Name Hint Interface

Collaboration diagram for Name Hint Interface:

Functions
int	snd_device_name_hint (int card, const char *iface, void ***hints)
	Get a set of device name hints.
int	snd_device_name_free_hint (void **hints)
	Free a list of device name hints.
char *	snd_device_name_get_hint (const void *hint, const char *id)
	Extract a value from a hint.

Detailed Description

The name hint interface - get descriptive information about a device (name, description, input/output).

Function Documentation

snd_device_name_free_hint()

int snd_device_name_free_hint

(

void **

hints

)

Free a list of device name hints.

Parameters

hints

List to free

Returns

zero if success, otherwise a negative error code

snd_device_name_get_hint()

char * snd_device_name_get_hint	(	const void *	hint,
		const char *	id
	)

Extract a value from a hint.

Parameters

hint	A pointer to hint
id	Hint value to extract ("NAME", "DESC", or "IOID", see below)

Returns

an allocated ASCII string if success, otherwise NULL

List of valid IDs: NAME - name of device DESC - description of device IOID - input / output identification ("Input" or "Output"), NULL means both

The return value should be freed when no longer needed.

snd_device_name_hint()

int snd_device_name_hint	(	int	card,
		const char *	iface,
		void ***	hints
	)

Get a set of device name hints.

Parameters

card	Card number or -1 (means all cards)
iface	Interface identification (like "pcm", "rawmidi", "timer", "seq")
hints	Result - array of device name hints

Returns

zero if success, otherwise a negative error code

hints will receive a NULL-terminated array of device name hints, which can be passed to snd_device_name_get_hint to extract usable values. When no longer needed, hints should be passed to snd_device_name_free_hint to release resources.

User-defined hints are gathered from namehint.IFACE tree like:

namehint.pcm [
myfile "file:FILE=/tmp/soundwave.raw|Save sound output to /tmp/soundwave.raw"
myplug "plug:front|Do all conversions for front speakers"
]

Note: The device description is separated with '|' char.

Special variables: defaults.namehint.showall specifies if all device definitions are accepted (boolean type).