control.c File Reference

CTL interface - primitive controls. More...

Functions
const char *	snd_ctl_name (snd_ctl_t *ctl)
	get identifier of CTL handle
snd_ctl_type_t	snd_ctl_type (snd_ctl_t *ctl)
	get type of CTL handle
int	snd_ctl_close (snd_ctl_t *ctl)
	close CTL handle
int	snd_ctl_nonblock (snd_ctl_t *ctl, int nonblock)
	set nonblock mode
int	snd_ctl_poll_descriptors_count (snd_ctl_t *ctl)
	get count of poll descriptors for CTL handle
int	snd_ctl_poll_descriptors (snd_ctl_t *ctl, struct pollfd *pfds, unsigned int space)
	get poll descriptors
int	snd_ctl_poll_descriptors_revents (snd_ctl_t *ctl, struct pollfd *pfds, unsigned int nfds, unsigned short *revents)
	get returned events from poll descriptors
int	snd_ctl_subscribe_events (snd_ctl_t *ctl, int subscribe)
	Ask to be informed about events (poll, snd_async_add_ctl_handler, snd_ctl_read)
int	snd_ctl_card_info (snd_ctl_t *ctl, snd_ctl_card_info_t *info)
	Get information about the sound card.
int	snd_ctl_elem_list (snd_ctl_t *ctl, snd_ctl_elem_list_t *list)
	Get a list of element identifiers.
int	snd_ctl_elem_info (snd_ctl_t *ctl, snd_ctl_elem_info_t *info)
	Get CTL element information.
int	snd_ctl_add_integer_elem_set (snd_ctl_t *ctl, snd_ctl_elem_info_t *info, unsigned int element_count, unsigned int member_count, long min, long max, long step)
	Create and add some user-defined control elements of integer type.
int	snd_ctl_add_integer64_elem_set (snd_ctl_t *ctl, snd_ctl_elem_info_t *info, unsigned int element_count, unsigned int member_count, long long min, long long max, long long step)
	Create and add some user-defined control elements of integer64 type.
int	snd_ctl_add_boolean_elem_set (snd_ctl_t *ctl, snd_ctl_elem_info_t *info, unsigned int element_count, unsigned int member_count)
	Create and add some user-defined control elements of boolean type.
int	snd_ctl_add_enumerated_elem_set (snd_ctl_t *ctl, snd_ctl_elem_info_t *info, unsigned int element_count, unsigned int member_count, unsigned int items, const char *const labels[])
	Create and add some user-defined control elements of enumerated type.
int	snd_ctl_add_bytes_elem_set (snd_ctl_t *ctl, snd_ctl_elem_info_t *info, unsigned int element_count, unsigned int member_count)
	Create and add some user-defined control elements of bytes type.
int	snd_ctl_elem_add_integer (snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, unsigned int member_count, long min, long max, long step)
	Create and add an user-defined control element of integer type.
int	snd_ctl_elem_add_integer64 (snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, unsigned int member_count, long long min, long long max, long long step)
	Create and add an user-defined control element of integer64 type.
int	snd_ctl_elem_add_boolean (snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, unsigned int member_count)
	Create and add an user-defined control element of boolean type.
int	snd_ctl_elem_add_enumerated (snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, unsigned int member_count, unsigned int items, const char *const labels[])
	Create and add a user-defined control element of enumerated type.
int	snd_ctl_elem_add_iec958 (snd_ctl_t *ctl, const snd_ctl_elem_id_t *id)
	Create and add a user-defined control element of IEC958 type.
int	snd_ctl_elem_remove (snd_ctl_t *ctl, snd_ctl_elem_id_t *id)
	Remove an user CTL element.
int	snd_ctl_elem_read (snd_ctl_t *ctl, snd_ctl_elem_value_t *data)
	Get CTL element value.
int	snd_ctl_elem_write (snd_ctl_t *ctl, snd_ctl_elem_value_t *data)
	Set CTL element value.
int	snd_ctl_elem_tlv_read (snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, unsigned int *tlv, unsigned int tlv_size)
	Read structured data from an element set to given buffer.
int	snd_ctl_elem_tlv_write (snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, const unsigned int *tlv)
	Write structured data from given buffer to an element set.
int	snd_ctl_elem_tlv_command (snd_ctl_t *ctl, const snd_ctl_elem_id_t *id, const unsigned int *tlv)
	Process structured data from given buffer for an element set.
int	snd_ctl_elem_lock (snd_ctl_t *ctl, snd_ctl_elem_id_t *id)
	Lock CTL element.
int	snd_ctl_elem_unlock (snd_ctl_t *ctl, snd_ctl_elem_id_t *id)
	Unlock CTL element.
int	snd_ctl_hwdep_next_device (snd_ctl_t *ctl, int *device)
	Get next hardware dependent device number.
int	snd_ctl_hwdep_info (snd_ctl_t *ctl, snd_hwdep_info_t *info)
	Get info about a hardware dependent device.
int	snd_ctl_pcm_next_device (snd_ctl_t *ctl, int *device)
	Get next PCM device number.
int	snd_ctl_pcm_info (snd_ctl_t *ctl, snd_pcm_info_t *info)
	Get info about a PCM device.
int	snd_ctl_pcm_prefer_subdevice (snd_ctl_t *ctl, int subdev)
	Set preferred PCM subdevice number of successive PCM open.
int	snd_ctl_rawmidi_next_device (snd_ctl_t *ctl, int *device)
	Get next RawMidi device number.
int	snd_ctl_rawmidi_info (snd_ctl_t *ctl, snd_rawmidi_info_t *info)
	Get info about a RawMidi device.
int	snd_ctl_rawmidi_prefer_subdevice (snd_ctl_t *ctl, int subdev)
	Set preferred RawMidi subdevice number of successive RawMidi open.
int	snd_ctl_ump_next_device (snd_ctl_t *ctl, int *device)
	Get next UMP device number.
int	snd_ctl_ump_endpoint_info (snd_ctl_t *ctl, snd_ump_endpoint_info_t *info)
	Get UMP Endpoint info about a UMP RawMidi device.
int	snd_ctl_ump_block_info (snd_ctl_t *ctl, snd_ump_block_info_t *info)
	Get UMP Block info about a UMP RawMidi device.
int	snd_ctl_set_power_state (snd_ctl_t *ctl, unsigned int state)
	Set Power State to given SND_CTL_POWER_* value and do the power management.
int	snd_ctl_get_power_state (snd_ctl_t *ctl, unsigned int *state)
	Get actual Power State.
int	snd_ctl_read (snd_ctl_t *ctl, snd_ctl_event_t *event)
	Read an event.
int	snd_ctl_wait (snd_ctl_t *ctl, int timeout)
	Wait for a CTL to become ready (i.e. at least one event pending)
int	snd_async_add_ctl_handler (snd_async_handler_t **handler, snd_ctl_t *ctl, snd_async_callback_t callback, void *private_data)
	Add an async handler for a CTL.
snd_ctl_t *	snd_async_handler_get_ctl (snd_async_handler_t *handler)
	Return CTL handle related to an async handler.
int	snd_ctl_open (snd_ctl_t **ctlp, const char *name, int mode)
	Opens a sound card.
int	snd_ctl_open_lconf (snd_ctl_t **ctlp, const char *name, int mode, snd_config_t *lconf)
	Opens a CTL using local configuration.
int	snd_ctl_open_fallback (snd_ctl_t **ctlp, snd_config_t *root, const char *name, const char *orig_name, int mode)
	Opens a fallback CTL.
const char *	snd_ctl_elem_type_name (snd_ctl_elem_type_t type)
	get name of a CTL element type
const char *	snd_ctl_elem_iface_name (snd_ctl_elem_iface_t iface)
	get name of a CTL element related interface
const char *	snd_ctl_event_type_name (snd_ctl_event_type_t type)
	get name of a CTL event type
int	snd_ctl_elem_list_alloc_space (snd_ctl_elem_list_t *obj, unsigned int entries)
	allocate space for CTL element identifiers list
void	snd_ctl_elem_list_free_space (snd_ctl_elem_list_t *obj)
	free previously allocated space for CTL element identifiers list
unsigned int	snd_ctl_event_elem_get_mask (const snd_ctl_event_t *obj)
	Get event mask for an element related event.
void	snd_ctl_event_elem_get_id (const snd_ctl_event_t *obj, snd_ctl_elem_id_t *ptr)
	Get CTL element identifier for an element related event.
unsigned int	snd_ctl_event_elem_get_numid (const snd_ctl_event_t *obj)
	Get element numeric identifier for an element related event.
snd_ctl_elem_iface_t	snd_ctl_event_elem_get_interface (const snd_ctl_event_t *obj)
	Get interface part of CTL element identifier for an element related event.
unsigned int	snd_ctl_event_elem_get_device (const snd_ctl_event_t *obj)
	Get device part of CTL element identifier for an element related event.
unsigned int	snd_ctl_event_elem_get_subdevice (const snd_ctl_event_t *obj)
	Get subdevice part of CTL element identifier for an element related event.
const char *	snd_ctl_event_elem_get_name (const snd_ctl_event_t *obj)
	Get name part of CTL element identifier for an element related event.
unsigned int	snd_ctl_event_elem_get_index (const snd_ctl_event_t *obj)
	Get index part of CTL element identifier for an element related event.
size_t	snd_ctl_elem_id_sizeof ()
	get size of #snd_ctl_elem_id_t
int	snd_ctl_elem_id_malloc (snd_ctl_elem_id_t **ptr)
	allocate an invalid #snd_ctl_elem_id_t using standard malloc
void	snd_ctl_elem_id_free (snd_ctl_elem_id_t *obj)
	frees a previously allocated #snd_ctl_elem_id_t
void	snd_ctl_elem_id_clear (snd_ctl_elem_id_t *obj)
	clear given #snd_ctl_elem_id_t object
void	snd_ctl_elem_id_copy (snd_ctl_elem_id_t *dst, const snd_ctl_elem_id_t *src)
	copy one #snd_ctl_elem_id_t to another
int	snd_ctl_elem_id_compare_numid (const snd_ctl_elem_id_t *id1, const snd_ctl_elem_id_t *id2)
	compare one #snd_ctl_elem_id_t to another using numid
int	snd_ctl_elem_id_compare_set (const snd_ctl_elem_id_t *id1, const snd_ctl_elem_id_t *id2)
	compare one #snd_ctl_elem_id_t to another
unsigned int	snd_ctl_elem_id_get_numid (const snd_ctl_elem_id_t *obj)
	Get numeric identifier from a CTL element identifier.
snd_ctl_elem_iface_t	snd_ctl_elem_id_get_interface (const snd_ctl_elem_id_t *obj)
	Get interface part of a CTL element identifier.
unsigned int	snd_ctl_elem_id_get_device (const snd_ctl_elem_id_t *obj)
	Get device part of a CTL element identifier.
unsigned int	snd_ctl_elem_id_get_subdevice (const snd_ctl_elem_id_t *obj)
	Get subdevice part of a CTL element identifier.
const char *	snd_ctl_elem_id_get_name (const snd_ctl_elem_id_t *obj)
	Get name part of a CTL element identifier.
unsigned int	snd_ctl_elem_id_get_index (const snd_ctl_elem_id_t *obj)
	Get index part of a CTL element identifier.
void	snd_ctl_elem_id_set_numid (snd_ctl_elem_id_t *obj, unsigned int val)
	Set numeric identifier for a CTL element identifier.
void	snd_ctl_elem_id_set_interface (snd_ctl_elem_id_t *obj, snd_ctl_elem_iface_t val)
	Set interface part for a CTL element identifier.
void	snd_ctl_elem_id_set_device (snd_ctl_elem_id_t *obj, unsigned int val)
	Set device part for a CTL element identifier.
void	snd_ctl_elem_id_set_subdevice (snd_ctl_elem_id_t *obj, unsigned int val)
	Set subdevice part for a CTL element identifier.
void	snd_ctl_elem_id_set_name (snd_ctl_elem_id_t *obj, const char *val)
	Set name part for a CTL element identifier.
void	snd_ctl_elem_id_set_index (snd_ctl_elem_id_t *obj, unsigned int val)
	Set index part for a CTL element identifier.
size_t	snd_ctl_card_info_sizeof ()
	get size of #snd_ctl_card_info_t.
int	snd_ctl_card_info_malloc (snd_ctl_card_info_t **ptr)
	Allocate an invalid #snd_ctl_card_info_t on the heap.
void	snd_ctl_card_info_free (snd_ctl_card_info_t *obj)
	Free an #snd_ctl_card_info_t previously allocated using snd_ctl_card_info_malloc().
void	snd_ctl_card_info_clear (snd_ctl_card_info_t *obj)
	Clear given card info object.
void	snd_ctl_card_info_copy (snd_ctl_card_info_t *dst, const snd_ctl_card_info_t *src)
	Bitwise copy of a #snd_ctl_card_info_t object.
int	snd_ctl_card_info_get_card (const snd_ctl_card_info_t *obj)
	Get the sound card index from the given info object.
const char *	snd_ctl_card_info_get_id (const snd_ctl_card_info_t *obj)
	Get the sound card ID from the given info object.
const char *	snd_ctl_card_info_get_driver (const snd_ctl_card_info_t *obj)
	Get the sound card driver from the given info object.
const char *	snd_ctl_card_info_get_name (const snd_ctl_card_info_t *obj)
	Get the sound card name from the given info object.
const char *	snd_ctl_card_info_get_longname (const snd_ctl_card_info_t *obj)
	Get the sound cards long name from the given info object.
const char *	snd_ctl_card_info_get_mixername (const snd_ctl_card_info_t *obj)
	Get the sound card mixer name from the given info object.
const char *	snd_ctl_card_info_get_components (const snd_ctl_card_info_t *obj)
	Get the sound cards "components" property from the given info object.
size_t	snd_ctl_event_sizeof ()
	get size of #snd_ctl_event_t
int	snd_ctl_event_malloc (snd_ctl_event_t **ptr)
	allocate an invalid #snd_ctl_event_t using standard malloc
void	snd_ctl_event_free (snd_ctl_event_t *obj)
	frees a previously allocated #snd_ctl_event_t
void	snd_ctl_event_clear (snd_ctl_event_t *obj)
	clear given #snd_ctl_event_t object
void	snd_ctl_event_copy (snd_ctl_event_t *dst, const snd_ctl_event_t *src)
	copy one #snd_ctl_event_t to another
snd_ctl_event_type_t	snd_ctl_event_get_type (const snd_ctl_event_t *obj)
	Get type of a CTL event.
size_t	snd_ctl_elem_list_sizeof ()
	get size of #snd_ctl_elem_list_t.
int	snd_ctl_elem_list_malloc (snd_ctl_elem_list_t **ptr)
	allocate a #snd_ctl_elem_list_t using standard malloc.
void	snd_ctl_elem_list_free (snd_ctl_elem_list_t *obj)
	frees a previously allocated #snd_ctl_elem_list_t.
void	snd_ctl_elem_list_clear (snd_ctl_elem_list_t *obj)
	Clear given #snd_ctl_elem_list_t object.
