Patent ID: 8788264

Claim:
An audio encoding method comprising: in an audio encoding device: transforming an input audio signal comprising a plurality of frames into a frequency signal for each frame of the plurality of frames of the input audio signal, the plurality of frames including a current frame and a past frame which is earlier in time than the current frame, and the frequency signal being divided into a plurality of bands; calculating, for each band of the plurality of bands, an initial gain for scaling the frequency signal for the current frame; correcting the initial gain by using a past gain for each band of the plurality of bands for the past frame of the plurality of frames, thereby calculating a corrected gain for each band of the plurality of bands for the current frame; generating a quantized signal by scaling and quantizing the frequency signal for the current frame by using the corrected gain for each band of the plurality of bands for the current frame; generating gain information by encoding, for each band of the plurality of bands for the current frame, a difference between the corrected gain and the past gain as the gain information; and generating encoded audio data by multiplexing, for each band of the plurality of bands for the current frame, the quantized signal and the gain information.