METHOD AND APPARATUS FOR COMMUNICATING COMPRESSED VIDEO¹USING TRELLIS CODED QAM

摘要

A method and apparatus for communicating high definition television signals is provided. Video signals are divided into blocks of PCM data. The PCM data is processed using motion estimation and compensation (150) to provide DPCM data. For each block, one of PCM and DPCM data is selected for transmission based on a predetermined criteria. The selected data is compressed using the discrete cosine transform (133, 134) to provide blocks of transform coefficients. The coefficients are quantized (135, 136) to improve their coding efficiency and then variable length coded (138). The variable length coded coefficients are coded using a concatenated coding scheme (180) with a Reed-Solomon outer code (200) and trellis inner code (204) to provide coded signals for transmission. The coded signals are transmitted using QAM (184).