Patent ID: 8478586

Claim:
A signal processing apparatus that performs signal processing on a code string obtained by dividing an input digital signal into blocks along the time axis, performing gain control on each block along the time axis, normalizing with a positive value a signal component on which the gain control has been performed, quantizing the normalized signal component, and coding and multiplexing along with gain control function generation information generating a gain control function for performing the gain control and normalization coefficient information, the signal processing apparatus comprising: a hardware processor; and a memory coupled to the processor and storing a program that, when executed by the processor, causes the apparatus to perform a method, the method comprising: adjusting a level of the signal by subtracting or adding an integer value from or to the normalization coefficient information in the code string; calculating a cutoff amount for a case where the normalization coefficient information after subtraction or addition is cut off at a minimum or maximum possible value thereof because a subtracted or added amount of the normalization coefficient information is large; and modifying the gain control function generation information according to the calculated cutoff amount.