Commit b05796c9 authored by Andy Wingo Wingo's avatar Andy Wingo Wingo
Browse files

ext/alsa/: Port to 0.9.

Original commit message from CVS:
2005-08-19  Andy Wingo  <wingo@pobox.com>

* ext/alsa/gstalsamixertrack.h:
* ext/alsa/gstalsamixertrack.c:
* ext/alsa/gstalsamixeroptions.h:
* ext/alsa/gstalsamixeroptions.c:
* ext/alsa/gstalsamixer.h:
* ext/alsa/gstalsamixer.c: Port to 0.9.

* ext/alsa/Makefile.am: Build mixer, mixeroptions, mixertracks.
Remove gstalsa.c and alsaclock. No more cruft here.
parent 256c7c11
2005-08-19 Andy Wingo <wingo@pobox.com>
* ext/alsa/gstalsamixertrack.h:
* ext/alsa/gstalsamixertrack.c:
* ext/alsa/gstalsamixeroptions.h:
* ext/alsa/gstalsamixeroptions.c:
* ext/alsa/gstalsamixer.h:
* ext/alsa/gstalsamixer.c: Port to 0.9.
* ext/alsa/Makefile.am: Build mixer, mixeroptions, mixertracks.
Remove gstalsa.c and alsaclock. No more cruft here.
2005-08-18 Wim Taymans <wim@fluendo.com>
 
* gst-libs/gst/rtp/gstbasertpdepayload.c:
......
......@@ -2,16 +2,11 @@ plugin_LTLIBRARIES = libgstalsa.la
libgstalsa_la_SOURCES = \
gstalsaplugin.c \
gstalsasink.c \
gstalsasrc.c
# port alsa stuff then add the _SOURCES above
EXTRA_DIST = \
gstalsamixer.c \
gstalsamixer.c \
gstalsamixertrack.c \
gstalsamixeroptions.c \
gstalsa.c \
gstalsaclock.c
gstalsasink.c \
gstalsasrc.c
libgstalsa_la_CFLAGS = $(GST_CFLAGS) $(ALSA_CFLAGS)
libgstalsa_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
......@@ -22,7 +17,6 @@ libgstalsa_la_LIBADD = \
noinst_HEADERS = \
gstalsa.h \
gstalsaclock.h \
gstalsasink.h \
gstalsasrc.h \
gstalsamixer.h \
......
This diff is collapsed.
......@@ -19,9 +19,11 @@
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __GST_ALSA_H__
#define __GST_ALSA_H__
#define ALSA_PCM_NEW_HW_PARAMS_API
#define ALSA_PCM_NEW_SW_PARAMS_API
......@@ -31,210 +33,4 @@
#include <gst/gst.h>
GST_DEBUG_CATEGORY_EXTERN (alsa_debug);
#define GST_CAT_DEFAULT alsa_debug
/* error checking for standard alsa functions */
/* NOTE: these functions require a GObject *this and can only be used in
functions that return TRUE on success and FALSE on error */
#define SIMPLE_ERROR_CHECK(value) G_STMT_START{ \
int err = (value); \
if (err < 0) { \
GST_WARNING_OBJECT (this, "\"" #value "\": %s", snd_strerror (err)); \
return FALSE; \
} \
}G_STMT_END
#ifdef G_HAVE_ISO_VARARGS
#define ERROR_CHECK(value, ...) G_STMT_START{ \
int err = (value); \
if (err < 0) { \
GST_WARNING_OBJECT (this, __VA_ARGS__, snd_strerror (err)); \
return FALSE; \
} \
}G_STMT_END
#elif defined(G_HAVE_GNUC_VARARGS)
#define ERROR_CHECK(value, args...) G_STMT_START{ \
int err = (value); \
if (err < 0) { \
GST_WARNING_OBJECT (this, ## args, snd_strerror (err)); \
return FALSE; \
} \
}G_STMT_END
#else
#define ERROR_CHECK(value, args...) G_STMT_START{ \
int err = (value); \
if (err < 0) { \
GST_WARNING_OBJECT (this, snd_strerror (err)); \
return FALSE; \
} \
}G_STMT_END
#endif
#define GST_ALSA_MIN_RATE 8000
#define GST_ALSA_MAX_RATE 192000
#define GST_ALSA_MIN_PERIOD_CNT 2
#define GST_ALSA_MAX_PERIOD_CNT 64
#define GST_ALSA_MIN_PERIOD_SZ 2
#define GST_ALSA_MAX_PERIOD_SZ 8192
