src/gstplugin.c

   1 /*
   2  * GStreamer
   3  * Copyright 2005 Thomas Vander Stichele <thomas@apestaart.org>
   4  * Copyright 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  *
  24  * Alternatively, the contents of this file may be used under the
  25  * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
  26  * which case the following provisions apply instead of the ones
  27  * mentioned above:
  28  *
  29  * This library is free software; you can redistribute it and/or
  30  * modify it under the terms of the GNU Library General Public
  31  * License as published by the Free Software Foundation; either
  32  * version 2 of the License, or (at your option) any later version.
  33  *
  34  * This library is distributed in the hope that it will be useful,
  35  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  36  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  37  * Library General Public License for more details.
  38  *
  39  * You should have received a copy of the GNU Library General Public
  40  * License along with this library; if not, write to the
  41  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  42  * Boston, MA 02111-1307, USA.
  43  */
  44
  45 /**
  46  * SECTION:element-plugin
  47  *
  48  * <refsect2>
  49  * <title>Example launch line</title>
  50  * <para>
  51  * <programlisting>
  52  * gst-launch -v -m audiotestsrc ! plugin ! fakesink silent=TRUE
  53  * </programlisting>
  54  * </para>
  55  * </refsect2>
  56  */
  57
  58 #ifdef HAVE_CONFIG_H
  59 #  include <config.h>
  60 #endif
  61
  62 #include <gst/gst.h>
  63
  64 #include "gstplugin.h"
  65
  66 GST_DEBUG_CATEGORY_STATIC (gst_plugin_template_debug);
  67 #define GST_CAT_DEFAULT gst_plugin_template_debug
  68
  69 /* Filter signals and args */
  70 enum
  71 {
  72   /* FILL ME */
  73   LAST_SIGNAL
  74 };
  75
  76 enum
  77 {
  78   ARG_0,
  79   ARG_SILENT
  80 };
  81
  82 static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
  83     GST_PAD_SINK,
  84     GST_PAD_ALWAYS,
  85     GST_STATIC_CAPS ("ANY")
  86     );
  87
  88 static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
  89     GST_PAD_SRC,
  90     GST_PAD_ALWAYS,
  91     GST_STATIC_CAPS ("ANY")
  92     );
  93
  94 GST_BOILERPLATE (GstPluginTemplate, gst_plugin_template, GstElement,
  95     GST_TYPE_ELEMENT);
  96
  97 static void gst_plugin_template_set_property (GObject * object, guint prop_id,
  98     const GValue * value, GParamSpec * pspec);
  99 static void gst_plugin_template_get_property (GObject * object, guint prop_id,
 100     GValue * value, GParamSpec * pspec);
 101
 102 static gboolean gst_plugin_template_set_caps (GstPad * pad, GstCaps * caps);
 103 static GstFlowReturn gst_plugin_template_chain (GstPad * pad, GstBuffer * buf);
 104
 105 static void
 106 gst_plugin_template_base_init (gpointer gclass)
 107 {
 108   static GstElementDetails element_details = {
 109     "PluginTemplate",
 110     "Generic/PluginTemplate",
 111     "Generic Template Element",
 112     "Thomas Vander Stichele <thomas@apestaart.org>"
 113   };
 114   GstElementClass *element_class = GST_ELEMENT_CLASS (gclass);
 115
 116   gst_element_class_add_pad_template (element_class,
 117       gst_static_pad_template_get (&src_factory));
 118   gst_element_class_add_pad_template (element_class,
 119       gst_static_pad_template_get (&sink_factory));
 120   gst_element_class_set_details (element_class, &element_details);
 121 }
 122
 123 /* initialize the plugin's class */
 124 static void
 125 gst_plugin_template_class_init (GstPluginTemplateClass * klass)
 126 {
 127   GObjectClass *gobject_class;
 128   GstElementClass *gstelement_class;
 129
 130   gobject_class = (GObjectClass *) klass;
 131   gstelement_class = (GstElementClass *) klass;
 132
 133   gobject_class->set_property = gst_plugin_template_set_property;
 134   gobject_class->get_property = gst_plugin_template_get_property;
 135
 136   g_object_class_install_property (gobject_class, ARG_SILENT,
 137       g_param_spec_boolean ("silent", "Silent", "Produce verbose output ?",
 138           FALSE, G_PARAM_READWRITE));
 139 }
 140
 141 /* initialize the new element
 142  * instantiate pads and add them to element