void	snd_ctl_elem_list_copy (snd_ctl_elem_list_t *dst, const snd_ctl_elem_list_t *src)
	copy one #snd_ctl_elem_list_t to another.
void	snd_ctl_elem_list_set_offset (snd_ctl_elem_list_t *obj, unsigned int val)
	Set index of first wanted CTL element identifier in a CTL element identifiers list.
unsigned int	snd_ctl_elem_list_get_used (const snd_ctl_elem_list_t *obj)
	Get number of used entries in CTL element identifiers list.
unsigned int	snd_ctl_elem_list_get_count (const snd_ctl_elem_list_t *obj)
	Get total count of elements present in CTL device.
void	snd_ctl_elem_list_get_id (const snd_ctl_elem_list_t *obj, unsigned int idx, snd_ctl_elem_id_t *ptr)
	Get CTL element identifier for an entry of a CTL element identifiers list.
unsigned int	snd_ctl_elem_list_get_numid (const snd_ctl_elem_list_t *obj, unsigned int idx)
	Get CTL element numeric identifier for an entry of a CTL element identifiers list.
snd_ctl_elem_iface_t	snd_ctl_elem_list_get_interface (const snd_ctl_elem_list_t *obj, unsigned int idx)
	Get interface part of CTL element identifier for an entry of a CTL element identifiers list.
unsigned int	snd_ctl_elem_list_get_device (const snd_ctl_elem_list_t *obj, unsigned int idx)
	Get the device part of CTL element identifier for an entry of a CTL element identifiers list.
unsigned int	snd_ctl_elem_list_get_subdevice (const snd_ctl_elem_list_t *obj, unsigned int idx)
	Get subdevice part of CTL element identifier for an entry of a CTL element identifiers list.
const char *	snd_ctl_elem_list_get_name (const snd_ctl_elem_list_t *obj, unsigned int idx)
	Get name part of CTL element identifier for an entry of a CTL element identifiers list.
unsigned int	snd_ctl_elem_list_get_index (const snd_ctl_elem_list_t *obj, unsigned int idx)
	Get index part of CTL element identifier for an entry of a CTL element identifiers list.
size_t	snd_ctl_elem_info_sizeof ()
	get size of #snd_ctl_elem_info_t
int	snd_ctl_elem_info_malloc (snd_ctl_elem_info_t **ptr)
	allocate an invalid #snd_ctl_elem_info_t using standard malloc
void	snd_ctl_elem_info_free (snd_ctl_elem_info_t *obj)
	frees a previously allocated #snd_ctl_elem_info_t
void	snd_ctl_elem_info_clear (snd_ctl_elem_info_t *obj)
	clear given #snd_ctl_elem_info_t object
void	snd_ctl_elem_info_copy (snd_ctl_elem_info_t *dst, const snd_ctl_elem_info_t *src)
	copy one #snd_ctl_elem_info_t to another
snd_ctl_elem_type_t	snd_ctl_elem_info_get_type (const snd_ctl_elem_info_t *obj)
	Get type from a CTL element id/info.
int	snd_ctl_elem_info_is_readable (const snd_ctl_elem_info_t *obj)
	Get info about readability from a CTL element id/info.
int	snd_ctl_elem_info_is_writable (const snd_ctl_elem_info_t *obj)
	Get info about writability from a CTL element id/info.
int	snd_ctl_elem_info_is_volatile (const snd_ctl_elem_info_t *obj)
	Get info about notification feasibility from a CTL element id/info.
int	snd_ctl_elem_info_is_inactive (const snd_ctl_elem_info_t *obj)
	Get info about status from a CTL element id/info.
int	snd_ctl_elem_info_is_locked (const snd_ctl_elem_info_t *obj)
	Get info whether an element is locked.
int	snd_ctl_elem_info_is_owner (const snd_ctl_elem_info_t *obj)
	Get info if I own an element.
int	snd_ctl_elem_info_is_user (const snd_ctl_elem_info_t *obj)
	Get info if it's a user element.
int	snd_ctl_elem_info_is_tlv_readable (const snd_ctl_elem_info_t *obj)
	Get info about TLV readability from a CTL element id/info.
int	snd_ctl_elem_info_is_tlv_writable (const snd_ctl_elem_info_t *obj)
	Get info about TLV writeability from a CTL element id/info.
int	snd_ctl_elem_info_is_tlv_commandable (const snd_ctl_elem_info_t *obj)
	Get info about TLV command possibility from a CTL element id/info.
int	snd_ctl_elem_info_is_indirect (const snd_ctl_elem_info_t *obj)
	(DEPRECATED) Get info about values passing policy from a CTL element value
pid_t	snd_ctl_elem_info_get_owner (const snd_ctl_elem_info_t *obj)
	Get owner of a locked element.
unsigned int	snd_ctl_elem_info_get_count (const snd_ctl_elem_info_t *obj)
	Get number of value entries from a CTL element id/info.
long	snd_ctl_elem_info_get_min (const snd_ctl_elem_info_t *obj)
	Get minimum value from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info.
long	snd_ctl_elem_info_get_max (const snd_ctl_elem_info_t *obj)
	Get maximum value from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info.
long	snd_ctl_elem_info_get_step (const snd_ctl_elem_info_t *obj)
	Get value step from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info.
long long	snd_ctl_elem_info_get_min64 (const snd_ctl_elem_info_t *obj)
	Get minimum value from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info.
long long	snd_ctl_elem_info_get_max64 (const snd_ctl_elem_info_t *obj)
	Get maximum value from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info.
long long	snd_ctl_elem_info_get_step64 (const snd_ctl_elem_info_t *obj)
	Get value step from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info.
unsigned int	snd_ctl_elem_info_get_items (const snd_ctl_elem_info_t *obj)
	Get number of items available from a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info.
void	snd_ctl_elem_info_set_item (snd_ctl_elem_info_t *obj, unsigned int val)
	Select item in a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info.
const char *	snd_ctl_elem_info_get_item_name (const snd_ctl_elem_info_t *obj)
	Get name for selected item in a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info.
int	snd_ctl_elem_info_get_dimensions (const snd_ctl_elem_info_t *obj)
	Get count of dimensions for given element.
int	snd_ctl_elem_info_get_dimension (const snd_ctl_elem_info_t *obj, unsigned int idx)
	Get specified of dimension width for given element.
int	snd_ctl_elem_info_set_dimension (snd_ctl_elem_info_t *info, const int dimension[4])
	Set width to a specified dimension level of given element information.
void	snd_ctl_elem_info_get_id (const snd_ctl_elem_info_t *obj, snd_ctl_elem_id_t *ptr)
	Get CTL element identifier of a CTL element id/info.
unsigned int	snd_ctl_elem_info_get_numid (const snd_ctl_elem_info_t *obj)
	Get element numeric identifier of a CTL element id/info.
snd_ctl_elem_iface_t	snd_ctl_elem_info_get_interface (const snd_ctl_elem_info_t *obj)
	Get interface part of CTL element identifier of a CTL element id/info.
unsigned int	snd_ctl_elem_info_get_device (const snd_ctl_elem_info_t *obj)
	Get device part of CTL element identifier of a CTL element id/info.
unsigned int	snd_ctl_elem_info_get_subdevice (const snd_ctl_elem_info_t *obj)
	Get subdevice part of CTL element identifier of a CTL element id/info.
const char *	snd_ctl_elem_info_get_name (const snd_ctl_elem_info_t *obj)
	Get name part of CTL element identifier of a CTL element id/info.
unsigned int	snd_ctl_elem_info_get_index (const snd_ctl_elem_info_t *obj)
	Get index part of CTL element identifier of a CTL element id/info.
void	snd_ctl_elem_info_set_id (snd_ctl_elem_info_t *obj, const snd_ctl_elem_id_t *ptr)
	Set CTL element identifier of a CTL element id/info.
void	snd_ctl_elem_info_set_numid (snd_ctl_elem_info_t *obj, unsigned int val)
	Set element numeric identifier of a CTL element id/info.
void	snd_ctl_elem_info_set_interface (snd_ctl_elem_info_t *obj, snd_ctl_elem_iface_t val)
	Set interface part of CTL element identifier of a CTL element id/info.
void	snd_ctl_elem_info_set_device (snd_ctl_elem_info_t *obj, unsigned int val)
	Set device part of CTL element identifier of a CTL element id/info.
void	snd_ctl_elem_info_set_subdevice (snd_ctl_elem_info_t *obj, unsigned int val)
	Set subdevice part of CTL element identifier of a CTL element id/info.
void	snd_ctl_elem_info_set_name (snd_ctl_elem_info_t *obj, const char *val)
	Set name part of CTL element identifier of a CTL element id/info.
void	snd_ctl_elem_info_set_index (snd_ctl_elem_info_t *obj, unsigned int val)
	Set index part of CTL element identifier of a CTL element id/info.
void	snd_ctl_elem_info_set_read_write (snd_ctl_elem_info_t *obj, int rval, int wval)
	Set readability/writeability parameter of a CTL element id/info.
void	snd_ctl_elem_info_set_tlv_read_write (snd_ctl_elem_info_t *obj, int rval, int wval)
	Set TLV readability/writeability parameter of a CTL element id/info.
void	snd_ctl_elem_info_set_inactive (snd_ctl_elem_info_t *obj, int val)
	Set inactive parameter of a CTL element id/info.
size_t	snd_ctl_elem_value_sizeof ()
	Get size of data structure for an element.
int	snd_ctl_elem_value_malloc (snd_ctl_elem_value_t **ptr)
	Allocate an invalid #snd_ctl_elem_value_t on the heap.
void	snd_ctl_elem_value_free (snd_ctl_elem_value_t *obj)
	Free an #snd_ctl_elem_value_t previously allocated using snd_ctl_elem_value_malloc().
void	snd_ctl_elem_value_clear (snd_ctl_elem_value_t *obj)
	Clear given data of an element.
void	snd_ctl_elem_value_copy (snd_ctl_elem_value_t *dst, const snd_ctl_elem_value_t *src)
	Bitwise copy of a snd_ctl_elem_value_t value.
int	snd_ctl_elem_value_compare (snd_ctl_elem_value_t *left, const snd_ctl_elem_value_t *right)
	Compare two snd_ctl_elem_value_t values, bytewise.
void	snd_ctl_elem_value_get_id (const snd_ctl_elem_value_t *obj, snd_ctl_elem_id_t *ptr)
	Get the element identifier from the given element value.
unsigned int	snd_ctl_elem_value_get_numid (const snd_ctl_elem_value_t *obj)
	Get the identifiers 'numid' part from the given element value.
snd_ctl_elem_iface_t	snd_ctl_elem_value_get_interface (const snd_ctl_elem_value_t *obj)
	Get the identifiers 'interface' part from the given element value.
unsigned int	snd_ctl_elem_value_get_device (const snd_ctl_elem_value_t *obj)
	Get the identifiers 'device' part from the given element value.
unsigned int	snd_ctl_elem_value_get_subdevice (const snd_ctl_elem_value_t *obj)
	Get the identifiers 'subdevice' part from the given element value.
const char *	snd_ctl_elem_value_get_name (const snd_ctl_elem_value_t *obj)
	Get the identifiers 'name' part from the given element value.
unsigned int	snd_ctl_elem_value_get_index (const snd_ctl_elem_value_t *obj)
	Get the identifiers 'index' part from the given element value.
void	snd_ctl_elem_value_set_id (snd_ctl_elem_value_t *obj, const snd_ctl_elem_id_t *ptr)
	Set the element identifier within the given element value.
void	snd_ctl_elem_value_set_numid (snd_ctl_elem_value_t *obj, unsigned int val)
	Set the identifiers 'numid' part within the given element value.
void	snd_ctl_elem_value_set_interface (snd_ctl_elem_value_t *obj, snd_ctl_elem_iface_t val)
	Set the identifiers 'interface' part within the given element value.
void	snd_ctl_elem_value_set_device (snd_ctl_elem_value_t *obj, unsigned int val)
	Set the identifiers 'device' part within the given element value.
void	snd_ctl_elem_value_set_subdevice (snd_ctl_elem_value_t *obj, unsigned int val)
	Set the identifiers 'subdevice' part within the given element value.
void	snd_ctl_elem_value_set_name (snd_ctl_elem_value_t *obj, const char *val)
	Set the identifiers 'name' part within the given element value.
void	snd_ctl_elem_value_set_index (snd_ctl_elem_value_t *obj, unsigned int val)
	Set the identifiers 'index' part within the given element value.
int	snd_ctl_elem_value_get_boolean (const snd_ctl_elem_value_t *obj, unsigned int idx)
	Get an element members value.
long	snd_ctl_elem_value_get_integer (const snd_ctl_elem_value_t *obj, unsigned int idx)
	Get an element members value.
long long	snd_ctl_elem_value_get_integer64 (const snd_ctl_elem_value_t *obj, unsigned int idx)
	Get an element members value.
unsigned int	snd_ctl_elem_value_get_enumerated (const snd_ctl_elem_value_t *obj, unsigned int idx)
	Get an element members value.
unsigned char	snd_ctl_elem_value_get_byte (const snd_ctl_elem_value_t *obj, unsigned int idx)
	Get an element members value.
void	snd_ctl_elem_value_set_boolean (snd_ctl_elem_value_t *obj, unsigned int idx, long val)
	Set an element members value.
void	snd_ctl_elem_value_set_integer (snd_ctl_elem_value_t *obj, unsigned int idx, long val)
	Set an element members value.
void	snd_ctl_elem_value_set_integer64 (snd_ctl_elem_value_t *obj, unsigned int idx, long long val)
	Set an element members value.
void	snd_ctl_elem_value_set_enumerated (snd_ctl_elem_value_t *obj, unsigned int idx, unsigned int val)
	Set an element members value.
void	snd_ctl_elem_value_set_byte (snd_ctl_elem_value_t *obj, unsigned int idx, unsigned char val)
	Set an element members value.
void	snd_ctl_elem_set_bytes (snd_ctl_elem_value_t *obj, void *data, size_t size)
	Replace the data stored within the element.
const void *	snd_ctl_elem_value_get_bytes (const snd_ctl_elem_value_t *obj)
	Get the data stored within the element.
void	snd_ctl_elem_value_get_iec958 (const snd_ctl_elem_value_t *obj, snd_aes_iec958_t *ptr)
	Get an elements IEC958 data.
void	snd_ctl_elem_value_set_iec958 (snd_ctl_elem_value_t *obj, const snd_aes_iec958_t *ptr)
	Set an elements IEC958 data.