#define GST_ALSA_MIN_BUFFER_SZ GST_ALSA_MIN_PERIOD_CNT*GST_ALSA_MIN_PERIOD_SZ
#define GST_ALSA_MAX_BUFFER_SZ 65536
#define GST_ALSA_MAX_TRACKS 64 /* we don't support more than 64 tracks */
#define GST_ALSA_MAX_CHANNELS 32 /* tracks can have up to 32 channels */
/* a few alsa functions return an int value and a 'direction', -1, 0 or +1
0 = exact value
-1 = real value is up to 1 before given value
+1 = real value is up to 1 after given value
*/
#define GST_ALSA_DIR_MIN(i) ((i == 1) ? 1 : 0)
#define GST_ALSA_DIR_MAX(i) ((i ==-1) ?-1 : 0)
/* Mono is 1 channel ; the 5.1 standard is 6 channels. The value for
GST_ALSA_MAX_CHANNELS comes from alsa/mixer.h. */
/* Max allowed discontinuity in time units between timestamp and playback
pointer before killing/inserting samples. This should be big enough to allow
smoothing errors on different video formats. */
#define GST_ALSA_DEFAULT_DISCONT (GST_SECOND / 10)
G_BEGIN_DECLS
#define GST_ALSA(obj) (G_TYPE_CHECK_INSTANCE_CAST(obj, GST_TYPE_ALSA, GstAlsa))
#define GST_ALSA_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST(klass, GST_TYPE_ALSA, GstAlsaClass))
#define GST_ALSA_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_ALSA, GstAlsaClass))
#define GST_IS_ALSA(obj) (G_TYPE_CHECK_INSTANCE_TYPE(obj, GST_TYPE_ALSA))
#define GST_IS_ALSA_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE(klass, GST_TYPE_ALSA))
#define GST_TYPE_ALSA (gst_alsa_get_type())
enum {
GST_ALSA_OPEN = GST_ELEMENT_FLAG_LAST,
GST_ALSA_RUNNING,
GST_ALSA_CAPS_NEGO,
GST_ALSA_FLAG_LAST = GST_ELEMENT_FLAG_LAST + 3
};
typedef enum {
GST_ALSA_CAPS_PAUSE = 0,
GST_ALSA_CAPS_RESUME,
GST_ALSA_CAPS_SYNC_START
/* add more */
} GstAlsaPcmCaps;
#define GST_ALSA_CAPS_IS_SET(obj, flag) (GST_ALSA (obj)->pcm_caps & (1<<(flag)))
#define GST_ALSA_CAPS_SET(obj, flag, set) G_STMT_START{ \
if (set) { (GST_ALSA (obj)->pcm_caps |= (1<<(flag))); } \
else { (GST_ALSA (obj)->pcm_caps &= ~(1<<(flag))); } \
}G_STMT_END
typedef struct _GstAlsaClock GstAlsaClock;
typedef struct _GstAlsaClockClass GstAlsaClockClass;
typedef struct _GstAlsa GstAlsa;
typedef struct _GstAlsaClass GstAlsaClass;
typedef int (*GstAlsaTransmitFunction) (GstAlsa *this, snd_pcm_sframes_t *avail);
typedef struct {
snd_pcm_format_t format;
guint rate;
gint channels;
} GstAlsaFormat;
struct _GstAlsa {
GstElement parent;
/* array of GstAlsaPads */
GstPad * pad[GST_ALSA_MAX_TRACKS];
gchar * device;
gchar * cardname;
snd_pcm_t * handle;
guint pcm_caps; /* capabilities of the pcm device, see GstAlsaPcmCaps */
snd_output_t * out;
GstAlsaFormat * format; /* NULL if undefined */
gboolean mmap; /* use mmap transmit (fast) or read/write (sloooow) */
GstAlsaTransmitFunction transmit;
GstCaps * cached_caps; /* we cache caps to speed up get_caps */
/* latency / performance parameters */
snd_pcm_uframes_t period_size;
unsigned int period_count;
gboolean autorecover;
/* clocking */
GstAlsaClock * clock; /* our provided clock */
GstClock * ext_clock; /* externally set clock. */
snd_pcm_uframes_t played; /* samples transmitted since last sync
This thing actually is our master clock.
