# /builddir/build/BUILD/alsa-lib-1.1.0/include/mixer.h File Reference

Application interface library for the ALSA driver. More...

Go to the source code of this file.

## Data Structures

struct | snd_mixer_selem_regopt

## Defines

#define | snd_mixer_class_alloca(ptr)
| allocate an invalid snd_mixer_class_t using standard alloca
#define | snd_mixer_selem_id_alloca(ptr)
| allocate an invalid snd_mixer_selem_id_t using standard alloca

## Typedefs

typedef struct _snd_mixer | snd_mixer_t
typedef struct _snd_mixer_class | snd_mixer_class_t
typedef struct _snd_mixer_elem | snd_mixer_elem_t
typedef int(* | snd_mixer_callback_t )(snd_mixer_t *ctl, unsigned int mask, snd_mixer_elem_t *elem)
| Mixer callback function.
typedef int(* | snd_mixer_elem_callback_t )(snd_mixer_elem_t *elem, unsigned int mask)
| Mixer element callback function.
typedef int(* | snd_mixer_compare_t )(const snd_mixer_elem_t *e1, const snd_mixer_elem_t *e2)
| Compare function for sorting mixer elements.
typedef int(* | snd_mixer_event_t )(snd_mixer_class_t *class_, unsigned int mask, snd_hctl_elem_t *helem, snd_mixer_elem_t *melem)
| Event callback for the mixer class.
typedef struct _snd_mixer_selem_id | snd_mixer_selem_id_t

## Enumerations

enum | snd_mixer_elem_type_t { SND_MIXER_ELEM_SIMPLE, SND_MIXER_ELEM_LAST = SND_MIXER_ELEM_SIMPLE }
enum | snd_mixer_selem_channel_id_t { SND_MIXER_SCHN_UNKNOWN = -1, SND_MIXER_SCHN_FRONT_LEFT = 0, SND_MIXER_SCHN_FRONT_RIGHT, SND_MIXER_SCHN_REAR_LEFT, SND_MIXER_SCHN_REAR_RIGHT, SND_MIXER_SCHN_FRONT_CENTER, SND_MIXER_SCHN_WOOFER, SND_MIXER_SCHN_SIDE_LEFT, SND_MIXER_SCHN_SIDE_RIGHT, SND_MIXER_SCHN_REAR_CENTER, SND_MIXER_SCHN_LAST = 31, SND_MIXER_SCHN_MONO = SND_MIXER_SCHN_FRONT_LEFT }
enum | snd_mixer_selem_regopt_abstract { SND_MIXER_SABSTRACT_NONE = 0, SND_MIXER_SABSTRACT_BASIC }

