Audio encoding apparatus and audio decoding apparatus for encoding in multiple stages a multi-pulse signal

An audio encoding apparatus for encoding in multiple stages an excitation signal of an audio signal by selecting pulse positions of a multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said excitation signal being expressed by said multi-pulse signal consisting of a plurality of pulses, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said apparatus comprising:

• main means for searching for a multi-pulse, wherein said main means encodes positions of pulses of said multi-pulse signal in a first stage by using said input audio signal on the basis of predetermined first pulse-position-candidate information;
• and
• at least one auxiliary means for searching for a multi-pulse;
• wherein said auxiliary means for searching for a multi-pulse comprises:
• an auxiliary multi-pulse setting circuit which sets second pulse-position-candidate information which will be used in a self-stage, on the basis of said multi-pulse signal which has been set in a preceding stage or stages;
• and
• an auxiliary multi-pulse searching circuit which encodes pulse positions of said multi-pulse signal in said self-stage by using said input audio signal on the basis of said second pulse-position-candidate information.

An audio decoding apparatus for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;

• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said apparatus comprising:
• main means for creating a reproduced signal, wherein said main means creates a reproduced signal of a first stage from an excitation signal of said first stage and said linear predictor coefficients, said excitation signal of said first stage being reproduced from predetermined first pulse-position-candidate information;
• and
• at least one auxiliary means for creating a reproduced signal;
• wherein said auxiliary means for creating a reproduced signal comprises:
• an auxiliary multi-pulse setting circuit which sets second pulse-position-candidate information which will be used in a self-stage, on the basis of an excitation signal which has been decoded in a preceding stage or stages;
• and
• an auxiliary multi-pulse decoding circuit which decodes an excitation signal of said self-stage on the basis of said second pulse-position-candidate information;
• and
• wherein said auxiliary means for creating a reproduced signal creates an auxiliary reproduced signal by using said excitation signal of said self-stage and said linear predictor coefficients.

An audio encoding/decoding apparatus comprising:

• an audio encoding apparatus for encoding in multiple stages an excitation signal of an audio signal by selecting pulse positions of a multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said excitation signal being expressed by said multi-pulse signal consisting of a plurality of pulses, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said apparatus comprising:
• main means for searching for a multi-pulse, wherein said main means encodes positions of pulses of said multi-pulse signal in a first stage by using said input audio signal on the basis of predetermined first pulse-position-candidate information;
• and
• at least one auxiliary means for searching for a multi-pulse;
• wherein said auxiliary means for searching for a multi-pulse comprises:
• an auxiliary multi-pulse setting circuit which sets second pulse-position-candidate information which will be used in a self-stage, on the basis of said multi-pulse signal which has been set in a preceding stage or stages;
• and
• an auxiliary multi-pulse encoding circuit which encodes pulse positions of said multi-pulse signal in said self-stage by using said input audio signal on the basis of said second pulse-position-candidate information;
• and
• an audio decoding apparatus for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;
• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said apparatus comprising:
• main means for creating a reproduced signal, wherein said main means creates a reproduced signal of a first stage from an excitation signal of said first stage and said linear predictor coefficients, said excitation signal of said first stage being reproduced from predetermined first pulse-position-candidate information;
• and
• at least one auxiliary means for creating a reproduced signal;
• wherein said auxiliary means for creating a reproduced signal comprises:
• an auxiliary multi-pulse setting circuit which sets second pulse-position-candidate information which will be used in a self-stage, on the basis of an excitation signal which has been decoded in a preceding stage or stages;
• and
• an auxiliary multi-pulse decoding circuit which decodes an excitation signal of said self-stage on the basis of said second pulse-position-candidate information;
• and
• wherein said auxiliary means for creating a reproduced signal creates an auxiliary reproduced signal by using said excitation signal of said self-stage and said linear predictor coefficients.

