Patent ID: 11935547
Assignee: HUAWEI TECHNOLOGIES CO., LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G

Claim 6:
7. An audio signal encoder, comprising:
a computer-readable medium to store instructions, which when executed by one or more processors, cause the audio signal encoder to:
determine a channel combination scheme for a current frame of a multi-channel signal, wherein the multi-channel signal includes at least two channels; and
determine a coding mode of the current frame based on a channel combination scheme for a previous frame and the channel combination scheme for the current frame;
wherein the channel combination scheme for the current frame is one of a plurality of channel combination schemes that comprise an anticorrelated signal channel combination scheme and a correlated signal channel combination scheme, the correlated signal channel combination scheme is a channel combination scheme corresponding to a near in phase signal, and the anticorrelated signal channel combination scheme is a channel combination scheme corresponding to a near out of phase signal;
wherein
to determine the channel combination scheme for the current frame, the instructions, which when executed by the one or more processor, cause the audio signal encoder to perform an initial channel combination scheme decision for the current frame to determine an initial channel combination scheme for the current frame; and to perform a channel combination scheme modification decision for the current frame based on the initial channel combination scheme for the current frame to determine the channel combination scheme for the current frame;
to perform the initial channel combination scheme decision for the current frame, the instructions, which when executed by the one or more processor, cause the audio signal encoder to determine a signal type of in/out of phase of a stereo signal in the current frame by using left and right channel signals in the current frame; and to determine the initial channel combination scheme for the current frame based on the signal type of in/out of phase of the stereo signal in the current frame and the channel combination scheme for the previous frame;
to determine the initial channel combination scheme for the current frame based on the signal type of in/out of phase of the stereo signal in the current frame and the channel combination scheme for the previous frame, the instructions, which when executed by the one or more processor, cause the audio signal encoder to
when the signal type of in/out of phase of the stereo signal in the current frame is the near in phase signal and the channel combination scheme for the previous frame is the correlated signal channel combination scheme, determine that the initial channel combination scheme for the current frame is the correlated signal channel combination scheme; or when the signal type of in/out of phase of the stereo signal in the current frame is the near out of phase signal and the channel combination scheme for the previous frame is the anticorrelated signal channel combination scheme, determine that the initial channel combination scheme for the current frame is the anticorrelated signal channel combination scheme; or
when the signal type of in/out of phase of the stereo signal in the current frame is the near in phase signal and the channel combination scheme for the previous frame is the anticorrelated signal channel combination scheme,
if signal-to-noise ratios of the left and right channel signals in the current frame are both less than a second threshold, determine that the initial channel combination scheme for the current frame is the correlated signal channel combination scheme; or
if the signal-to-noise ratio of the left channel signal or the signal-to-noise ratio of the right channel signal in the current frame are/is greater than or equal to the second threshold, determine that the initial channel combination scheme for the current frame is the anticorrelated signal channel combination scheme; or

when the signal type of in/out of phase of the stereo signal in the current frame is the near out of phase signal and the channel combination scheme for the previous frame is the correlated signal channel combination scheme,
if the signal-to-noise ratios of the left and right channel signals in the current frame are both less than the second threshold, determine that the initial channel combination scheme for the current frame is the anticorrelated signal channel combination scheme; or
if the signal-to-noise ratio of the left channel signal or the signal-to-noise ratio of the right channel signal in the current frame are/is greater than or equal to the second threshold, determine that the initial channel combination scheme for the current frame is the correlated signal channel combination scheme.