Patent ID: 9672835
Date: 2017-06-06
CPC Classifications: G10L

Claim:
1. A method of classifying an audio signal into a fast signal or a slow signal for audio coding, comprising: determining, by an encoder comprising a processor, a parameter of each of the plurality of frames of the audio signal, wherein the audio signal has a plurality of frames, wherein each of the plurality of frames has at least two spectral sub-bands; comparing, by the encoder, the parameter with a pre-defined threshold as one of determination elements to determine whether each of the plurality of frames should be classified into a fast frame or a slow frame; processing, by the encoder, the fast frame in a fast mode to obtain a processed fast frame suitable for writing into a bitstream for storing or transmitting; or processing, by the encoder, the slow frame in a slow mode to obtain a processed slow frame suitable for writing into a bitstream for storing or transmitting; wherein the parameter is determined according to spectral sharpness, Spec_Sharp, which is defined as follows: wherein MDCT