Signal processing device, method, and program

Abstract

The present technology relates to a signal processing device, method, and program that may obtain audio at a higher audio quality when decoding an audio signal. An envelope information generating unit 24 generates envelope information representing an envelope form of high frequency components of an audio signal to be encoded. A sine wave information generating unit 26 extracts a sine wave signal from the high frequency components of the audio signal, and generates a sine wave information representing an emergence start position of the sine wave signal. An encoding stream generating unit 27 multiplexes the envelope information, the sine wave information, and low frequency components of the audio signal that have been encoded, and outputs an encoding stream obtained as the result. As a result, the high frequency components included in the sine wave signal may be predicted at a higher accuracy from the envelope information and the sine wave information at the receiving side of the encoding stream. The present invention may be applied to a signal processing device.

1 . A signal processing device comprising:
 an extracting unit configured to extract an envelope information representing low frequency components of an audio signal and an envelope of high frequency components of the audio signal and a sine wave information used for identifying the frequency and emergence position of sine wave components included in the high frequency components;   a pseudo high frequency generating unit configured to generate a pseudo high frequency signal configuring the high frequency components on the basis of the low frequency signal as the low frequency component and the envelope information;   a sine wave generating unit configured to generate a sine wave signal at a frequency represented by the sine wave information and which designates the emergence position identified from the sine wave information as the start position; and   a combining unit configured to combine the low frequency signal, the pseudo high frequency signal, and the sine wave signal to generate the audio signal.   
     
     
         2 . The signal processing device according to  claim 1 , wherein the sine wave information includes information representing the distance from the start position of a frame of the high frequency component until the emergence start position of the sine wave component as information used for identifying the emergence position. 
     
     
         3 . The signal processing device according to  claim 1 , further comprising:
 a noise generating unit configured to generate a noise signal configuring the high frequency components by adjusting the gain of each zone of a predetermined signal, in which the zones are divided by a noise boundary position represented by a noise envelope information, on the basis of information representing the gain of each zone represented by the noise envelope information;   wherein the extracting unit further extracts the noise envelope information;   and wherein the sine wave information includes information representing the distance from the noise boundary position until the emergence start position of the sine wave components as the information used for identifying the emergence position;   and wherein the combining unit combines the low frequency signal, the pseudo high frequency signal, the sine wave signal, and the noise signal to generate the audio signal.   
     
     
         4 . The signal processing device according to  claim 1 , wherein the sine wave information includes information representing the distance from a peak position of the high frequency component envelope until the emergence start position of the sine wave component as the information used for identifying the emergence position. 
     
     
         5 . The signal processing device according to  claim 1 , wherein the sine wave information is extracted for each frame, and the sine wave generating unit generates the sine wave signal for the high frequency components of each frame. 
     
     
         6 . The signal processing device according to  claim 1 , wherein the sine wave information is extracted for each band configuring the high frequency components, and the sine wave generating unit generates the sine wave signal for each band. 
     
     
         7 . A signal processing method to control a signal processing device, the signal processing device including
 an extracting unit configured to extract an envelope information representing low frequency components of an audio signal and an envelope of high frequency components of the audio signal and a sine wave information used for identifying the frequency and emergence position of sine wave components included in the high frequency components,   a pseudo high frequency generating unit configured to generate a pseudo high frequency signal configuring the high frequency components on the basis of the low frequency signal as the low frequency component and the envelope information,   a sine wave generating unit configured to generate a sine wave signal at a frequency represented by the sine wave information and which designates the emergence position identified from the sine wave information as the start position, and   a combining unit configured to combine the low frequency signal, the pseudo high frequency signal, and the sine wave signal to generate the audio signal,   the method comprising the steps of:   the extracting unit extracting the low frequency components, the envelope information, and the sine wave information;   the pseudo high frequency generating unit generating the pseudo high frequency signal;   the sine wave generating unit generating the sine wave information; and   the combining unit combining the low frequency signal, the pseudo high frequency signal, and the sine wave signal to generate the audio signal.   
     
     
         8 . A program executing processing on a computer, the processing including the steps of
 envelope information representing low frequency components of an audio signal and an envelope of high frequency components of the audio signal and sine wave information used for identifying the frequency and emergence position of sine wave components included in the high frequency components are extracted,   a pseudo high frequency signal configuring the high frequency components is generated on the basis of the low frequency signal as the low frequency component and the envelope information,   a sine wave signal at a frequency represented by the sine wave information and which designates the emergence position identified from the sine wave information as the start position is generated, and   the low frequency signal, the pseudo high frequency signal, and the sine wave information are combined to generate the audio signal.   
     
     
         9 . A signal processing device comprising:
 an envelope information generating unit configured to generate envelope information representing an envelope of a high frequency signal, which is the high frequency component of an audio signal;   a sine wave information generating unit configured to detect a sine wave signal included in the high frequency signal, and generating a sine wave information used for identifying the frequency and emergence position of the sine wave signal; and   an output unit configured to generate and outputting data made up from a low frequency signal, which is a low frequency component of the audio signal, the envelope information, and the sine wave information.   
     
     
         10 . The signal processing device according to  claim 9 , wherein the sine wave information includes information representing the distance from the start position of a frame of the high frequency component until the emergence start position of the sine wave signal as information used for identifying the emergence position. 
     
     
         11 . The signal processing device according to  claim 9 , further comprising:
 a noise envelope information generating unit configured to detect a noise signal included in the high frequency signal, and generating a noise envelope information made up from information representing a noise boundary position which divides the noise signal into a plurality of zones and information representing the gain of the noise signal in the zone;   wherein the sine wave information includes information representing the distance from the noise boundary position until the emergence start position of the sine wave components as the information used for identifying the emergence position;   and wherein the output unit generates and outputs data made up from the low frequency signal, the envelope information, the sine wave information, and the noise envelope information.   
     
     
         12 . The signal processing device according to  claim 9 , wherein the sine wave information includes information representing the distance from a peak position of the high frequency component envelope until the emergence start position of the sine wave component as the information used for identifying the emergence position. 
     
     
         13 . The signal processing device according to  claim 9 , wherein the sine wave information is generated for each frame. 
     
     
         14 . The signal processing device according to  claim 9 , wherein the sine wave information is generated for each band configuring the high frequency components. 
     
     
         15 . A signal processing method to control a signal processing device, the signal processing device including
 an envelope information generating unit configured to generate envelope information representing an envelope of a high frequency signal, which is the high frequency component of an audio signal;   a sine wave information generating unit configured to detect sine wave information included in the high frequency signal, and generating a sine wave information used for identifying the frequency and emergence position of the sine wave signal; and   an output unit configured to generate and output data made up from the low frequency signal, which is the low frequency component of the audio signal, the envelope information, and the sine wave information,   the method comprising the steps of:   the envelope information generating unit generating the envelope information;   the sine wave information generating unit generating the sine wave information; and   the output unit generating and outputting data made up from the low frequency signal, the envelope information, and the sine wave information.   
     
     
         16 . A program executing processing on a computer, the processing including the steps of
 generating envelope information representing an envelope of a high frequency signal, which is a high frequency component of an audio signal,   detecting a sine wave signal included in the high frequency signal, and generating a sine wave information used for identifying the frequency and emergence position of the sine wave signal, and   generating and outputting data made up from a low frequency signal, which is a low frequency component of the audio signal, the envelope information, and the sine wave information.