USB_Audio_Descriptor_FeatureUnit_t Struct Reference

Audio class-specific Feature Unit Descriptor (LUFA naming conventions). More...

Data Fields
USB_Descriptor_Header_t	Header
u8	Subtype
u8	UnitID
u8	SourceID
u8	ControlSize
u8	ChannelControls [3]
u8	FeatureUnitStrIndex

Detailed Description

Audio class-specific Feature Unit Descriptor (LUFA naming conventions).

Type define for an Audio class-specific Feature Unit descriptor. This indicates to the host what features are present in the device's audio stream for basic control, such as per-channel volume. See the USB Audio specification for more details.

See also

USB_Audio_StdDescriptor_FeatureUnit_t for the version of this type with standard element names.

Note

Regardless of CPU architecture, these values should be stored as little endian.

Field Documentation

Header

USB_Descriptor_Header_t USB_Audio_Descriptor_FeatureUnit_t::Header

Regular descriptor header containing the descriptor's type and length.

Subtype

u8 USB_Audio_Descriptor_FeatureUnit_t::Subtype

Sub type value used to distinguish between audio class-specific descriptors, must be AUDIO_DSUBTYPE_CSInterface_Feature.

UnitID

u8 USB_Audio_Descriptor_FeatureUnit_t::UnitID

ID value of this feature unit - must be a unique value within the device.

SourceID

u8 USB_Audio_Descriptor_FeatureUnit_t::SourceID

Source ID value of the audio source input into this feature unit.

ControlSize

u8 USB_Audio_Descriptor_FeatureUnit_t::ControlSize

Size of each element in the ChannelControls array.

ChannelControls

u8 USB_Audio_Descriptor_FeatureUnit_t::ChannelControls[3]

Feature masks for the control channel, and each separate audio channel.

FeatureUnitStrIndex

u8 USB_Audio_Descriptor_FeatureUnit_t::FeatureUnitStrIndex

Index of a string descriptor describing this descriptor within the device.