SIGNAL PROCESSING DEVICE, METHOD, AND PROGRAM

• US 20170148452A1
• Filed: 02/03/2017
• Published: 05/25/2017
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Chinen, Toru, Hatanaka, Mitsuyuki
• Granted Patent: US 10,431,229 B2
• Time in Patent Office: Days
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/0204 using subband decomposition
• CPC Class Codes: G10L 19/0208 Subband vocoders
• CPC Class Codes: G10L 19/028 Noise substitution, i.e. substituting non-tonal spectral components by noisy source comfort noise for discontinuous speech transmission G10L19/012
• CPC Class Codes: G10L 19/093 using sinusoidal excitation models
• CPC Class Codes: G10L 21/038 using band spreading techniques
• CPC Class Codes: H03M 7/40 Conversion to or from variable length codes, e.g. Shannon-Fano code, Huffman code, Morse code

Abstract

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 generates envelope information representing an envelope form of high frequency components of an audio signal to be encoded. A sine wave information generating unit 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 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. 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.

Claims

1. A signal processing device comprising:

an extracting unit that extracts a low frequency component of an audio signal, envelope information representing an envelope of a high frequency component of the audio signal, and sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of a sine wave component included in the high frequency component, and is for specifying a frequency and an appearance position of the sine wave component;

a pseudo high frequency generating unit that generates a pseudo high frequency signal configuring the high frequency component on the basis of a low frequency signal as the low frequency component and the envelope information;

a sine wave generating unit that generates a sine wave signal which is at a frequency represented by the sine wave information and in which the appearance start position specified from the sine wave information is set as a start position; and

a combining unit that combines the low frequency signal, the pseudo high frequency signal, and the sine wave signal to generate an audio signal.

2. The signal processing device according to claim 1, further comprising:

a noise generating unit that generates a noise signal configuring the high frequency component by adjusting a gain of sections of a predetermined signal on the basis of information representing a gain of the section represented by noise envelope information, the sections being divided by a noise boundary position represented by the noise envelope information,

wherein the extracting unit further extracts the noise envelope information, 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 an audio signal.

3. 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 each frame of the high frequency component.

4. The signal processing device according to claim 1,

wherein the sine wave information is extracted for each band configuring the high frequency component, and the sine wave generating unit generates the sine wave signal for each band.

5. A signal processing method of a signal processing device including an extracting unit that extracts a low frequency component of an audio signal, envelope information representing an envelope of a high frequency component of the audio signal, and sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of a sine wave component included in the high frequency component, and is for specifying a frequency and an appearance position of the sine wave component, a pseudo high frequency generating unit that generates a pseudo high frequency signal configuring the high frequency component on the basis of a low frequency signal as the low frequency component and the envelope information, a sine wave generating unit that generates a sine wave signal which is at a frequency represented by the sine wave information and in which the appearance start position specified from the sine wave information is set as a start position, and a combining unit that combines the low frequency signal, the pseudo high frequency signal, and the sine wave signal to generate an audio signal, the method comprising steps of:

causing the extracting unit to extract the low frequency component, the envelope information, and the sine wave information;

causing the pseudo high frequency generating unit to generate the pseudo high frequency signal;

causing the sine wave generating unit to generate the sine wave signal; and

causing the combining unit to combine the low frequency signal, the pseudo high frequency signal, and the sine wave signal to generate an audio signal.

6. A program causing a computer to execute a process including steps of:

extracting a low frequency component of an audio signal, envelope information representing an envelope of a high frequency component of the audio signal, and sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of a sine wave component included in the high frequency component, and is for specifying a frequency and an appearance position of the sine wave component;

generating a pseudo high frequency signal configuring the high frequency component on the basis of a low frequency signal as the low frequency component and the envelope information;

generating a sine wave signal which is at a frequency represented by the sine wave information and in which the appearance start position specified from the sine wave information is set as a start position; and

combining the low frequency signal, the pseudo high frequency signal, and the sine wave signal to generate an audio signal.

7. A signal processing device comprising:

an envelope information generating unit that generates envelope information representing an envelope of a high frequency signal as a high frequency component of an audio signal;

a sine wave information generating unit that detects a sine wave signal included in the high frequency signal, and generates sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of the sine wave signal, and is for specifying a frequency and an appearance position of the sine wave signal; and

an output unit that generates and outputs data configured of a low frequency signal as a low frequency component of the audio signal, the envelope information, and the sine wave information.