Detailed Description

CTL interface - primitive controls.

CTL interface - parse ASCII identifiers and values.

Author

Abramo Bagnara abram.nosp@m.o@al.nosp@m.sa-pr.nosp@m.ojec.nosp@m.t.org

Date

2000

CTL interface is designed to access primitive controls. See Control interface page for more details.

Author

Jaroslav Kysela perex.nosp@m.@per.nosp@m.ex.cz

Date

2010

Function Documentation

snd_async_add_ctl_handler()

int snd_async_add_ctl_handler	(	snd_async_handler_t **	handler,
		snd_ctl_t *	ctl,
		snd_async_callback_t	callback,
		void *	private_data )

Add an async handler for a CTL.

Parameters

handler	Returned handler handle
ctl	CTL handle
callback	Callback function
private_data	Callback private data

Returns

0 otherwise a negative error code on failure

snd_async_handler_get_ctl()

snd_ctl_t * snd_async_handler_get_ctl

(

snd_async_handler_t *

handler

)

Return CTL handle related to an async handler.

Parameters

handler

Async handler handle

Returns

CTL handle

snd_ctl_add_boolean_elem_set()

int snd_ctl_add_boolean_elem_set	(	snd_ctl_t *	ctl,
		snd_ctl_elem_info_t *	info,
		unsigned int	element_count,
		unsigned int	member_count )

Create and add some user-defined control elements of boolean type.

Parameters

ctl	A handle of backend module for control interface.
info	Common information for a new element set, with ID of the first new element.
element_count	The number of elements added by this operation.
member_count	The number of members which a element has to represent its states.

This function creates some user elements with boolean type. These elements are not controlled by device drivers in kernel. They can be operated by the same way as usual elements added by the device drivers.

The name field of id must be set with unique value to identify new control elements. After returning, all fields of id are filled. A element can be identified by the combination of name and index, or by numid.

All of members in the new elements are locked. The value of each member is initialized with false.

Errors:

-EBUSY

A element with ID id already exists.

-EINVAL

Some parameters include invalid value; i.e. ID has no name, or the number of members is not between 1 to 127.

-ENOMEM

Out of memory, or there are too many user elements.

-ENXIO

This backend module does not support user elements of boolean type.

-ENODEV

Device unplugged.

Compatibility:

This function is added in version 1.1.2.

snd_ctl_add_bytes_elem_set()

int snd_ctl_add_bytes_elem_set	(	snd_ctl_t *	ctl,
		snd_ctl_elem_info_t *	info,
		unsigned int	element_count,
		unsigned int	member_count )

Create and add some user-defined control elements of bytes type.

Parameters

ctl	A handle of backend module for control interface.
info	Common information for a new element set, with ID of the first new element.
element_count	The number of elements added by this operation.
member_count	The number of members which a element has to represent its states.

Returns

Zero on success, otherwise a negative error code.

This function creates some user elements with bytes type. These elements are not controlled by device drivers in kernel. They can be operated by the same way as usual elements added by the device drivers.

The name field of id must be set with unique value to identify new control elements. After returning, all fields of id are filled. A element can be identified by the combination of name and index, or by numid.

All of members in the new elements are locked. The value of each member is initialized with the minimum value.

Errors:

-EBUSY

A element with ID id already exists.

-EINVAL

Some arguments include invalid value; i.e. ID has no name, or the number of members is not between 1 to 511.

-ENOMEM

Out of memory, or there are too many user elements.

-ENXIO

This backend module does not support user elements of bytes type.

-ENODEV

Device unplugged.

Compatibility:

This function is added in version 1.1.2.

snd_ctl_add_enumerated_elem_set()

int snd_ctl_add_enumerated_elem_set	(	snd_ctl_t *	ctl,
		snd_ctl_elem_info_t *	info,
		unsigned int	element_count,
		unsigned int	member_count,
		unsigned int	items,
		const char *const	labels[] )

Create and add some user-defined control elements of enumerated type.

Parameters

ctl	A handle of backend module for control interface.
info	Common information for a new element set, with ID of the first new element.
element_count	The number of elements added by this operation.
member_count	The number of members which a element has to represent its states.
items	Range of possible values (0 ... items - 1).
labels	An array containing items strings.

Returns

Zero on success, otherwise a negative error code.

This function creates some user elements with enumerated type. These elements are not controlled by device drivers in kernel. They can be operated by the same way as usual elements added by the device drivers.

The name field of id must be set with unique value to identify new control elements. After returning, all fields of id are filled. A element can be identified by the combination of name and index, or by numid.

All of members in the new elements are locked. The value of each member is initialized with the first entry of labels.

Errors:

-EBUSY

A control element with ID id already exists.

-EINVAL

Some arguments include invalid value; i.e. element_count is not between 1 to 127, or items is not at least one, or a string in labels is empty, or longer than 63 bytes, or total length of the labels requires more than 64 KiB storage.

-ENOMEM

Out of memory, or there are too many user control elements.

-ENXIO

This driver does not support (enumerated) user controls.

-ENODEV

Device unplugged.

Compatibility:

This function is added in version 1.1.2.

snd_ctl_add_integer64_elem_set()

int snd_ctl_add_integer64_elem_set	(	snd_ctl_t *	ctl,
		snd_ctl_elem_info_t *	info,
		unsigned int	element_count,
		unsigned int	member_count,
		long long	min,
		long long	max,
		long long	step )

Create and add some user-defined control elements of integer64 type.

Parameters

ctl	A handle of backend module for control interface.
info	Common information for a new element set, with ID of the first new element.
element_count	The number of elements added by this operation.
member_count	The number of members which a element has to represent its states.
min	Minimum value for each member of the elements.
max	Maximum value for each member of the elements.
step	The step of value for each member in the elements.

Returns

Zero on success, otherwise a negative error code.

This function creates some user elements with integer64 type. These elements are not controlled by device drivers in kernel. They can be operated by the same way as usual elements added by the device drivers.

The name field of id must be set with unique value to identify new control elements. After returning, all fields of id are filled. A element can be identified by the combination of name and index, or by numid.

All of members in the new elements are locked. The value of each member is initialized with the minimum value.

Errors:

-EBUSY

A element with ID id already exists.

-EINVAL

Some arguments include invalid value; i.e. ID has no name, or the number of members is not between 1 to 127.

