Have your mind that a byte consists of 8 bit. The amount of data at a video is measured in bits per second. The data rate for a video file is the bitrate. In a video that plays with 1 megabyte per second, the bitrate is 8 megabits per second (8 Mbps). The bitrate for Blu-ray HD is usually 20 Mbps, for DVD is usually 6 mbps, high quality video on the Internet, 2 mbps.