SIGNAL PROCESSING APPARATUS AND SIGNAL PROCESSING METHOD, ENCODER AND ENCODING METHOD, DECODER AND DECODING METHOD, AND PROGRAM

• US 20130028427A1
• Filed: 04/11/2011
• Published: 01/31/2013
• Est. Priority Date: 04/13/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamamoto, Yuki, Chinen, Toru, Honma, Hiroyuki, Mitsufuji, Yuhki
• Granted Patent: US 9,406,312 B2
• Time in Patent Office: Days
• US Class Current: 381/22
• CPC Class Codes: G10L 19/0204 using subband decomposition
• CPC Class Codes: G10L 19/0208 Subband vocoders
• CPC Class Codes: G10L 19/167 Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes
• CPC Class Codes: G10L 21/038 using band spreading techniques
• CPC Class Codes: G10L 21/0388 Details of processing therefor

Abstract

The present invention relates to a signal processing apparatus and a signal processing method, an encoder and an encoding method, a decoder and a decoding method, and a program capable of reproducing music signal having a better sound quality by expansion of frequency band.

An encoder sets an interval including 16 frames as interval section to be processed, outputs high band encoded data for obtaining the high band component of an input signal and low band encoded data obtained by encoding the low band signal of the input signal for each section to be processed. In this case, for each frame, a coefficient used in estimation of the high band component is selected and the section to be processed is divided into continuous frame segments including continuous frames from which the coefficient with the same section to be processed is selected. In addition, high band encoded data is produced which includes data including information indicating a length of each continuous frame segment, information indicating the number of continuous frame segments included in the section to be processed and a coefficient index indicating the coefficient selected in each continuous frame segment. The present invention is applicable to the encoder.

Claims

1. A signal processing apparatus comprising:

a demultiplexing unit that demultiplexes input encoded data into data including information on a segment including frames in which the same coefficient as a coefficient used in producing a high band signal is selected in a section to be processed including a plurality of frames, and coefficient information for obtaining the coefficient selected in the frames of the segment, and low band encoded data;

a low band decoding unit that decodes the low band encoded data to produce a low band signal;

a selection unit that selects a coefficient of a frame to be processed from a plurality of the coefficients based on the data;

a high band sub-band power calculation unit that calculates a high band sub-band power of a high band sub-band signal of each sub-band constituting the high band signal of the frame to be processed based on a low band sub-band signal of each sub-band constituting the low band signal of the frame to be processed and the selected coefficient; and

a high band signal production unit that produces the high band signal of the frame to be processed based on the high band sub-band power and the low band sub-band signal.

2. The signal processing apparatus according to claim 1,

wherein the section to be processed is divided into the segments so that positions of the frames adjacent to each other in which different coefficients are selected are set as boundary positions of the segments, and information indicating a length of each of the segments is set as information on the segments.

3. The signal processing apparatus according to claim 1,

wherein the section to be processed is divided into the several segments having the same length so that a length of the segment is the longest and information indicating the length and information indicating whether the selected coefficient is varied before and after each boundary position of the segments are set as information on the segments.

4. The signal processing apparatus according to claim 3,

wherein when the same coefficient is selected in continuous several segments, the data includes one piece of coefficient information for obtaining the coefficient selected in the several continuous segments.

5. The signal processing apparatus according to claim 1,

wherein the data is produced for each section to be processed by a system having a less data amount between a first system and a second system,

wherein, in the first system, the section to be processed is divided into the segments so that the positions of frames adjacent to each other in which the different coefficients are selected, are set as a boundary position of the segments and information indicating a length of each of the segments is set as information on the segments,

wherein, in the second system, the section to be processed is divided into the several segments having the same length so that a length of the segment is the longest and information indicating the length and information indicating whether the selected coefficient is varied before and after a boundary position of the segments are set as information on the segment, and

wherein the data further includes information indicating whether the data is obtained by the first system or second system.

