Method and apparatus for processing an audio signal using window transitions for coding schemes

• US 9,064,490 B2
• Filed: 08/06/2013
• Issued: 06/23/2015
• 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, Lee, Chang Heon, Kang, Hong Goo, Song, Jung Wook
• Primary Examiner(s): PULLIAS, JESSE SCOTT
• Application Number:
  US13/960,252
• Publication Number:
  US 20130325486A1
• Time in Patent Office: 686 Days
• Field of Search: 704200-256, 704500-504
• US Class Current: 1/1
• 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:

when a second coding scheme is applied to a current frame of the audio signal, receiving, by an audio processing apparatus, window type information indicating a particular window for the current frame from among a plurality of windows; and

,

applying a current window to the current frame based on the window type information,

wherein, when a first coding scheme is applied to a previous frame, the plurality of windows includes a short window, a first transition window, and a second transition window,

wherein the short window has at least one ascending line which width is N/8, and the first transition window and the second transition window have an ascending line which width is N/4, and wherein the N is the frame length.

2. The method of claim 1, wherein the length of the short window the first transition window and the second transition window is 2N.

3. The method of claim 1, wherein the left half of the short window the first transition window and the second transition window corresponds to 1024 samples.

4. The method of claim 1, wherein a cross point between the current window and a previous window is at N/2 distance from the start of the current window.

5. The method of claim 1, wherein the first transition window has no zero part in the right half,

the second transition window has a zero part in the right half,

the short window has a plurality of short parts which are overlapped together, and the short part has the ascending line and a descending line.

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

a de-multiplexer, when a second coding scheme is applied to a current frame of the audio signal, for receiving window type information indicating a particular window for the current frame from among a plurality of windows; and

a second coding unit applying a current window to the current frame based on the window type information,

wherein, when a first coding scheme is applied to a previous frame, the plurality of windows includes a short window, a first transition window, and a second transition window,

wherein the short window has at least one ascending line which width is N/8, and the first transition window and the second transition window have an ascending line which width is N/4, and wherein the N is the frame length.

7. The apparatus of claim 6, wherein the length of the short window, the first transition window and the second transition window is 2N.

9. The apparatus of claim 6, wherein a cross point between the current window and a previous window is at N/2 distance from the start of the current window.

10. The apparatus of claim 6, wherein the first transition window has no zero part in the right half,

the second transition window has a zero part in the right half,

the short window has a plurality of short parts which are overlapped together, and the short part has the ascending line and a descending line.

8. The apparatus of clam 6, wherein the left half of the short window, the first transition window and the second transition window corresponds to 1024 samples.