VIDEO ENCODER/DECODER FOR DIGITAL VIDEO DISPLAYS

An improved multimedia encoder having features advantageous for use in a computer system. These features provide for the reduction of bandwidth and storage requirements, the enhancement of noise immunity, the evening of computational loading, and the use of multimedia drives for general purpose data storage. In one embodiment, the encoder receives image data representing a sequence of video frames and display text data representing a sequence of text fields to be overlaid on the sequence of video frames. The multimedia encoder produces a compressed video frame only for each subsequent video frame which is different from the current video frame. After each video frame is compressed, it becomes the current frame. The multimedia encoder provides error correction encoding to enhance noise immunity, and performs interframe compression using a dynamic search area to even out computational loading. Additionally, the multimedia encoder allows text file storage using a sub-picture unit bitstream and direct binary file storage, thereby enabling a write-able multimedia disk to displace a hard disk drive. A companion multimedia decoder recognizes these features and decodes a multimedia bitstream accordingly.