An audio encoding method for encoding in multiple stages an excitation signal of an audio signal by selecting pulse positions of a multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said excitation signal being expressed by said multi-pulse signal consisting of a plurality of pulses, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said method comprising:

• a main step of searching for a multi-pulse, wherein said main step encodes positions of pulses of said multi-pulse signal in a first stage by using said input audio signal on the basis of predetermined first pulse-position-candidate information;
• and
• at least one auxiliary step of searching for a multi-pulse, wherein said auxiliary step comprises:
• an auxiliary multi-pulse setting step which sets second pulse-position-candidate information which will be used in a self-stage, on the basis of said multi-pulse signal which has been set in a preceding stage or stages;
• and
• an auxiliary multi-pulse searching step which encodes pulse positions of said multi-pulse signal in said self-stage by using said input audio signal on the basis of said second pulse-position-candidate information.

An audio decoding method for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;

• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said method comprising:
• a main step of creating a reproduced signal, wherein said main step creates a reproduced signal of a first stage from an excitation signal of said first stage and said linear predictor coefficients, said excitation signal of said first stage being reproduced from predetermined first pulse-position-candidate information;
• and
• at least one auxiliary step of creating a reproduced signal, wherein said auxiliary step comprises:
• an auxiliary multi-pulse setting step which sets second pulse-position-candidate information which will be used in a self-stage, on the basis of an excitation signal which has been decoded in a preceding stage or stages;
• and
• an auxiliary multi-pulse decoding step which decodes an excitation signal of said self-stage on the basis of said second pulse-position-candidate information;
• and
• wherein said auxiliary step of creating a reproduced signal creates an auxiliary reproduced signal by using said excitation signal of said self-stage and said linear predictor coefficients.

An audio encoding/decoding method comprising the steps of:

• an audio encoding method for encoding in multiple stages an excitation signal of an audio signal by selecting pulse positions of a multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said excitation signal being expressed by said multi-pulse signal consisting of a plurality of pulses, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said method comprising:
• a main step of searching for a multi-pulse, wherein said main step encodes positions of pulses of said multi-pulse signal in a first stage by using said input audio signal on the basis of predetermined first pulse-position-candidate information;
• and
• at least one auxiliary step of searching for a multi-pulse, wherein said auxiliary step comprises:
• an auxiliary multi-pulse setting step which sets second pulse-position-candidate information which will be used in a self-stage, on the basis of said multi-pulse signal which has been set in a preceding stage or stages;
• and
• an auxiliary multi-pulse encoding step which encodes pulse positions of said multi-pulse signal in said self-stage by using said input audio signal on the basis of said second pulse-position-candidate information;
• and
• an audio decoding method for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;
• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said method comprising:
• a main step of creating a reproduced signal, wherein said main step creates a reproduced signal of a first stage from an excitation signal of said first stage and said linear predictor coefficients, said excitation signal of said first stage being reproduced from predetermined first pulse-position-candidate information;
• and
• at least one auxiliary step of creating a reproduced signal, wherein said auxiliary step comprises:
• an auxiliary multi-pulse setting step which sets second pulse-position-candidate information which will be used in a self-stage, on the basis of an excitation signal which has been decoded in a preceding stage or stages;
• and
• an auxiliary multi-pulse decoding step which decodes an excitation signal of said self-stage on the basis of said second pulse-position-candidate information;
• and
• wherein said auxiliary step of creating a reproduced signal creates an auxiliary reproduced signal by using said excitation signal of said self-stage and said linear predictor coefficients.

