PKEY_AudioEndpoint_FullRangeSpeakers Property
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PKEY_AudioEndpoint_FullRangeSpeakers Property
The PKEY_AudioEndpoint_FullRangeSpeakers property specifies the channel-configuration mask for the full-range speakers that are connected to the audio endpoint device. The mask indicates the physical configuration of the full-range speakers and specifies the assignment of channels to those speakers.
The vt member of the PROPVARIANT structure is set to VT_UI4.
The uintVal member of the PROPVARIANT structure contains a channel-configuration mask that is cast to type UINT.
A full-range speaker is capable of playing sounds over the full range from bass to treble. Typically, larger speakers are full range but smaller speakers are significantly less capable of playing bass sounds. In Windows Vista, the audio engine uses this property to manage bass levels in the audio output stream that is played by the audio endpoint device.
The channel-configuration mask for this property is in the same format as the channel-configuration mask for the PKEY_AudioEndpoint_PhysicalSpeakers property. For more information about channel-configuration masks, see the following:
- The description of the KSPROPERTY_AUDIO_CHANNEL_CONFIG property in the Windows DDK documentation.
- The white paper titled "Audio Driver Support for Home Theater Speaker Configurations" at the Audio Device Technologies for Windows Web site.
The system obtains the channel-configuration mask for the PKEY_AudioEndpoint_FullRangeSpeakers property from the user. The user enters this information through the Windows multimedia control panel, Mmsys.cpl. For more information about Mmsys.cpl, see the Windows DDK documentation.
The channel-configuration mask for the PKEY_AudioEndpoint_FullRangeSpeakers property of an audio endpoint device is a subset of the channel-configuration mask for the PKEY_AudioEndpoint_PhysicalSpeakers property of the same device.
For example, if an audio endpoint device drives a set of 5.1 surround-sound speakers, then the channel-configuration mask for the PKEY_AudioEndpoint_PhysicalSpeakers property is KSAUDIO_SPEAKER_5POINT1. This mask indicates the presence of front-left, front-right, front-center, side-left, and side-right speakers—plus a subwoofer. If the front-left and front-right speakers are large enough to produce bass sounds but the smaller front-center and side speakers are not, then the channel-configuration mask for the PKEY_AudioEndpoint_FullRangeSpeakers property is KSAUDIO_SPEAKER_STEREO, which indicates only the front-left and front-right speakers. Channel-configuration masks KSAUDIO_SPEAKER_5POINT1 and KSAUDIO_SPEAKER_STEREO are defined in header file Ksmedia.h.
Requirements
Client: Windows Vista
Header: Include Mmdeviceapi.h.
See Also
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