Collaboration diagram for High level Control Interface:

Typedefs
typedef struct _snd_hctl_elem	snd_hctl_elem_t

typedef struct _snd_hctl	snd_hctl_t

typedef int(*	snd_hctl_compare_t) (const snd_hctl_elem_t e1, const snd_hctl_elem_t e2)
	Compare function for sorting HCTL elements. More...

typedef int(*	snd_hctl_callback_t) (snd_hctl_t hctl, unsigned int mask, snd_hctl_elem_t elem)
	HCTL callback function. More...

typedef int(*	snd_hctl_elem_callback_t) (snd_hctl_elem_t *elem, unsigned int mask)
	HCTL element callback function. More...

Functions
int	snd_hctl_compare_fast (const snd_hctl_elem_t c1, const snd_hctl_elem_t c2)
	A "don't care" fast compare functions that may be used with snd_hctl_set_compare. More...

int	snd_hctl_open (snd_hctl_t *hctl, const char name, int mode)
	Opens an HCTL. More...

int	snd_hctl_open_ctl (snd_hctl_t *hctlp, snd_ctl_t ctl)
	Opens an HCTL. More...

int	snd_hctl_close (snd_hctl_t *hctl)
	close HCTL handle More...

int	snd_hctl_nonblock (snd_hctl_t *hctl, int nonblock)
	set nonblock mode More...

int	snd_hctl_poll_descriptors_count (snd_hctl_t *hctl)
	get count of poll descriptors for HCTL handle More...

int	snd_hctl_poll_descriptors (snd_hctl_t hctl, struct pollfd pfds, unsigned int space)
	get poll descriptors More...

int	snd_hctl_poll_descriptors_revents (snd_hctl_t ctl, struct pollfd pfds, unsigned int nfds, unsigned short *revents)
	get returned events from poll descriptors More...

unsigned int	snd_hctl_get_count (snd_hctl_t *hctl)
	Get number of loaded elements for an HCTL. More...

int	snd_hctl_set_compare (snd_hctl_t *hctl, snd_hctl_compare_t hsort)
	Change HCTL compare function and reorder elements. More...

snd_hctl_elem_t *	snd_hctl_first_elem (snd_hctl_t *hctl)
	get first element for an HCTL More...

snd_hctl_elem_t *	snd_hctl_last_elem (snd_hctl_t *hctl)
	get last element for an HCTL More...

snd_hctl_elem_t *	snd_hctl_find_elem (snd_hctl_t hctl, const snd_ctl_elem_id_t id)
	Search an HCTL element. More...

void	snd_hctl_set_callback (snd_hctl_t *hctl, snd_hctl_callback_t callback)
	Set callback function for an HCTL. More...

void	snd_hctl_set_callback_private (snd_hctl_t hctl, void data)
	Set callback private value for an HCTL. More...

void *	snd_hctl_get_callback_private (snd_hctl_t *hctl)
	Get callback private value for an HCTL. More...

int	snd_hctl_load (snd_hctl_t *hctl)
	Load an HCTL with all elements and sort them. More...

int	snd_hctl_free (snd_hctl_t *hctl)
	free HCTL loaded elements More...

int	snd_hctl_handle_events (snd_hctl_t *hctl)
	Handle pending HCTL events invoking callbacks. More...

const char *	snd_hctl_name (snd_hctl_t *hctl)
	get identifier of HCTL handle More...

int	snd_hctl_wait (snd_hctl_t *hctl, int timeout)
	Wait for a HCTL to become ready (i.e. at least one event pending) More...

snd_ctl_t *	snd_hctl_ctl (snd_hctl_t *hctl)
	Get a ctl handle associated to the given hctl handle. More...

snd_hctl_elem_t *	snd_hctl_elem_next (snd_hctl_elem_t *elem)
	get next HCTL element More...

snd_hctl_elem_t *	snd_hctl_elem_prev (snd_hctl_elem_t *elem)
	get previous HCTL element More...

int	snd_hctl_elem_info (snd_hctl_elem_t elem, snd_ctl_elem_info_t info)
	Get information for an HCTL element. More...

int	snd_hctl_elem_read (snd_hctl_elem_t elem, snd_ctl_elem_value_t value)
	Get value for an HCTL element. More...

int	snd_hctl_elem_write (snd_hctl_elem_t elem, snd_ctl_elem_value_t value)
	Set value for an HCTL element. More...