An audio encoding/decoding apparatus comprising:

• an audio encoding apparatus for encoding in multiple stages an excitation signal of an audio signal by selecting pulse positions of a multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said excitation signal being expressed by said multi-pulse signal consisting of a plurality of pulses, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said apparatus comprising:
• at least one auxiliary means for searching for a multi-pulse, wherein said auxiliary means encodes pulse positions of a multi-pulse signal of a self-stage from said input audio signal on the basis of pulse-position-candidate information which gives priority to pulse positions where no pulse has been located rather than pulse positions which already have been encoded in a preceding stage or stages;
• and
• an audio decoding apparatus for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;
• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said apparatus comprising:
• at least one auxiliary means for creating a reproduced signal, wherein said auxiliary means decodes an excitation signal of a self-stage on the basis of pulse-position-candidate information which gives priority to pulse positions where no pulse has been located rather than pulse positions which already have been set by decoding in a preceding stage or stages, and creates an auxiliary reproduced signal by using said excitation signal of said self-stage and said linear predictor coefficients.

An audio decoding method for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;

• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said method comprising:
• a first step of decoding an excitation signal of a self-stage on the basis of pulse-position-candidate information which gives priority to pulse locations where no pulse has been located rather than pulse positions which have been set in decoding in a preceding stage or stages;
• and
• a second step of creating an auxiliary reproduced signal by using said excitation signal of said self-stage reproduced at said first step and said linear predictor coefficients.

An audio encoding/decoding method comprising an audio encoding method for encoding in multiple stages an excitation signal of an audio signal by selecting pulse positions of a multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said excitation signal being expressed by said multi-pulse signal consisting of a plurality of pulses, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said method comprising:

• a first step of setting pulse-position-candidate information which gives priority to pulse positions where no pulse has been located rather than pulse positions which already have been encoded in a preceding stage or stages;
• and
• a second step of encoding pulse positions of said multi-pulse signal in a self-stage by using said input audio signal on the basis of said pulse-position-candidate information set at said first step;
• and
• an audio decoding method for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;
• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said method comprising:
• a first step of decoding an excitation signal of a self-stage on the basis of pulse-position-candidate information which gives priority to pulse locations where no pulse has been located rather than pulse positions which have been set in decoding in a preceding stage or stages;
• and
• a second step of creating an auxiliary reproduced signal by using said excitation signal of said self-stage reproduced at said first step and said linear predictor coefficients.

A recordable medium on which a computer program is recorded, said computer program comprising instructions for executing an audio decoding method for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;

• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said method comprising:
• a first step of decoding an excitation signal of a self-stage on the basis of pulse-position-candidate information which gives priority to pulse locations where no pulse has been located rather than pulse positions which have been set in decoding in a preceding stage or stages;
• and
• a second step of creating an auxiliary reproduced signal by using said excitation signal of said self-stage reproduced at said first step and said linear predictor coefficients.

A recordable medium on which a computer program is recorded, said computer program comprising instructions for executing an audio encoding method for encoding in multiple stages an excitation signal of an audio signal, said excitation signal being expressed by a multi-pulse signal consisting of a plurality of pulses, by selecting pulse positions of said multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said method comprising:

• a first step of setting pulse-position-candidate information which gives priority to pulse positions where no pulse has been located rather than pulse positions which already have been encoded in a preceding stage or stages;
• and
• a second step of encoding pulse positions of said multi-pulse signal in a self-stage by using said input audio signal on the basis of said pulse-position-candidate information set at said first step;
• and
• said computer program comprising instructions for executing an audio decoding method for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;
• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said method comprising:
• a first step of decoding an excitation signal of a self-stage on the basis of pulse-position-candidate information which gives priority to pulse locations where no pulse has been located rather than pulse positions which have been set in decoding in a preceding stage or stages;
• and
• a second step of creating an auxiliary reproduced signal by using said excitation signal of said self-stage reproduced at said first step and said linear predictor coefficients.

