AecQualityMetrics_Struct Structure

Contains quality metrics for acoustic echo cancellation (AEC). This structure is used with the MFPKEY_WMAAECMA_RETRIEVE_TS_STATS property.

Syntax

typedef struct {
  LONGLONG i64Timestamp;
  BYTE     ConvergenceFlag;
  BYTE     MicClippedFlag;
  BYTE     MicSilenceFlag;
  BYTE     PstvFeadbackFlag;
  BYTE     SpkClippedFlag;
  BYTE     SpkMuteFlag;
  BYTE     GlitchFlag;
  BYTE     DoubleTalkFlag;
  ULONG    uGlitchCount;
  ULONG    uMicClipCount;
  float    fDuration;
  float    fTSVariance;
  float    fTSDriftRate;
  float    fVoiceLevel;
  float    fNoiseLevel;
  float    fERLE;
  float    fAvgERLE;
  DWORD    dwReserved;
} AecQualityMetrics_Struct;

Members

• i64Timestamp
  Time stamp that indicates when the quality metrics were collected.

• ConvergenceFlag
  AEC convergence flag.

• MicClippedFlag
  If TRUE, the input signal from the audio capture device was clipped.

• MicSilenceFlag
  If TRUE, the input signal from the audio capture device was silent or too quiet.

• PstvFeadbackFlag
  If TRUE, positive feedback is causing a chirping sound.

• SpkClippedFlag
  If TRUE, the input signal from the audio rendering device was clipped.

• SpkMuteFlag
  If TRUE, the input signal from the audio rendering device was silent or too quiet.

• GlitchFlag
  A glitch occurred in the input data.

• DoubleTalkFlag
  Double talk flag.

• uGlitchCount
  Number of glitches.

• uMicClipCount
  Number of times the audio capture signal was clipped.

• fDuration
  Running duration of the AEC process.

• fTSVariance
  Long-term average variance in the time stamps.

• fTSDriftRate
  Long-term average drift rate in the time stamps.

• fVoiceLevel
  Near-end voice level after AEC processing.

• fNoiseLevel
  Noise level of the audio capture signal.

• fERLE
  Echo return loss enhancement (ERLE).

• fAvgERLE
  Average ERLE over the entire duration of AEC processing.

• dwReserved
  Reserved

Requirements

Minimum supported client	Windows XP
Minimum supported server	Windows Server 2003
Header	Wmcodecdsp.h

See Also

Structures

Using the Voice Capture DSP

Voice Capture DSP

 

 

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Build date: 4/7/2010