FilterNoiseDetectModerate_EC

Performs noise detection for EC noise filtering.

Syntax

IppStatus ippsFilterNoiseDetectModerate_EC_32f64f(const Ipp32f* pSrcSin[16], const Ipp32f* pSrcRin[16], Ipp64f* pNoisePower, Ipp32f* pMean, int* pNoiseFlag, IppsFilterNoiseState_EC_32f* pNRStateMem);

Parameters

pSrcSin

Pointer to the input vector containing echo.

pSrcRin

Pointer to the vector containing echo source.

pNoisePower

Pointer to the output power of noise pattern.

pMean

Pointer to the weighted mean value of noise.

pNoiseFlag

Pointer to the flag indicated the noise presence: 1 - noise is detected, 0 - no noise is detected.

pNRStateMem

Pointer to the filter state structure.

Description

The function ippsFilterNoiseDetectModerate_EC is declared in the ippsc.h file.

The function performs detection of noise similar to the function ippsFilterNoiseDetect_EC. The difference is that the noise detection performed on the signals containing echo provides higher noise mitigation by the following processing with the function ippsFilterNoise_EC.

Using the function ippsFilterNoiseDetectModerate_EC in the echo canceller operations gives no misdetects during the normal speech and provides more stable NLP block performance on the signals with echo.

The detection result is returned by pNoiseFlag. The value of the average noise power is stored in the pNoisePower, it can be used for dynamic noise level control by the function ippsFilterNoiseLevel_EC. The weighted mean value of noise pMean can be considered as the DC offset. The filter state pNRStateMem must be initialized beforehand by the function ippsFilterNoiseInit_EC. If the noise is detected, then the filter state memory is updated with the signal history, noise statistics, and noise pattern.

Return Values

ippStsNoErr

Indicates no error.

ippStsNullPtrErr

Indicates an error when one of the specified pointer is NULL.

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