## Functions

int | snd_mixer_open (snd_mixer_t **mixer, int mode)
| Opens an empty mixer.
int | snd_mixer_close (snd_mixer_t *mixer)
| Close a mixer and free all related resources.
snd_mixer_elem_t * | snd_mixer_first_elem (snd_mixer_t *mixer)
| get first element for a mixer
snd_mixer_elem_t * | snd_mixer_last_elem (snd_mixer_t *mixer)
| get last element for a mixer
int | snd_mixer_handle_events (snd_mixer_t *mixer)
| Handle pending mixer events invoking callbacks.
int | snd_mixer_attach (snd_mixer_t *mixer, const char *name)
| Attach an HCTL specified with the CTL device name to an opened mixer.
int | snd_mixer_attach_hctl (snd_mixer_t *mixer, snd_hctl_t *hctl)
| Attach an HCTL to an opened mixer.
int | snd_mixer_detach (snd_mixer_t *mixer, const char *name)
| Detach a previously attached HCTL to an opened mixer freeing all related resources.
int | snd_mixer_detach_hctl (snd_mixer_t *mixer, snd_hctl_t *hctl)
| Detach a previously attached HCTL to an opened mixer freeing all related resources.
int | snd_mixer_get_hctl (snd_mixer_t *mixer, const char *name, snd_hctl_t **hctl)
| Obtain a HCTL pointer associated to given name.
int | snd_mixer_poll_descriptors_count (snd_mixer_t *mixer)
| get count of poll descriptors for mixer handle
int | snd_mixer_poll_descriptors (snd_mixer_t *mixer, struct pollfd *pfds, unsigned int space)
| get poll descriptors
int | snd_mixer_poll_descriptors_revents (snd_mixer_t *mixer, struct pollfd *pfds, unsigned int nfds, unsigned short *revents)
| get returned events from poll descriptors
int | snd_mixer_load (snd_mixer_t *mixer)
| Load a mixer elements.
void | snd_mixer_free (snd_mixer_t *mixer)
| Unload all mixer elements and free all related resources.
int | snd_mixer_wait (snd_mixer_t *mixer, int timeout)
| Wait for a mixer to become ready (i.e. at least one event pending).
int | snd_mixer_set_compare (snd_mixer_t *mixer, snd_mixer_compare_t msort)
| Change mixer compare function and reorder elements.
void | snd_mixer_set_callback (snd_mixer_t *obj, snd_mixer_callback_t val)
| Set callback function for a mixer.
void * | snd_mixer_get_callback_private (const snd_mixer_t *obj)
| Get callback private value for a mixer.
void | snd_mixer_set_callback_private (snd_mixer_t *obj, void *val)
| Set callback private value for a mixer.
unsigned int | snd_mixer_get_count (const snd_mixer_t *obj)
| Get elements count for a mixer.
int | snd_mixer_class_unregister (snd_mixer_class_t *clss)
| Unregister mixer element class and remove all its elements.
snd_mixer_elem_t * | snd_mixer_elem_next (snd_mixer_elem_t *elem)
| get next mixer element
snd_mixer_elem_t * | snd_mixer_elem_prev (snd_mixer_elem_t *elem)
| get previous mixer element
void | snd_mixer_elem_set_callback (snd_mixer_elem_t *obj, snd_mixer_elem_callback_t val)
| Set callback function for a mixer element.
void * | snd_mixer_elem_get_callback_private (const snd_mixer_elem_t *obj)
| Get callback private value for a mixer element.
void | snd_mixer_elem_set_callback_private (snd_mixer_elem_t *obj, void *val)
| Set callback private value for a mixer element.
snd_mixer_elem_type_t | snd_mixer_elem_get_type (const snd_mixer_elem_t *obj)
| Get type for a mixer element.
int | snd_mixer_class_register (snd_mixer_class_t *class_, snd_mixer_t *mixer)
| Register mixer element class.
int | snd_mixer_elem_new (snd_mixer_elem_t **elem, snd_mixer_elem_type_t type, int compare_weight, void *private_data, void(*private_free)(snd_mixer_elem_t *elem))
| Allocate a new mixer element.
int | snd_mixer_elem_add (snd_mixer_elem_t *elem, snd_mixer_class_t *class_)
| Add an element for a registered mixer element class.
int | snd_mixer_elem_remove (snd_mixer_elem_t *elem)
| Remove a mixer element.
void | snd_mixer_elem_free (snd_mixer_elem_t *elem)
| Free a mixer element.
int | snd_mixer_elem_info (snd_mixer_elem_t *elem)
| Mixer element informations are changed.
int | snd_mixer_elem_value (snd_mixer_elem_t *elem)
| Mixer element values is changed.
int | snd_mixer_elem_attach (snd_mixer_elem_t *melem, snd_hctl_elem_t *helem)
| Attach an HCTL element to a mixer element.
