Audio-encoding method and apparatus, audio-decoding method and apparatus, recoding medium thereof, and multimedia device employing same

• US 9,858,934 B2
• Filed: 03/06/2017
• Issued: 01/02/2018
• Est. Priority Date: 06/01/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Porov, Anton, Osipov, Konstantin, Choo, Ki-hyun
• Primary Examiner(s): Baker, Charlotte M
• Application Number:
  US15/450,672
• Publication Number:
  US 20170178637A1
• Time in Patent Office: 302 Days
• Field of Search: 704235, 704500, 704200, 7042001, 704201, 704219, 704221, 704222, 704223, 704501, 704502, 704 5
• CPC Class Codes: G10L 19/0017 Lossless audio signal coding; Perfect reconstruction of coded audio signal by transmission of coding error G10L19/24 takes precedence
• CPC Class Codes: G10L 19/002 Dynamic bit allocation for perceptual audio coders G10L19/032
• 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 19/032 Quantisation or dequantisation of spectral components
• 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

Abstract

Provided is an audio encoding method. The audio encoding method includes: acquiring envelopes based on a predetermined sub-band for an audio spectrum; quantizing the envelopes based on the predetermined sub-band; and obtaining a difference value between quantized envelopes for adjacent sub-bands and lossless encoding a difference value of a current sub-band by using a difference value of a previous sub-band as a context. Accordingly, the number of bits required to encode envelope information of an audio spectrum may be reduced in a limited bit range, thereby increasing the number of bits required to encode an actual spectral component.

Claims

1. An audio decoding method comprising:

receiving a bitstream including a coded quantization differential index of an envelope of a sub-band in an audio spectrum; and

lossless decoding a coded quantization differential index of a current sub-band, by referring one of a plurality of tables based on a context which is obtained from a decoded quantization differential index of a previous sub-band,

wherein the one of the plurality of tables is selected by one among a plurality of groups which are determined by the context.

2. The audio decoding method of claim 1, wherein the envelope is one of average energy, average amplitude, power, and a norm value of a corresponding sub-band.

3. A non-transitory computer-readable recording medium storing a computer-readable program for executing the audio decoding method of claim 1.

4. The audio decoding method of claim 1, wherein the lossless decoding is performed by referring the plurality of tables including a first table for a second group and a second table for sharing to first and third groups, where the first to third groups are obtained by grouping a decoded quantization differential index corresponding to the context.

5. The audio decoding method of claim 4, wherein the context obtained from the decoded quantization differential index of the previous sub-band is used as it is or after reversing, when the second table is shared.

6. The audio decoding method of claim 1, wherein the lossless decoding comprises decoding a coded quantization index of a first sub-band in which the previous sub-band does not exist as it is and decoding a coded quantization differential index of a second sub-band next to the first sub-band based on the decoded quantization index of the first sub-band and a predetermined reference value.

7. An audio decoding apparatus comprising:

at least one processor configured to;

receive a bitstream including a coded quantization differential index of an envelope of a sub-band in an audio spectrum; and

lossless decode a coded quantization differential index of a current sub-band, by referring one of a plurality of tables based on a context which is obtained from a decoded quantization differential index of a previous sub-band,

wherein the one of the plurality of tables is selected by one among a plurality of groups which are determined by the context.

8. The audio decoding apparatus of claim 7, wherein the at least one processor is configured to decode a coded quantization index of a first sub-band in which the previous sub-band does not exist as it is and decode a coded quantization differential index of a second sub-band next to the first sub-band based on a the decoded quantization index of the first sub-band and a predetermined reference value.

9. The audio decoding apparatus of claim 7, wherein the envelope is one of average energy, average amplitude, power, and a norm value of a corresponding sub-band.

10. The audio decoding apparatus of claim 7, wherein the at least one processor is configured to perform the lossless decoding by referring the plurality of tables including a first table for a second group and a second table for sharing to first and third groups, where the first to third groups are obtained by grouping a decoded quantization differential index corresponding to the context.

11. The audio decoding apparatus of claim 10, wherein the context obtained from the decoded quantization differential index of the previous sub-band is used as it is or after reversing, when the second table is shared.