Alsa audio subsystem. More...

#include <math.h>
#include <glib.h>
#include <alsa/asoundlib.h>
#include "support-log.h"
#include "alsa.h"

Include dependency graph for alsa.c:

Data Structures
struct	alsa_card_iter

struct	alsa_card

Macros
#define	_GNU_SOURCE /* exp10() */

#define	ALSA_DEFAULT_CARD "(default)"

#define	ALSA_DEFAULT_HCTL "default"

#define	ALSA_ERR(err, ...) alsa_log_msg(LOG_ERROR, NULL, snd_strerror(err), __VA_ARGS__)

#define	ALSA_CARD_DEBUG(card, ...) alsa_log_msg(LOG_DEBUG, card, NULL, __VA_ARGS__)

#define	ALSA_CARD_WARN(card, ...) alsa_log_msg(LOG_WARN, card, NULL, __VA_ARGS__)

#define	ALSA_CARD_ERR(card, err, ...) alsa_log_msg(LOG_ERROR, card, snd_strerror(err), __VA_ARGS__)

#define	MAX_LINEAR_DB_SCALE 24

Typedefs
typedef struct alsa_card_iter	AlsaCardIter

Functions
static void	alsa_log_msg (enum log_level level, const char card, const char strerr, const char *format,...)

static gboolean	use_linear_dB_scale (long db_min, long db_max)

static long	lrint_dir (double x, int dir)

static const char *	elem_get_name (snd_mixer_elem_t *elem)

static double	elem_get_volume (const char hctl, snd_mixer_elem_t elem, double *volume)

static gboolean	elem_set_volume (const char hctl, snd_mixer_elem_t elem, double volume, int dir)

static gboolean	elem_get_volume_normalized (const char hctl, snd_mixer_elem_t elem, double *volume)

static gboolean	elem_set_volume_normalized (const char hctl, snd_mixer_elem_t elem, double volume, int dir)

static gboolean	elem_has_mute (G_GNUC_UNUSED const char hctl, snd_mixer_elem_t elem)

static gboolean	elem_get_mute (const char hctl, snd_mixer_elem_t elem, gboolean *muted)

static gboolean	elem_set_mute (const char hctl, snd_mixer_elem_t elem, gboolean mute)

static struct pollfd *	mixer_get_poll_descriptors (const char hctl, snd_mixer_t mixer)

static GSList *	mixer_list_playable (G_GNUC_UNUSED const char hctl, snd_mixer_t mixer)

static gboolean	mixer_is_playable (const char hctl, snd_mixer_t mixer)

static snd_mixer_elem_t *	mixer_get_playable_elem (const char hctl, snd_mixer_t mixer, const char *channel)

static snd_mixer_elem_t *	mixer_get_first_playable_elem (const char hctl, snd_mixer_t mixer)

static void	mixer_close (const char hctl, snd_mixer_t mixer)

static snd_mixer_t *	mixer_open (const char *hctl)

static void	alsa_card_iter_free (AlsaCardIter *iter)

static AlsaCardIter *	alsa_card_iter_new (void)

static gboolean	alsa_card_iter_loop (AlsaCardIter *iter)

static guint *	watch_poll_descriptors (const char hctl, struct pollfd pollfds, GIOFunc func, gpointer data)

static void	unwatch_poll_descriptors (guint *watch_ids)

static gboolean	poll_watch_cb (GIOChannel source, GIOCondition condition, AlsaCard card)

const char *	alsa_card_get_name (AlsaCard *card)

const char *	alsa_card_get_channel (AlsaCard *card)

gboolean	alsa_card_has_mute (AlsaCard *card)

gboolean	alsa_card_is_muted (AlsaCard *card)

void	alsa_card_toggle_mute (AlsaCard *card)

gdouble	alsa_card_get_volume (AlsaCard *card)

void	alsa_card_set_volume (AlsaCard *card, gdouble value, int dir)

void	alsa_card_install_callback (AlsaCard *card, AlsaCb callback, gpointer user_data)

void	alsa_card_free (AlsaCard *card)

AlsaCard *	alsa_card_new (const char card_name, const char channel, gboolean normalize)

GSList *	alsa_list_cards (void)

GSList *	alsa_list_channels (const char *card_name)

Detailed Description

Alsa audio subsystem.