-ENOMEM

Out of memory, or there are too many user elements.

-ENXIO

This backend module does not support user elements of integer64 type.

-ENODEV

Device unplugged.

Compatibility:

This function is added in version 1.1.2.

snd_ctl_add_integer_elem_set()

int snd_ctl_add_integer_elem_set	(	snd_ctl_t *	ctl,
		snd_ctl_elem_info_t *	info,
		unsigned int	element_count,
		unsigned int	member_count,
		long	min,
		long	max,
		long	step )

Create and add some user-defined control elements of integer type.

Parameters

ctl	A handle of backend module for control interface.
info	Common information for a new element set, with ID of the first new element.
element_count	The number of elements added by this operation.
member_count	The number of members which a element has to represent its states.
min	Minimum value for each member of the elements.
max	Maximum value for each member of the elements.
step	The step of value for each member in the elements.

Returns

Zero on success, otherwise a negative error code.

This function creates some user elements with integer type. These elements are not controlled by device drivers in kernel. They can be operated by the same way as usual elements added by the device drivers.

The name field of id must be set with unique value to identify new control elements. After returning, all fields of id are filled. A element can be identified by the combination of name and index, or by numid.

All of members in the new elements are locked. The value of each member is initialized with the minimum value.

Errors:

-EBUSY

A element with ID id already exists.

-EINVAL

Some arguments include invalid value; i.e. ID field in info has no name, or the number of members is not between 1 to 127.

-ENOMEM

Out of memory, or there are too many user elements.

-ENXIO

This backend module does not support user elements of integer type.

-ENODEV

Device unplugged.

Compatibility:

This function is added in version 1.1.2.

snd_ctl_card_info()

int snd_ctl_card_info	(	snd_ctl_t *	ctl,
		snd_ctl_card_info_t *	info )

Get information about the sound card.

Obtain information about the sound card previously opened using snd_ctl_open(). The object "info" must be allocated prior to calling this function. See snd_ctl_card_info_t for details.

Parameters

ctl	The CTL handle.
info	The card information is stored here.

Returns

0 on success, otherwise a negative error code.

snd_ctl_card_info_clear()

void snd_ctl_card_info_clear

(

snd_ctl_card_info_t *

obj

)

Clear given card info object.

See snd_ctl_elem_value_t for details.

Parameters

obj	Card info object.

snd_ctl_card_info_copy()

void snd_ctl_card_info_copy	(	snd_ctl_card_info_t *	dst,
		const snd_ctl_card_info_t *	src )

Bitwise copy of a #snd_ctl_card_info_t object.

Parameters

dst	Pointer to destination.
src	Pointer to source.

snd_ctl_card_info_free()

void snd_ctl_card_info_free

(

snd_ctl_card_info_t *

obj

)

Free an #snd_ctl_card_info_t previously allocated using snd_ctl_card_info_malloc().

Parameters

obj	Pointer to the snd_ctl_card_info_t.

snd_ctl_card_info_get_card()

int snd_ctl_card_info_get_card

(

const snd_ctl_card_info_t *

obj

)

Get the sound card index from the given info object.

See snd_ctl_card_info_t for more details.

Parameters

obj	The card info object.

Returns

Sound card index.

snd_ctl_card_info_get_components()

const char * snd_ctl_card_info_get_components

(

const snd_ctl_card_info_t *

obj

)

Get the sound cards "components" property from the given info object.

See snd_ctl_card_info_t for more details.

Parameters

obj	The card info object.

Returns

Sound cards "components" property.

snd_ctl_card_info_get_driver()

const char * snd_ctl_card_info_get_driver

(

const snd_ctl_card_info_t *

obj

)

Get the sound card driver from the given info object.

See snd_ctl_card_info_t for more details.

Parameters

obj	The card info object.

Returns

The sound card driver.

snd_ctl_card_info_get_id()

const char * snd_ctl_card_info_get_id

(

const snd_ctl_card_info_t *

obj

)

Get the sound card ID from the given info object.

See snd_ctl_card_info_t for more details.

Parameters

obj	The card info object.

Returns

Sound card ID.

snd_ctl_card_info_get_longname()

const char * snd_ctl_card_info_get_longname

(

const snd_ctl_card_info_t *

obj

)

Get the sound cards long name from the given info object.

See snd_ctl_card_info_t for more details.

Parameters

obj	The card info object.

Returns

Sound cards long name.

snd_ctl_card_info_get_mixername()

const char * snd_ctl_card_info_get_mixername

(

const snd_ctl_card_info_t *

obj

)

Get the sound card mixer name from the given info object.

See snd_ctl_card_info_t for more details.

Parameters

obj	The card info object.

Returns

Sound card mixer name.

snd_ctl_card_info_get_name()

const char * snd_ctl_card_info_get_name

(

const snd_ctl_card_info_t *

obj

)

Get the sound card name from the given info object.

See snd_ctl_card_info_t for more details.

Parameters

obj	The card info object.

Returns

Sound card name.

snd_ctl_card_info_malloc()

int snd_ctl_card_info_malloc

(

snd_ctl_card_info_t **

ptr

)

Allocate an invalid #snd_ctl_card_info_t on the heap.

Allocate space for a card info object on the heap. The allocated memory must be freed using snd_ctl_card_info_free().

See snd_ctl_card_info_t for details.

Parameters

ptr	Pointer to a snd_ctl_card_info_t pointer. The address of the allocated space will be returned here.

Returns

0 on success, otherwise a negative error code.

snd_ctl_card_info_sizeof()

size_t snd_ctl_card_info_sizeof

(

)

get size of #snd_ctl_card_info_t.

Returns

Size in bytes.

snd_ctl_close()

int snd_ctl_close

(

snd_ctl_t *

ctl

)

close CTL handle

Parameters

ctl	CTL handle

Returns

0 on success otherwise a negative error code

Closes the specified CTL handle and frees all associated resources.

snd_ctl_elem_add_boolean()

int snd_ctl_elem_add_boolean	(	snd_ctl_t *	ctl,
		const snd_ctl_elem_id_t *	id,
		unsigned int	member_count )

Create and add an user-defined control element of boolean type.

This is a wrapper function to snd_ctl_add_boolean_elem_set() for a single control element. This doesn't fill the id data with full information, thus it's recommended to use snd_ctl_add_boolean_elem_set(), instead.

snd_ctl_elem_add_enumerated()

int snd_ctl_elem_add_enumerated	(	snd_ctl_t *	ctl,
		const snd_ctl_elem_id_t *	id,
		unsigned int	member_count,
		unsigned int	items,
		const char *const	labels[] )

Create and add a user-defined control element of enumerated type.

This is a wrapper function to snd_ctl_add_enumerated_elem_set() for a single control element. This doesn't fill the id data with full information, thus it's recommended to use snd_ctl_add_enumerated_elem_set(), instead.

This function is added in version 1.0.25.

snd_ctl_elem_add_iec958()

int snd_ctl_elem_add_iec958	(	snd_ctl_t *	ctl,
		const snd_ctl_elem_id_t *	id )

Create and add a user-defined control element of IEC958 type.

Parameters

[in]	ctl	A handle of backend module for control interface.
[in,out]	id	ID of the new control element.

This function creates an user element with IEC958 type. This element is not controlled by device drivers in kernel. It can be operated by the same way as usual elements added by the device drivers.

The name field of id must be set with unique value to identify a new control element. After returning, all fields of id are filled. A element can be identified by the combination of name and index, or by numid.

A member in the new element is locked and filled with zero.

Errors:

-EBUSY

A control element with ID id already exists.

-EINVAL

ID has no name.

-ENOMEM

Out of memory, or there are too many user elements.

-ENXIO

This backend module does not support user elements of IEC958 type.

-ENODEV

Device unplugged.

snd_ctl_elem_add_integer()

int snd_ctl_elem_add_integer	(	snd_ctl_t *	ctl,
		const snd_ctl_elem_id_t *	id,
		unsigned int	member_count,
		long	min,
		long	max,
		long	step )

Create and add an user-defined control element of integer type.

This is a wrapper function to snd_ctl_add_integer_elem_set() for a control element. This doesn't fill the id data with full information, thus it's recommended to use snd_ctl_add_integer_elem_set(), instead.

snd_ctl_elem_add_integer64()

int snd_ctl_elem_add_integer64	(	snd_ctl_t *	ctl,
		const snd_ctl_elem_id_t *	id,
		unsigned int	member_count,
		long long	min,
		long long	max,
		long long	step )

Create and add an user-defined control element of integer64 type.

This is a wrapper function to snd_ctl_add_integer64_elem_set() for a single control element. This doesn't fill the id data with full information, thus it's recommended to use snd_ctl_add_integer64_elem_set(), instead.

snd_ctl_elem_id_clear()

void snd_ctl_elem_id_clear

(

snd_ctl_elem_id_t *

obj

)

clear given #snd_ctl_elem_id_t object

Parameters

obj	pointer to object to clear

snd_ctl_elem_id_compare_numid()

int snd_ctl_elem_id_compare_numid	(	const snd_ctl_elem_id_t *	id1,
		const snd_ctl_elem_id_t *	id2 )

compare one #snd_ctl_elem_id_t to another using numid

Parameters

id1	pointer to first id
id2	pointer to second id

Return values

zero	when values are identical, other value on a difference (like strcmp)

This comparison ignores the set of fields part.

The return value can be used for sorting like qsort(). It gives persistent results.

snd_ctl_elem_id_compare_set()

int snd_ctl_elem_id_compare_set	(	const snd_ctl_elem_id_t *	id1,
		const snd_ctl_elem_id_t *	id2 )

compare one #snd_ctl_elem_id_t to another

Parameters

id1	pointer to first id
id2	pointer to second id

Return values

zero	when values are identical, other value on a difference (like strcmp)

This comparison ignores the numid part. The numid comparison can be easily implemented using snd_ctl_elem_id_get_numid() calls.

The identifier set fields are compared in this order: interface, device, subdevice, name, index.

The return value can be used for sorting like qsort(). It gives persistent results.

snd_ctl_elem_id_copy()

void snd_ctl_elem_id_copy	(	snd_ctl_elem_id_t *	dst,
		const snd_ctl_elem_id_t *	src )

copy one #snd_ctl_elem_id_t to another

Parameters

dst	pointer to destination
src	pointer to source

snd_ctl_elem_id_free()

void snd_ctl_elem_id_free

(

snd_ctl_elem_id_t *

obj

)

frees a previously allocated #snd_ctl_elem_id_t

Parameters

obj	pointer to object to free

snd_ctl_elem_id_get_device()

unsigned int snd_ctl_elem_id_get_device

(

const snd_ctl_elem_id_t *

obj

)

Get device part of a CTL element identifier.

Parameters

obj	CTL element identifier

Returns

CTL element related device

snd_ctl_elem_id_get_index()

unsigned int snd_ctl_elem_id_get_index

(

const snd_ctl_elem_id_t *

obj

)

Get index part of a CTL element identifier.

Parameters

obj	CTL element identifier

Returns

CTL element index

snd_ctl_elem_id_get_interface()

snd_ctl_elem_iface_t snd_ctl_elem_id_get_interface

(

const snd_ctl_elem_id_t *

obj

)

Get interface part of a CTL element identifier.

Parameters

obj	CTL element identifier

Returns

CTL element related interface

snd_ctl_elem_id_get_name()

const char * snd_ctl_elem_id_get_name

(

const snd_ctl_elem_id_t *

obj

)

Get name part of a CTL element identifier.

Parameters

obj	CTL element identifier

Returns

CTL element name

snd_ctl_elem_id_get_numid()

unsigned int snd_ctl_elem_id_get_numid

(

const snd_ctl_elem_id_t *

obj

)

Get numeric identifier from a CTL element identifier.

Parameters

obj	CTL element identifier

Returns

CTL element numeric identifier

snd_ctl_elem_id_get_subdevice()

unsigned int snd_ctl_elem_id_get_subdevice

(

const snd_ctl_elem_id_t *

obj

)

Get subdevice part of a CTL element identifier.

