The 3ivx v4.5.1 un-installer performs the following:
but that's a pretty old version.
Quicktime codecs are usually in:
/Users/YOUR_USERNAME/Library/QuickTime/
or
/Library/QuickTime/
ONLY delete the 3ivx files... others may be installed and required by iLife
#!/bin/sh
#uninstalls 3ivx
rm -f "/Library/QuickTime/3ivx D4 4.5.1 for OSX"
rm -f "/Library/QuickTime/3ivx D4 4.5.1 Plus for OSX"
rm -f "/Library/QuickTime/3ivx D4 4.5.1 Pro for OSX"
rm -f "/Library/QuickTime/3ivx D4 4.5.1 Decoder OSX"
#rm -f "/Applications/3ivx/History.txt"
rm -f "/Applications/3ivx/How To Play AVI Files"
rm -f "/Applications/3ivx/ReadMe.pdf"
rm -f "/Applications/3ivx/forums.3ivx.com"
rm -f "/Applications/3ivx/www.3ivx.com"
rm -f "/Applications/3ivx/.DS_Store"
rm -rf "/Applications/3ivx/Uninstall 3ivx.app"
rmdir "/Applications/3ivx"
rm -f "/Library/Receipts/com.3ivx.3ivx-codec/.DS_Store"
rm -f "/Library/Receipts/com.3ivx.3ivx-codec/uninstall"
rmdir "/Library/Receipts/com.3ivx.3ivx-codec"
The 3ivx v5.0.4 installer installs these:
/Applications/3ivx/
~/Library/Receipts/com.3ivx.3ivx-codec
~/Library/QuickTime/3ivxMediaExporter.component
~/Library/QuickTime/libtmux.dylib
~/Library/QuickTime/openquicktime.framework
~/Library/QuickTime/3ivxPrefPane.prefPane
~/Library/QuickTime/3ivxVideoCodec.component
~/Library/QuickTime/lib3ivxEnc.dylib
~/Library/QuickTime/trial.pbm
BUT... there should be an un-installer named "Uninstall 3ivx" located in:
/Applications/3ivx/
If you've lost the un-installer, re-install version 5.0.4, and then use the un-installer:
http://www.3ivx.com/download/macos.html
The v4.5.1 installer can still be grabbed here:
http://web.archive.org/web/20050316190609/http://mirror2.3ivx.com/3ivx_d4_451_osx.dmg