METHOD AND APPARATUS FOR ENCODING AND DECODING AN AUDIO SIGNAL

• US 20090216543A1
• Filed: 06/30/2006
• Published: 08/27/2009
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Pang, Hee Suk, Oh, Hyen-O, Lim, Jae Hyun, Kim, Dong Soo, Jung, Yang-Won
• Granted Patent: US 8,214,221 B2
• Time in Patent Office: Days
• US Class Current: 704/500
• 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 19/167 Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes

Abstract

A method and apparatus for encoding and decoding an audio signal are provided. The present invention includes receiving an audio signal including an audio descriptor, recognizing that the audio signal includes a downmix signal and a spatial information signal using the audio descriptor, and converting the downmix signal to a multi-channel signal using the spatial information signal, wherein the spatial information signal includes a header each a preset temporal or spatial interval, and the spatial information signal includes a header each a preset temporal or spatial interval thereby the header can be selectively included in the spatial information signal and if the header is plurally included in the spatial information signal, it is able to decode spatial information in case of reproducing the audio signal from a random point.

Claims

1. A method of decoding an audio signal, comprising:

receiving an audio signal including a downmix signal and an ancillary signal;

obtaining type information of the ancillary signal;

checking header identification information indicating whether a header is included in the ancillary signal based on the type information of the ancillary signal;

extracting time align information from the header when the header is included in the ancillary signal according to the header identification information;

identifying a start position of a frame of the ancillary signal using the time align information,

wherein the type information indicates whether the ancillary signal includes only a frame or both a frame and a header.

2. The method of claim 1, wherein the time align information indicates a time delay between the ancillary signal and the downmix signal when the ancillary signal being embedded in the downmix signal is transported.

3. The method of claim 2, wherein the ancillary signal indicates spatial information signal.

4. The method of claim 3, further comprising:

applying a parameter included in the spatial information signal to a corresponding time slot using position information of the corresponding time slot included in the spatial information signal.

5. The method of claim 3, wherein the audio signal includes signal identification information indicating whether the spatial information signal is combined with the downmix signal.

6. The method of claim 3, further comprising:

adjusting a position of a time slot to which a parameter included in the spatial information signal is to be applied using position information of the time slot included in the spatial information signal.

7. The method of claim 6, wherein a position information representing quantity of the time slot is variable.

8. The method of claim 6, wherein position information representing quantity of the time slot to which an N^th parameter is applied is obtained using at least one of a number of the time slots, a number of the parameters, N and position information of a time slot to which an (N−

1)^th the parameter is applied.

9. The method of claim 8, wherein the position information representing quantity of the time slot to which the parameter after the second is applied is obtained by ceil (log₂ (k−

i+N−

j (N−

1))) wherein ‘

k’

, ‘

i’ and

‘

j(N−

1)’

are the number of the time slots, the number of the parameters and the position information of the time slot to which the (N−

1)^th parameter is applied, respectively.

10. The method of claim 8, wherein the position information representing quantity of the time slot to which a first parameter is applied is obtained by ceil (log₂ (k−

i+1)) wherein ‘

k’ and

‘

i’

are the number of the time slots and the number of the parameters, respectively.

11. The method of claim 9, wherein the position information of the time slot to which an N^th parameter is applied is obtained by j(N−

1)+r(N)+1 wherein ‘

r(N)’

is a number of time slots existing between the time slot to which the N^th parameter is applied and the time slot to which (N−

1)^th parameter is applied.

12. The method of claim 1, wherein the ancillary signal includes at least one header in each a preset temporal or spatial interval.

13. The method of claim 12, further comprising:

determining whether a currently transported header and a previously transported header is the same header when the ancillary signal includes two or more headers;

if the currently transported header is different from the previously transported header based on the determining step, detecting that an error occurs in the header.

14. An apparatus of decoding an audio signal, comprising:

a receiving unit receiving an audio signal including a downmix signal and an ancillary signal;

an ancillary signal decoding unit obtaining type information of the ancillary signal, and checking header identification information indicating whether a header is included in the ancillary signal based on the type information of the ancillary signal, and identifying a start position of a frame of the ancillary signal using the time align information obtained from the header when the header is included in the ancillary signal according to the header identification information,

wherein the type information indicates whether the ancillary signal includes only a frame or both a frame and a header.