Reader Elizabeth Dickinson has tired of watching blank movies. She writes:
I’ve downloaded several movie clips from the web and QuickTime won’t play them. Well, the sound plays, but the movies show nothing but white—no video. What’s going on?
My guess is that these movies end with a .avi extension. This is confusing to a lot of people because QuickTime is supposed to handle .avi movies. This is true for only some varieties of .avi.
If that movie is encoded with the DivX codec (and most .avi movies you find on the web these days are), the movie appears as you describe when you try to play it in QuickTime Play—sound but no video.
Fortunately, you can put things right by downloading
DivX 6 for Mac. Doing so packs your Mac with a free 15-day trial of the DivX Converter (a tool for, well, converting movies to the DivX format), a codec for encoding DivX movies, and, most importantly for your purposes, the DivX 6 Decoder.component file. This is a component placed in the QuickTime folder within the Library folder at the root level of your hard drive that lets QuickTime play DivX-encoded movies.
Unlike the DivX Converter application and the DivX encoding component, the decoder doesn’t expire after a set period of time. You can continue to use it from here to eternity to watch DivX-encoded movies.