We will event insert silent samples or
drop some to sync to incoming timestamps.
*/
snd_pcm_uframes_t captured;
GstClockTime max_discont; /* max difference between current
playback timestamp and buffers timestamps
*/
};
struct _GstAlsaClass {
GstElementClass parent_class;
snd_pcm_stream_t stream;
/* different transmit functions */
GstAlsaTransmitFunction transmit_mmap;
GstAlsaTransmitFunction transmit_rw;
/* autodetected devices available */
GList *devices;
};
GType gst_alsa_get_type (void);
void gst_alsa_set_eos (GstAlsa * this);
GstPadLinkReturn gst_alsa_link (GstPad * pad,
const GstCaps * caps);
GstCaps * gst_alsa_get_caps (GstPad * pad);
GstCaps * gst_alsa_fixate (GstPad * pad,
const GstCaps * caps);
GstCaps * gst_alsa_caps (snd_pcm_format_t format,
gint rate,
gint channels);
/* audio processing functions */
inline snd_pcm_sframes_t gst_alsa_update_avail (GstAlsa * this);
inline gboolean gst_alsa_pcm_wait (GstAlsa * this);
inline gboolean gst_alsa_start (GstAlsa * this);
gboolean gst_alsa_xrun_recovery (GstAlsa * this);
/* format conversions */
inline snd_pcm_uframes_t gst_alsa_timestamp_to_samples (GstAlsa * this,
GstClockTime time);
inline GstClockTime gst_alsa_samples_to_timestamp (GstAlsa * this,
snd_pcm_uframes_t samples);
inline snd_pcm_uframes_t gst_alsa_bytes_to_samples (GstAlsa * this,
guint bytes);
inline guint gst_alsa_samples_to_bytes (GstAlsa * this,
snd_pcm_uframes_t samples);
inline GstClockTime gst_alsa_bytes_to_timestamp (GstAlsa * this,
guint bytes);
inline guint gst_alsa_timestamp_to_bytes (GstAlsa * this,
GstClockTime time);
/* debugging functions (useful in gdb) - require running with --gst-debug=alsa:4 or better */
void gst_alsa_sw_params_dump (GstAlsa * this,
snd_pcm_sw_params_t * sw_params);
void gst_alsa_hw_params_dump (GstAlsa * this,
snd_pcm_hw_params_t * hw_params);
G_END_DECLS
#endif /* __GST_ALSA_H__ */
/*
* Copyright (C) 2001 CodeFactory AB
* Copyright (C) 2001 Thomas Nyberg <thomas@codefactory.se>
* Copyright (C) 2001-2002 Andy Wingo <apwingo@eos.ncsu.edu>
* Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstalsaclock.h"
/* clock functions */
static void gst_alsa_clock_class_init (gpointer g_class, gpointer class_data);
static void gst_alsa_clock_init (GstAlsaClock * clock);
static GstClockTime gst_alsa_clock_get_internal_time (GstClock * clock);
static guint64 gst_alsa_clock_get_resolution (GstClock * clock);
static GstClockEntryStatus gst_alsa_clock_wait (GstClock * clock,
GstClockEntry * entry);
static void gst_alsa_clock_unlock (GstClock * clock, GstClockEntry * entry);
static GstClockClass *clock_parent_class = NULL;
/* static guint gst_alsa_clock_signals[LAST_SIGNAL] = { 0 }; */
GType
gst_alsa_clock_get_type (void)
{
static GType clock_type = 0;
if (!clock_type) {
static const GTypeInfo clock_info = {
sizeof (GstAlsaClockClass),
NULL,
NULL,
