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KSPROPSETID_AudioLoopback

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The KSPROPSETID_AudioLoopback property set is used by the audio driver to indicate the loopback tap point pre and post volume and mute.

The Ksmedia.h header file defines the KSPROPSETID_AudioLoopback property set as follows:

#define STATIC_KSPROPSETID_AudioLoopback 0xb3648bc8, 0x5b91, 0x468a, 0xb9, 0x4d, 0xf4, 0x64, 0x12, 0x50, 0x91, 0x7c
DEFINE_GUIDSTRUCT("B3648BC8-5B91-468A-B94D-F4641250917C", KSPROPSETID_AudioLoopback);
#define KSPROPSETID_AudioLoopback DEFINE_GUIDNAMED(KSPROPSETID_AudioLoopback)

The KSPROPSETID_AudioLoopback property set contains the following KS property:

KSPROPERTY_AUDIOLOOPBACK

Remarks

KSPROPSETID_AudioLoopback with KSPROPERTY_AUDIOLOOPBACK_TAPPOINT_CAPS requesting KSPROPERTY_TYPE_BASICSUPPORT will return flags indicating support for get and basic support.

KSPROPERTY_TYPE_SET is not supported.

KSPROPSETID_AudioLoopback with KSPROPERTY_AUDIOLOOPBACK_TAPPOINT_CAPS and KSPROPERTY_TYPE_GET will return a bitwise OR of the supported capabilities:

AUDIOLOOPBACK_TAPPOINT_CAPS_PREVOLUMEMUTE | AUDIOLOOPBACK_TAPPOINT_CAPS_POSTVOLUMEMUTE

For backwards compatibility, if KSPROPERTY_AUDIOLOOPBACK_TAPPOINT_CAPS is not supported, then the driver is assumed to support AUDIOLOOPBACK_TAPPOINT_CAPS_PREVOLUMEMUTE.

By policy, support for AUDIOLOOPBACK_TAPPOINT_CAPS_PREVOLUMEMUTE is required. A driver implementing KSPROPERTY_AUDIOLOOPBACK_TAPPOINT_CAPS should return either AUDIOLOOPBACK_TAPPOINT_CAPS_PREVOLUMEMUTE or AUDIOLOOPBACK_TAPPOINT_CAPS_PREVOLUMEMUTE | AUDIOLOOPBACK_TAPPOINT_CAPS_POSTVOLUMEMUTE.

A driver which only supports AUDIOLOOPBACK_TAPPOINT_CAPS_POSTVOLUMEMUTE will fail HLK testing.

AUDIOLOOPBACK_TAPPOINT_TYPE enum

The AUDIOLOOPBACK_TAPPOINT_TYPE enum contains the pre and post tap point definitions. For more information, see AUDIOLOOPBACK_TAPPOINT_TYPE enum.

See also

KSPROPERTY_AUDIOLOOPBACK

KSPROPERTY structure

AUDIOLOOPBACK_TAPPOINT_TYPE enum

KSATTRIBUTE_AUDIOLOOPBACK_TAPPOINT structure