VLC supports a huge array of codecs and can play nearly any AVI file with accompanying crazy AVI Codec directly on a Mac. In any of these cases the best solution is to get the AVI to play on your Mac is to just download a free app called VLC. Not to worry, we will show you how to play them for free! How to Play AVI and DivX Codec Video on Mac OS X for Free This is often the case with DIVX files in particular, but it happens with many AVI formatted movies quite often. There are also times when just the audio of an AVI doesn’t work and sometimes just the video won’t work, in these cases it’s likely because you need to get a particular codec on your Mac to watch the AVI file. The movie is not in a format that QuickTime Player understands.” Followed with some fine print “You may need to install additional software to open this type of file.” “The document “movie.avi” could not be opened. But what if it doesn’t? There are situations when AVI movies won’t play at all, this is usually a video codec issue, and you might get an error message like the following:

How to open avi files in quicktime