b frame

An MPEG video frame type that provides bidirectional interframe compression. Note: A b frame derives its content from the closest 1 or P frame, one in the past and one in the future. Generating b frames requires greater computing power than does generating 1 or P frames. The use of b frames enables compression ratios of 200:1. Robust MPEG encoders employ a combination of b, 1, and P frame encoding. [After Silicon]