6. The signal processing apparatus according to claim 1,

wherein the data further includes reuse information indicating whether the coefficient of an initial frame in the section to be processed is the same as the coefficient of a frame just before the initial frame, and

when the data includes the reuse information indicating that the coefficients are the same, the data does not include coefficient information of the initial segment of the section to be processed.

7. The signal processing apparatus according to claim 6,

wherein when a mode in which the coefficient information is reused, is designated, the data includes the reuse information, and when a mode in which the reuse of the coefficient information is prohibited, is designated, the data does not include the reuse information.

8. A signal processing method for a signal processing apparatus including:

a demultiplexing unit that demultiplexes input encoded data into data including information on a segment including frames in which the same coefficient as a coefficient used in producing a high band signal is selected in a section to be processed including a plurality of frames, and coefficient information for obtaining the coefficient selected in the frames of the segment, and low band encoded data;

a low band decoding unit that decodes the low band encoded data to produce a low band signal;

a selection unit that selects a coefficient of a frame to be processed from a plurality of the coefficients based on the data;

a high band sub-band power calculation unit that calculates a high band sub-band power of a high band sub-band signal of each sub-band constituting the high band signal of the frame to be processed based on a low band sub-band signal of each sub-band constituting the low band signal of the frame to be processed and the selected coefficient; and

a high band signal production unit that produces the high band signal of the frame to be processed based on the high band sub-band power and the low band sub-band signal,

the signal processing method comprising the steps of;

demultiplexing the encoded data into the data and the low band encoded data by the demultiplexing unit;

decoding the low band encoded data by the low band decoding unit;

selecting the coefficient of the frames to be processed by the selection unit;

calculating the high band sub-band power by the high band sub-band power calculation unit; and

producing the high band signal by the high band signal production unit.

9. A program causing a computer to execute processes comprising the steps of:

demultiplexing input encoded data into data including information on a segment including frames in which the same coefficient as a coefficient used in producing a high band signal is selected in a section to be processed including a plurality of frames, and coefficient information for obtaining the coefficient selected in the frames of the segment, and low band encoded data;

decoding the low band encoded data to produce a low band signal;

selecting a coefficient of a frame to be processed from a plurality of the coefficients based on the data;

calculating a high band sub-band power of a high band sub-band signal of each sub-band constituting the high band signal of the frame to be processed based on a low band sub-band signal of each sub-band constituting the low band signal of the frame to be processed and the selected coefficient; and

producing the high band signal of the frame to be processed based on the high band sub-band power and the low band sub-band signal.

10. A signal processing apparatus comprising:

a sub-band division unit that produces a low band sub-band signal of a plurality of sub-bands in a low band side of an input signal, and a high band sub-band signal of a plurality of sub-bands in a high band side of the input signal;

a pseudo high band sub-band power calculation unit that calculates a pseudo high band sub-band power which is an estimation value of power of the high band sub-band signal based on the low band sub-band signal and a predetermined coefficient;

a selection unit that selects any of a plurality of the coefficients for respective frames of the input signal by comparing the high band sub-band power of the high band sub-band signal and the pseudo high band sub-band power; and

a production unit that produces data including information on a segment having frames in which the same coefficient is selected in a section to be processed having a plurality of frames of the input signal, and coefficient information for obtaining the coefficient selected in frames of the segment.

11. The signal processing apparatus according to claim 10,

wherein the production unit divides the section to be processed into the segments so that the positions of frames adjacent to each other in which different coefficients are selected, are set as boundary positions of the segments, and sets information indicating a length of each of the segments as information on the segment.

12. The signal processing apparatus according to claim 10,

wherein the production unit divides the section to be processed into the several segments having the same length so that a length of the segment is the longest and information indicating the length and information indicating whether the selected coefficient is varied before and after boundary positions of the segments are set as information on the segments.

13. The signal processing apparatus according to claim 12,

wherein the production unit produces the data including one piece of coefficient information for obtaining the coefficient selected in the several continuous segments when the same coefficient is selected in the several continuous segments.

