This article describe a digital coding system for video signals called redundancy estimation ADPCM which provide a good quality for transmission of video in 6.5 Mbits or 1.6 Mbits channel. It uses a differential pulse-code modulation (ADPCM), adaptative prediction and adaptative quantization based on redundancy estimation. This system could be use for video monitoring on return way of cable networks, so that it could be possible to manage several video monitoring sources in the same numeric channel.