Alsa audio subsystem. All the alsa-related code is enclosed in here, and this is the only file that uses the alsa library. This is the lowest-level part of PNMixer, that's why it doesn't include any other local headers. If you do so, it probably means that you're starting messing up the code, so think twice.

Definition in file alsa.c.

Macro Definition Documentation

◆ _GNU_SOURCE

#define _GNU_SOURCE /* exp10() */

Definition at line 26 of file alsa.c.

◆ ALSA_CARD_DEBUG

#define ALSA_CARD_DEBUG	(	card,
		...
	)	alsa_log_msg(LOG_DEBUG, card, NULL, __VA_ARGS__)

Definition at line 65 of file alsa.c.

◆ ALSA_CARD_ERR

#define ALSA_CARD_ERR	(	card,
		err,
		...
	)	alsa_log_msg(LOG_ERROR, card, snd_strerror(err), __VA_ARGS__)

Definition at line 71 of file alsa.c.

◆ ALSA_CARD_WARN

#define ALSA_CARD_WARN	(	card,
		...
	)	alsa_log_msg(LOG_WARN, card, NULL, __VA_ARGS__)

Definition at line 68 of file alsa.c.

◆ ALSA_DEFAULT_CARD

#define ALSA_DEFAULT_CARD "(default)"

Definition at line 34 of file alsa.c.

◆ ALSA_DEFAULT_HCTL

#define ALSA_DEFAULT_HCTL "default"

Definition at line 35 of file alsa.c.

◆ ALSA_ERR

#define ALSA_ERR	(	err,
		...
	)	alsa_log_msg(LOG_ERROR, NULL, snd_strerror(err), __VA_ARGS__)

Definition at line 62 of file alsa.c.

◆ MAX_LINEAR_DB_SCALE

#define MAX_LINEAR_DB_SCALE 24

Definition at line 86 of file alsa.c.

Typedef Documentation

◆ AlsaCardIter

typedef struct alsa_card_iter AlsaCardIter

Definition at line 508 of file alsa.c.

Function Documentation

◆ alsa_card_free()

void alsa_card_free ( AlsaCard * card )

Free a card instance, therefore closing mixer and freeing any allocated ressources.

Parameters

card	a Card instance.

Definition at line 862 of file alsa.c.

◆ alsa_card_get_channel()

const char* alsa_card_get_channel ( AlsaCard * card )

Get the name of the channel. This is an internal string that shouldn't be modified.

Parameters

card	a Card instance.

Returns: the name of the channel.

Definition at line 750 of file alsa.c.

◆ alsa_card_get_name()

const char* alsa_card_get_name ( AlsaCard * card )

Get the name of the card. This is an internal string that shouldn't be modified.

Parameters

card	a Card instance.

Returns: the name of the card.

Definition at line 737 of file alsa.c.

◆ alsa_card_get_volume()

gdouble alsa_card_get_volume ( AlsaCard * card )

Get the volume in percent (value between 0 and 100).

Parameters

card	a Card instance.

Returns: the volume in percent.

Definition at line 804 of file alsa.c.

◆ alsa_card_has_mute()

gboolean alsa_card_has_mute ( AlsaCard * card )

Whether the card has mute capabilities.

Parameters

card	a Card instance.

Returns: TRUE if the card can be muted, FALSE otherwise.

Definition at line 762 of file alsa.c.

◆ alsa_card_install_callback()

void alsa_card_install_callback	(	AlsaCard *	card,
		AlsaCb	callback,
		gpointer	user_data
	)

Set a callback invoked on volume/mute changes.

Parameters

card	a Card instance.
callback	the callback to be invoked.
user_data	the user data passed to the callback.

Definition at line 850 of file alsa.c.

◆ alsa_card_is_muted()

gboolean alsa_card_is_muted ( AlsaCard * card )

Get the mute state, either TRUE or FALSE.

Parameters

card	a Card instance.

Returns: TRUE if the card is muted, FALSE otherwise.

Definition at line 774 of file alsa.c.

