Video and audio data multiplexing into atm cells with no dummy cell used

Abstract

For cell multiplexing an original video signal and an original audio signal which are encoded into an encoded video signal and an encoded audio signal, a buffer unit buffers the encoded video signal for read out by a control unit as video data of a common data length. The video data and the encoded audio signal are supplied to processors for inserting additional information, such as a header, therein for production of video and audio cells, which are multiplexed by a cell multiplexer into a cell multiplexed video and audio signal. Preferably, the buffer unit comprises a video buffer for buffering the encoded video signal for read out as read video data, a delay detector for detecting a delay needed to produce the read out data, and a delay information multiplexer for multiplexing, on each read out datum for production of the read out data, delay information indicative of the delay. The cell multiplexer uses with a higher priority degree each audio cell concurrently supplied thereto with one of the video cells and uses at least one empty cell while none of the video and the audio cells are supplied thereto. For reproduction of the original video and audio signals, a data demultiplexer device is adapted to the cell multiplexed video and audio signal in which the delay information is multiplexed on each video cell.