1 /* OSS mixer interface element.
2 * Copyright (C) 2005 Andrew Vander Wingo <wingo@pobox.com>
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
21 * SECTION:element-ossmixer
23 * This element lets you adjust sound input and output levels with the
24 * Open Sound System (OSS). It supports the #GstMixer interface, which can be
25 * used to obtain a list of available mixer tracks. Set the mixer element to
26 * READY state before using the #GstMixer interface on it.
29 * <title>Example pipelines</title>
31 * ossmixer can't be used in a sensible way in gst-launch.
40 #include "gstossmixerelement.h"
42 GST_DEBUG_CATEGORY_EXTERN (oss_debug);
43 #define GST_CAT_DEFAULT oss_debug
45 #define DEFAULT_DEVICE "/dev/mixer"
46 #define DEFAULT_DEVICE_NAME NULL
55 GST_BOILERPLATE_WITH_INTERFACE (GstOssMixerElement, gst_oss_mixer_element,
56 GstElement, GST_TYPE_ELEMENT, GstMixer, GST_TYPE_MIXER,
57 gst_oss_mixer_element);
59 GST_IMPLEMENT_OSS_MIXER_METHODS (GstOssMixerElement, gst_oss_mixer_element);
61 static GstStateChangeReturn gst_oss_mixer_element_change_state (GstElement *
62 element, GstStateChange transition);
64 static void gst_oss_mixer_element_set_property (GObject * object,
65 guint prop_id, const GValue * value, GParamSpec * pspec);
66 static void gst_oss_mixer_element_get_property (GObject * object,
67 guint prop_id, GValue * value, GParamSpec * pspec);
68 static void gst_oss_mixer_element_finalize (GObject * object);
71 gst_oss_mixer_element_base_init (gpointer klass)
73 gst_element_class_set_details_simple (GST_ELEMENT_CLASS (klass), "OSS Mixer",
75 "Control sound input and output levels with OSS",
76 "Andrew Vander Wingo <wingo@pobox.com>");
80 gst_oss_mixer_element_class_init (GstOssMixerElementClass * klass)
82 GstElementClass *element_class;
83 GObjectClass *gobject_class;
85 element_class = (GstElementClass *) klass;
86 gobject_class = (GObjectClass *) klass;
88 gobject_class->finalize = gst_oss_mixer_element_finalize;
89 gobject_class->set_property = gst_oss_mixer_element_set_property;
90 gobject_class->get_property = gst_oss_mixer_element_get_property;
93 * GstOssMixerElement:device
95 * OSS mixer device (usually /dev/mixer)
99 g_object_class_install_property (gobject_class, PROP_DEVICE,
100 g_param_spec_string ("device", "Device",
101 "OSS mixer device (usually /dev/mixer)", DEFAULT_DEVICE,
102 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
104 g_object_class_install_property (gobject_class, PROP_DEVICE_NAME,
105 g_param_spec_string ("device-name", "Device name",
106 "Human-readable name of the sound device", DEFAULT_DEVICE_NAME,
107 G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
109 element_class->change_state =
110 GST_DEBUG_FUNCPTR (gst_oss_mixer_element_change_state);
114 gst_oss_mixer_element_finalize (GObject * obj)
116 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (obj);
118 g_free (this->device);
120 G_OBJECT_CLASS (parent_class)->finalize (obj);
124 gst_oss_mixer_element_init (GstOssMixerElement * this,
125 GstOssMixerElementClass * g_class)
128 this->device = g_strdup (DEFAULT_DEVICE);
132 gst_oss_mixer_element_set_property (GObject * object, guint prop_id,
133 const GValue * value, GParamSpec * pspec)
135 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (object);
139 g_free (this->device);
140 this->device = g_value_dup_string (value);
141 /* make sure we never set NULL */
142 if (this->device == NULL) {
143 this->device = g_strdup (DEFAULT_DEVICE);
147 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
153 gst_oss_mixer_element_get_property (GObject * object, guint prop_id,
154 GValue * value, GParamSpec * pspec)
156 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (object);
160 g_value_set_string (value, this->device);
162 case PROP_DEVICE_NAME:
164 g_value_set_string (value, this->mixer->cardname);
166 g_value_set_string (value, NULL);
170 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
175 static GstStateChangeReturn
176 gst_oss_mixer_element_change_state (GstElement * element,
177 GstStateChange transition)
179 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
180 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (element);
182 switch (transition) {
183 case GST_STATE_CHANGE_NULL_TO_READY:
185 this->mixer = gst_ossmixer_new (this->device, GST_OSS_MIXER_ALL);
195 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
196 if (ret == GST_STATE_CHANGE_FAILURE)
199 switch (transition) {
200 case GST_STATE_CHANGE_READY_TO_NULL:
202 gst_ossmixer_free (this->mixer);
214 GST_ELEMENT_ERROR (element, RESOURCE, OPEN_READ_WRITE, (NULL),
215 ("Failed to open oss mixer device '%s'", this->device));
216 return GST_STATE_CHANGE_FAILURE;