14. The signal processing apparatus according to claim 10,

wherein the production unit produces data for each section to be processed with a system having a less data amount between a first system and a second system,

wherein, in the first system, the section to be processed is divided into the segments so that the positions of frames adjacent to each other in which the different coefficients are selected, are set as boundary positions of the segments, and information indicating a length of each of the segments is set as information on the segments, and

wherein, in the second system, the section to be processed is divided into the several segments having the same length so that a length of the segment is the longest and information indicating the length and information indicating whether the selected coefficient is varied before and after a boundary position of the segments are set as information on the segments.

15. The signal processing apparatus according to claim 14,

wherein the data further includes information indicating whether the data is obtained by the first system or the second system.

16. The signal processing apparatus according to claim 10,

wherein the production unit produces the data including reuse information indicating whether the coefficient of an initial frame of the section to be processed is the same as the coefficient of a frame just before the initial frame, and

when the reuse information indicating that the coefficients are the same is included in the data, the data in which the coefficient information of an initial segment of the section to be processed is not included, is produced.

17. The signal processing apparatus according to claim 16,

wherein when a mode in which the coefficient information is reused, is designated, the production unit produces the data including the reuse information, and when a mode in which the reuse of the coefficient information is prohibited, is designated, the production unit produces the data in which the reuse information is not included.

18. A signal processing method for a signal processing apparatus including:

a sub-band division unit that produces a low band sub-band signal of a plurality of sub-bands in a low band side of an input signal, and a high band sub-band signal of a plurality of sub-bands in a high band side of the input signal;

a pseudo high band sub-band power calculation unit that calculates a pseudo high band sub-band power which is an estimation value of power of the high band sub-band signal based on the low band sub-band signal and a predetermined coefficient;

a selection unit that selects any of a plurality of the coefficients for respective frames of the input signal by comparing the high band sub-band power of the high band sub-band signal and the pseudo high band sub-band power; and

a production unit that produces data including information on a segment having frames in which the same coefficient is selected in a section to be processed having a plurality of frames of the input signal, and coefficient information for obtaining the coefficient selected in frames of the segment,

the signal processing method comprising the steps of;

producing the low band sub-band signal and the high band sub-band signal by the sub-band division unit;

calculating the pseudo high band sub-band power by the pseudo high band sub-band power calculation unit;

selecting any of a plurality of the coefficients by the selection unit; and

producing the data by the production unit.

19. A program causing a computer to execute processes comprising the steps of:

producing a low band sub-band signal of a plurality of sub-bands in a low band side of an input signal, and a high band sub-band signal of a plurality of sub-bands in a high band side of the input signal;

calculating a pseudo high band sub-band power which is an estimation value of power of the high band sub-band signal based on the low band sub-band signal and a predetermined coefficient;

selecting any of a plurality of the coefficients for respective frames of the input signal by comparing the high band sub-band power of the high band sub-band signal and the pseudo high band sub-band power; and

producing data including information on a segment having frames in which the same coefficient is selected in a section to be processed having a plurality of frames of the input signal, and coefficient information for obtaining the coefficient selected in frames of the segment.

20. A decoder comprising:

a demultiplexing unit that demultiplexes input encoded data into data including information on a segment including frames in which the same coefficient as a coefficient used in producing a high band signal is selected in a section to be processed including a plurality of frames, and coefficient information for obtaining the coefficient selected in the frames of the segment, and low band encoded data;

a low band decoding unit that decodes the low band encoded data to produce a low band signal;

a selection unit that selects a coefficient of a frame to be processed from a plurality of the coefficients based on the data;

a high band sub-band power calculation unit that calculates a high band sub-band power of a high band sub-band signal of each sub-band constituting the high band signal of the frame to be processed based on a low band sub-band signal of each sub-band constituting the low band signal of the frame to be processed and the selected coefficient;

a high band signal production unit that produces the high band signal of the frame to be processed based on the high band sub-band power and the low band sub-band signal; and

a synthesis unit that synthesizes the low band signal and the high band signal to produce an output signal.

