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Contains quality metrics for acoustic echo cancellation (AEC). This structure is used with the MFPKEY_WMAAECMA_RETRIEVE_TS_STATS property.
Syntax
typedef struct tagAecQualityMetrics_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
| Requirement | Value | 
|---|---|
| Minimum supported client | Windows XP [desktop apps only] | 
| Minimum supported server | Windows Server 2003 [desktop apps only] | 
| Header | wmcodecdsp.h |