Parameters

obj	CTL element identifier

Returns

CTL element related subdevice

snd_ctl_elem_id_malloc()

int snd_ctl_elem_id_malloc

(

snd_ctl_elem_id_t **

ptr

)

allocate an invalid #snd_ctl_elem_id_t using standard malloc

Parameters

ptr	returned pointer

Returns

0 on success otherwise negative error code

snd_ctl_elem_id_set_device()

void snd_ctl_elem_id_set_device	(	snd_ctl_elem_id_t *	obj,
		unsigned int	val )

Set device part for a CTL element identifier.

Parameters

obj	CTL element identifier
val	CTL element related device

snd_ctl_elem_id_set_index()

void snd_ctl_elem_id_set_index	(	snd_ctl_elem_id_t *	obj,
		unsigned int	val )

Set index part for a CTL element identifier.

Parameters

obj	CTL element identifier
val	CTL element index

snd_ctl_elem_id_set_interface()

void snd_ctl_elem_id_set_interface	(	snd_ctl_elem_id_t *	obj,
		snd_ctl_elem_iface_t	val )

Set interface part for a CTL element identifier.

Parameters

obj	CTL element identifier
val	CTL element related interface

snd_ctl_elem_id_set_name()

void snd_ctl_elem_id_set_name	(	snd_ctl_elem_id_t *	obj,
		const char *	val )

Set name part for a CTL element identifier.

Parameters

obj	CTL element identifier
val	CTL element name

snd_ctl_elem_id_set_numid()

void snd_ctl_elem_id_set_numid	(	snd_ctl_elem_id_t *	obj,
		unsigned int	val )

Set numeric identifier for a CTL element identifier.

Parameters

obj	CTL element identifier
val	CTL element numeric identifier

snd_ctl_elem_id_set_subdevice()

void snd_ctl_elem_id_set_subdevice	(	snd_ctl_elem_id_t *	obj,
		unsigned int	val )

Set subdevice part for a CTL element identifier.

Parameters

obj	CTL element identifier
val	CTL element related subdevice

snd_ctl_elem_id_sizeof()

size_t snd_ctl_elem_id_sizeof

(

)

get size of #snd_ctl_elem_id_t

Returns

size in bytes

snd_ctl_elem_iface_name()

const char * snd_ctl_elem_iface_name

(

snd_ctl_elem_iface_t

iface

)

get name of a CTL element related interface

Parameters

iface

CTL element related interface

Returns

ascii name of CTL element related interface

snd_ctl_elem_info()

int snd_ctl_elem_info	(	snd_ctl_t *	ctl,
		snd_ctl_elem_info_t *	info )

Get CTL element information.

Parameters

ctl	CTL handle
info	CTL element id/information pointer

Returns

0 on success otherwise a negative error code

snd_ctl_elem_info_clear()

void snd_ctl_elem_info_clear

(

snd_ctl_elem_info_t *

obj

)

clear given #snd_ctl_elem_info_t object

Parameters

obj	pointer to object to clear

snd_ctl_elem_info_copy()

void snd_ctl_elem_info_copy	(	snd_ctl_elem_info_t *	dst,
		const snd_ctl_elem_info_t *	src )

copy one #snd_ctl_elem_info_t to another

Parameters

dst	pointer to destination
src	pointer to source

snd_ctl_elem_info_free()

void snd_ctl_elem_info_free

(

snd_ctl_elem_info_t *

obj

)

frees a previously allocated #snd_ctl_elem_info_t

Parameters

obj	pointer to object to free

snd_ctl_elem_info_get_count()

unsigned int snd_ctl_elem_info_get_count

(

const snd_ctl_elem_info_t *

obj

)

Get number of value entries from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

value entries count

snd_ctl_elem_info_get_device()

unsigned int snd_ctl_elem_info_get_device

(

const snd_ctl_elem_info_t *

obj

)

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

Parameters

obj	CTL element id/info

Returns

device part of element identifier

snd_ctl_elem_info_get_dimension()

int snd_ctl_elem_info_get_dimension	(	const snd_ctl_elem_info_t *	obj,
		unsigned int	idx )

Get specified of dimension width for given element.

Parameters

obj	CTL element id/info
idx	The dimension index

Returns

zero value if no dimension width is defined, otherwise positive value with with of specified dimension

Deprecated

Since 1.1.5 snd_ctl_elem_info_get_dimension is deprecated without any replacement.

snd_ctl_elem_info_get_dimensions()

int snd_ctl_elem_info_get_dimensions

(

const snd_ctl_elem_info_t *

obj

)

Get count of dimensions for given element.

Parameters

obj	CTL element id/info

Returns

zero value if no dimensions are defined, otherwise positive value with count of dimensions

Deprecated

Since 1.1.5 snd_ctl_elem_info_get_dimensions is deprecated without any replacement.

snd_ctl_elem_info_get_id()

void snd_ctl_elem_info_get_id	(	const snd_ctl_elem_info_t *	obj,
		snd_ctl_elem_id_t *	ptr )

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

Parameters

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

snd_ctl_elem_info_get_index()

unsigned int snd_ctl_elem_info_get_index

(

const snd_ctl_elem_info_t *

obj

)

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

Parameters

obj	CTL element id/info

Returns

index part of element identifier

snd_ctl_elem_info_get_interface()

snd_ctl_elem_iface_t snd_ctl_elem_info_get_interface

(

const snd_ctl_elem_info_t *

obj

)

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

Parameters

obj	CTL element id/info

Returns

interface part of element identifier

snd_ctl_elem_info_get_item_name()

const char * snd_ctl_elem_info_get_item_name

(

const snd_ctl_elem_info_t *

obj

)

Get name for selected item in a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info.

Parameters

obj	CTL element id/info

Returns

name of chosen item

snd_ctl_elem_info_get_items()

unsigned int snd_ctl_elem_info_get_items

(

const snd_ctl_elem_info_t *

obj

)

Get number of items available from a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info.

Parameters

obj	CTL element id/info

Returns

items count

snd_ctl_elem_info_get_max()

long snd_ctl_elem_info_get_max

(

const snd_ctl_elem_info_t *

obj

)

Get maximum value from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info.

Parameters

obj	CTL element id/info

Returns

Maximum value

snd_ctl_elem_info_get_max64()

long long snd_ctl_elem_info_get_max64

(

const snd_ctl_elem_info_t *

obj

)

Get maximum value from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info.

Parameters

obj	CTL element id/info

Returns

Maximum value

snd_ctl_elem_info_get_min()

long snd_ctl_elem_info_get_min

(

const snd_ctl_elem_info_t *

obj

)

Get minimum value from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info.

Parameters

obj	CTL element id/info

Returns

Minimum value

snd_ctl_elem_info_get_min64()

long long snd_ctl_elem_info_get_min64

(

const snd_ctl_elem_info_t *

obj

)

Get minimum value from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info.

Parameters

obj	CTL element id/info

Returns

Minimum value

snd_ctl_elem_info_get_name()

const char * snd_ctl_elem_info_get_name

(

const snd_ctl_elem_info_t *

obj

)

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

Parameters

obj	CTL element id/info

Returns

name part of element identifier

snd_ctl_elem_info_get_numid()

unsigned int snd_ctl_elem_info_get_numid

(

const snd_ctl_elem_info_t *

obj

)

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

Parameters

obj	CTL element id/info

Returns

element numeric identifier

snd_ctl_elem_info_get_owner()

pid_t snd_ctl_elem_info_get_owner

(

const snd_ctl_elem_info_t *

obj

)

Get owner of a locked element.

Parameters

obj	CTL element id/info

Returns

value entries count

snd_ctl_elem_info_get_step()

long snd_ctl_elem_info_get_step

(

const snd_ctl_elem_info_t *

obj

)

Get value step from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info.

Parameters

obj	CTL element id/info

Returns

Step

snd_ctl_elem_info_get_step64()

long long snd_ctl_elem_info_get_step64

(

const snd_ctl_elem_info_t *

obj

)

Get value step from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info.

Parameters

obj	CTL element id/info

Returns

Step

snd_ctl_elem_info_get_subdevice()

unsigned int snd_ctl_elem_info_get_subdevice

(

const snd_ctl_elem_info_t *

obj

)

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

Parameters

obj	CTL element id/info

Returns

subdevice part of element identifier

snd_ctl_elem_info_get_type()

snd_ctl_elem_type_t snd_ctl_elem_info_get_type

(

const snd_ctl_elem_info_t *

obj

)

Get type from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

CTL element content type

snd_ctl_elem_info_is_inactive()

int snd_ctl_elem_info_is_inactive

(

const snd_ctl_elem_info_t *

obj

)

Get info about status from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

0 if element value is not active, 1 if is active

snd_ctl_elem_info_is_indirect()

int snd_ctl_elem_info_is_indirect

(

const snd_ctl_elem_info_t *

obj

)

(DEPRECATED) Get info about values passing policy from a CTL element value

Parameters

obj	CTL element id/info

Returns

0 if element value need to be passed by contents, 1 if need to be passed with a pointer

snd_ctl_elem_info_is_locked()

int snd_ctl_elem_info_is_locked

(

const snd_ctl_elem_info_t *

obj

)

Get info whether an element is locked.

Parameters

obj	CTL element id/info

Returns

0 if element value is currently changeable, 1 if it's locked by another application

snd_ctl_elem_info_is_owner()

int snd_ctl_elem_info_is_owner

(

const snd_ctl_elem_info_t *

obj

)

Get info if I own an element.

Parameters

obj	CTL element id/info

Returns

0 if element value is currently changeable, 1 if it's locked by another application

snd_ctl_elem_info_is_readable()

int snd_ctl_elem_info_is_readable

(

const snd_ctl_elem_info_t *

obj

)

Get info about readability from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

0 if element is not readable, 1 if element is readable

snd_ctl_elem_info_is_tlv_commandable()

int snd_ctl_elem_info_is_tlv_commandable

(

const snd_ctl_elem_info_t *

obj

)

Get info about TLV command possibility from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

0 if element's TLV command is not possible, 1 if element's TLV command is supported

snd_ctl_elem_info_is_tlv_readable()

int snd_ctl_elem_info_is_tlv_readable

(

const snd_ctl_elem_info_t *

obj

)

Get info about TLV readability from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

0 if element's TLV is not readable, 1 if element's TLV is readable

snd_ctl_elem_info_is_tlv_writable()

int snd_ctl_elem_info_is_tlv_writable

(

const snd_ctl_elem_info_t *

obj

)

Get info about TLV writeability from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

0 if element's TLV is not writable, 1 if element's TLV is writable

snd_ctl_elem_info_is_user()

int snd_ctl_elem_info_is_user

(

const snd_ctl_elem_info_t *

obj

)

Get info if it's a user element.

Parameters

obj	CTL element id/info

Returns

0 if element value is a system element, 1 if it's a user-created element

snd_ctl_elem_info_is_volatile()

int snd_ctl_elem_info_is_volatile

(

const snd_ctl_elem_info_t *

obj

)

Get info about notification feasibility from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

0 if all element value changes are notified to subscribed applications, 1 otherwise

snd_ctl_elem_info_is_writable()

int snd_ctl_elem_info_is_writable

(

const snd_ctl_elem_info_t *

obj

)

Get info about writability from a CTL element id/info.

Parameters

obj	CTL element id/info

Returns

0 if element is not writable, 1 if element is not writable

snd_ctl_elem_info_malloc()

int snd_ctl_elem_info_malloc

(

snd_ctl_elem_info_t **

ptr

)

allocate an invalid #snd_ctl_elem_info_t using standard malloc

Parameters

ptr	returned pointer

Returns

0 on success otherwise negative error code

snd_ctl_elem_info_set_device()

void snd_ctl_elem_info_set_device	(	snd_ctl_elem_info_t *	obj,
		unsigned int	val )

Set device part of CTL element identifier of a CTL element id/info.