int	snd_hctl_elem_tlv_read (snd_hctl_elem_t elem, unsigned int tlv, unsigned int tlv_size)
	Get TLV value for an HCTL element. More...

int	snd_hctl_elem_tlv_write (snd_hctl_elem_t elem, const unsigned int tlv)
	Set TLV value for an HCTL element. More...

int	snd_hctl_elem_tlv_command (snd_hctl_elem_t elem, const unsigned int tlv)
	Set TLV value for an HCTL element. More...

snd_hctl_t *	snd_hctl_elem_get_hctl (snd_hctl_elem_t *elem)
	Get HCTL handle for an HCTL element. More...

void	snd_hctl_elem_get_id (const snd_hctl_elem_t obj, snd_ctl_elem_id_t ptr)
	Get CTL element identifier of a CTL element id/value. More...

unsigned int	snd_hctl_elem_get_numid (const snd_hctl_elem_t *obj)
	Get element numeric identifier of a CTL element id/value. More...

snd_ctl_elem_iface_t	snd_hctl_elem_get_interface (const snd_hctl_elem_t *obj)
	Get interface part of CTL element identifier of a CTL element id/value. More...

unsigned int	snd_hctl_elem_get_device (const snd_hctl_elem_t *obj)
	Get device part of CTL element identifier of a CTL element id/value. More...

unsigned int	snd_hctl_elem_get_subdevice (const snd_hctl_elem_t *obj)
	Get subdevice part of CTL element identifier of a CTL element id/value. More...

const char *	snd_hctl_elem_get_name (const snd_hctl_elem_t *obj)
	Get name part of CTL element identifier of a CTL element id/value. More...

unsigned int	snd_hctl_elem_get_index (const snd_hctl_elem_t *obj)
	Get index part of CTL element identifier of a CTL element id/value. More...

void	snd_hctl_elem_set_callback (snd_hctl_elem_t *obj, snd_hctl_elem_callback_t val)
	Set callback function for an HCTL element. More...

void *	snd_hctl_elem_get_callback_private (const snd_hctl_elem_t *obj)
	Get callback private value for an HCTL element. More...

void	snd_hctl_elem_set_callback_private (snd_hctl_elem_t obj, void val)
	Set callback private value for an HCTL element. More...

Detailed Description

The high level control interface. See High level control interface page for more details.

Typedef Documentation

◆ snd_hctl_callback_t

typedef int(* snd_hctl_callback_t) (snd_hctl_t *hctl, unsigned int mask, snd_hctl_elem_t *elem)

HCTL callback function.

Parameters

hctl	HCTL handle
mask	event mask
elem	related HCTL element (if any)

Returns: 0 on success otherwise a negative error code

◆ snd_hctl_compare_t

typedef int(* snd_hctl_compare_t) (const snd_hctl_elem_t *e1, const snd_hctl_elem_t *e2)

Compare function for sorting HCTL elements.

Parameters

e1	First element
e2	Second element

Returns: -1 if e1 < e2, 0 if e1 == e2, 1 if e1 > e2

◆ snd_hctl_elem_callback_t

typedef int(* snd_hctl_elem_callback_t) (snd_hctl_elem_t *elem, unsigned int mask)

HCTL element callback function.

Parameters

elem	HCTL element
mask	event mask

Returns: 0 on success otherwise a negative error code

◆ snd_hctl_elem_t

typedef struct _snd_hctl_elem snd_hctl_elem_t

HCTL element handle

◆ snd_hctl_t

typedef struct _snd_hctl snd_hctl_t

HCTL handle

Function Documentation

◆ snd_hctl_close()

int snd_hctl_close ( snd_hctl_t * hctl )

close HCTL handle

Parameters

hctl	HCTL handle

Returns: 0 on success otherwise a negative error code

Closes the specified HCTL handle and frees all associated resources.

◆ snd_hctl_compare_fast()

int snd_hctl_compare_fast	(	const snd_hctl_elem_t *	c1,
		const snd_hctl_elem_t *	c2
	)

A "don't care" fast compare functions that may be used with snd_hctl_set_compare.

Parameters

c1	First HCTL element
c2	Second HCTL element

Returns: -1 if c1 < c2, 0 if c1 == c2, 1 if c1 > c2

◆ snd_hctl_ctl()

snd_ctl_t * snd_hctl_ctl ( snd_hctl_t * hctl )

Get a ctl handle associated to the given hctl handle.

