A system for transmitting multiple video signals via a single video channel, each video signal having a luminance component in respective sequential horizontal line periods. Luminance components of the video signals are separated and compressed. An output video signal having sequential output horizontal line periods is formed and the compressed luminance components are inserted in the output horizontal line periods. Chroma components are compressed by a higher compression factor and inserted in the blanking intervals. The two color video signals are compressed into one standard 4.2 MHz channel, permitting the system to replace directly any existing 6 MHz audio/video transmission system. An encoder aspect of the invention combines plural video source channels to form an output video channel for transmission, using first and second decoders for separating the input video signal into respective luminance and chroma signals. A compressor compresses the luminance and chroma signals, and a multiplexer selects alternately between the decoders. A decoder system extracts the video channels from the encoded video signal. An analog-to-digital converter issues luminance digital data corresponding to a luminance component of the encoded video signal. A luminance expander expands the luminance digital data, and a demultiplexer alternately produces portions of the time-expanded luminance digital data corresponding to respective ones of the video channels. Sync information is regenerated at the decoders from the vertical sync pulses which are left intact in the transmitted signal. Interpolated chroma information is provided to reconstructed video channels.