ALSA project - the C library reference
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
Functions
mixer.c File Reference

Mixer Interface. More...

Functions

int snd_mixer_open (snd_mixer_t **mixerp, int mode)
 Opens an empty mixer.
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.
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.
void * snd_mixer_elem_get_private (const snd_mixer_elem_t *elem)
 Get private data associated to give mixer element.
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_class_register (snd_mixer_class_t *class, snd_mixer_t *mixer)
 Register mixer element class.
int snd_mixer_class_unregister (snd_mixer_class_t *class)
 Unregister mixer element class and remove all its elements.
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_close (snd_mixer_t *mixer)
 Close a mixer and free all related resources.
int snd_mixer_set_compare (snd_mixer_t *mixer, snd_mixer_compare_t compare)
 Change mixer compare function and reorder elements.
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_wait (snd_mixer_t *mixer, int timeout)
 Wait for a mixer to become ready (i.e. at least one event pending)
snd_mixer_elem_tsnd_mixer_first_elem (snd_mixer_t *mixer)
 get first element for a mixer
snd_mixer_elem_tsnd_mixer_last_elem (snd_mixer_t *mixer)
 get last element for a mixer
snd_mixer_elem_tsnd_mixer_elem_next (snd_mixer_elem_t *elem)
 get next mixer element
snd_mixer_elem_tsnd_mixer_elem_prev (snd_mixer_elem_t *elem)
 get previous mixer element
int snd_mixer_handle_events (snd_mixer_t *mixer)
 Handle pending mixer events invoking callbacks.
void snd_mixer_set_callback (snd_mixer_t *obj, snd_mixer_callback_t val)
 Set callback function for a mixer.
void snd_mixer_set_callback_private (snd_mixer_t *mixer, void *val)
 Set callback private value for a mixer.
void * snd_mixer_get_callback_private (const snd_mixer_t *mixer)
 Get callback private value for a mixer.
unsigned int snd_mixer_get_count (const snd_mixer_t *mixer)
 Get elements count for a mixer.
void snd_mixer_elem_set_callback (snd_mixer_elem_t *mixer, snd_mixer_elem_callback_t val)
 Set callback function for a mixer element.
void snd_mixer_elem_set_callback_private (snd_mixer_elem_t *mixer, void *val)
 Set callback private value for a mixer element.
void * snd_mixer_elem_get_callback_private (const snd_mixer_elem_t *mixer)
 Get callback private value for a mixer element.
snd_mixer_elem_type_t snd_mixer_elem_get_type (const snd_mixer_elem_t *mixer)
 Get type for a mixer element.
size_t snd_mixer_class_sizeof ()
 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_tsnd_mixer_class_get_mixer (const snd_mixer_class_t *obj)
 Get a mixer associated to given mixer class.
snd_mixer_event_t snd_mixer_class_get_event (const snd_mixer_class_t *obj)
 Get mixer event callback associated to given mixer class.
void * snd_mixer_class_get_private (const snd_mixer_class_t *obj)
 Get mixer private data associated to given mixer class.
snd_mixer_compare_t snd_mixer_class_get_compare (const snd_mixer_class_t *obj)
 Get mixer compare callback associated to given mixer class.
int snd_mixer_class_set_event (snd_mixer_class_t *obj, snd_mixer_event_t event)
 Set mixer event callback to given mixer class.
int snd_mixer_class_set_private (snd_mixer_class_t *obj, void *private_data)
 Set mixer private data to given mixer class.
int snd_mixer_class_set_private_free (snd_mixer_class_t *obj, 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 *obj, snd_mixer_compare_t compare)
 Set mixer compare callback to given mixer class.

Detailed Description

Mixer Interface.

Author:
Jaroslav Kysela perex.nosp@m.@per.nosp@m.ex.cz
Abramo Bagnara abram.nosp@m.o@al.nosp@m.sa-pr.nosp@m.ojec.nosp@m.t.org
Date:
2001

Mixer interface is designed to access mixer elements. Callbacks may be used for event handling.