Parameters

hctl	HCTL handle

Returns: a ctl handle otherwise NULL

◆ snd_hctl_elem_get_callback_private()

void * snd_hctl_elem_get_callback_private ( const snd_hctl_elem_t * obj )

Get callback private value for an HCTL element.

Parameters

obj	HCTL element

Returns: callback private value

◆ snd_hctl_elem_get_device()

unsigned int snd_hctl_elem_get_device ( const snd_hctl_elem_t * obj )

Get device part of CTL element identifier of a CTL element id/value.

Parameters

obj	CTL element id/value

Returns: device part of element identifier

◆ snd_hctl_elem_get_hctl()

snd_hctl_t * snd_hctl_elem_get_hctl ( snd_hctl_elem_t * elem )

Get HCTL handle for an HCTL element.

Parameters

elem	HCTL element

Returns: HCTL handle

◆ snd_hctl_elem_get_id()

void snd_hctl_elem_get_id	(	const snd_hctl_elem_t *	obj,
		snd_ctl_elem_id_t *	ptr
	)

Get CTL element identifier of a CTL element id/value.

Parameters

obj	CTL element id/value
ptr	Pointer to returned CTL element identifier

◆ snd_hctl_elem_get_index()

unsigned int snd_hctl_elem_get_index ( const snd_hctl_elem_t * obj )

Get index part of CTL element identifier of a CTL element id/value.

Parameters

obj	CTL element id/value

Returns: index part of element identifier

◆ snd_hctl_elem_get_interface()

snd_ctl_elem_iface_t snd_hctl_elem_get_interface ( const snd_hctl_elem_t * obj )

Get interface part of CTL element identifier of a CTL element id/value.

Parameters

obj	CTL element id/value

Returns: interface part of element identifier

◆ snd_hctl_elem_get_name()

const char * snd_hctl_elem_get_name ( const snd_hctl_elem_t * obj )

Get name part of CTL element identifier of a CTL element id/value.

Parameters

obj	CTL element id/value

Returns: name part of element identifier

◆ snd_hctl_elem_get_numid()

unsigned int snd_hctl_elem_get_numid ( const snd_hctl_elem_t * obj )

Get element numeric identifier of a CTL element id/value.

Parameters

obj	CTL element id/value

Returns: element numeric identifier

◆ snd_hctl_elem_get_subdevice()

unsigned int snd_hctl_elem_get_subdevice ( const snd_hctl_elem_t * obj )

Get subdevice part of CTL element identifier of a CTL element id/value.

Parameters

obj	CTL element id/value

Returns: subdevice part of element identifier

◆ snd_hctl_elem_info()

int snd_hctl_elem_info	(	snd_hctl_elem_t *	elem,
		snd_ctl_elem_info_t *	info
	)

Get information for an HCTL element.

Parameters

elem	HCTL element
info	HCTL element information

Returns: 0 otherwise a negative error code on failure

◆ snd_hctl_elem_next()

snd_hctl_elem_t * snd_hctl_elem_next ( snd_hctl_elem_t * elem )

get next HCTL element

Parameters

elem	HCTL element

Returns: pointer to next element

◆ snd_hctl_elem_prev()

snd_hctl_elem_t * snd_hctl_elem_prev ( snd_hctl_elem_t * elem )

get previous HCTL element

Parameters

elem	HCTL element

Returns: pointer to previous element

◆ snd_hctl_elem_read()

int snd_hctl_elem_read	(	snd_hctl_elem_t *	elem,
		snd_ctl_elem_value_t *	value
	)

Get value for an HCTL element.

Parameters

elem	HCTL element
value	HCTL element value

Returns: 0 otherwise a negative error code on failure

◆ snd_hctl_elem_set_callback()

void snd_hctl_elem_set_callback	(	snd_hctl_elem_t *	obj,
		snd_hctl_elem_callback_t	val
	)

Set callback function for an HCTL element.

Parameters

obj	HCTL element
val	callback function

◆ snd_hctl_elem_set_callback_private()

void snd_hctl_elem_set_callback_private	(	snd_hctl_elem_t *	obj,
		void *	val
	)

Set callback private value for an HCTL element.

Parameters

obj	HCTL element
val	callback private value

◆ snd_hctl_elem_tlv_command()

int snd_hctl_elem_tlv_command	(	snd_hctl_elem_t *	elem,
		const unsigned int *	tlv
	)

Set TLV value for an HCTL element.

