Method and apparatus for encoding and decoding high frequency for bandwidth extension

• US 10,339,948 B2
• Filed: 09/11/2017
• Issued: 07/02/2019
• Est. Priority Date: 03/21/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choo, Ki-hyun
• Primary Examiner(s): Yen, Eric
• Application Number:
  US15/700,737
• Publication Number:
  US 20170372718A1
• Time in Patent Office: 659 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 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: G10L 19/08 Determination or coding of the excitation function; Determination or coding of the long-term prediction parameters
• CPC Class Codes: G10L 19/18 Vocoders using multiple modes
• CPC Class Codes: G10L 19/20 using sound class specific coding, hybrid encoders or object based coding
• CPC Class Codes: G10L 19/22 Mode decision, i.e. based on audio signal content versus external parameters
• CPC Class Codes: G10L 21/038 using band spreading techniques
• CPC Class Codes: G10L 21/0388 Details of processing therefor

Abstract

Disclosed are a method and apparatus for encoding and decoding a high frequency for bandwidth extension. The method includes: estimating a weight; and generating a high frequency excitation signal by applying the weight between random noise and a decoded low frequency spectrum.

Claims

1. A decoding apparatus for generating a high frequency spectrum, the decoding apparatus comprising:

a receiving unit configured to receive a bitstream including one of first excitation class information, second excitation class information and third excitation class information as an excitation class of a current frame; and

a processor configured to;

decode a low frequency spectrum of the current frame from the bitstream;

obtain a high frequency excitation spectrum of the current frame by copying the low frequency spectrum, based on the excitation class of the current frame;

generate a high frequency spectrum based on the high frequency excitation spectrum; and

combine the low frequency spectrum and the high frequency spectrum,

wherein the first excitation class information for the current frame indicates that the excitation class of the current frame corresponds to a speech class, if the current frame has a speech characteristic,

wherein the second excitation class information for the current frame indicates that the excitation class of the current frame corresponds to a first non-speech class, if the current frame does not have the speech characteristic,

wherein the third excitation class information for the current frame indicates that the excitation class of the current frame corresponds to a second non-speech class, if the current frame does not have the speech characteristic, and

wherein whether the excitation class of the current frame corresponds to the first non-speech class or the second non-speech class is determined based on a tonal characteristic of the current frame.

2. The decoding apparatus of claim 1, wherein whether the excitation class of the current frame corresponds to the first non-speech class or the second non-speech class is determined based on a comparison of the tonal characteristic with a threshold.

3. A decoding method, performed by a decoding apparatus comprising a processor, comprising:

receiving a bitstream including one of first excitation class information, second excitation class information and third excitation class information as an excitation class of a current frame;

decoding a low frequency spectrum of the current frame from the bitstream;

obtaining a high frequency excitation spectrum of the current frame by copying the low frequency spectrum, based on the excitation class of the current frame;

generating a high frequency spectrum based on the high frequency excitation spectrum; and

combining the low frequency spectrum and the high frequency spectrum,

wherein the first excitation class information for the current frame indicates that the excitation class of the current frame corresponds to a speech class, when the current frame has a speech characteristic,

wherein the second excitation class information for the current frame indicates that the excitation class of the current frame corresponds to a first non-speech class, when the current frame does not have the speech characteristic,

wherein the third excitation class information for the current frame indicates that the excitation class of the current frame corresponds to a second non-speech class, when the current frame does not have the speech characteristic, and

wherein whether the excitation class of the current frame corresponds to the first non-speech class or the second non-speech class is determined based on a tonal characteristic of the current frame.

4. The decoding method of claim 3, wherein whether the excitation class of the current frame corresponds to the first non-speech class or the second non-speech class is determined based on a comparison of the tonal characteristic with a threshold.