int | snd_mixer_elem_detach (snd_mixer_elem_t *melem, snd_hctl_elem_t *helem)
| Detach an HCTL element from a mixer element.
int | snd_mixer_elem_empty (snd_mixer_elem_t *melem)
| Return true if a mixer element does not contain any HCTL elements.
void * | snd_mixer_elem_get_private (const snd_mixer_elem_t *melem)
| Get private data associated to give mixer element.
size_t | snd_mixer_class_sizeof (void)
| get size of snd_mixer_class_t
int | snd_mixer_class_malloc (snd_mixer_class_t **ptr)
| allocate an invalid snd_mixer_class_t using standard malloc
void | snd_mixer_class_free (snd_mixer_class_t *obj)
| frees a previously allocated snd_mixer_class_t
void | snd_mixer_class_copy (snd_mixer_class_t *dst, const snd_mixer_class_t *src)
| copy one snd_mixer_class_t to another
snd_mixer_t * | snd_mixer_class_get_mixer (const snd_mixer_class_t *class_)
| Get a mixer associated to given mixer class.
snd_mixer_event_t | snd_mixer_class_get_event (const snd_mixer_class_t *class_)
| Get mixer event callback associated to given mixer class.
void * | snd_mixer_class_get_private (const snd_mixer_class_t *class_)
| Get mixer private data associated to given mixer class.
snd_mixer_compare_t | snd_mixer_class_get_compare (const snd_mixer_class_t *class_)
| Get mixer compare callback associated to given mixer class.
int | snd_mixer_class_set_event (snd_mixer_class_t *class_, snd_mixer_event_t event)
| Set mixer event callback to given mixer class.
int | snd_mixer_class_set_private (snd_mixer_class_t *class_, void *private_data)
| Set mixer private data to given mixer class.
int | snd_mixer_class_set_private_free (snd_mixer_class_t *class_, void(*private_free)(snd_mixer_class_t *))
| Set mixer private data free callback to given mixer class.
int | snd_mixer_class_set_compare (snd_mixer_class_t *class_, snd_mixer_compare_t compare)
| Set mixer compare callback to given mixer class.
const char * | snd_mixer_selem_channel_name (snd_mixer_selem_channel_id_t channel)
| Return name of mixer simple element channel.
int | snd_mixer_selem_register (snd_mixer_t *mixer, struct snd_mixer_selem_regopt *options, snd_mixer_class_t **classp)
| Register mixer simple element class.
void | snd_mixer_selem_get_id (snd_mixer_elem_t *element, snd_mixer_selem_id_t *id)
| Get mixer simple element identifier.
const char * | snd_mixer_selem_get_name (snd_mixer_elem_t *elem)
| Get name part of mixer simple element identifier.
unsigned int | snd_mixer_selem_get_index (snd_mixer_elem_t *elem)
| Get index part of mixer simple element identifier.
snd_mixer_elem_t * | snd_mixer_find_selem (snd_mixer_t *mixer, const snd_mixer_selem_id_t *id)
| Find a mixer simple element.
int | snd_mixer_selem_is_active (snd_mixer_elem_t *elem)
| Get info about the active state of a mixer simple element.
int | snd_mixer_selem_is_playback_mono (snd_mixer_elem_t *elem)
| Get info about channels of playback stream of a mixer simple element.
int | snd_mixer_selem_has_playback_channel (snd_mixer_elem_t *obj, snd_mixer_selem_channel_id_t channel)
| Get info about channels of playback stream of a mixer simple element.
int | snd_mixer_selem_is_capture_mono (snd_mixer_elem_t *elem)
| Get info about channels of capture stream of a mixer simple element.
int | snd_mixer_selem_has_capture_channel (snd_mixer_elem_t *obj, snd_mixer_selem_channel_id_t channel)
| Get info about channels of capture stream of a mixer simple element.
int | snd_mixer_selem_get_capture_group (snd_mixer_elem_t *elem)
| Return info about capture switch control of a mixer simple element.
int | snd_mixer_selem_has_common_volume (snd_mixer_elem_t *elem)
| Return true if mixer simple element has only one volume control for both playback and capture.
int | snd_mixer_selem_has_playback_volume (snd_mixer_elem_t *elem)
| Return info about playback volume control of a mixer simple element.
int | snd_mixer_selem_has_playback_volume_joined (snd_mixer_elem_t *elem)
| Return info about playback volume control of a mixer simple element.
int | snd_mixer_selem_has_capture_volume (snd_mixer_elem_t *elem)
| Return info about capture volume control of a mixer simple element.