◆ alsa_card_iter_free()

static void alsa_card_iter_free ( AlsaCardIter * iter )

static

Definition at line 512 of file alsa.c.

◆ alsa_card_iter_loop()

static gboolean alsa_card_iter_loop ( AlsaCardIter * iter )

static

Definition at line 540 of file alsa.c.

◆ alsa_card_iter_new()

static AlsaCardIter* alsa_card_iter_new ( void )

static

Definition at line 524 of file alsa.c.

◆ alsa_card_new()

AlsaCard* alsa_card_new	(	const char *	card_name,
		const char *	channel,
		gboolean	normalize
	)

Create a new Card instance. Look for the selected card among the available cards. If found, open it, and look for the selected channel. If found, all is well, the card is ready to be used. Otherwise, NULL is returned.

Parameters

card_name	the name of the card, or NULL to use the default card.
channel	the name of the channel, or NULL to use the first playable channel.
normalize	whether we use normalized volume or not.

Returns: a newly allocated Card instance, or NULL on failure.

Definition at line 891 of file alsa.c.

◆ alsa_card_set_volume()

void alsa_card_set_volume	(	AlsaCard *	card,
		gdouble	value,
		int	dir
	)

Set the volume in percent (value between 0 and 100).

Parameters

card	a Card instance.
value	the volume in percent.
dir	the direction of the volume change (-1: lowering, +1: raising, 0: setting).

Definition at line 827 of file alsa.c.

◆ alsa_card_toggle_mute()

void alsa_card_toggle_mute ( AlsaCard * card )

Toggle the mute state.

Parameters

card	a Card instance.

Definition at line 788 of file alsa.c.

◆ alsa_list_cards()

GSList* alsa_list_cards ( void )

Return the list of playable cards as a GSList. Must be freed using g_slist_free_full() and g_free().

Returns: a list of playable cards.

Definition at line 966 of file alsa.c.

◆ alsa_list_channels()

GSList* alsa_list_channels ( const char * card_name )

For a given card name, return the list of playable channels as a GSList. Must be freed using g_slist_free_full() and g_free().

Parameters

card_name the name of the card for which we list the channels

Returns: a list of playable channels.

Definition at line 1002 of file alsa.c.

◆ alsa_log_msg()

static void alsa_log_msg	(	enum log_level	level,
		const char *	card,
		const char *	strerr,
		const char *	format,
			...
	)

static

Definition at line 42 of file alsa.c.

◆ elem_get_mute()

static gboolean elem_get_mute	(	const char *	hctl,
		snd_mixer_elem_t *	elem,
		gboolean *	muted
	)

static

Definition at line 266 of file alsa.c.

◆ elem_get_name()

static const char* elem_get_name ( snd_mixer_elem_t * elem )

static

Definition at line 107 of file alsa.c.

◆ elem_get_volume()

static double elem_get_volume	(	const char *	hctl,
		snd_mixer_elem_t *	elem,
		double *	volume
	)

static

Definition at line 114 of file alsa.c.

◆ elem_get_volume_normalized()

static gboolean elem_get_volume_normalized	(	const char *	hctl,
		snd_mixer_elem_t *	elem,
		double *	volume
	)

static

Definition at line 175 of file alsa.c.

◆ elem_has_mute()

static gboolean elem_has_mute	(	G_GNUC_UNUSED const char *	hctl,
		snd_mixer_elem_t *	elem
	)

static

Definition at line 259 of file alsa.c.

◆ elem_set_mute()

static gboolean elem_set_mute	(	const char *	hctl,
		snd_mixer_elem_t *	elem,
		gboolean	mute
	)

static

Definition at line 295 of file alsa.c.

◆ elem_set_volume()

static gboolean elem_set_volume	(	const char *	hctl,
		snd_mixer_elem_t *	elem,
		double	volume,
		int	dir
	)

static

Definition at line 146 of file alsa.c.

◆ elem_set_volume_normalized()

static gboolean elem_set_volume_normalized	(	const char *	hctl,
		snd_mixer_elem_t *	elem,
		double	volume,
		int	dir
	)

static

Definition at line 220 of file alsa.c.

◆ lrint_dir()

static long lrint_dir	(	double	x,
		int	dir
	)

static

Definition at line 95 of file alsa.c.