Parameters

obj	CTL element id/info
val	device part of element identifier

snd_ctl_elem_info_set_dimension()

int snd_ctl_elem_info_set_dimension	(	snd_ctl_elem_info_t *	info,
		const int	dimension[4] )

Set width to a specified dimension level of given element information.

Parameters

info	Information of an element.
dimension	Dimension width for each level by member unit.

Returns

Zero on success, otherwise a negative error code.

Errors:

-EINVAL

Invalid arguments are given as parameters.

Compatibility:

This function is added in version 1.1.2.

Deprecated

Since 1.1.5 snd_ctl_elem_info_set_dimension is deprecated without any replacement.

snd_ctl_elem_info_set_id()

void snd_ctl_elem_info_set_id	(	snd_ctl_elem_info_t *	obj,
		const snd_ctl_elem_id_t *	ptr )

Set CTL element identifier of a CTL element id/info.

Parameters

obj	CTL element id/info
ptr	CTL element identifier

snd_ctl_elem_info_set_inactive()

void snd_ctl_elem_info_set_inactive	(	snd_ctl_elem_info_t *	obj,
		int	val )

Set inactive parameter of a CTL element id/info.

Parameters

obj	CTL element id/info
val	inactive part of element identifier

snd_ctl_elem_info_set_index()

void snd_ctl_elem_info_set_index	(	snd_ctl_elem_info_t *	obj,
		unsigned int	val )

Set index part of CTL element identifier of a CTL element id/info.

Parameters

obj	CTL element id/info
val	index part of element identifier

snd_ctl_elem_info_set_interface()

void snd_ctl_elem_info_set_interface	(	snd_ctl_elem_info_t *	obj,
		snd_ctl_elem_iface_t	val )

Set interface part of CTL element identifier of a CTL element id/info.

Parameters

obj	CTL element id/info
val	interface part of element identifier

snd_ctl_elem_info_set_item()

void snd_ctl_elem_info_set_item	(	snd_ctl_elem_info_t *	obj,
		unsigned int	val )

Select item in a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info.

Parameters

obj	CTL element id/info
val	item number

snd_ctl_elem_info_set_name()

void snd_ctl_elem_info_set_name	(	snd_ctl_elem_info_t *	obj,
		const char *	val )

Set name part of CTL element identifier of a CTL element id/info.

Parameters

obj	CTL element id/info
val	name part of element identifier

snd_ctl_elem_info_set_numid()

void snd_ctl_elem_info_set_numid	(	snd_ctl_elem_info_t *	obj,
		unsigned int	val )

Set element numeric identifier of a CTL element id/info.

Parameters

obj	CTL element id/info
val	element numeric identifier

snd_ctl_elem_info_set_read_write()

void snd_ctl_elem_info_set_read_write	(	snd_ctl_elem_info_t *	obj,
		int	rval,
		int	wval )

Set readability/writeability parameter of a CTL element id/info.

Parameters

obj	CTL element id/info
rval	readability part of element identifier
wval	writeability part of element identifier

snd_ctl_elem_info_set_subdevice()

void snd_ctl_elem_info_set_subdevice	(	snd_ctl_elem_info_t *	obj,
		unsigned int	val )

Set subdevice part of CTL element identifier of a CTL element id/info.

Parameters

obj	CTL element id/info
val	subdevice part of element identifier

snd_ctl_elem_info_set_tlv_read_write()

void snd_ctl_elem_info_set_tlv_read_write	(	snd_ctl_elem_info_t *	obj,
		int	rval,
		int	wval )

Set TLV readability/writeability parameter of a CTL element id/info.

Parameters

obj	CTL element id/info
rval	TLV readability part of element identifier
wval	TLV writeability part of element identifier

snd_ctl_elem_info_sizeof()

size_t snd_ctl_elem_info_sizeof

(

)

get size of #snd_ctl_elem_info_t

Returns

size in bytes

snd_ctl_elem_list()

int snd_ctl_elem_list	(	snd_ctl_t *	ctl,
		snd_ctl_elem_list_t *	list )

Get a list of element identifiers.

Before calling this function, memoru must be allocated using snd_ctl_elem_list_malloc().

This function obtains data from the sound card driver and puts it into the list.

If there was space allocated for the element identifiers (using snd_ctl_elem_list_alloc_space()), information will be filled in. If too little space was allocated, only a part of the elements will be queried. If there was too much space allocated, some of it remains unused. Use snd_ctl_elem_list_get_count() and snd_ctl_elem_list_get_used() to obtain information about space usage. See #snd_ctl_elem_list_t to learn more.

Parameters

ctl	CTL handle
list	CTL element identifiers list pointer

Returns

0 on success otherwise a negative error code

snd_ctl_elem_list_alloc_space()

int snd_ctl_elem_list_alloc_space	(	snd_ctl_elem_list_t *	obj,
		unsigned int	entries )

allocate space for CTL element identifiers list

The space can be released with snd_ctl_elem_list_free_space().

Parameters

obj	CTL element identifiers list.
entries	How many entries to allocate. See #snd_ctl_elem_list_t to learn how to obtain this number in advance.

Returns

0 on success otherwise a negative error code.

snd_ctl_elem_list_clear()

void snd_ctl_elem_list_clear

(

snd_ctl_elem_list_t *

obj

)

Clear given #snd_ctl_elem_list_t object.

This will make the stored identifiers inaccessible without freeing their space.

Warning

The element identifier space cannot be freed after calling this function. Therefore, snd_ctl_elem_list_free_space() must be called in advance.

Parameters

obj	pointer to object to clear

snd_ctl_elem_list_copy()

void snd_ctl_elem_list_copy	(	snd_ctl_elem_list_t *	dst,
		const snd_ctl_elem_list_t *	src )

copy one #snd_ctl_elem_list_t to another.

This performs a shallow copy. That means the both lists will share the same space for the elements. The elements will not be copied.

Parameters

dst	pointer to destination
src	pointer to source

snd_ctl_elem_list_free()

void snd_ctl_elem_list_free

(

snd_ctl_elem_list_t *

obj

)

frees a previously allocated #snd_ctl_elem_list_t.

Release memory previously allocated using snd_ctl_elem_list_malloc().

If you used snd_ctl_elem_list_alloc_space() on the list, you must use snd_ctl_elem_list_free_space() before calling this function.

Parameters

obj	pointer to object to free

snd_ctl_elem_list_free_space()

void snd_ctl_elem_list_free_space

(

snd_ctl_elem_list_t *

obj

)

free previously allocated space for CTL element identifiers list

Releases space previously allocated using snd_ctl_elem_list_alloc_space().

Parameters

obj	CTL element identifiers list

snd_ctl_elem_list_get_count()

unsigned int snd_ctl_elem_list_get_count

(

const snd_ctl_elem_list_t *

obj

)

Get total count of elements present in CTL device.

This function returns how many entries were allocated using snd_ctl_elem_list_alloc_space(). This information is present after snd_ctl_elem_list() was called.

See also snd_ctl_elem_list_get_used().

Parameters

obj	CTL element identifier list

Returns

total number of elements

snd_ctl_elem_list_get_device()

unsigned int snd_ctl_elem_list_get_device	(	const snd_ctl_elem_list_t *	obj,
		unsigned int	idx )

Get the device part of CTL element identifier for an entry of a CTL element identifiers list.

Parameters

obj	CTL element identifier list
idx	Index of entry

Returns

CTL element related device

snd_ctl_elem_list_get_id()

void snd_ctl_elem_list_get_id	(	const snd_ctl_elem_list_t *	obj,
		unsigned int	idx,
		snd_ctl_elem_id_t *	ptr )

Get CTL element identifier for an entry of a CTL element identifiers list.

Parameters

obj	CTL element identifier list
idx	Index of entry
ptr	Pointer to returned CTL element identifier

snd_ctl_elem_list_get_index()

unsigned int snd_ctl_elem_list_get_index	(	const snd_ctl_elem_list_t *	obj,
		unsigned int	idx )

Get index part of CTL element identifier for an entry of a CTL element identifiers list.

Parameters

obj	CTL element identifier list
idx	Index of entry

Returns

CTL element index

snd_ctl_elem_list_get_interface()

snd_ctl_elem_iface_t snd_ctl_elem_list_get_interface	(	const snd_ctl_elem_list_t *	obj,
		unsigned int	idx )

Get interface part of CTL element identifier for an entry of a CTL element identifiers list.

Parameters

obj	CTL element identifier list
idx	Index of entry

Returns

CTL element related interface

snd_ctl_elem_list_get_name()

const char * snd_ctl_elem_list_get_name	(	const snd_ctl_elem_list_t *	obj,
		unsigned int	idx )

Get name part of CTL element identifier for an entry of a CTL element identifiers list.

Parameters

obj	CTL element identifier list
idx	Index of entry

Returns

CTL element name

snd_ctl_elem_list_get_numid()

unsigned int snd_ctl_elem_list_get_numid	(	const snd_ctl_elem_list_t *	obj,
		unsigned int	idx )

Get CTL element numeric identifier for an entry of a CTL element identifiers list.

Parameters

obj	CTL element identifier list
idx	Index of entry

Returns

CTL element numeric identifier

snd_ctl_elem_list_get_subdevice()

unsigned int snd_ctl_elem_list_get_subdevice	(	const snd_ctl_elem_list_t *	obj,
		unsigned int	idx )

Get subdevice part of CTL element identifier for an entry of a CTL element identifiers list.

Parameters

obj	CTL element identifier list
idx	Index of entry

Returns

CTL element related subdevice

snd_ctl_elem_list_get_used()

unsigned int snd_ctl_elem_list_get_used

(

const snd_ctl_elem_list_t *

obj

)

Get number of used entries in CTL element identifiers list.

This function returns how many entries are actually filled with useful information.

See also snd_ctl_elem_list_get_count().

Parameters

obj	CTL element identifier list

Returns

number of used entries

snd_ctl_elem_list_malloc()

int snd_ctl_elem_list_malloc

(

snd_ctl_elem_list_t **

ptr

)

allocate a #snd_ctl_elem_list_t using standard malloc.

The memory can be released using snd_ctl_elem_list_free().

Parameters

ptr	returned pointer

Returns

0 on success otherwise negative error code

snd_ctl_elem_list_set_offset()

void snd_ctl_elem_list_set_offset	(	snd_ctl_elem_list_t *	obj,
		unsigned int	val )

Set index of first wanted CTL element identifier in a CTL element identifiers list.

Parameters

obj	CTL element identifiers list
val	index of CTL element to put at position 0 of list

snd_ctl_elem_list_sizeof()

size_t snd_ctl_elem_list_sizeof

(

)

get size of #snd_ctl_elem_list_t.

Returns

size in bytes

snd_ctl_elem_lock()

int snd_ctl_elem_lock	(	snd_ctl_t *	ctl,
		snd_ctl_elem_id_t *	id )

Lock CTL element.

Parameters

ctl	CTL handle
id	CTL element id pointer

Returns

0 on success otherwise a negative error code

snd_ctl_elem_read()

int snd_ctl_elem_read	(	snd_ctl_t *	ctl,
		snd_ctl_elem_value_t *	data )

Get CTL element value.

Read information from sound card. You must set the ID of the element before calling this function.

See snd_ctl_elem_value_t for details.

Parameters

ctl	CTL handle.
data	The element value. The ID must be set before calling the function, and the actual value will be returned here.

Returns

0 on success otherwise a negative error code.

snd_ctl_elem_remove()

int snd_ctl_elem_remove	(	snd_ctl_t *	ctl,
		snd_ctl_elem_id_t *	id )

Remove an user CTL element.

Parameters

ctl	CTL handle
id	CTL element identification

Returns

0 on success otherwise a negative error code

snd_ctl_elem_set_bytes()

void snd_ctl_elem_set_bytes	(	snd_ctl_elem_value_t *	obj,
		void *	data,
		size_t	size )

Replace the data stored within the element.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_BYTES. It replaces the data stored in the element. Note that "bytes" elements don't have members. They have only one single block of data.