21. A decoding method for a decoder including:

a demultiplexing unit that demultiplexes input encoded data into data including information on a segment including frames in which the same coefficient as a coefficient used in producing a high band signal is selected in a section to be processed including a plurality of frames, and coefficient information for obtaining the coefficient selected at the frames of the segment, and low band encoded data;

a low band decoding unit that decodes the low band encoded data to produce a low band signal;

a selection unit that selects a coefficient of a frame to be processed from a plurality of the coefficients based on the data;

a high band sub-band power calculation unit that calculates a high band sub-band power of a high band sub-band signal of each sub-band constituting the high band signal of the frame to be processed based on a low band sub-band signal of each sub-band constituting the low band signal of the frame to be processed and the selected coefficient;

a high band signal production unit that produces the high band signal of the frame to be processed based on the high band sub-band power and the low band sub-band signal; and

a synthesis unit that synthesizes the low band signal and the high band signal to produce an output signal,

the decoding method comprising the steps of;

demultiplexing the encoded data into the data and the low band encoded data by the demultiplexing unit;

decoding the low band encoded data by the low band decoding unit;

selecting the coefficient of the frame to be processed by the selection unit;

calculating the high band sub-band power by the high band sub-band power calculation unit;

producing the high band signal by the high band signal production unit; and

producing the output signal by the synthesis unit.

22. An encoder comprising:

a sub-band division unit that produces a low band sub-band signal of a plurality of sub-bands in a low band side of an input signal, and a high band sub-band signal of a plurality of sub-bands in a high band side of the input signal;

a pseudo high band sub-band power calculation unit that calculates a pseudo high band sub-band power which is an estimation value of power of the high band sub-band signal based on the low band sub-band signal and a predetermined coefficient;

a selection unit that selects any of a plurality of the coefficients for respective frames of the input signal by comparing the high band sub-band power of the high band sub-band signal and the pseudo high band sub-band power;

a high band encoding unit that produces high band encoded data by encoding information on a segment having frames in which the same coefficient is selected in a section to be processed including a plurality of frames of the input signal, and coefficient information for obtaining the coefficient selected in the frames of the segment;

a low band encoding unit that encodes a low band signal of the input signal and produces low band encoded data; and

a multiplexing unit that produces an output code string by multiplexing the low band encoded data and the high band encoded data.

23. An encoding method for an encoder including:

a sub-band division unit that produces a low band sub-band signal of a plurality of sub-bands in a low band side of an input signal, and a high band sub-band signal of a plurality of sub-bands in a high band side of the input signal;

a pseudo high band sub-band power calculation unit that calculates a pseudo high band sub-band power which is an estimation value of power of the high band sub-band signal based on the low band sub-band signal and a predetermined coefficient;

a selection unit that selects any of a plurality of the coefficients for respective frames of the input signal by comparing the high band sub-band power of the high band sub-band signal and the pseudo high band sub-band power;

a high band encoding unit that produces high band encoded data by encoding information on a segment having frames in which the same coefficient is selected in a section to be processed including a plurality of frames of the input signal, and coefficient information for obtaining the coefficient selected in the frames of the segment;

a low band encoding unit that encodes a low band signal of the input signal and produces low band encoded data; and

a multiplexing unit that produces an output code string by multiplexing the low band encoded data and the high band encoded data,

the encoding method comprising the steps of;

producing the low band sub-band signal and the high band sub-band signal by the sub-band division unit;

calculating the pseudo high band sub-band power by the pseudo high band sub-band power calculation unit;

selecting any of a plurality of the coefficients by the selection unit;

producing the high band encoded data by the high band encoding unit;

producing the low band encoded data by the low band encoding unit; and

producing the output code string by the multiplexing unit.