gst_alsa_clock_class_init,
NULL,
NULL,
sizeof (GstAlsaClock),
4,
(GInstanceInitFunc) gst_alsa_clock_init,
NULL
};
clock_type = g_type_register_static (GST_TYPE_CLOCK, "GstAlsaClock",
&clock_info, 0);
}
return clock_type;
}
static void
gst_alsa_clock_class_init (gpointer g_class, gpointer class_data)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
GstClockClass *gstclock_class;
GstAlsaClockClass *klass;
klass = (GstAlsaClockClass *) g_class;
gobject_class = (GObjectClass *) klass;
gstobject_class = (GstObjectClass *) klass;
gstclock_class = (GstClockClass *) klass;
clock_parent_class = g_type_class_ref (GST_TYPE_CLOCK);
gstclock_class->get_internal_time = gst_alsa_clock_get_internal_time;
gstclock_class->get_resolution = gst_alsa_clock_get_resolution;
gstclock_class->wait = gst_alsa_clock_wait;
gstclock_class->unlock = gst_alsa_clock_unlock;
}
static void
gst_alsa_clock_init (GstAlsaClock * clock)
{
gst_object_set_name (GST_OBJECT (clock), "GstAlsaClock");
clock->start_time = GST_CLOCK_TIME_NONE;
}
GstAlsaClock *
gst_alsa_clock_new (gchar * name, GstAlsaClockGetTimeFunc get_time,
GstAlsa * owner)
{
GstAlsaClock *alsa_clock =
GST_ALSA_CLOCK (g_object_new (GST_TYPE_ALSA_CLOCK, NULL));
g_assert (alsa_clock);
alsa_clock->get_time = get_time;
alsa_clock->owner = owner;
alsa_clock->adjust = 0;
gst_object_set_name (GST_OBJECT (alsa_clock), name);
gst_object_set_parent (GST_OBJECT (alsa_clock), GST_OBJECT (owner));
return alsa_clock;
}
void
gst_alsa_clock_start (GstAlsaClock * clock)
{
g_assert (!GST_CLOCK_TIME_IS_VALID (clock->start_time));
if (clock->owner->format) {
clock->start_time = gst_clock_get_event_time (GST_CLOCK (clock))
- clock->get_time (clock->owner);
} else {
clock->start_time = gst_clock_get_event_time (GST_CLOCK (clock));
}
}
void
gst_alsa_clock_stop (GstAlsaClock * clock)
{
GTimeVal timeval;
g_get_current_time (&timeval);
g_assert (GST_CLOCK_TIME_IS_VALID (clock->start_time));
clock->adjust +=
GST_TIMEVAL_TO_TIME (timeval) -
gst_clock_get_event_time (GST_CLOCK (clock));
clock->start_time = GST_CLOCK_TIME_NONE;
}
static GstClockTime
gst_alsa_clock_get_internal_time (GstClock * clock)
{
GstAlsaClock *alsa_clock = GST_ALSA_CLOCK (clock);
if (GST_CLOCK_TIME_IS_VALID (alsa_clock->start_time)) {
return alsa_clock->get_time (alsa_clock->owner) + alsa_clock->start_time;
} else {
GTimeVal timeval;
g_get_current_time (&timeval);
return GST_TIMEVAL_TO_TIME (timeval) + alsa_clock->adjust;
}
}
static guint64
gst_alsa_clock_get_resolution (GstClock * clock)
{
GstAlsaClock *this = GST_ALSA_CLOCK (clock);
if (this->owner->format) {
return GST_SECOND / this->owner->format->rate;
} else {
/* FIXME: is there an "unknown" value? We just return the sysclock's time by default */
return 1 * GST_USECOND;
}
}
static GstClockEntryStatus
gst_alsa_clock_wait (GstClock * clock, GstClockEntry * entry)
{
