Method and an apparatus for processing an audio signal

• US 8,892,427 B2
• Filed: 07/27/2010
• Issued: 11/18/2014
• Est. Priority Date: 07/27/2009
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Industry Academic Cooperation Foundation
• Inventors: Oh, Hyen-O, Kang, Hong Goo, Lee, Chang Heon, Song, Jeong Ook
• Primary Examiner(s): PULLIAS, JESSE SCOTT
• Application Number:
  US13/387,248
• Publication Number:
  US 20120185257A1
• Time in Patent Office: 1,575 Days
• Field of Search: 704200-201, 704/211
• US Class Current: 704/211
• CPC Class Codes: G10L 19/005 Correction of errors induced by the transmission channel, if related to the coding algorithm
• CPC Class Codes: G10L 19/022 Blocking, i.e. grouping of samples in time; Choice of analysis windows; Overlap factoring
• CPC Class Codes: G10L 19/04 using predictive techniques
• CPC Class Codes: G10L 19/18 Vocoders using multiple modes
• CPC Class Codes: G10L 25/45 characterised by the type of analysis window

Abstract

An apparatus for processing an audio signal and method thereof are disclosed. The present invention includes receiving, by an audio processing apparatus, an audio signal including a first data of a first block encoded with rectangular coding scheme and a second data of a second block encoded with non-rectangular coding scheme; receiving a compensation signal corresponding to the second block; estimating a prediction of an aliasing part using the first data; and, obtaining a reconstructed signal for the second block based on the second data, the compensation signal and the prediction of aliasing part.

Claims

1. A method for processing an audio signal, comprising:

receiving, by an audio processing apparatus, an audio signal including a first data of a first block encoded with rectangular coding scheme and a second data of a second block encoded with non-rectangular coding scheme, wherein the rectangular coding scheme is to encode or decode with rectangular window and the non-rectangular coding scheme is to encode or decode with non-rectangular window;

generating an output signal for the first block using the first data of the first block based on the rectangular coding scheme;

receiving a compensation signal corresponding to the second block;

obtaining a prediction of an aliasing part by applying the non-rectangular window to the output signal for the first block; and

,

obtaining a reconstructed signal for the second block based on the second data, the compensation signal and the prediction of aliasing part.

2. The method of claim 1, wherein the compensation signal is generated based on a correction part and an error of aliasing part, wherein the correction part corresponds to a difference related to asymmetry between rectangular window and non-rectangular window, wherein the error of aliasing part corresponds to a difference between the aliasing part and the prediction of aliasing part.

3. The method of claim 1, wherein the aliasing part corresponds to overlapping part between the first block and non-rectangular window used for the non-rectangular coding scheme.

4. The method of claim 1, wherein the reconstructed signal is approximate to a signal processed with rectangular window that differs from non-rectangular window used for the non-rectangular coding scheme.

5. The method 1, wherein the obtaining of the reconstructed signal comprises:

inverse-frequency-transforming the second data to generate a time-domain second signal;

inverse-frequency-transforming the compensation signal to generate a time-domain compensation signal; and

, obtaining the reconstructed signal, by adding the time-domain compensation signal to the time-domain second signal and the prediction of the aliasing part.

6. The method 1, wherein the first block corresponds to one of frame and subframe, and the second block corresponds to one of frame and subframe.

7. An apparatus for processing an audio signal, comprising:

a de-multiplexer receiving an audio signal including a first data of a first block encoded with rectangular coding scheme and a second data of a second block encoded with non-rectangular coding scheme, and receiving a compensation signal corresponding to the second block, wherein the rectangular coding scheme is to encode or decode with rectangular window and the non-rectangular coding scheme is to encode or decode with non-rectangular window;

a rectangular decoding unit generating an output signal for the first block using the first data of the first block based on the rectangular coding scheme, and obtaining a prediction of an aliasing part by applying the non-rectangular window to the output signal for the first block; and

,

a non-rectangular decoding unit obtaining a reconstructed signal for the second block based on the second data, the compensation signal and the prediction of aliasing part.

8. The apparatus of claim 7, wherein the compensation signal is generated based on a correction part and an error of aliasing part, wherein the correction part corresponds to a difference related to asymmetry between rectangular window and non-rectangular window, wherein the error of aliasing part corresponds to a difference between the aliasing part and the prediction of aliasing part.

9. The apparatus of claim 7, wherein the aliasing part corresponds to overlapping part between the first block and non-rectangular window used for the non-rectangular coding scheme.

10. The apparatus of claim 7, wherein the reconstructed signal is approximate to a signal processed with rectangular window that differs from non-rectangular window used for the non-rectangular coding scheme.

11. The apparatus of claim 7, wherein the non-rectangular decoding unit configured to:

inverse-frequency-transform the second data to generate a time-domain second signal;

inverse-frequency-transform the compensation signal to generate a time-domain compensation signal; and

,

obtain the reconstructed signal, by adding the time-domain compensation signal to the time-domain second signal and the prediction of the aliasing part.

12. The apparatus of claim 7, wherein the first block corresponds to one of frame and subframe, and the second block corresponds to one of frame and subframe.