Decoding apparatus and method, and program

A decoding method comprising:

• reading out, from a code string, encoded gain values at least at two gain sample positions at different times in an audio time series signal;
• reading out, from the code string, interpolation information indicating an interpolation mode used to obtain the gain value at each sample position of the audio time series signal;
• and
• obtaining the gain value at each sample position located at a time between the two gain sample positions of the audio time series signal based on the gain values at the gain sample positions through non-linear interpolation, in response to the interpolation information indicating non-linear interpolation.

A non-transitory computer readable medium storing instructions that, when executed by processing circuitry, performs a decoding method comprising:

• reading out, from a code string, encoded gain values at least at two gain sample positions at different times in an audio time series signal;
• reading out, from the code string, interpolation information indicating an interpolation mode used to obtain the gain value at each sample position of the audio time series signal;
• and
• obtaining the gain value at each sample position located at a time between the two gain sample positions of the audio time series signal based on the gain values at the gain sample positions through non-linear interpolation, in response to the interpolation information indicating non-linear interpolation.