gstreamer/sys/oss/gstossmixerelement.c
2012-04-10 00:51:41 +01:00

218 lines
6.1 KiB
C

/* OSS mixer interface element.
* Copyright (C) 2005 Andrew Vander Wingo <wingo@pobox.com>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-ossmixer
*
* This element lets you adjust sound input and output levels with the
* Open Sound System (OSS). It supports the #GstMixer interface, which can be
* used to obtain a list of available mixer tracks. Set the mixer element to
* READY state before using the #GstMixer interface on it.
*
* <refsect2>
* <title>Example pipelines</title>
* <para>
* ossmixer can't be used in a sensible way in gst-launch.
* </para>
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstossmixerelement.h"
GST_DEBUG_CATEGORY_EXTERN (oss_debug);
#define GST_CAT_DEFAULT oss_debug
#define DEFAULT_DEVICE "/dev/mixer"
#define DEFAULT_DEVICE_NAME NULL
enum
{
PROP_0,
PROP_DEVICE,
PROP_DEVICE_NAME
};
GST_BOILERPLATE_WITH_INTERFACE (GstOssMixerElement, gst_oss_mixer_element,
GstElement, GST_TYPE_ELEMENT, GstMixer, GST_TYPE_MIXER,
gst_oss_mixer_element);
GST_IMPLEMENT_OSS_MIXER_METHODS (GstOssMixerElement, gst_oss_mixer_element);
static GstStateChangeReturn gst_oss_mixer_element_change_state (GstElement *
element, GstStateChange transition);
static void gst_oss_mixer_element_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_oss_mixer_element_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec);
static void gst_oss_mixer_element_finalize (GObject * object);
static void
gst_oss_mixer_element_base_init (gpointer klass)
{
gst_element_class_set_static_metadata (GST_ELEMENT_CLASS (klass), "OSS Mixer",
"Generic/Audio",
"Control sound input and output levels with OSS",
"Andrew Vander Wingo <wingo@pobox.com>");
}
static void
gst_oss_mixer_element_class_init (GstOssMixerElementClass * klass)
{
GstElementClass *element_class;
GObjectClass *gobject_class;
element_class = (GstElementClass *) klass;
gobject_class = (GObjectClass *) klass;
gobject_class->finalize = gst_oss_mixer_element_finalize;
gobject_class->set_property = gst_oss_mixer_element_set_property;
gobject_class->get_property = gst_oss_mixer_element_get_property;
/**
* GstOssMixerElement:device
*
* OSS mixer device (usually /dev/mixer)
*
* Since: 0.10.5
**/
g_object_class_install_property (gobject_class, PROP_DEVICE,
g_param_spec_string ("device", "Device",
"OSS mixer device (usually /dev/mixer)", DEFAULT_DEVICE,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_DEVICE_NAME,
g_param_spec_string ("device-name", "Device name",
"Human-readable name of the sound device", DEFAULT_DEVICE_NAME,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
element_class->change_state =
GST_DEBUG_FUNCPTR (gst_oss_mixer_element_change_state);
}
static void
gst_oss_mixer_element_finalize (GObject * obj)
{
GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (obj);
g_free (this->device);
G_OBJECT_CLASS (parent_class)->finalize (obj);
}
static void
gst_oss_mixer_element_init (GstOssMixerElement * this,
GstOssMixerElementClass * g_class)
{
this->mixer = NULL;
this->device = g_strdup (DEFAULT_DEVICE);
}
static void
gst_oss_mixer_element_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (object);
switch (prop_id) {
case PROP_DEVICE:
g_free (this->device);
this->device = g_value_dup_string (value);
/* make sure we never set NULL */
if (this->device == NULL) {
this->device = g_strdup (DEFAULT_DEVICE);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_oss_mixer_element_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (object);
switch (prop_id) {
case PROP_DEVICE:
g_value_set_string (value, this->device);
break;
case PROP_DEVICE_NAME:
if (this->mixer) {
g_value_set_string (value, this->mixer->cardname);
} else {
g_value_set_string (value, NULL);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstStateChangeReturn
gst_oss_mixer_element_change_state (GstElement * element,
GstStateChange transition)
{
GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (element);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
if (!this->mixer) {
this->mixer = gst_ossmixer_new (this->device, GST_OSS_MIXER_ALL);
if (!this->mixer)
goto open_failed;
}
break;
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
if (ret == GST_STATE_CHANGE_FAILURE)
return ret;
switch (transition) {
case GST_STATE_CHANGE_READY_TO_NULL:
if (this->mixer) {
gst_ossmixer_free (this->mixer);
this->mixer = NULL;
}
break;
default:
break;
}
return ret;
/* ERRORS */
open_failed:
{
GST_ELEMENT_ERROR (element, RESOURCE, OPEN_READ_WRITE, (NULL),
("Failed to open oss mixer device '%s'", this->device));
return GST_STATE_CHANGE_FAILURE;
}
}