关键词: 声频, 编码, 滤波, 预测, 量化, 研究

Abstract: Audio-coding technique is one of the important problems of a Video Confelence System. The article describes sub-band adaptivo differential pulse code modulation with a bit rate below 64kbit/s. The transmission quadrature mirror tilters comprise two linear-phase non-recursive digital tilters which split the frequency band illto two sub-bands.The difference signals are quantized to 6 and 2 bit for the lower and higher sub(bands respectively.The adaptive predictors compute predicted signal values for the lower and higher sub-bands respectively. The decoding results show that the restored audio is successful and the odd order form of audio is as same as the even ord e r.