H.120

The first standard for digital video coding was H.120, specified in the 1980s by the Video Coding Experts Group( VCEG).

This early standard used differential time division multiplexing( PCM), scalable quantization, and variable length coding( VLC). In the second version of H.120, functionality was expanded to include motion compensation and background prediction. H.120 has been little used and no corresponding video codec exists.