DVD-Video is a consumer video format used to store digital video on DVD (DVD-ROM) discs, and is currently the dominant form of consumer video formats in the United States, Canada, Europe and Australia. Discs using the DVD-Video specification require a DVD drive and an MPEG-2 decoder (e.g., a DVD player, or a DVD computer drive with a software DVD player). Commercial DVD movies are encoded using a combination of MPEG-2 compressed video and audio of varying formats (often multi-channel formats as described below). Typical data rates for DVD movies range from 3-10 Mbit/s, and the bit rate is usually adaptive.