 143  * set functions
 144  * initialize structure
 145  */
 146 static void
 147 gst_plugin_template_init (GstPluginTemplate * filter,
 148     GstPluginTemplateClass * gclass)
 149 {
 150   GstElementClass *klass = GST_ELEMENT_GET_CLASS (filter);
 151
 152   filter->sinkpad =
 153       gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
 154           "sink"), "sink");
 155   gst_pad_set_setcaps_function (filter->sinkpad,
 156                                 GST_DEBUG_FUNCPTR(gst_plugin_template_set_caps));
 157   gst_pad_set_getcaps_function (filter->sinkpad,
 158                                 GST_DEBUG_FUNCPTR(gst_pad_proxy_getcaps));
 159
 160   filter->srcpad =
 161       gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
 162           "src"), "src");
 163   gst_pad_set_getcaps_function (filter->srcpad,
 164                                 GST_DEBUG_FUNCPTR(gst_pad_proxy_getcaps));
 165
 166   gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
 167   gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);
 168   gst_pad_set_chain_function (filter->sinkpad,
 169                               GST_DEBUG_FUNCPTR(gst_plugin_template_chain));
 170   filter->silent = FALSE;
 171 }
 172
 173 static void
 174 gst_plugin_template_set_property (GObject * object, guint prop_id,
 175     const GValue * value, GParamSpec * pspec)
 176 {
 177   GstPluginTemplate *filter = GST_PLUGIN_TEMPLATE (object);
 178
 179   switch (prop_id) {
 180     case ARG_SILENT:
 181       filter->silent = g_value_get_boolean (value);
 182       break;
 183     default:
 184       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 185       break;
 186   }
 187 }
 188
 189 static void
 190 gst_plugin_template_get_property (GObject * object, guint prop_id,
 191     GValue * value, GParamSpec * pspec)
 192 {
 193   GstPluginTemplate *filter = GST_PLUGIN_TEMPLATE (object);
 194
 195   switch (prop_id) {
 196     case ARG_SILENT:
 197       g_value_set_boolean (value, filter->silent);
 198       break;
 199     default:
 200       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 201       break;
 202   }
 203 }
 204
 205 /* GstElement vmethod implementations */
 206
 207 /* this function handles the link with other elements */
 208 static gboolean
 209 gst_plugin_template_set_caps (GstPad * pad, GstCaps * caps)
 210 {
 211   GstPluginTemplate *filter;
 212   GstPad *otherpad;
 213
 214   filter = GST_PLUGIN_TEMPLATE (gst_pad_get_parent (pad));
 215   otherpad = (pad == filter->srcpad) ? filter->sinkpad : filter->srcpad;
 216
 217   return gst_pad_set_caps (pad, caps);
 218 }
 219
 220 /* chain function
 221  * this function does the actual processing
 222  */
 223
 224 static GstFlowReturn
 225 gst_plugin_template_chain (GstPad * pad, GstBuffer * buf)
 226 {
 227   GstPluginTemplate *filter;
 228
 229   filter = GST_PLUGIN_TEMPLATE (GST_OBJECT_PARENT (pad));
 230
 231   if (filter->silent == FALSE)
 232     g_print ("I'm plugged, therefore I'm in.\n");
 233
 234   /* just push out the incoming buffer without touching it */
 235   return gst_pad_push (filter->srcpad, buf);
 236 }
 237
 238
 239 /* entry point to initialize the plug-in
 240  * initialize the plug-in itself
 241  * register the element factories and pad templates
 242  * register the features
 243  *
 244  * exchange the string 'plugin' with your elemnt name
 245  */
 246 static gboolean
 247 plugin_init (GstPlugin * plugin)
 248 {
 249   /* exchange the strings 'plugin' and 'Template plugin' with your
 250    * plugin name and description */
 251   GST_DEBUG_CATEGORY_INIT (gst_plugin_template_debug, "plugin",
 252       0, "Template plugin");
 253
 254   return gst_element_register (plugin, "myelement",
 255       GST_RANK_NONE, GST_TYPE_PLUGIN_TEMPLATE);
 256 }
 257
 258 /* this is the structure that gstreamer looks for to register plugins
 259  *
 260  * exchange the strings 'plugin' and 'Template plugin' with you plugin name and
 261  * description
 262  */
 263 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
 264     GST_VERSION_MINOR,
 265     "plugin",
 266     "Template plugin",
 267     plugin_init, VERSION, "LGPL", "GStreamer", "http://gstreamer.net/")