GstClockTime target, entry_time, glib_start, glib_cur;
GstClockTimeDiff diff;
GstAlsaClock *this = GST_ALSA_CLOCK (clock);
GTimeVal t;
entry_time = gst_alsa_clock_get_internal_time (clock);
diff = GST_CLOCK_ENTRY_TIME (entry) - gst_clock_get_time (clock);
if (diff < 0)
return GST_CLOCK_ENTRY_EARLY;
if (diff > clock->max_diff) {
GST_INFO_OBJECT (this,
"GstAlsaClock: abnormal clock request diff: %" GST_TIME_FORMAT ") >"
" %" GST_TIME_FORMAT, GST_TIME_ARGS (diff),
GST_TIME_ARGS (clock->max_diff));
return GST_CLOCK_ENTRY_EARLY;
}
target = entry_time + diff;
GST_DEBUG_OBJECT (this, "real_target %" GST_TIME_FORMAT
" target %" GST_TIME_FORMAT
" now %" GST_TIME_FORMAT,
GST_TIME_ARGS (target), GST_TIME_ARGS (GST_CLOCK_ENTRY_TIME (entry)),
GST_TIME_ARGS (entry_time));
g_get_current_time (&t);
glib_cur = glib_start = GST_TIMEVAL_TO_TIME (t);
while (gst_alsa_clock_get_internal_time (clock) < target &&
this->last_unlock < entry_time && glib_start + diff * 1.5 > glib_cur) {
g_usleep (gst_alsa_clock_get_resolution (clock) * G_USEC_PER_SEC /
GST_SECOND);
g_get_current_time (&t);
glib_cur = GST_TIMEVAL_TO_TIME (t);
}
return entry->status;
}
static void
gst_alsa_clock_unlock (GstClock * clock, GstClockEntry * entry)
{
GstAlsaClock *this = GST_ALSA_CLOCK (clock);
this->last_unlock = this->get_time (this->owner);
}
/*
* Copyright (C) 2001 CodeFactory AB
* Copyright (C) 2001 Thomas Nyberg <thomas@codefactory.se>
* Copyright (C) 2001-2002 Andy Wingo <apwingo@eos.ncsu.edu>
* Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __GST_ALSA_CLOCK_H__
#define __GST_ALSA_CLOCK_H__
#include "gstalsa.h"
G_BEGIN_DECLS
#define GST_ALSA_CLOCK(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_ALSA_CLOCK,GstAlsaClock))
#define GST_ALSA_CLOCK_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ALSA_CLOCK,GstAlsaClockClass))
#define GST_IS_ALSA_CLOCK(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_ALSA_CLOCK))
#define GST_IS_ALSA_CLOCK_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ALSA_CLOCK))
#define GST_TYPE_ALSA_CLOCK (gst_alsa_clock_get_type())
typedef GstClockTime (*GstAlsaClockGetTimeFunc) (GstAlsa *);
struct _GstAlsaClock {
GstSystemClock parent;
GstAlsaClockGetTimeFunc get_time;
GstAlsa * owner;
GstClockTimeDiff adjust; /* adjustment to real clock (recalculated when stopping) */
GstClockTime start_time; /* time when the stream started (NONE when stopped) */
GstClockTime last_unlock; /* time of last unlock request */
};
struct _GstAlsaClockClass {
GstSystemClockClass parent_class;
};
GType gst_alsa_clock_get_type (void);
GstAlsaClock * gst_alsa_clock_new (gchar * name,
GstAlsaClockGetTimeFunc func,
GstAlsa * owner);
void gst_alsa_clock_start (GstAlsaClock * clock);
void gst_alsa_clock_stop (GstAlsaClock * clock);
G_END_DECLS
#endif /* __GST_ALSA_CLOCK_H__ */
......@@ -17,113 +17,91 @@
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstalsamixer.h"
