as far as I know the Avid Meridian codecs that are available for direct download from Avid support are not OSX10.4 compatible.
one way to get Tiger compatible versions tho’, is to register for and download the free Avid FreeDV installer (from Avid’s website) … you don’t actually need to install the app, you just need to extract and install the quicktime components from the installers package:
right-click on the .pkg file and choose “Show Package Contents”
then double-click the Content>Archive.pax.qz file, which will un-archive first to an “Archive.pax” file and then to an “Archive” folder
inside Archive>Library>QuickTime are the codec components –
AvidAVDJCodec.component
AvidAVUICodec.component
and also, if you want it, the AvidAVdvCodec.component (which is Avid’s DV codec)
drop these into your root Library>QuickTime folder then trash Archive.pax.gz, Archive.pax and the Archive folder
cheers
Andy