A recordable medium on which a computer program is recorded, said computer program comprising instructions for executing an audio encoding method for encoding in multiple stages an excitation signal of an audio signal, said excitation signal being expressed by a multi-pulse signal consisting of a plurality of pulse, by selecting pulse positions of said multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said method comprising:

• a main step of searching for a multi-pulse, wherein said main step encodes positions of pulses of said multi-pulse signal in a first stage by using said input audio signal on the basis of first pulse-position-candidate information which already has been determined;
• and
• at least one auxiliary step of searching for a multi-pulse, wherein said auxiliary step comprises:
• an auxiliary multi-pulse setting step which sets second pulse-position-candidate information, which will be used in a self-stage, on the basis of said multi-pulse signal which has been set in a preceding stage or stages;
• and
• an auxiliary multi-pulse encoding step which encodes pulse positions of said multi-pulse signal in said self-stage by using said input audio signal on the basis of said second pulse-position-candidate information.

A recordable medium on which a computer program is recorded, said computer program comprising instructions for executing an audio decoding method for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;

• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said method comprising:
• a main step of creating a reproduced signal, wherein said main step creates a reproduced signal of a first stage from an excitation signal of said first stage and said linear predictor coefficients, said excitation signal of said first stage being reproduced from predetermined first pulse-position-candidate information;
• and
• at least one auxiliary step of creating a reproduced signal, wherein said auxiliary step comprises:
• an auxiliary multi-pulse setting step which sets second pulse-position-candidate information, which will be used in a self-stage, on the basis of an excitation signal which has been decoded in a preceding stage or stages;
• and
• an auxiliary multi-pulse decoding step which decodes an excitation signal of said self-stage on the basis of said second pulse-position-candidate information;
• and
• wherein said auxiliary step of creating a reproduced signal creates an auxiliary reproduced signal by using said excitation signal of said self-stage and said linear predictor coefficients.

A recordable medium on which a computer program is recorded, said computer program comprising instructions for executing an audio encoding method for encoding in multiple stages an excitation signal of an audio signal, said excitation signal being expressed by a multi-pulse signal consisting of a plurality of pulse, by selecting pulse positions of said multi-pulse signal which minimize distortion between an input audio signal and a reproduced audio signal, said reproduced audio signal being obtained by exciting a linear predictive synthesis filter by said excitation signal, said method comprising:

• a main step of searching for a multi-pulse, wherein said main step encodes positions of pulses of said multi-pulse signal in a first stage by using said input audio signal on the basis of first pulse-position-candidate information which already has been determined;
• and
• at least one auxiliary step of searching for a multi-pulse, wherein said auxiliary step comprises:
• an auxiliary multi-pulse setting step which sets second pulse-position-candidate information, which will be used in a self-stage, on the basis of said multi-pulse signal which has been set in a preceding stage or stages;
• and
• an auxiliary multi-pulse encoding step which encodes pulse positions of said multi-pulse signal in said self-stage by using said input audio signal on the basis of said second pulse-position-candidate information;
• and
• said computer program comprising instructions for executing an audio decoding method for decoding, from encoded data, an excitation signal which has been encoded into an expression by a multi-pulse signal consisting of a plurality of pulses in multiple stages;
• decoding linear predictor coefficients from said encoded data;
• exciting a linear predictive synthesis filter having said linear predictor coefficients by said excitation signal, and thereby reproducing a reproduction of an audio signal, said method comprising:
• a main step of creating a reproduced signal, wherein said main step creates a reproduced signal of a first stage from an excitation signal of said first stage and said linear predictor coefficients, said excitation signal of said first stage being reproduced from predetermined first pulse-position-candidate information;
• and
• at least one auxiliary step of creating a reproduced signal, wherein said auxiliary step comprises:
• an auxiliary multi-pulse setting step which sets second pulse-position-candidate information, which will be used in a self-stage, on the basis of an excitation signal which has been decoded in a preceding stage or stages;
• and
• an auxiliary multi-pulse decoding step which decodes an excitation signal of said self-stage on the basis of said second pulse-position-candidate information;
• and
• wherein said auxiliary step of creating a reproduced signal creates an auxiliary reproduced signal by using said excitation signal of said self-stage and said linear predictor coefficients.