/* elementfactory information */
static GstElementDetails gst_alsa_mixer_details =
GST_ELEMENT_DETAILS ("Alsa Mixer",
"Generic/Audio",
"Control sound input and output levels with ALSA",
"Leif Johnson <leif@ambient.2y.net>");
static void gst_alsa_interface_init (GstImplementsInterfaceClass * klass);
static void gst_alsa_mixer_class_init (gpointer g_class, gpointer class_data);
static void gst_alsa_mixer_init (GstAlsaMixer * mixer);
static void gst_alsa_mixer_interface_init (GstMixerClass * klass);
static gboolean gst_alsa_mixer_supported (GstImplementsInterface * iface,
GType iface_type);
#define GST_BOILERPLATE_WITH_INTERFACE(type, type_as_function, parent_type, \
parent_type_as_macro, interface_type, interface_type_as_macro, \
interface_as_function) \
\
static void interface_as_function ## _interface_init (interface_type ## Class *klass); \
static gboolean interface_as_function ## _supported (type *object, GType iface_type); \
\
static void \
type_as_function ## _implements_interface_init (GstImplementsInterfaceClass *klass) \
{ \
klass->supported = (gpointer)interface_as_function ## _supported; \
} \
\
static void \
type_as_function ## _init_interfaces (GType type) \
{ \
static const GInterfaceInfo implements_iface_info = { \
(GInterfaceInitFunc) type_as_function ## _implements_interface_init, \
NULL, \
NULL, \
}; \
static const GInterfaceInfo iface_info = { \
(GInterfaceInitFunc) interface_as_function ## _interface_init, \
NULL, \
NULL, \
}; \
\
g_type_add_interface_static (type, GST_TYPE_IMPLEMENTS_INTERFACE, \
&implements_iface_info); \
g_type_add_interface_static (type, interface_type_as_macro, &iface_info); \
} \
\
GST_BOILERPLATE_FULL (type, type_as_function, parent_type, \
parent_type_as_macro, type_as_function ## _init_interfaces)
GST_BOILERPLATE_WITH_INTERFACE (GstAlsaMixer, gst_alsa_mixer, GstElement,
GST_TYPE_ELEMENT, GstMixer, GST_TYPE_MIXER, gst_alsa_mixer);
/* GStreamer stuff */
static GstElementStateReturn gst_alsa_mixer_change_state (GstElement * element);
static void gst_alsa_mixer_build_list (GstAlsaMixer * mixer);
static void gst_alsa_mixer_free_list (GstAlsaMixer * mixer);
/* interface implementation */
/* GstMixer */
static const GList *gst_alsa_mixer_list_tracks (GstMixer * mixer);
static void gst_alsa_mixer_set_volume (GstMixer * mixer,
GstMixerTrack * track, gint * volumes);
static void gst_alsa_mixer_get_volume (GstMixer * mixer,
GstMixerTrack * track, gint * volumes);
static void gst_alsa_mixer_set_record (GstMixer * mixer,
GstMixerTrack * track, gboolean record);
static void gst_alsa_mixer_set_mute (GstMixer * mixer,
GstMixerTrack * track, gboolean mute);
static void gst_alsa_mixer_set_option (GstMixer * mixer,
GstMixerOptions * opts, gchar * value);
static const gchar *gst_alsa_mixer_get_option (GstMixer * mixer,
GstMixerOptions * opts);