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

• US 9,361,895 B2
• Filed: 06/01/2012
• Issued: 06/07/2016
• 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:
  US14/123,359
• Publication Number:
  US 20140156284A1
• Time in Patent Office: 1,467 Days
• Field of Search: 704/200.1, 704/200, 704/201, 704/205, 704/207, 704/219, 704/220, 704/221, 704/222, 704/223, 704/502, 704/503, 704/504, 704/500, 704/230
• US Class Current: 1/1
• 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 encoding method comprising:

obtaining an envelope of an audio spectrum by transforming an audio signal from a time domain to a frequency domain, where the audio spectrum comprises a plurality of sub-bands;

quantizing, by performed by at least one processor, the envelope to obtain quantization indices including a quantization index of a previous sub-band and a quantization index of a current sub-band;

obtaining a differential quantization index of the current sub-band from the quantization index of a previous sub-band and the quantization index of a current sub-band;

obtaining a context of the current sub-band by using a differential quantization index of the previous sub-band; and

lossless encoding the differential quantization index of the current sub-band based on the context of the current sub-band.

2. The audio encoding method of claim 1, wherein the lossless encoding comprises Huffman coding the quantization index as it is for a first sub-band for which a previous sub-band does not exist and performing Huffman coding on the differential quantization index of a second sub-band next to the first sub-band by using a difference between the quantization index of the first sub-band and a predetermined reference value as the context.

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

4. The audio encoding method of claim 1, wherein the lossless encoding comprises adjusting the differential quantization index to have a specific range.

5. The audio encoding method of claim 1, wherein the lossless encoding comprises grouping the differential quantization index corresponding to the context into one of a plurality of groups and performing Huffman coding on the differential quantization index of the current sub-band by using a Huffman table defined for each group.

6. The audio encoding method of claim 1, wherein the lossless encoding comprises grouping the differential quantization index corresponding to the context into one of first to third groups and allocating two Huffman tables including a first Huffman table for the second group and a second Huffman table for sharing to the first and third groups.

7. The audio encoding method of claim 6, wherein the lossless encoding comprises using the differential quantization index of the previous sub-band as it is or after reversing, as the context when the second Huffman table is shared.

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