I have tried several different examples but I cannot get any video to show. I hear sound but no video. I thought maybe I just had a incorrect video format so I downloaded a
If you are using the emulator, it may not work. The emulator lacks the hardware acceleration available in Android devices. For example, on a 2.6GHz Core 2 Duo, I sometimes can get a video to play back, but not always. On slower machines, video playback never works. On a 2.5GHz Core 2 Quad, I always get video playback. That being said, I usually test video playback on actual devices.
I am also uncertain if video playback works from raw resources. I strongly encourage you to try using a video from a file on the SD card first.
With respect to videos that definitely work, I know that "Documentaries and You" and "Music for our Grandchildren" from here work in their MP4 forms.