See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
data	Pointer to the new data.
size	The size of the new data, in bytes.

snd_ctl_elem_tlv_command()

int snd_ctl_elem_tlv_command	(	snd_ctl_t *	ctl,
		const snd_ctl_elem_id_t *	id,
		const unsigned int *	tlv )

Process structured data from given buffer for an element set.

Parameters

ctl	A handle of backend module for control interface.
id	ID of an element.
tlv	An array with members of unsigned int type. The second member must represent total bytes of the rest of array.

Return values

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

The format of an array of tlv argument is: tlv[0]: Type. One of SND_CTL_TLVT_XXX. tlv[1]: Length. The length of value in units of byte. tlv[2..]: Value. Depending on the type.

Details are described in <sound/tlv.h>.

snd_ctl_elem_tlv_read()

int snd_ctl_elem_tlv_read	(	snd_ctl_t *	ctl,
		const snd_ctl_elem_id_t *	id,
		unsigned int *	tlv,
		unsigned int	tlv_size )

Read structured data from an element set to given buffer.

Parameters

ctl	A handle of backend module for control interface.
id	ID of an element.
tlv	An array with members of unsigned int type.
tlv_size	The length of the array.

Returns

0 on success otherwise a negative error code

The format of an array of tlv argument is: tlv[0]: Type. One of SND_CTL_TLVT_XXX. tlv[1]: Length. The length of value in units of byte. tlv[2..]: Value. Depending on the type.

Details are described in <sound/tlv.h>.

snd_ctl_elem_tlv_write()

int snd_ctl_elem_tlv_write	(	snd_ctl_t *	ctl,
		const snd_ctl_elem_id_t *	id,
		const unsigned int *	tlv )

Write structured data from given buffer to an element set.

Parameters

ctl	A handle of backend module for control interface.
id	ID of an element.
tlv	An array with members of unsigned int type. The second member must represent total bytes of the rest of array.

Return values

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

The format of an array of tlv argument is: tlv[0]: Type. One of SND_CTL_TLVT_XXX. tlv[1]: Length. The length of value in units of byte. tlv[2..]: Value. Depending on the type.

Details are described in <sound/tlv.h>.

snd_ctl_elem_type_name()

const char * snd_ctl_elem_type_name

(

snd_ctl_elem_type_t

type

)

get name of a CTL element type

Parameters

type	CTL element type

Returns

ascii name of CTL element type

snd_ctl_elem_unlock()

int snd_ctl_elem_unlock	(	snd_ctl_t *	ctl,
		snd_ctl_elem_id_t *	id )

Unlock CTL element.

Parameters

ctl	CTL handle
id	CTL element id pointer

Returns

0 on success otherwise a negative error code

snd_ctl_elem_value_clear()

void snd_ctl_elem_value_clear

(

snd_ctl_elem_value_t *

obj

)

Clear given data of an element.

See snd_ctl_elem_value_t for details.

Parameters

obj	Data of an element.

snd_ctl_elem_value_compare()

int snd_ctl_elem_value_compare	(	snd_ctl_elem_value_t *	left,
		const snd_ctl_elem_value_t *	right )

Compare two snd_ctl_elem_value_t values, bytewise.

Parameters

left	First value.
right	Second value.

Returns

0 on match, less than or greater than otherwise, see memcmp(3).

snd_ctl_elem_value_copy()

void snd_ctl_elem_value_copy	(	snd_ctl_elem_value_t *	dst,
		const snd_ctl_elem_value_t *	src )

Bitwise copy of a snd_ctl_elem_value_t value.

Parameters

dst	Pointer to destination.
src	Pointer to source.

snd_ctl_elem_value_free()

void snd_ctl_elem_value_free

(

snd_ctl_elem_value_t *

obj

)

Free an #snd_ctl_elem_value_t previously allocated using snd_ctl_elem_value_malloc().

Parameters

obj	Pointer to the snd_ctl_elem_value_t.

snd_ctl_elem_value_get_boolean()

int snd_ctl_elem_value_get_boolean	(	const snd_ctl_elem_value_t *	obj,
		unsigned int	idx )

Get an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_BOOLEAN. It returns the value of one member. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object
idx	The index of the member.

Returns

The members value.

snd_ctl_elem_value_get_byte()

unsigned char snd_ctl_elem_value_get_byte	(	const snd_ctl_elem_value_t *	obj,
		unsigned int	idx )

Get an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_BYTE. It returns the value of one member. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the member.

Returns

The members value.

snd_ctl_elem_value_get_bytes()

const void * snd_ctl_elem_value_get_bytes

(

const snd_ctl_elem_value_t *

obj

)

Get the data stored within the element.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_BYTES. It returns the data stored in the element. Note that "bytes" elements don't have members. They have only one single block of data.

See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.

Returns

Pointer to the elements data.

snd_ctl_elem_value_get_device()

unsigned int snd_ctl_elem_value_get_device

(

const snd_ctl_elem_value_t *

obj

)

Get the identifiers 'device' part from the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.

Returns

The device part of element identifier.

snd_ctl_elem_value_get_enumerated()

unsigned int snd_ctl_elem_value_get_enumerated	(	const snd_ctl_elem_value_t *	obj,
		unsigned int	idx )

Get an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_ENUMERATED. It returns the index of the active item. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the requested member.

Returns

The index of the active item.

snd_ctl_elem_value_get_id()

void snd_ctl_elem_value_get_id	(	const snd_ctl_elem_value_t *	obj,
		snd_ctl_elem_id_t *	ptr )

Get the element identifier from the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.
ptr	Pointer to an identifier object. The identifier is stored there.

snd_ctl_elem_value_get_iec958()

void snd_ctl_elem_value_get_iec958	(	const snd_ctl_elem_value_t *	obj,
		snd_aes_iec958_t *	ptr )

Get an elements IEC958 data.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_IEC958. Note that "IEC958" elements don't have members. They have only one single IEC958 information block.

See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
ptr	Pointer to an IEC958 structure. The data is stored there.

snd_ctl_elem_value_get_index()

unsigned int snd_ctl_elem_value_get_index

(

const snd_ctl_elem_value_t *

obj

)

Get the identifiers 'index' part from the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.

Returns

The index part of element identifier.

snd_ctl_elem_value_get_integer()

long snd_ctl_elem_value_get_integer	(	const snd_ctl_elem_value_t *	obj,
		unsigned int	idx )

Get an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_INTEGER. It returns the value of one member. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the member.

Returns

The members value.

snd_ctl_elem_value_get_integer64()

long long snd_ctl_elem_value_get_integer64	(	const snd_ctl_elem_value_t *	obj,
		unsigned int	idx )

Get an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_INTEGER64. It returns the value of one member. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the member.

Returns

The members value.

snd_ctl_elem_value_get_interface()

snd_ctl_elem_iface_t snd_ctl_elem_value_get_interface

(

const snd_ctl_elem_value_t *

obj

)

Get the identifiers 'interface' part from the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.

Returns

The interface part of element identifier.

snd_ctl_elem_value_get_name()

const char * snd_ctl_elem_value_get_name

(

const snd_ctl_elem_value_t *

obj

)

Get the identifiers 'name' part from the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.

Returns

The "name" part of element identifier.

snd_ctl_elem_value_get_numid()

unsigned int snd_ctl_elem_value_get_numid

(

const snd_ctl_elem_value_t *

obj

)

Get the identifiers 'numid' part from the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.

Returns

The numid.

snd_ctl_elem_value_get_subdevice()

unsigned int snd_ctl_elem_value_get_subdevice

(

const snd_ctl_elem_value_t *

obj

)

Get the identifiers 'subdevice' part from the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.

Returns

The subdevice part of element identifier.

snd_ctl_elem_value_malloc()

int snd_ctl_elem_value_malloc

(

snd_ctl_elem_value_t **

ptr

)

Allocate an invalid #snd_ctl_elem_value_t on the heap.

Allocate space for a value object on the heap. The allocated memory must be freed using snd_ctl_elem_value_free().

See snd_ctl_elem_value_t for details.

Parameters

ptr	Pointer to a snd_ctl_elem_value_t pointer. The address of the allocated space will be returned here.

Returns

0 on success, otherwise a negative error code.

snd_ctl_elem_value_set_boolean()

void snd_ctl_elem_value_set_boolean	(	snd_ctl_elem_value_t *	obj,
		unsigned int	idx,
		long	val )

Set an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_BOOLEAN. It sets the value of one member. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the member.
val	The new value.

snd_ctl_elem_value_set_byte()

void snd_ctl_elem_value_set_byte	(	snd_ctl_elem_value_t *	obj,
		unsigned int	idx,
		unsigned char	val )

Set an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_BYTE. It sets the value of one member. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the member.
val	The new value.

snd_ctl_elem_value_set_device()

void snd_ctl_elem_value_set_device	(	snd_ctl_elem_value_t *	obj,
		unsigned int	val )

Set the identifiers 'device' part within the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.
val	The new device.

snd_ctl_elem_value_set_enumerated()

void snd_ctl_elem_value_set_enumerated	(	snd_ctl_elem_value_t *	obj,
		unsigned int	idx,
		unsigned int	val )

Set an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_ENUMERATED. It activates the specified item. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the requested member.
val	The new index of the item to be activated.

snd_ctl_elem_value_set_id()

void snd_ctl_elem_value_set_id	(	snd_ctl_elem_value_t *	obj,
		const snd_ctl_elem_id_t *	ptr )

Set the element identifier within the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.
ptr	The new identifier.

snd_ctl_elem_value_set_iec958()

void snd_ctl_elem_value_set_iec958	(	snd_ctl_elem_value_t *	obj,
		const snd_aes_iec958_t *	ptr )

Set an elements IEC958 data.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_IEC958. Note that "IEC958" elements don't have members. They have only one single IEC958 information block.

See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
ptr	Pointer to the new IEC958 data.

snd_ctl_elem_value_set_index()

void snd_ctl_elem_value_set_index	(	snd_ctl_elem_value_t *	obj,
		unsigned int	val )

Set the identifiers 'index' part within the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.
val	The new index.

snd_ctl_elem_value_set_integer()

void snd_ctl_elem_value_set_integer	(	snd_ctl_elem_value_t *	obj,
		unsigned int	idx,
		long	val )

Set an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_INTEGER. It sets the value of one member. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the member.
val	The new value.

snd_ctl_elem_value_set_integer64()

void snd_ctl_elem_value_set_integer64	(	snd_ctl_elem_value_t *	obj,
		unsigned int	idx,
		long long	val )

Set an element members value.

Use this function if the element is of type SNDRV_CTL_ELEM_TYPE_INTEGER64. It sets the value of one member. See snd_ctl_elem_value_t and Control interface for more details.

Parameters

obj	The element value object.
idx	The index of the member.
val	The new value.

snd_ctl_elem_value_set_interface()

void snd_ctl_elem_value_set_interface	(	snd_ctl_elem_value_t *	obj,
		snd_ctl_elem_iface_t	val )

Set the identifiers 'interface' part within the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.
val	The new interface.

snd_ctl_elem_value_set_name()

void snd_ctl_elem_value_set_name	(	snd_ctl_elem_value_t *	obj,
		const char *	val )

Set the identifiers 'name' part within the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.
val	The new name.

snd_ctl_elem_value_set_numid()

void snd_ctl_elem_value_set_numid	(	snd_ctl_elem_value_t *	obj,
		unsigned int	val )

Set the identifiers 'numid' part within the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.
val	The new numid.

snd_ctl_elem_value_set_subdevice()

void snd_ctl_elem_value_set_subdevice	(	snd_ctl_elem_value_t *	obj,
		unsigned int	val )

Set the identifiers 'subdevice' part within the given element value.

See snd_ctl_elem_value_t for more details.

Parameters

obj	The element value.
val	The new subdevice.

snd_ctl_elem_value_sizeof()

size_t snd_ctl_elem_value_sizeof

(

)

Get size of data structure for an element.

Returns

Size in bytes.

snd_ctl_elem_write()

int snd_ctl_elem_write	(	snd_ctl_t *	ctl,
		snd_ctl_elem_value_t *	data )

Set CTL element value.

