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KSAUDIO_MIC_ARRAY_GEOMETRY structure

The KSAUDIO_MIC_ARRAY_GEOMETRY structure specifies the type and the geometry of the microphone array. The usNumberOfMicrophones member indicates the number of microphones in the physical array. The KsMicCoord member is a variable of type KSAUDIO_MICROPHONE_COORDINATES and it is an array of structures. The number of entries in this array is given by the value of the usNumberOfMicrophones member.

Syntax


typedef struct {
  USHORT                         usVersion;
  USHORT                         usMicArrayType;
  SHORT                          wVerticalAngleBegin;
  SHORT                          wVerticalAngleEnd;
  SHORT                          wHorizontalAngleBegin;
  SHORT                          wHorizontalAngleEnd;
  USHORT                         usFrequencyBandLo;
  USHORT                         usFrequencyBandHi;
  USHORT                         usNumberOfMicrophones;
  KSAUDIO_MICROPHONE_COORDINATES KsMicCoord[1];
} KSAUDIO_MIC_ARRAY_GEOMETRY, *PKSAUDIO_MIC_ARRAY_GEOMETRY;

Members

usVersion

Specifies the version number of the KSAUDIO_MIC_ARRAY_GEOMETRY structure. This member is a BCD value and is currently set to 0x0100, which represents a version number of 1.0.

usMicArrayType

Specifies the type of microphone array in use. This member can be any one of the KSMICARRAY_MICARRAYTYPE enumeration values shown in the following table.

Value

Microphone array type

KSMICARRAY_MICARRAYTYPE_LINEAR

Linear

KSMICARRAY_MICARRAYTYPE_PLANAR

Planar

KSMICARRAY_MICARRAYTYPE_3D

3D

 

wVerticalAngleBegin

Specifies the vertical angle of the start of the working volume of the microphone array.

wVerticalAngleEnd

Specifies the vertical angle of the end of the working volume of the microphone array.

wHorizontalAngleBegin

Work Volume HorizontalAngle Begin

wHorizontalAngleEnd

Work Volume HorizontalAngle End

usFrequencyBandLo

Specifies the low end of the frequency range for the microphone array.

usFrequencyBandHi

Specifies the high end of the frequency range for the microphone array.

usNumberOfMicrophones

Specifies the number of microphones in the microphone array.

KsMicCoord

Specifies the array of KSAUDIO_MICROPHONE_COORDINATES structures that contains the locations of the microphones in the array.

Remarks

All angle values are expressed in units of 1/10000th of a radian. For example, 3.1416 radians is expressed as 31416 units. Acceptable values range from -31416 to 31416 units.

All coordinate values are expressed in millimeters. Acceptable values range from 0 to 65535 millimeters, inclusive.

Frequency values are expressed in Hertz (Hz).

For more information about how to process a microphone array in Windows Vista, see the Audio Technologies for Windows page on the WHDC website and refer to the following white papers:

Microphone Array Support in Windows Vista

How to Build and Use Microphone Arrays for Windows Vista

Requirements

Header

Ksmedia.h (include Ksmedia.h)

See also

KSAUDIO_MICROPHONE_COORDINATES

 

 

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