Can't open DV video (dvsd) AVI file with QuickTime

QuickTime doesn't accept 'plug-in codecs' any more, not since QuickTime 7.

There used to be a plug-in set by the name of Perian, which was the Swiss army knife for QuickTime, but it no longer works.

Your best bet would be to transcode from VLC or any of the other encoding apps available, if you specifically need it in QuickTime.

I always think of .AVI as being very much a 'Windows' structure [even if that's not strictly true], so I've avoided it on Mac for many years, or immediately transcode to something more portable.