int | snd_mixer_selem_has_capture_volume_joined (snd_mixer_elem_t *elem)
| Return info about capture volume control of a mixer simple element.
int | snd_mixer_selem_has_common_switch (snd_mixer_elem_t *elem)
| Return true if mixer simple element has only one switch control for both playback and capture.
int | snd_mixer_selem_has_playback_switch (snd_mixer_elem_t *elem)
| Return info about playback switch control existence of a mixer simple element.
int | snd_mixer_selem_has_playback_switch_joined (snd_mixer_elem_t *elem)
| Return info about playback switch control of a mixer simple element.
int | snd_mixer_selem_has_capture_switch (snd_mixer_elem_t *elem)
| Return info about capture switch control existence of a mixer simple element.
int | snd_mixer_selem_has_capture_switch_joined (snd_mixer_elem_t *elem)
| Return info about capture switch control of a mixer simple element.
int | snd_mixer_selem_has_capture_switch_exclusive (snd_mixer_elem_t *elem)
| Return info about capture switch control of a mixer simple element.
int | snd_mixer_selem_ask_playback_vol_dB (snd_mixer_elem_t *elem, long value, long *dBvalue)
| Return corresponding dB value to an integer playback volume for a mixer simple element.
int | snd_mixer_selem_ask_capture_vol_dB (snd_mixer_elem_t *elem, long value, long *dBvalue)
| Return corresponding dB value to an integer capture volume for a mixer simple element.
int | snd_mixer_selem_ask_playback_dB_vol (snd_mixer_elem_t *elem, long dBvalue, int dir, long *value)
| Return corresponding integer playback volume for given dB value for a mixer simple element.
int | snd_mixer_selem_ask_capture_dB_vol (snd_mixer_elem_t *elem, long dBvalue, int dir, long *value)
| Return corresponding integer capture volume for given dB value for a mixer simple element.
int | snd_mixer_selem_get_playback_volume (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value)
| Return value of playback volume control of a mixer simple element.
int | snd_mixer_selem_get_capture_volume (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value)
| Return value of capture volume control of a mixer simple element.
int | snd_mixer_selem_get_playback_dB (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value)
| Return value of playback volume in dB control of a mixer simple element.
int | snd_mixer_selem_get_capture_dB (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value)
| Return value of capture volume in dB control of a mixer simple element.
int | snd_mixer_selem_get_playback_switch (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, int *value)
| Return value of playback switch control of a mixer simple element.
int | snd_mixer_selem_get_capture_switch (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, int *value)
| Return value of capture switch control of a mixer simple element.
int | snd_mixer_selem_set_playback_volume (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long value)
| Set value of playback volume control of a mixer simple element.
int | snd_mixer_selem_set_capture_volume (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long value)
| Set value of capture volume control of a mixer simple element.
int | snd_mixer_selem_set_playback_dB (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long value, int dir)
| Set value in dB of playback volume control of a mixer simple element.
int | snd_mixer_selem_set_capture_dB (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long value, int dir)
| Set value in dB of capture volume control of a mixer simple element.
int | snd_mixer_selem_set_playback_volume_all (snd_mixer_elem_t *elem, long value)
| Set value of playback volume control for all channels of a mixer simple element.
int | snd_mixer_selem_set_capture_volume_all (snd_mixer_elem_t *elem, long value)
| Set value of capture volume control for all channels of a mixer simple element.
int | snd_mixer_selem_set_playback_dB_all (snd_mixer_elem_t *elem, long value, int dir)
| Set value in dB of playback volume control for all channels of a mixer simple element.
int | snd_mixer_selem_set_capture_dB_all (snd_mixer_elem_t *elem, long value, int dir)
