Method, apparatus, and medium for bandwidth extension encoding and decoding

• US 8,990,075 B2
• Filed: 07/09/2012
• Issued: 03/24/2015
• Est. Priority Date: 01/12/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Oh, Eun-mi, Choo, Ki-Hyun, Kim, Jung-hoo
• Primary Examiner(s): YEN, ERIC L
• Application Number:
  US13/544,543
• Publication Number:
  US 20120316887A1
• Time in Patent Office: 988 Days
• Field of Search: 704/219, 704/262, 704/269, 704/500, 704/225, 704/230
• US Class Current: 704/219
• CPC Class Codes: G10L 19/0212 using orthogonal transformation
• CPC Class Codes: G10L 19/12 the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders
• CPC Class Codes: G10L 19/20 using sound class specific coding, hybrid encoders or object based coding
• CPC Class Codes: G10L 21/038 using band spreading techniques

Abstract

Provided are a method, apparatus, and medium for encoding/decoding a high frequency band signal by using a low frequency band signal corresponding to an audio signal or a speech signal. Accordingly, since the high frequency band signal is encoded and decoded by using the low frequency band signal, encoding and decoding can be carried out with a small data size while avoiding deterioration of sound quality.

Claims

1. A method of bandwidth extension decoding, comprising:

checking whether a signal is encoded in a first domain or a second domain other than the first domain;

lossless decoding and de-quantizing the signal, and inverse-transforming the de-quantized signal to the second domain if the checking result shows that the signal is encoded in the first domain;

decoding the signal using CELP (code excited linear prediction) if the checking result shows that the signal is encoded in the second domain;

transforming the signal that is inverse-transformed to the second domain, by using a quadrature mirror filterbank (QMF), or transforming the signal that is decoded using the CELP, by using the QMF;

generating, in a QMF domain, a high band signal using the transformed signal;

generating a stereo signal from the high band signal and the transformed signal; and

inverse-transforming the stereo signal, by using an inverse QMF,

wherein the method is performed using at least one processor.

3. The method of claim 1, wherein the signal corresponds to a band signal lower than a predetermined frequency.

5. The method of claim 1, wherein the first domain is a frequency domain.

6. The method of claim 1, wherein the second domain is a time domain.

2. An apparatus for bandwidth extension decoding, comprising:

a domain checking unit which checks whether a signal is encoded in a first domain or a second domain other than the first domain;

a first decoding unit which performs lossless decoding and de-quantization of the signal, and which inverse-transforms the de-quantized signal to the second domain if the checking result shows that the signal is encoded in the first domain;

a second decoding unit, implemented using a processor, which performs decoding the signal using CELP (code excited linear prediction) if the checking result shows that the signal is encoded in the second domain;

a transform unit which transforms the signal that is inverse-transformed to the second domain by using a quadrature mirror filterbank (QMF), or transforms the signal that is decoded using the CELP, by using the QMF;

a high band generating unit which generates, in a QMF domain, a high band signal using the transformed signal;

a stereo signal generating unit which generates a stereo signal from the high band signal and the transformed signal; and

an inverse transform unit which inverse-transforms the stereo signal, by using an inverse QMF.

4. The apparatus of claim 2, wherein the signal corresponds to a band signal lower than a predetermined frequency.

7. The apparatus of claim 2, wherein the first domain is a frequency domain.

8. The apparatus of claim 2, wherein the second domain is a time domain.