ac3 codec for quicktime osx

[MichaelHo]

Hi,
I have a hi-def avi file which plays in quicktime but it does not play the audio. When i open it with divx the audio plays but the video plays very slowly. i think the audio codec it requires is AC3, i downloaded this and put it into the quicktime folder in library but quicktime still doesnt play the audio.
Can anyone help?

 

[MichaelHo]

Here ya go. Works great. http://www.versiontracker.com/dyn/moreinfo/macosx/27300

thanks a lot guys for the replies. Used the link above, installed and it works fine now.

How comes HD video files play so smoothly in QT but other players such as VLC struggle?