Slot position coding of TTT syntax of spatial audio coding application

• US 7,761,303 B2
• Filed: 08/30/2006
• Issued: 07/20/2010
• Est. Priority Date: 08/30/2005
• 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, Jung, Yang Won, Kim, Dong Soo
• Primary Examiner(s): Dorvil; Richemond
• Assistant Examiner(s): GODBOLD, DOUGLAS
• Application Number:
  US11/513,896
• Publication Number:
  US 20070091938A1
• Time in Patent Office: 1,420 Days
• Field of Search: 704/200, 704/200.1, 704/201, 704/500, 704/501, 381/23
• 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
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04S 1/007 in which the audio signals are in digital form data reduction aspects thereof based on psychoacoustics G10L19/02
• CPC Class Codes: H04S 2420/03 Application of parametric coding in stereophonic audio systems
• CPC Class Codes: H04S 3/002 Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution control circuits for electronic adaptation of the sound field H04S7/30

Abstract

Spatial information associated with an audio signal is encoded into a bitstream, which can be transmitted to a decoder or recorded to a storage media. The bitstream can include different syntax related to time, frequency and spatial domains. In some embodiments, the bitstream includes one or more data structures (e.g., frames) that contain ordered sets of slots for which parameters can be applied. The data structures can be fixed or variable. The data structure can include position information that can be used by a decoder to identify the correct slot for which a given parameter set is applied. The slot position information can be encoded with a fixed number of bits or a variable number of bits based on the data structure type.

Claims

1. A method of decoding an audio signal performed by an audio coding system, comprising:

receiving an audio signal including at least one frame, the frame comprising at least one time slot and at least one parameter set;

determining whether a Low Frequency Enhancement (LFE) mode is selected, the LFE mode being different from a normal mode for an LFE channel;

extracting time slot information in variable bit length, the time slot information indicating a time slot to which a parameter set is applied;

extracting LFE parameter band information in fixed bit length, the LFE parameter band information indicating a number of parameter bands for the LFE channel; and

decoding the audio signal by applying the parameter of the parameter set to a parameter band of the time slot, based on the LFE parameter band information and the time slot information,

wherein the process of extracting the time slot information comprises;

extracting a number of time slots and a number of parameter sets from the audio signal to identify the time slot information;

determining a bit length of the time slot information, the bit length being variable according to the number of time slots and the number of parameter sets; and

extracting the time slot information based on the bit length,

wherein a number of time slot information is equal to the number of parameter sets.

2. The method of claim 1, wherein the time slot information is position information indicating a position of the time slot to which the parameter set is applied.

3. The method of claim 1, wherein the time slot information includes an absolute value indicating a time slot to which a first parameter set is applied or a difference value indicating a time slot to which a following parameter set of the first parameter set is applied.

4. The method of claim 3, wherein the time slot to which the following parameter set is applied is determined by adding the difference value to a previous time slot, the previous time slot to which a previous parameter set is applied.

5. The method of claim 3, wherein the absolute value is determined within a first maximum range, the first maximum range being calculated using the number of parameter sets and the number of time slots, and

wherein the difference value is determined within a second maximum range, the second maximum range being calculated according to previous time slot information.

6. An apparatus of decoding an audio signal, including a downmix signal and spatial information, the spatial information including at least one frame, the frame comprising at least one time slot and at least one parameter set, comprising:

a spatial information decoding unit configured to determine whether a Low Frequency Enhancement (LFE) mode is selected, the LFE mode being different from a normal mode for an LFE channel, to extract LFE parameter band information in fixed bit length, the LFE parameter band information indicating a number of parameter bands for the LFE channel, and to extract a number of time slots and a number of parameter sets from the audio signal to identify time slot information, and to determine a bit length of the time slot information, the bit length being variable according to the number of time slots and the number of parameter sets, and to extract the time slot information in variable bit length based on the bit length,

wherein a number of time slot information is equal to the number of parameter sets;

a downmix signal decoding unit configured to decode the downmix signal; and

a multi channel generating unit configured to generate a multi-channel audio signal by applying the parameter of the parameter set to a parameter band of the time slot, based on the LFE parameter band information and the time slot information,

wherein at least one of the spatial information decoding unit, the downmix signal decoding unit, and the multi channel generating unit includes a processor.

7. The apparatus of claim 6, wherein the time slot information is position information indicating a position of the time slot to which the parameter set is applied.

8. The apparatus of claim 6, wherein the time slot information includes an absolute value indicating a time slot to which a first parameter set is applied or difference value indicating a time slot to which a following parameter set of the first parameter set is applied.

9. The apparatus of claim 8, wherein the time slot to which the following parameter set is applied is determined by adding the difference value to a previous time slot, the previous time slot to which a previous parameter set is applied.

10. The apparatus of claim 8, wherein the absolute value is determined within a first maximum range, the first maximum range being calculated using the number of parameter sets and the number of time slots, and

wherein the difference value is determined within a second maximum range, the second maximum range being calculated according to previous time slot information.