Parameters

elem	HCTL element
tlv	TLV array for value

Return values

0	on success
>1	on success when value was changed
<0	a negative error code on failure

◆ snd_hctl_elem_tlv_read()

int snd_hctl_elem_tlv_read	(	snd_hctl_elem_t *	elem,
		unsigned int *	tlv,
		unsigned int	tlv_size
	)

Get TLV value for an HCTL element.

Parameters

elem	HCTL element
tlv	TLV array for value
tlv_size	size of TLV array in bytes

Returns: 0 otherwise a negative error code on failure

◆ snd_hctl_elem_tlv_write()

int snd_hctl_elem_tlv_write	(	snd_hctl_elem_t *	elem,
		const unsigned int *	tlv
	)

Set TLV value for an HCTL element.

Parameters

elem	HCTL element
tlv	TLV array for value

Return values

0	on success
>1	on success when value was changed
<0	a negative error code on failure

◆ snd_hctl_elem_write()

int snd_hctl_elem_write	(	snd_hctl_elem_t *	elem,
		snd_ctl_elem_value_t *	value
	)

Set value for an HCTL element.

Parameters

elem	HCTL element
value	HCTL element value

Return values

0	on success
>1	on success when value was changed
<0	a negative error code on failure

◆ snd_hctl_find_elem()

snd_hctl_elem_t * snd_hctl_find_elem	(	snd_hctl_t *	hctl,
		const snd_ctl_elem_id_t *	id
	)

Search an HCTL element.

Parameters

hctl	HCTL handle
id	Element identifier

Returns: pointer to found HCTL element or NULL if it does not exists

◆ snd_hctl_first_elem()

snd_hctl_elem_t * snd_hctl_first_elem ( snd_hctl_t * hctl )

get first element for an HCTL

Parameters

hctl	HCTL handle

Returns: pointer to first element

◆ snd_hctl_free()

int snd_hctl_free ( snd_hctl_t * hctl )

free HCTL loaded elements

Parameters

hctl	HCTL handle

Returns: 0 on success otherwise a negative error code

◆ snd_hctl_get_callback_private()

void * snd_hctl_get_callback_private ( snd_hctl_t * hctl )

Get callback private value for an HCTL.

Parameters

hctl	HCTL handle

Returns: callback private value

◆ snd_hctl_get_count()

unsigned int snd_hctl_get_count ( snd_hctl_t * hctl )

Get number of loaded elements for an HCTL.

Parameters

hctl	HCTL handle

Returns: elements count

◆ snd_hctl_handle_events()

int snd_hctl_handle_events ( snd_hctl_t * hctl )

Handle pending HCTL events invoking callbacks.

Parameters

hctl	HCTL handle

Returns: 0 otherwise a negative error code on failure

◆ snd_hctl_last_elem()

snd_hctl_elem_t * snd_hctl_last_elem ( snd_hctl_t * hctl )

get last element for an HCTL

Parameters

hctl	HCTL handle

Returns: pointer to last element

◆ snd_hctl_load()

int snd_hctl_load ( snd_hctl_t * hctl )

Load an HCTL with all elements and sort them.

Parameters

hctl	HCTL handle

Returns: 0 on success otherwise a negative error code

◆ snd_hctl_name()

const char * snd_hctl_name ( snd_hctl_t * hctl )

get identifier of HCTL handle

Parameters

hctl	HCTL handle

Returns: ascii identifier of HCTL handle

Returns the ASCII identifier of given HCTL handle. It's the same identifier specified in snd_hctl_open().

◆ snd_hctl_nonblock()

int snd_hctl_nonblock	(	snd_hctl_t *	hctl,
		int	nonblock
	)

set nonblock mode

Parameters

hctl	HCTL handle
nonblock	0 = block, 1 = nonblock mode

Returns: 0 on success otherwise a negative error code

◆ snd_hctl_open()

int snd_hctl_open	(	snd_hctl_t **	hctlp,
		const char *	name,
		int	mode
	)

Opens an HCTL.

Parameters

hctlp	Returned HCTL handle
name	ASCII identifier of the underlying CTL handle
mode	Open mode (see SND_CTL_NONBLOCK, SND_CTL_ASYNC)

Returns: 0 on success otherwise a negative error code

◆ snd_hctl_open_ctl()

int snd_hctl_open_ctl	(	snd_hctl_t **	hctlp,
		snd_ctl_t *	ctl
	)

Opens an HCTL.

