Inverse quantization processing method and device

An inverse quantization processing device, applied to a decoder, comprising:

• a determining unit, consecutively receiving a plurality of quantized frequency-domain data, for generating a determining signal when, among the quantized frequency-domain data, an accumulated count value of a plurality of valid bit numbers greater than a second threshold reaches a second threshold, wherein the adjustment factor is an integer, and each valid bit number represents a bit number of a first non-zero bit of the corresponding quantized frequency-domain data;
• a bit reduction unit, coupled to the determining unit, for performing a bit reduction on a current quantized frequency-domain data of the quantized frequency-domain data utilizing an adjusting factor according to the determining signal to output a bit-reduced quantized frequency-domain data;
• a frequency/time domain conversion unit, coupled to the bit reduction unit, for receiving the bit-reduced quantized frequency-domain data outputted by the bit reduction unit and performing a frequency/time domain conversion to obtain a bit-reduced time-domain PCM data;
• and
• a bit addition unit, coupled to the frequency/time domain conversion unit, for performing a bit addition on the bit-reduced time-domain PCM data to obtain a time-domain PCM data.