Write new value(s) to the sound card. You must set the ID and the value of the element before calling this function.

See snd_ctl_elem_value_t for details.

Parameters

ctl	CTL handle.
data	The new value.

Return values

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

snd_ctl_event_clear()

void snd_ctl_event_clear

(

snd_ctl_event_t *

obj

)

clear given #snd_ctl_event_t object

Parameters

obj	pointer to object to clear

snd_ctl_event_copy()

void snd_ctl_event_copy	(	snd_ctl_event_t *	dst,
		const snd_ctl_event_t *	src )

copy one #snd_ctl_event_t to another

Parameters

dst	pointer to destination
src	pointer to source

snd_ctl_event_elem_get_device()

unsigned int snd_ctl_event_elem_get_device

(

const snd_ctl_event_t *

obj

)

Get device part of CTL element identifier for an element related event.

Parameters

obj

CTL event

Returns

device part of element identifier

snd_ctl_event_elem_get_id()

void snd_ctl_event_elem_get_id	(	const snd_ctl_event_t *	obj,
		snd_ctl_elem_id_t *	ptr )

Get CTL element identifier for an element related event.

Parameters

obj	CTL event
ptr	Pointer to returned CTL element identifier

snd_ctl_event_elem_get_index()

unsigned int snd_ctl_event_elem_get_index

(

const snd_ctl_event_t *

obj

)

Get index part of CTL element identifier for an element related event.

Parameters

obj

CTL event

Returns

index part of element identifier

snd_ctl_event_elem_get_interface()

snd_ctl_elem_iface_t snd_ctl_event_elem_get_interface

(

const snd_ctl_event_t *

obj

)

Get interface part of CTL element identifier for an element related event.

Parameters

obj

CTL event

Returns

interface part of element identifier

snd_ctl_event_elem_get_mask()

unsigned int snd_ctl_event_elem_get_mask

(

const snd_ctl_event_t *

obj

)

Get event mask for an element related event.

Parameters

obj

CTL event

Returns

event mask for element related event

snd_ctl_event_elem_get_name()

const char * snd_ctl_event_elem_get_name

(

const snd_ctl_event_t *

obj

)

Get name part of CTL element identifier for an element related event.

Parameters

obj

CTL event

Returns

name part of element identifier

snd_ctl_event_elem_get_numid()

unsigned int snd_ctl_event_elem_get_numid

(

const snd_ctl_event_t *

obj

)

Get element numeric identifier for an element related event.

Parameters

obj

CTL event

Returns

element numeric identifier

snd_ctl_event_elem_get_subdevice()

unsigned int snd_ctl_event_elem_get_subdevice

(

const snd_ctl_event_t *

obj

)

Get subdevice part of CTL element identifier for an element related event.

Parameters

obj

CTL event

Returns

subdevice part of element identifier

snd_ctl_event_free()

void snd_ctl_event_free

(

snd_ctl_event_t *

obj

)

frees a previously allocated #snd_ctl_event_t

Parameters

obj	pointer to object to free

snd_ctl_event_get_type()

snd_ctl_event_type_t snd_ctl_event_get_type

(

const snd_ctl_event_t *

obj

)

Get type of a CTL event.

Parameters

obj

CTL event

Returns

CTL event type

snd_ctl_event_malloc()

int snd_ctl_event_malloc

(

snd_ctl_event_t **

ptr

)

allocate an invalid #snd_ctl_event_t using standard malloc

Parameters

ptr	returned pointer

Returns

0 on success otherwise negative error code

snd_ctl_event_sizeof()

size_t snd_ctl_event_sizeof

(

)

get size of #snd_ctl_event_t

Returns

size in bytes

snd_ctl_event_type_name()

const char * snd_ctl_event_type_name

(

snd_ctl_event_type_t

type

)

get name of a CTL event type

Parameters

type	CTL event type

Returns

ascii name of CTL event type

snd_ctl_get_power_state()

int snd_ctl_get_power_state	(	snd_ctl_t *	ctl,
		unsigned int *	state )

Get actual Power State.

Parameters

ctl	CTL handle
state	Destination value

Returns

0 on success otherwise a negative error code

snd_ctl_hwdep_info()

int snd_ctl_hwdep_info	(	snd_ctl_t *	ctl,
		snd_hwdep_info_t *	info )

Get info about a hardware dependent device.

Parameters

ctl	CTL handle
info	Hardware dependent device id/info pointer

Returns

0 on success otherwise a negative error code

snd_ctl_hwdep_next_device()

int snd_ctl_hwdep_next_device	(	snd_ctl_t *	ctl,
		int *	device )

Get next hardware dependent device number.

Parameters

ctl	CTL handle
device	current device on entry and next device on return

Returns

0 on success otherwise a negative error code

snd_ctl_name()

const char * snd_ctl_name

(

snd_ctl_t *

ctl

)

get identifier of CTL handle

Parameters

ctl	CTL handle

Returns

ascii identifier of CTL handle

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

snd_ctl_nonblock()

int snd_ctl_nonblock	(	snd_ctl_t *	ctl,
		int	nonblock )

set nonblock mode

Parameters

ctl	CTL handle
nonblock	0 = block, 1 = nonblock mode, 2 = abort

Returns

0 on success otherwise a negative error code

snd_ctl_open()

int snd_ctl_open	(	snd_ctl_t **	ctlp,
		const char *	name,
		int	mode )

Opens a sound card.

Parameters

ctlp	Returned CTL handle.
name	A string identifying the card (See Identifying and Opening Control Interfaces).
mode	Open mode (see #SND_CTL_NONBLOCK, #SND_CTL_ASYNC).

Returns

0 on success otherwise a negative error code.

snd_ctl_open_fallback()

int snd_ctl_open_fallback	(	snd_ctl_t **	ctlp,
		snd_config_t *	root,
		const char *	name,
		const char *	orig_name,
		int	mode )

Opens a fallback CTL.

Parameters

ctlp	Returned CTL handle
root	Configuration root
name	ASCII identifier of the CTL handle used as fallback
orig_name	The original ASCII name
mode	Open mode (see #SND_CTL_NONBLOCK, #SND_CTL_ASYNC)

Returns

0 on success otherwise a negative error code

snd_ctl_open_lconf()

int snd_ctl_open_lconf	(	snd_ctl_t **	ctlp,
		const char *	name,
		int	mode,
		snd_config_t *	lconf )

Opens a CTL using local configuration.

Parameters

ctlp	Returned CTL handle
name	ASCII identifier of the CTL handle
mode	Open mode (see #SND_CTL_NONBLOCK, #SND_CTL_ASYNC)
lconf	Local configuration

Returns

0 on success otherwise a negative error code

snd_ctl_pcm_info()

int snd_ctl_pcm_info	(	snd_ctl_t *	ctl,
		snd_pcm_info_t *	info )

Get info about a PCM device.

Parameters

ctl	CTL handle
info	PCM device id/info pointer

Returns

0 on success otherwise a negative error code

snd_ctl_pcm_next_device()

int snd_ctl_pcm_next_device	(	snd_ctl_t *	ctl,
		int *	device )

Get next PCM device number.

Parameters

ctl	CTL handle
device	current device on entry and next device on return

Returns

0 on success otherwise a negative error code

snd_ctl_pcm_prefer_subdevice()

int snd_ctl_pcm_prefer_subdevice	(	snd_ctl_t *	ctl,
		int	subdev )

Set preferred PCM subdevice number of successive PCM open.

Parameters

ctl	CTL handle
subdev	Preferred PCM subdevice number

Returns

0 on success otherwise a negative error code

snd_ctl_poll_descriptors()

int snd_ctl_poll_descriptors	(	snd_ctl_t *	ctl,
		struct pollfd *	pfds,
		unsigned int	space )

get poll descriptors

Parameters

ctl	CTL handle
pfds	array of poll descriptors
space	space in the poll descriptor array

Returns

count of filled descriptors

snd_ctl_poll_descriptors_count()

int snd_ctl_poll_descriptors_count

(

snd_ctl_t *

ctl

)

get count of poll descriptors for CTL handle

Parameters

ctl	CTL handle

Returns

count of poll descriptors

snd_ctl_poll_descriptors_revents()

int snd_ctl_poll_descriptors_revents	(	snd_ctl_t *	ctl,
		struct pollfd *	pfds,
		unsigned int	nfds,
		unsigned short *	revents )

get returned events from poll descriptors

Parameters

ctl	CTL handle
pfds	array of poll descriptors
nfds	count of poll descriptors
revents	returned events

Returns

zero if success, otherwise a negative error code

snd_ctl_rawmidi_info()

int snd_ctl_rawmidi_info	(	snd_ctl_t *	ctl,
		snd_rawmidi_info_t *	info )

Get info about a RawMidi device.

Parameters

ctl	CTL handle
info	RawMidi device id/info pointer

Returns

0 on success otherwise a negative error code

snd_ctl_rawmidi_next_device()

int snd_ctl_rawmidi_next_device	(	snd_ctl_t *	ctl,
		int *	device )

Get next RawMidi device number.

Parameters

ctl	CTL handle
device	current device on entry and next device on return

Returns

0 on success otherwise a negative error code

snd_ctl_rawmidi_prefer_subdevice()

int snd_ctl_rawmidi_prefer_subdevice	(	snd_ctl_t *	ctl,
		int	subdev )

Set preferred RawMidi subdevice number of successive RawMidi open.

Parameters

ctl	CTL handle
subdev	Preferred RawMidi subdevice number

Returns

0 on success otherwise a negative error code

snd_ctl_read()

int snd_ctl_read	(	snd_ctl_t *	ctl,
		snd_ctl_event_t *	event )

Read an event.

Parameters

ctl	CTL handle
event	Event pointer

Returns

number of events read otherwise a negative error code on failure

snd_ctl_set_power_state()

int snd_ctl_set_power_state	(	snd_ctl_t *	ctl,
		unsigned int	state )

Set Power State to given SND_CTL_POWER_* value and do the power management.

Parameters

ctl	CTL handle
state	Desired Power State

Returns

0 on success otherwise a negative error code

snd_ctl_subscribe_events()

int snd_ctl_subscribe_events	(	snd_ctl_t *	ctl,
		int	subscribe )

Ask to be informed about events (poll, snd_async_add_ctl_handler, snd_ctl_read)

Parameters

ctl	CTL handle
subscribe	0 = unsubscribe, 1 = subscribe, -1 = check subscribe or not

Returns

0 on success otherwise a negative error code

snd_ctl_type()

snd_ctl_type_t snd_ctl_type

(

snd_ctl_t *

ctl

)

get type of CTL handle

Parameters

ctl	CTL handle

Returns

type of CTL handle

Returns the type #snd_ctl_type_t of given CTL handle.

snd_ctl_ump_block_info()

int snd_ctl_ump_block_info	(	snd_ctl_t *	ctl,
		snd_ump_block_info_t *	info )

Get UMP Block info about a UMP RawMidi device.

Parameters

ctl	CTL handle
info	UMP Block info pointer

Returns

0 on success otherwise a negative error code

snd_ctl_ump_endpoint_info()

int snd_ctl_ump_endpoint_info	(	snd_ctl_t *	ctl,
		snd_ump_endpoint_info_t *	info )

Get UMP Endpoint info about a UMP RawMidi device.

Parameters

ctl	CTL handle
info	UMP Endpoint info pointer

Returns

0 on success otherwise a negative error code

snd_ctl_ump_next_device()

int snd_ctl_ump_next_device	(	snd_ctl_t *	ctl,
		int *	device )

Get next UMP device number.

Parameters

ctl	CTL handle
device	current device on entry and next device on return

Returns

0 on success otherwise a negative error code

snd_ctl_wait()

int snd_ctl_wait	(	snd_ctl_t *	ctl,
		int	timeout )

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

Parameters

ctl	CTL handle
timeout	maximum time in milliseconds to wait

Returns

0 otherwise a negative error code on failure