8. The signal processing device according to claim 7, further comprising:

a noise envelope information generating unit that detects a noise signal included in the high frequency signal, and generates noise envelope information configured of information representing a noise boundary position which divides the noise signal into several sections, and information representing a gain of the noise signal of the section,

wherein the output unit generates and outputs data configured of the low frequency signal, the envelope information, the sine wave information, and the noise envelope information.

9. The signal processing device according to claim 7,

wherein the sine wave information is generated for each frame.

10. The signal processing device according to claim 7,

wherein the sine wave information is generated for each band configuring the high frequency component.

11. A signal processing method of a signal processing device including an envelope information generating unit that generates envelope information representing an envelope of a high frequency signal as a high frequency component of an audio signal, a sine wave information generating unit that detects a sine wave signal included in the high frequency signal, and generates sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of the sine wave signal, and is for specifying a frequency and an appearance position of the sine wave signal, and an output unit that generates and outputs data configured of a low frequency signal as a low frequency component of the audio signal, the envelope information, and the sine wave information, the method comprising steps of:

causing the envelope information generating unit to generate the envelope information;

causing the sine wave information generating unit to generate the sine wave information;

causing the output unit to generate and output data configured of the low frequency signal, the envelope information, and the sine wave information.

12. A program causing a computer to execute a process including steps of:

generating envelope information representing an envelope of a high frequency signal as a high frequency component of an audio signal;

detecting a sine wave signal included in the high frequency signal, and generating sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of the sine wave signal, and is for specifying a frequency and an appearance position of the sine wave signal; and

generating and outputting data configured of a low frequency signal as a low frequency component of the audio signal, the envelope information, and the sine wave information.

13. A signal processing device comprising:

a low frequency decoding unit that decodes a low frequency signal as a low frequency component of an audio signal;

an envelope information decoding unit that decodes envelope information representing an envelope of a high frequency signal as a high frequency component of the audio signal;

a sine wave information decoding unit that decodes sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of a sine wave included in the high frequency signal, and is for specifying a frequency and an appearance position of the sine wave;

a pseudo high frequency signal generating unit that generates a pseudo high frequency signal from the decoded low frequency signal and the decoded envelope information;

a sine wave signal generating unit that generates a sine wave signal from the decoded sine wave information; and

an audio signal generating unit that generates an output audio signal from the decoded low frequency signal, the pseudo high frequency signal, and the sine wave signal.

14. The signal processing device according to claim 13, further comprising:

a noise envelope information decoding unit that decodes noise envelope information configured of information representing a noise boundary position which divides the noise signal included in the high frequency signal into several sections, and information representing a gain of the noise signal of the section,

wherein the pseudo high frequency signal generating unit generates a pseudo high frequency signal from the decoded low frequency signal, the decoded envelope information, and the decoded noise envelope information.

15. The signal processing device according to claim 13,

wherein the sine wave information is generated for each band configuring the high frequency component.

16. A signal processing method of a signal processing device including a low frequency decoding unit that decodes a low frequency signal as a low frequency component of an audio signal, an envelope information decoding unit that decodes envelope information representing an envelope of a high frequency signal as a high frequency component of the audio signal, a sine wave information decoding unit that decodes sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of a sine wave included in the high frequency signal, and is for specifying a frequency and an appearance position of the sine wave, a pseudo high frequency signal generating unit that generates a pseudo high frequency signal from the decoded low frequency signal and the decoded envelope information, a sine wave signal generating unit that generates a sine wave signal from the decoded sine wave information, and an audio signal generating unit that generates an output audio signal from the decoded low frequency signal, the pseudo high frequency signal, and the sine wave signal, the method comprising steps of:

causing the low frequency decoding unit to decode the low frequency signal;

causing the envelope information decoding unit to decode the envelope information;

causing the sine wave information decoding unit to decode the sine wave information;

causing the pseudo high frequency signal generating unit to generate the pseudo high frequency signal;

causing the sine wave signal generating unit to generate the sine wave signal; and

causing the audio signal generating unit to generate the output audio signal.

17. A program causing a computer to execute a process including steps of:

decoding a low frequency signal as a low frequency component of an audio signal;

decoding envelope information representing an envelope of a high frequency signal as a high frequency component of the audio signal;

decoding sine wave information which includes information representing a distance from a start position of a frame of the high frequency component to an appearance start position of a sine wave included in the high frequency signal, and is for specifying a frequency and an appearance position of the sine wave;

generating a pseudo high frequency signal from the decoded low frequency signal and the decoded envelope information;

generating a sine wave signal from the decoded sine wave information; and

generating an output audio signal from the decoded low frequency signal, the pseudo high frequency signal, and the sine wave signal.