UAC - USB Audio Class 1.0

Collaboration diagram for UAC - USB Audio Class 1.0:

Files
file	uac.h
	USB Audio Class 1.0 (UAC1) device class: speaker + microphone, app API.

Data Structures
struct	uac_opts
	UAC1 configuration: microphone source + speaker sink callbacks. More...

Typedefs
typedef struct uac_audio	uac_audio
	One USB Audio function: a single instance of the class on a device.

Functions
uac_audio *	uac_add (usbip_device *dev, const uac_opts *opts)
	Add a UAC1 audio interface (speaker + microphone) to a device.
void	uac_tone (uint8_t *buf, int frames, uint32_t index)
	Fill a buffer with the built-in synthetic microphone tone.

Variables
const usbip_device_class	usbip_device_uac
	The UAC1 audio class, for usbip_device_add_class()

Detailed Description

Typedef Documentation

uac_audio

typedef struct uac_audio uac_audio

One USB Audio function: a single instance of the class on a device.

Opaque - create one with uac_add() and use the functions below. Distinct from the other classes' handles, so mixing them up is a compile error rather than a misread state block.

Function Documentation

uac_add()

uac_audio * uac_add	(	usbip_device *	dev,
		const uac_opts *	opts
	)

Add a UAC1 audio interface (speaker + microphone) to a device.

Leaves the device class triple at 0/0/0 (UAC1 predates the IAD; the AudioControl header collects the streaming interfaces).

Parameters

dev	the device.
opts	microphone source + speaker sink callbacks (see uac_opts).

Returns

the new function, or NULL on error.

uac_tone()

void uac_tone	(	uint8_t *	buf,
		int	frames,
		uint32_t	index
	)

Fill a buffer with the built-in synthetic microphone tone.

Writes frames mono 16-bit-LE samples of a 440 Hz sine (48 kHz) starting at sample index. Pure integer, so it is byte-identical to the Python uac.tone() - exposed for cross-language parity tests.

Parameters

buf	output buffer (>= frames * 2 bytes).
frames	number of mono samples to write.
index	running sample counter (the phase origin).

Variable Documentation

usbip_device_uac

const usbip_device_class usbip_device_uac

extern

The UAC1 audio class, for usbip_device_add_class()