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
22 * @short_description: element to control sound input and output levels with OSS
26 * This element lets you adjust sound input and output levels with the
27 * Open Sound System (OSS). It supports the GstMixer interface, which can be
28 * used to obtain a list of available mixer tracks. Set the mixer element to
29 * READY state before using the GstMixer interface on it.
31 * <title>Example pipelines</title>
33 * ossmixer can't be used in a sensible way in gst-launch.
42 #include "gstossmixerelement.h"
44 GST_DEBUG_CATEGORY_EXTERN (oss_debug);
45 #define GST_CAT_DEFAULT oss_debug
47 #define DEFAULT_DEVICE "/dev/mixer"
48 #define DEFAULT_DEVICE_NAME NULL
58 static const GstElementDetails gst_oss_mixer_element_details =
59 GST_ELEMENT_DETAILS ("OSS Mixer",
61 "Control sound input and output levels with OSS",
62 "Andrew Vander Wingo <wingo@pobox.com>");
65 GST_BOILERPLATE_WITH_INTERFACE (GstOssMixerElement, gst_oss_mixer_element,
66 GstElement, GST_TYPE_ELEMENT, GstMixer, GST_TYPE_MIXER,
67 gst_oss_mixer_element);
69 GST_IMPLEMENT_OSS_MIXER_METHODS (GstOssMixerElement, gst_oss_mixer_element);
71 static GstStateChangeReturn gst_oss_mixer_element_change_state (GstElement *
72 element, GstStateChange transition);
74 static void gst_oss_mixer_element_set_property (GObject * object,
75 guint prop_id, const GValue * value, GParamSpec * pspec);
76 static void gst_oss_mixer_element_get_property (GObject * object,
77 guint prop_id, GValue * value, GParamSpec * pspec);
78 static void gst_oss_mixer_element_finalize (GObject * object);
81 gst_oss_mixer_element_base_init (gpointer klass)
83 gst_element_class_set_details (GST_ELEMENT_CLASS (klass),
84 &gst_oss_mixer_element_details);
88 gst_oss_mixer_element_class_init (GstOssMixerElementClass * klass)
90 GstElementClass *element_class;
91 GObjectClass *gobject_class;
93 element_class = (GstElementClass *) klass;
94 gobject_class = (GObjectClass *) klass;
96 gobject_class->finalize = gst_oss_mixer_element_finalize;
97 gobject_class->set_property = gst_oss_mixer_element_set_property;
98 gobject_class->get_property = gst_oss_mixer_element_get_property;
101 * GstOssMixerElement:device
103 * OSS mixer device (usually /dev/mixer)
107 g_object_class_install_property (gobject_class, PROP_DEVICE,
108 g_param_spec_string ("device", "Device",
109 "OSS mixer device (usually /dev/mixer)", DEFAULT_DEVICE,
112 g_object_class_install_property (gobject_class, PROP_DEVICE_NAME,
113 g_param_spec_string ("device-name", "Device name",
114 "Human-readable name of the sound device", DEFAULT_DEVICE_NAME,
117 element_class->change_state =
118 GST_DEBUG_FUNCPTR (gst_oss_mixer_element_change_state);
122 gst_oss_mixer_element_finalize (GObject * obj)
124 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (obj);
126 g_free (this->device);
128 G_OBJECT_CLASS (parent_class)->finalize (obj);
132 gst_oss_mixer_element_init (GstOssMixerElement * this,
133 GstOssMixerElementClass * g_class)
136 this->device = g_strdup (DEFAULT_DEVICE);
140 gst_oss_mixer_element_set_property (GObject * object, guint prop_id,
141 const GValue * value, GParamSpec * pspec)
143 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (object);
147 g_free (this->device);
148 this->device = g_value_dup_string (value);
149 /* make sure we never set NULL */
150 if (this->device == NULL) {
151 this->device = g_strdup (DEFAULT_DEVICE);
155 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
161 gst_oss_mixer_element_get_property (GObject * object, guint prop_id,
162 GValue * value, GParamSpec * pspec)
164 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (object);
168 g_value_set_string (value, this->device);
170 case PROP_DEVICE_NAME:
172 g_value_set_string (value, this->mixer->cardname);
174 g_value_set_string (value, NULL);
178 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
183 static GstStateChangeReturn
184 gst_oss_mixer_element_change_state (GstElement * element,
185 GstStateChange transition)
187 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
188 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (element);
190 switch (transition) {
191 case GST_STATE_CHANGE_NULL_TO_READY:
193 this->mixer = gst_ossmixer_new (this->device, GST_OSS_MIXER_ALL);
203 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
204 if (ret == GST_STATE_CHANGE_FAILURE)
207 switch (transition) {
208 case GST_STATE_CHANGE_READY_TO_NULL:
210 gst_ossmixer_free (this->mixer);
222 GST_ELEMENT_ERROR (element, RESOURCE, OPEN_READ_WRITE, (NULL),
223 ("Failed to open oss mixer device '%s'", this->device));
224 return GST_STATE_CHANGE_FAILURE;