There are 2 commonly used aspect ratios (“4:3 standard” and “16:9 wide” width-to-height ratios) for video content, but many kinds of displays, esp. if using a computer display. If you play 4:3 video on a 16:9 display (or vice versa), a circle becomes oval, and the picture takes on a stretched (or squeezed) look. To avoid this distorted look, adding black bars are a common technique.

CMP and NMP players always stretch the video to the full extents of your display. If your video source does not correspond with the display, you need to add black bars into the video file itself to correct the distortion. You can use a video editing program such as Windows Movie Maker, which is included free with Windows XP or Vista PCs. Refer to the Windows Movie Maker help system and search for the keywords “aspect ratio.”

HMP and XMP players can be configured to automatically add black bars for certain types of displays. You can set the player's logical resolution to match the native resolution of your display unit.