| 摘要 |
PURPOSE:To offer a quantization bit allocation system which can effectively utilize the total number of bits in a composite frame and improve the quality of a playback signal. CONSTITUTION:The quantization bit allocation system of a system which quantizes and encodes signals of plural channels CH0-CHm-1, and then puts them together in a frame and sends the frame evaluates specific properties of the respective channel signals at a time and allocates bits adaptively to the quantization of the respective channels CH0-CHm-1 based on the evaluation result so that quantization errors of the respective channel signals are minimized without exceeding the number of sent frame bits of the system. The specific properties of the respective channel signals are preferably masking levels obtained in consideration of the amplitudes of input signals S0-Sm-1, the amplitudes of signals C0-Cm-1 after quantization, or the power spectra of the input signals S0-Sm-1 and noises and human auditory characteristics. |
