DESIGN AND DEVELOPMENT OF A CODEC FOR TWO ″SOUND-IN-SYNC″ CHANNELS IN A TELEVISION SYSTEM.

The transmission of multiple sound along with a single picture has many applications. In this work, two sound channels in addition to the one that normally accompanies a picture are time multiplexed with the television signal. The extra audio signals are coded with eight-bit PCM and placed in the horizontal synchronization interval of the video signal. At the receiver, these pulses are extracted to recover the audio signals. The prototype CODEC developed has shown satisfactory results for two extra speech channels over a normal television channel. The system can be used with a standard television receiver without any modifications by the addition of the decoding unit.