◆ mixer_close()

static void mixer_close	(	const char *	hctl,
		snd_mixer_t *	mixer
	)

static

Definition at line 438 of file alsa.c.

◆ mixer_get_first_playable_elem()

static snd_mixer_elem_t* mixer_get_first_playable_elem	(	const char *	hctl,
		snd_mixer_t *	mixer
	)

static

Definition at line 414 of file alsa.c.

◆ mixer_get_playable_elem()

static snd_mixer_elem_t* mixer_get_playable_elem	(	const char *	hctl,
		snd_mixer_t *	mixer,
		const char *	channel
	)

static

Definition at line 384 of file alsa.c.

◆ mixer_get_poll_descriptors()

static struct pollfd* mixer_get_poll_descriptors	(	const char *	hctl,
		snd_mixer_t *	mixer
	)

static

Definition at line 326 of file alsa.c.

◆ mixer_is_playable()

static gboolean mixer_is_playable	(	const char *	hctl,
		snd_mixer_t *	mixer
	)

static

Definition at line 369 of file alsa.c.

◆ mixer_list_playable()

static GSList* mixer_list_playable	(	G_GNUC_UNUSED const char *	hctl,
		snd_mixer_t *	mixer
	)

static

Definition at line 350 of file alsa.c.

◆ mixer_open()

static snd_mixer_t* mixer_open ( const char * hctl )

static

Definition at line 457 of file alsa.c.

◆ poll_watch_cb()

static gboolean poll_watch_cb	(	GIOChannel *	source,
		GIOCondition	condition,
		AlsaCard *	card
	)

static

Callback function for volume changes. We forward changes to higher level, through a callback mechanism again.

Parameters

source	the GIOChannel event source.
condition	the condition which has been satisfied.
card	data set in g_io_add_watch().

Returns: FALSE if the event source should be removed.

Definition at line 660 of file alsa.c.

◆ unwatch_poll_descriptors()

static void unwatch_poll_descriptors ( guint * watch_ids )

static

Definition at line 621 of file alsa.c.

◆ use_linear_dB_scale()

static gboolean use_linear_dB_scale	(	long	db_min,
		long	db_max
	)

inlinestatic

Definition at line 89 of file alsa.c.

◆ watch_poll_descriptors()

static guint* watch_poll_descriptors	(	const char *	hctl,
		struct pollfd *	pollfds,
		GIOFunc	func,
		gpointer	data
	)

static

Definition at line 591 of file alsa.c.

Data Structures

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ _GNU_SOURCE

◆ ALSA_CARD_DEBUG

◆ ALSA_CARD_ERR

◆ ALSA_CARD_WARN

◆ ALSA_DEFAULT_CARD

◆ ALSA_DEFAULT_HCTL

◆ ALSA_ERR

◆ MAX_LINEAR_DB_SCALE

Typedef Documentation

◆ AlsaCardIter

Function Documentation

◆ alsa_card_free()

◆ alsa_card_get_channel()

◆ alsa_card_get_name()

◆ alsa_card_get_volume()

◆ alsa_card_has_mute()

◆ alsa_card_install_callback()

◆ alsa_card_is_muted()

◆ alsa_card_iter_free()

◆ alsa_card_iter_loop()

◆ alsa_card_iter_new()

◆ alsa_card_new()

◆ alsa_card_set_volume()

◆ alsa_card_toggle_mute()

◆ alsa_list_cards()

◆ alsa_list_channels()

◆ alsa_log_msg()

◆ elem_get_mute()

◆ elem_get_name()

◆ elem_get_volume()

◆ elem_get_volume_normalized()

◆ elem_has_mute()

◆ elem_set_mute()

◆ elem_set_volume()

◆ elem_set_volume_normalized()

◆ lrint_dir()

◆ mixer_close()

◆ mixer_get_first_playable_elem()

◆ mixer_get_playable_elem()

◆ mixer_get_poll_descriptors()

◆ mixer_is_playable()

◆ mixer_list_playable()

◆ mixer_open()

◆ poll_watch_cb()

◆ unwatch_poll_descriptors()

◆ use_linear_dB_scale()

◆ watch_poll_descriptors()