Method for encoding signal, and method for decoding signal

A signal decoding method, comprising:

• decoding a received bit stream to obtain a first-domain predictive residual signal and a long-term flag value, wherein the first-domain predictive residual signal is formatted into frames, each frame comprises one or more sample points;
• decoding the first sample point of a current frame of the first-domain predictive residual signal;
• performing the following decoding steps consecutively for every current sample point of the current frame of the first-domain predictive residual from the second sample point of the current frame of the first-domain predictive residual signal:
• calculating a Linear Prediction (LP) signal of a current sample point according to a second-domain signal of the decoded sample point, wherein the bit stream comprises both a best pitch and a pitch gain, or both the bit stream comprises the best pitch and a pitch gain;
• if the long-term flag value is a first value, obtaining a second-domain predictive signal according to the LP signal and a Long-Term Prediction (LTP) contribution signal, wherein the LTP contribution signal is obtained based on the LP residual signal of the decoded sample point;
• or
• if the long-term flag value is not the first value, obtaining the second-domain predictive signal based on the LP signal;
• converting the second-domain predictive signal into a first-domain predictive signal, and decoding a first-domain signal of the current sample point according to the first-domain predictive residual signal and the first-domain predictive signal;
• and
• converting the first-domain signal of the current sample point into a second-domain signal, and obtaining an LP residual signal according to the second-domain signal and the LP signal.

A signal encoding apparatus, comprising a signal converter, a signal processor and a signal output, wherein

• the signal converter is configured to convert a first-domain signal into a second-domain signal;
• the signal processor is configured to:
• perform a Linear Prediction (LP) processing and a Long-Term Prediction (LTP) processing for the second-domain signal to obtain a LP processing result and a LTP processing result,
• wherein the LP processing result comprises a LP signal and a LP residual signal, the LTP processing result comprises a LTP residual signal, a best pitch of the LP residual signal or both the best pitch of the LP residual signal and a pitch gain of the LP residual signal;
• obtain a long-term flag value based on a comparison between the LP residual signal and the LTP residual signal;
• and
• obtain a second-domain predictive signal based on the LP processing result and the LTP processing result if the long-term flag value is a first value, or obtain the second-domain predictive signal based on the LP processing result if the long-term flag value is a second value;
• the signal converter is further configured to convert the second-domain predictive signal into a first-domain predictive signal;
• the signal processor is further configured to calculate a first-domain predictive residual signal according to the first-domain predictive signal;
• and
• the signal output is configured to output a bit stream that comprises the first-domain predictive residual signal.

A signal decoding apparatus, comprising:

• a bit stream decoding module, configured to decode a received bit stream to obtain a first-domain predictive residual signal and a long-term flag value, wherein the first-domain predictive residual signal is formatted into frames, each frame comprises one or more sample points;
• a first sample point decoding module, configured to decode a first sample point of a current frame signal;
• a sample point decoding module, configured to perform the following decoding steps consecutively for every current sample point of the current frame of the first-domain predictive residual from the second sample point of the current frame of the first-domain predictive residual signal:
• calculate an LP signal of a current sample point according to a second-domain signal of the decoded sample point, wherein the bit stream comprises both a best pitch and a pitch gain, or both the bit stream comprises the best pitch and a pitch gain;
• and
• obtain a second-domain predictive signal according to the LP signal and a Long-Term Prediction (LTP) contribution signal if the obtained long-term flag value is a first value, or obtain a second-domain predictive signal according to the LP signal if the obtained long-term flag value is not a first value, wherein the LTP contribution signal is obtained according to the LP residual signal of the decoded sample point;
• a converting module, configured to convert the second-domain predictive signal into a first-domain predictive signal, and convert the first-domain signal of the current sample point into the second-domain signal;
• a current sample point decoding module, configured to decode the first-domain signal of the current sample point according to the first-domain predictive residual signal and the first-domain predictive signal;
• and
• an LP residual module, configured to obtain an LP residual signal according to the second-domain signal and the LP signal,
• wherein at least one of the bit stream decoding module, the first sample point decoding module, the sample point decoding module, the converting module, the current sample point decoding module or the LP residual module, is a hardware module.

A signal codec system, comprising:

• a signal coding apparatus, configured to convert a first-domain signal into a second-domain signal, perform a Linear Prediction (LP) processing and a Long-Term Prediction (LTP) processing for the second-domain signal to obtain a LP processing result and a LTP processing result, wherein the LTP processing result comprises a LTP residual signal, a best pitch of the LP residual signal or both the best pitch of the LP residual signal and a pitch gain of the LP residual signal, obtain a long-term flag value;
• obtain a second-domain predictive signal based on the LP processing result and the LTP processing result if the long-term flag value is a first value, or obtain a second-domain predictive signal based on the LP processing result if the long-term flag value is a second value;
• convert the second-domain predictive signal into a first-domain predictive signal, and calculate a first-domain predictive residual signal according to the first-domain predictive signal;
• and output a bit stream that comprises the first-domain predictive residual signal;
• a signal decoding apparatus, configured to decode the received bit stream to obtain the first-domain predictive residual signal and the long-term flag value, wherein the first-domain predictive residual signal is formatted into frames, each frame comprises one or more sample points;
• decode a first sample point of the signals of a current frame, and perform the following decoding steps consecutively for every current sample point from a second sample point of the signals of the current frame of the first-domain predictive residual from the second sample point of the current frame of the first-domain predictive residual signal:
• calculating an LP signal of a current sample point according to the second-domain signal of the decoded sample point, wherein the bit stream comprises both a best pitch and a pitch gain, or both the bit stream comprises the best pitch and a pitch gain;
• obtaining the second-domain predictive signal according to the LP signal and an LTP contribution signal if the obtained long-term flag value is the first value, or obtaining the second-domain predictive signal according to the LP signal if the obtained long-term flag value is not the first value, wherein the LTP contribution signal is obtained according to the LP residual signal of the decoded sample point, converting the second-domain predictive signal into the first-domain predictive signal;
• decoding the first-domain signal of the current sample point according to the first-domain predictive residual signal and the first-domain predictive signal, converting the first-domain signal of the current sample point into the second-domain signal, and obtaining the LP residual signal according to the second-domain signal and the LP signal.