| Set value in dB of capture volume control for all channels of a mixer simple element.
int | snd_mixer_selem_set_playback_switch (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, int value)
| Set value of playback switch control of a mixer simple element.
int | snd_mixer_selem_set_capture_switch (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, int value)
| Set value of capture switch control of a mixer simple element.
int | snd_mixer_selem_set_playback_switch_all (snd_mixer_elem_t *elem, int value)
| Set value of playback switch control for all channels of a mixer simple element.
int | snd_mixer_selem_set_capture_switch_all (snd_mixer_elem_t *elem, int value)
| Set value of capture switch control for all channels of a mixer simple element.
int | snd_mixer_selem_get_playback_volume_range (snd_mixer_elem_t *elem, long *min, long *max)
| Get range for playback volume of a mixer simple element.
int | snd_mixer_selem_get_playback_dB_range (snd_mixer_elem_t *elem, long *min, long *max)
| Get range in dB for playback volume of a mixer simple element.
int | snd_mixer_selem_set_playback_volume_range (snd_mixer_elem_t *elem, long min, long max)
| Set range for playback volume of a mixer simple element.
int | snd_mixer_selem_get_capture_volume_range (snd_mixer_elem_t *elem, long *min, long *max)
| Get range for capture volume of a mixer simple element.
int | snd_mixer_selem_get_capture_dB_range (snd_mixer_elem_t *elem, long *min, long *max)
| Get range in dB for capture volume of a mixer simple element.
int | snd_mixer_selem_set_capture_volume_range (snd_mixer_elem_t *elem, long min, long max)
| Set range for capture volume of a mixer simple element.
int | snd_mixer_selem_is_enumerated (snd_mixer_elem_t *elem)
| Return true if mixer simple element is an enumerated control.
int | snd_mixer_selem_is_enum_playback (snd_mixer_elem_t *elem)
| Return true if mixer simple enumerated element belongs to the playback direction.
int | snd_mixer_selem_is_enum_capture (snd_mixer_elem_t *elem)
| Return true if mixer simple enumerated element belongs to the capture direction.
int | snd_mixer_selem_get_enum_items (snd_mixer_elem_t *elem)
| Return the number of enumerated items of the given mixer simple element.
int | snd_mixer_selem_get_enum_item_name (snd_mixer_elem_t *elem, unsigned int idx, size_t maxlen, char *str)
| get the enumerated item string for the given mixer simple element
int | snd_mixer_selem_get_enum_item (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, unsigned int *idxp)
| get the current selected enumerated item for the given mixer simple element
int | snd_mixer_selem_set_enum_item (snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, unsigned int idx)
| set the current selected enumerated item for the given mixer simple element
size_t | snd_mixer_selem_id_sizeof (void)
| get size of snd_mixer_selem_id_t
int | snd_mixer_selem_id_malloc (snd_mixer_selem_id_t **ptr)
| allocate an invalid snd_mixer_selem_id_t using standard malloc
void | snd_mixer_selem_id_free (snd_mixer_selem_id_t *obj)
| frees a previously allocated snd_mixer_selem_id_t
void | snd_mixer_selem_id_copy (snd_mixer_selem_id_t *dst, const snd_mixer_selem_id_t *src)
| copy one snd_mixer_selem_id_t to another
const char * | snd_mixer_selem_id_get_name (const snd_mixer_selem_id_t *obj)
| Get name part of a mixer simple element identifier.
unsigned int | snd_mixer_selem_id_get_index (const snd_mixer_selem_id_t *obj)
| Get index part of a mixer simple element identifier.
void | snd_mixer_selem_id_set_name (snd_mixer_selem_id_t *obj, const char *val)
| Set name part of a mixer simple element identifier.
void | snd_mixer_selem_id_set_index (snd_mixer_selem_id_t *obj, unsigned int val)
| Set index part of a mixer simple element identifier.

## Detailed Description

Application interface library for the ALSA driver.

Author:
  Jaroslav Kysela <perex@perex.cz>
  Abramo Bagnara <abramo@alsa-project.org>
  Takashi Iwai <tiwai@suse.de>

Date:
  1998-2001

Application interface library for the ALSA driver

All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Defines