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
56 static const GstElementDetails gst_oss_mixer_element_details =
57 GST_ELEMENT_DETAILS ("OSS Mixer",
59 "Control sound input and output levels with OSS",
60 "Andrew Vander Wingo <wingo@pobox.com>");
63 GST_BOILERPLATE_WITH_INTERFACE (GstOssMixerElement, gst_oss_mixer_element,
64 GstElement, GST_TYPE_ELEMENT, GstMixer, GST_TYPE_MIXER,
65 gst_oss_mixer_element);
67 GST_IMPLEMENT_OSS_MIXER_METHODS (GstOssMixerElement, gst_oss_mixer_element);
69 static GstStateChangeReturn gst_oss_mixer_element_change_state (GstElement *
70 element, GstStateChange transition);
72 static void gst_oss_mixer_element_set_property (GObject * object,
73 guint prop_id, const GValue * value, GParamSpec * pspec);
74 static void gst_oss_mixer_element_get_property (GObject * object,
75 guint prop_id, GValue * value, GParamSpec * pspec);
76 static void gst_oss_mixer_element_finalize (GObject * object);
79 gst_oss_mixer_element_base_init (gpointer klass)
81 gst_element_class_set_details (GST_ELEMENT_CLASS (klass),
82 &gst_oss_mixer_element_details);
86 gst_oss_mixer_element_class_init (GstOssMixerElementClass * klass)
88 GstElementClass *element_class;
89 GObjectClass *gobject_class;
91 element_class = (GstElementClass *) klass;
92 gobject_class = (GObjectClass *) klass;
94 gobject_class->finalize = gst_oss_mixer_element_finalize;
95 gobject_class->set_property = gst_oss_mixer_element_set_property;
96 gobject_class->get_property = gst_oss_mixer_element_get_property;
99 * GstOssMixerElement:device
101 * OSS mixer device (usually /dev/mixer)
105 g_object_class_install_property (gobject_class, PROP_DEVICE,
106 g_param_spec_string ("device", "Device",
107 "OSS mixer device (usually /dev/mixer)", DEFAULT_DEVICE,
110 g_object_class_install_property (gobject_class, PROP_DEVICE_NAME,
111 g_param_spec_string ("device-name", "Device name",
112 "Human-readable name of the sound device", DEFAULT_DEVICE_NAME,
115 element_class->change_state =
116 GST_DEBUG_FUNCPTR (gst_oss_mixer_element_change_state);
120 gst_oss_mixer_element_finalize (GObject * obj)
122 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (obj);
124 g_free (this->device);
126 G_OBJECT_CLASS (parent_class)->finalize (obj);
130 gst_oss_mixer_element_init (GstOssMixerElement * this,
131 GstOssMixerElementClass * g_class)
134 this->device = g_strdup (DEFAULT_DEVICE);
138 gst_oss_mixer_element_set_property (GObject * object, guint prop_id,
139 const GValue * value, GParamSpec * pspec)
141 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (object);
145 g_free (this->device);
146 this->device = g_value_dup_string (value);
147 /* make sure we never set NULL */
148 if (this->device == NULL) {
149 this->device = g_strdup (DEFAULT_DEVICE);
153 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
159 gst_oss_mixer_element_get_property (GObject * object, guint prop_id,
160 GValue * value, GParamSpec * pspec)
162 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (object);
166 g_value_set_string (value, this->device);
168 case PROP_DEVICE_NAME:
170 g_value_set_string (value, this->mixer->cardname);
172 g_value_set_string (value, NULL);
176 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
181 static GstStateChangeReturn
182 gst_oss_mixer_element_change_state (GstElement * element,
183 GstStateChange transition)
185 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
186 GstOssMixerElement *this = GST_OSS_MIXER_ELEMENT (element);
188 switch (transition) {
189 case GST_STATE_CHANGE_NULL_TO_READY:
191 this->mixer = gst_ossmixer_new (this->device, GST_OSS_MIXER_ALL);
201 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
202 if (ret == GST_STATE_CHANGE_FAILURE)
205 switch (transition) {
206 case GST_STATE_CHANGE_READY_TO_NULL:
208 gst_ossmixer_free (this->mixer);
220 GST_ELEMENT_ERROR (element, RESOURCE, OPEN_READ_WRITE, (NULL),
221 ("Failed to open oss mixer device '%s'", this->device));
222 return GST_STATE_CHANGE_FAILURE;