Audio signal encoding method and apparatus
AssigneeHuawei Technologies Co., Ltd.
InventorsEyal Shlomot, Jonathan Alastair Gibbs, Halting Li
Life of this patent
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Abstract
An encoding method includes determining an adaptive broadening factor based on a quantized line spectral frequency (LSF) vector of a first channel of a current frame of an audio signal and an LSF vector of a second channel of the current frame, and writing the quantized LSF vector and the adaptive broadening factor into a bitstream.
Claims20
An audio signal encoding method, comprising:
- obtaining a current frame of an audio signal, wherein the current frame comprises a first channel and a second channel;
- obtaining a first quantized line spectral frequency (LSF) vector of the first channel;
- obtaining a second LSF vector of the second channel;
- obtaining a first adaptive broadening factor based on the first quantized LSF vector and the second LSF vector at least in part by:
- calculating a second adaptive broadening factor based on the first quantized LSF vector and the second LSF vector;
- and
- quantizing the second adaptive broadening factor to obtain the first adaptive broadening factor;
- and
- writing the first quantized LSF vector and the first adaptive broadening factor into a bitstream,
- wherein the first quantized LSF vector, the second LSF vector, and the second adaptive broadening factor satisfy a first equation comprising:
- β
- =
- ∑
- i
- =
- 1
- M
- w
- i
- [
- -
- LSF
- _
- S
- 2
- (
- i
- )
- +
- LSF
- S
- (
- i
- )
-
- LSF
- _
- S
- (
- i
- )
- -
- LSF
- S
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- +
- LSF
- _
- S
-
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- ]
- ∑
- i
- =
- 1
- M
- w
- i
- [
- -
- LSF
- _
- S
- 2
- (
- i
- )
- -
- LSF
- P
- 2
- (
- i
- )
- +
- 2
-
- LSF
- _
- S
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- ]
- ,
- wherein β represents the second adaptive broadening factor, wherein LSFS represents the second LSF vector, wherein LSFP represents the first quantized LSF vector, wherein LSFS represents a mean vector associated with the second LSF vector, wherein i is a vector index, wherein i is an integer and 1≤i≤M, wherein M is a linear prediction order, and wherein w is a weighting coefficient.
An audio signal encoding apparatus, comprising:
- at least one processor;
- and
- one or more memories coupled to the at least one processor and configured to store programming instructions for execution by the at least one processor to cause the audio signal encoding apparatus to:
- obtain a current frame of an audio signal, wherein the current frame comprises a first channel and a second channel;
- obtain a first quantized line spectral frequency (LSF) vector of the first channel;
- obtain a second LSF vector of the second channel;
- obtain a first adaptive broadening factor based on the first quantized LSF vector and the second LSF vector at least in part by:
- calculating a second adaptive broadening factor based on the first quantized LSF vector and the second LSF vector;
- and
- quantizing the second adaptive broadening factor to obtain the first adaptive broadening factor;
- and
- write the first quantized LSF vector and the first adaptive broadening factor into a bitstream,
- wherein the first quantized LSF vector, the second LSF vector, and the second adaptive broadening factor satisfy a first equation comprising:
- β
- =
- ∑
- i
- =
- 1
- M
- w
- i
- [
- -
- LSF
- _
- S
- 2
- (
- i
- )
- +
- LSF
- S
- (
- i
- )
-
- LSF
- _
- S
- (
- i
- )
- -
- LSF
- S
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- +
- LSF
- _
- S
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- ]
- ∑
- i
- =
- 1
- M
- w
- i
- [
- -
- LSF
- _
- S
- 2
- (
- i
- )
- -
- LSF
- P
- 2
- (
- i
- )
- +
- 2
-
- LSF
- _
- S
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- ]
- ,
- wherein β represents the second adaptive broadening factor, wherein LSFS represents the second LSF vector, wherein LSFP represents the first quantized LSF vector, wherein LSFS represents a mean vector associated with the second LSF vector, wherein i is a vector index, wherein i is an integer and 1≤i≤M, wherein M is a linear prediction order, and wherein w is a weighting coefficient.
A computer program product comprising computer-executable instructions that are stored on a non-transitory computer-readable medium and that, when executed by a processor, cause an audio signal encoding apparatus to:
- obtain a current frame of an audio signal, wherein the current frame comprises a first channel and a second channel;
- obtain a first quantized line spectral frequency (LSF) vector of the first channel;
- obtain a second LSF vector of the second channel;
- obtain a first adaptive broadening factor based on the first quantized LSF vector and the second LSF vector at least in part by:
- calculating a second adaptive broadening factor based on the first quantized LSF vector and the second LSF vector;
- and
- quantizing the second adaptive broadening factor to obtain the first adaptive broadening factor;
- and
- write the first quantized LSF vector and the first adaptive broadening factor into a bitstream,
- wherein the first quantized LSF vector, the second LSF vector, and the second adaptive broadening factor satisfy a first equation comprising:
- β
- =
- ∑
- i
- =
- 1
- M
- w
- i
- [
- -
- LSF
- _
- S
- 2
- (
- i
- )
- +
- LSF
- S
- (
- i
- )
-
- LSF
- _
- S
- (
- i
- )
- -
- LSF
- S
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- +
- LSF
- _
- S
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- ]
- ∑
- i
- =
- 1
- M
- w
- i
- [
- -
- LSF
- _
- S
- 2
- (
- i
- )
- -
- LSF
- P
- 2
- (
- i
- )
- +
- 2
-
- LSF
- _
- S
- (
- i
- )
-
- LSF
- P
- (
- i
- )
- ]
- ,
- wherein β represents the second adaptive broadening factor, wherein LSFS represents the second LSF vector, wherein LSFP represents the first quantized LSF vector, wherein LSFS represents a mean vector associated with the second LSF vector, wherein i is a vector index, wherein i is an integer and 1≤i≤M, wherein M is a linear prediction order, and wherein w is a weighting coefficient.
Dependencies are inferred from the claim text.