I have sound, but no picture
 

I only have sound without picture. What codec do I need or something else?

Have you tried different Overlay settings?

Settings-->Video
Try turning off Overlay or using Mode1 or Mode2. If the movie is opened and played (only no picture), you usually have the right codec.

If the overlay doesn't help, check your brightness settings of the codec used (if it's on the left side, it is of course totally dark). To see the settings:
right click on (black) picture-->Properties-->.....video decoder