Have you ever used JMF? Well many people have tried and if they didn’t need it that hard they stop trying soon. One main problem is in my opinion that you have to install the whole thing on your system (libraries outside Java are needed) to get reasonable performance, but you won’t get a lot of codecs. So DivX, MP4, AVC and others are not supported out of the box.
Recently I found two JMF implementation based on FFMPEG, whereas one of them had a really impressive feature: It just worked and did it well. Basically you get a pure Java JMF, but every codec that is not supported by the pure Java JMF, is handled by an FFMPEG shared library. This works out fine for Windows and is also supported for Linux (Ubuntu) and Mac.
If you ever wanted to program some multimedia features in Java: Give Omnividea FOBS a try. Best of all: It’s open source! The screenshot above shows a screenshot while playing the Spiderman game trailer (DivX codec & container, HD).