CODEC APPARATUS OF NTSC TV

The codec is to compress or expand NTSC TV signal with the North America style DS3 transmission speed. The codec consists of an A/D converter and an analog module (4) which outputs 8 bit data signals and clock signals with the NTSC video signals, a DPCM (5) which generates the compressed signals of 4 bit data and clock an audio encoder module (7) which generates the output signals with the input of audio signals, an encoding unit (2) which has DS3 multiple module (6) that outputs DS3 data and the clock signals (ADCLK), a DS3 reverse multiple module (10) which outputs the data channel signals, a DPCM replay module (9) which inputs the 4 bit data and the clock signals of the DS3 reverse multiple module, a D/A converter and an analog module (8) which outputs the NTSC video signals with the 8 bit data and the clock signals, and a decoding unit (3) which has an audio decoder module (11).