| 摘要 |
PURPOSE:To compress an audio signal with various sampling frequencies effectively in response to a human audible sense characteristic and to effectively utilize a transmission line by variable-control-bit allocation algorithm in the case of compression coding of an input signal depending on a sampling frequency of the input signal. CONSTITUTION:An FS discrimination circuit 11 of a DSP (encoder) 10 measures a sampling frequency of an input digital audio signal and a compression table selection circuit 12 selects a fixed table in response to sampling frequency information of a measured input signal from plural fixed tables including a prepared different allocation bit components in advance. That is, an optimum fixed table is selected for use in response to a sampling frequency when an information quantity is shared. Then a compression rate selection circuit 13 and a compression coding circuit analyze a spectrum of the input signal to share bits with respect to each block. Thus, the optimum compression in response to the content of the input signal is attained. |
