Sound signal high frequency compensation method, sound signal post processing method, sound signal decode method, apparatus thereof, program, and storage medium

A sound signal high-frequency compensation method for obtaining, for each frame, an n-th channel compensated decoded sound signal {tilde over ( )}X′n that is a signal obtained by compensating a high frequency of an n-th channel purified decoded sound signal {tilde over ( )}Xn obtained by performing signal processing in a time domain on an n-th channel decoded sound signal {circumflex over ( )}Xn (n is each integer of 1 or more and N or less) that is a decoded sound signal of each channel of stereo obtained by decoding a stereo code CS, the sound signal high-frequency compensation method comprising:

• an n-th channel high-frequency compensation gain estimation step of obtaining, for the each frame with respect to the each channel, an n-th channel high-frequency compensation gain ρn that is a value for bringing high-frequency energy of the n-th channel compensated decoded sound signal {tilde over ( )}X′n close to high-frequency energy of the n-th channel decoded sound signal {circumflex over ( )}Xn;
• and
• an n-th channel high-frequency compensation step of obtaining and outputting, for the each frame with respect to the each channel, a signal obtained by adding the n-th channel purified decoded sound signal {tilde over ( )}Xn and a signal obtained by multiplying a high-frequency component of a monaural decoded sound signal {circumflex over ( )}XM that is obtained by decoding a monaural code CM that is a code different from the stereo code CS by the n-th channel high-frequency compensation gain ρn, as the n-th channel compensated decoded sound signal {tilde over ( )}X′n.

A sound signal high-frequency compensation device for obtaining, for each frame, an n-th channel compensated decoded sound signal {tilde over ( )}X′n that is a signal obtained by compensating a high frequency of an n-th channel purified decoded sound signal {tilde over ( )}Xn obtained by performing signal processing in a time domain on an n-th channel decoded sound signal {circumflex over ( )}Xn (n is each integer of 1 or more and N or less) that is a decoded sound signal of each channel of stereo obtained by decoding a stereo code CS, the sound signal high-frequency compensation device comprising:

• an n-th channel high-frequency compensation gain estimation circuitry configured to obtain, for the each frame with respect to the each channel, an n-th channel high-frequency compensation gain ρn that is a value for bringing high-frequency energy of the n-th channel compensated decoded sound signal {tilde over ( )}X′n close to high-frequency energy of the n-th channel decoded sound signal {circumflex over ( )}Xn;
• and
• an n-th channel high-frequency compensation circuitry configured to obtain and output, for the each frame with respect to the each channel, a signal obtained by adding the n-th channel purified decoded sound signal {tilde over ( )}Xn and a signal obtained by multiplying a high-frequency component of an n-th channel upmixed monaural decoded sound signal {circumflex over ( )}XMn that is a signal obtained by upmixing, for the each channel, a monaural decoded sound signal {circumflex over ( )}XM that is obtained by decoding a monaural code CM that is a code different from the stereo code CS by the n-th channel high-frequency compensation gain ρn, as the n-th channel compensated decoded sound signal {tilde over ( )}X′n.

A sound signal high-frequency compensation device for obtaining, for each frame, an n-th channel compensated decoded sound signal {tilde over ( )}X′n that is a signal obtained by compensating a high frequency of an n-th channel purified decoded sound signal {tilde over ( )}Xn obtained by performing signal processing in a time domain on an n-th channel decoded sound signal {circumflex over ( )}Xn (n is each integer of 1 or more and N or less) that is a decoded sound signal of each channel of stereo obtained by decoding a stereo code CS, the sound signal high-frequency compensation device comprising:

• an n-th channel high-frequency compensation gain estimation circuitry configured to obtain, for the each frame with respect to the each channel, an n-th channel high-frequency compensation gain ρn that is a value for bringing high-frequency energy of the n-th channel compensated decoded sound signal {tilde over ( )}X′n close to high-frequency energy of the n-th channel decoded sound signal {circumflex over ( )}Xn;
• and
• an n-th channel high-frequency compensation circuitry configured to obtain and output, for the each frame with respect to the each channel, a signal obtained by adding the n-th channel purified decoded sound signal {tilde over ( )}Xn and a signal obtained by multiplying a high-frequency component of a monaural decoded sound signal {circumflex over ( )}XM that is obtained by decoding a monaural code CM that is a code different from the stereo code CS by the n-th channel high-frequency compensation gain ρn, as the n-th channel compensated decoded sound signal {tilde over ( )}X′n.