Not Getting Audio on .avi's.
 

I spent a few days downloading some .avi's onto my computer only to find they they would not give me any audio. The .avi's that I've been using before still work just fine, but Quicktime also says that I need a new codec to play these files. However, the video still plays fine.

My question to you is, could this be the files themselves, and should I replace them if possible, or has this happened to you and do you now what codec could fix this issue. I already have a DivX and an Xvid codec and I'm using Quicktime on my Mac, if that makes a difference.

Some avis don't play in Quicktime. In fact, many things won't. That's why there's VLC

VideoLAN - Free Software and Open Source video streaming solution for every OS!

That is THE best media player out there. It will play everything.

Thanks very much, help much appreciated.

VLC runs into problems with .wmv and .mpeg. It also throws up weird colors sometimes. I prefer Combined Community Codec Pack which comes with either ZoomPlayer or MPlayer.

I doubt that it (VLC) has problems with MPEG1 streams. VLC features the FFmpeg decoding engine. That's the same engine MPlayer uses (MPlayer however can also use libmpeg). Also ffdshow, the core of the CCCP, is based on FFmpeg. ffdshow is basically a DirectShow wrapper around FFmpeg, with a few tweaks, nothing more.

The bulk of the decoding work in done by FFmpeg. If VLC has really a bug when it comes to MPEG1 playback then MPlayer and ffdshow should have the same problem.

The same goes for WMV. FFmpeg can decode WMV1, 2 and 3 - including the WMV-HD/VC-1 format.
You either use an outdated version of VLC, you have configured something wrong with your video output settings or your system has some (driver?) issues.

Correction: If I remember correctly also ffdshow allows it to select libmpeg for decoding. I don't know which decoder engine is default though. You should probably try to switch the engine in ffdshow and try to reproduce what you saw with VLC.