer for video and most audio. You'll need Timidity for midi(get it from lp.n because the package has the needed insturment files built in).
Go to the web-site for all the info.
http://fredrik.hubbe.net/plugger.html