Parameters

hctlp	Returned HCTL handle
ctl	underlying CTL handle

Returns: 0 on success otherwise a negative error code

◆ snd_hctl_poll_descriptors()

int snd_hctl_poll_descriptors	(	snd_hctl_t *	hctl,
		struct pollfd *	pfds,
		unsigned int	space
	)

get poll descriptors

Parameters

hctl	HCTL handle
pfds	array of poll descriptors
space	space in the poll descriptor array

Returns: count of filled descriptors

◆ snd_hctl_poll_descriptors_count()

int snd_hctl_poll_descriptors_count ( snd_hctl_t * hctl )

get count of poll descriptors for HCTL handle

Parameters

hctl	HCTL handle

Returns: count of poll descriptors

◆ snd_hctl_poll_descriptors_revents()

int snd_hctl_poll_descriptors_revents	(	snd_hctl_t *	hctl,
		struct pollfd *	pfds,
		unsigned int	nfds,
		unsigned short *	revents
	)

get returned events from poll descriptors

Parameters

hctl	HCTL handle
pfds	array of poll descriptors
nfds	count of poll descriptors
revents	returned events

Returns: zero if success, otherwise a negative error code

◆ snd_hctl_set_callback()

void snd_hctl_set_callback	(	snd_hctl_t *	hctl,
		snd_hctl_callback_t	callback
	)

Set callback function for an HCTL.

Parameters

hctl	HCTL handle
callback	callback function

◆ snd_hctl_set_callback_private()

void snd_hctl_set_callback_private	(	snd_hctl_t *	hctl,
		void *	callback_private
	)

Set callback private value for an HCTL.

Parameters

hctl	HCTL handle
callback_private	callback private value

◆ snd_hctl_set_compare()

int snd_hctl_set_compare	(	snd_hctl_t *	hctl,
		snd_hctl_compare_t	compare
	)

Change HCTL compare function and reorder elements.

Parameters

hctl	HCTL handle
compare	Element compare function

Returns: 0 on success otherwise a negative error code

◆ snd_hctl_wait()

int snd_hctl_wait	(	snd_hctl_t *	hctl,
		int	timeout
	)

Wait for a HCTL to become ready (i.e. at least one event pending)

Parameters

hctl	HCTL handle
timeout	maximum time in milliseconds to wait

Returns: a positive value on success otherwise a negative error code

Return values

0	timeout occurred
1	an event is pending

Typedefs

Functions

Detailed Description

Typedef Documentation

◆ snd_hctl_callback_t

◆ snd_hctl_compare_t

◆ snd_hctl_elem_callback_t

◆ snd_hctl_elem_t

◆ snd_hctl_t

Function Documentation

◆ snd_hctl_close()

◆ snd_hctl_compare_fast()

◆ snd_hctl_ctl()

◆ snd_hctl_elem_get_callback_private()

◆ snd_hctl_elem_get_device()

◆ snd_hctl_elem_get_hctl()

◆ snd_hctl_elem_get_id()

◆ snd_hctl_elem_get_index()

◆ snd_hctl_elem_get_interface()

◆ snd_hctl_elem_get_name()

◆ snd_hctl_elem_get_numid()

◆ snd_hctl_elem_get_subdevice()

◆ snd_hctl_elem_info()

◆ snd_hctl_elem_next()

◆ snd_hctl_elem_prev()

◆ snd_hctl_elem_read()

◆ snd_hctl_elem_set_callback()

◆ snd_hctl_elem_set_callback_private()

◆ snd_hctl_elem_tlv_command()

◆ snd_hctl_elem_tlv_read()

◆ snd_hctl_elem_tlv_write()

◆ snd_hctl_elem_write()

◆ snd_hctl_find_elem()

◆ snd_hctl_first_elem()

◆ snd_hctl_free()

◆ snd_hctl_get_callback_private()

◆ snd_hctl_get_count()

◆ snd_hctl_handle_events()

◆ snd_hctl_last_elem()

◆ snd_hctl_load()

◆ snd_hctl_name()

◆ snd_hctl_nonblock()

◆ snd_hctl_open()

◆ snd_hctl_open_ctl()

◆ snd_hctl_poll_descriptors()

◆ snd_hctl_poll_descriptors_count()

◆ snd_hctl_poll_descriptors_revents()

◆ snd_hctl_set_callback()

◆ snd_hctl_set_callback_private()

◆ snd_hctl_set_compare()

◆ snd_hctl_wait()