3 * appsrc-stream.c: example for using appsrc in streaming mode.
5 * Copyright (C) 2008 Wim Taymans <wim.taymans@gmail.com>
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
33 /* FIXME: remove once we depend on GLib >= 2.22 */
34 #if !GLIB_CHECK_VERSION (2, 21, 3)
35 #define g_mapped_file_unref g_mapped_file_free
38 GST_DEBUG_CATEGORY (appsrc_playbin_debug);
39 #define GST_CAT_DEFAULT appsrc_playbin_debug
42 * an example application of using appsrc in streaming push mode. We simply push
43 * buffers into appsrc. The size of the buffers we push can be any size we
46 * This example is very close to how one would deal with a streaming webserver
47 * that does not support range requests or does not report the total file size.
49 * Some optimisations are done so that we don't push too much data. We connect
50 * to the need-data and enough-data signals to start/stop sending buffers.
52 * Appsrc in streaming mode (the default) does not support seeking so we don't
53 * have to handle any seek callbacks.
55 * Some formats are able to estimate the duration of the media file based on the
56 * file length (mp3, mpeg,..), others report an unknown length (ogg,..).
58 typedef struct _App App;
76 #define CHUNK_SIZE 4096
78 /* This method is called by the idle GSource in the mainloop. We feed CHUNK_SIZE
80 * The ide handler is added to the mainloop when appsrc requests us to start
81 * sending data (need-data signal) and is removed when appsrc has enough data
82 * (enough-data signal).
91 buffer = gst_buffer_new ();
93 if (app->offset >= app->length) {
94 /* we are EOS, send end-of-stream and remove the source */
95 g_signal_emit_by_name (app->appsrc, "end-of-stream", &ret);
99 /* read the next chunk */
101 if (app->offset + len > app->length)
102 len = app->length - app->offset;
104 GST_BUFFER_DATA (buffer) = app->data + app->offset;
105 GST_BUFFER_SIZE (buffer) = len;
107 GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer,
109 g_signal_emit_by_name (app->appsrc, "push-buffer", buffer, &ret);
110 gst_buffer_unref (buffer);
111 if (ret != GST_FLOW_OK) {
112 /* some error, stop sending data */
121 /* This signal callback is called when appsrc needs data, we add an idle handler
122 * to the mainloop to start pushing data into the appsrc */
124 start_feed (GstElement * playbin, guint size, App * app)
126 if (app->sourceid == 0) {
127 GST_DEBUG ("start feeding");
128 app->sourceid = g_idle_add ((GSourceFunc) read_data, app);
132 /* This callback is called when appsrc has enough data and we can stop sending.
133 * We remove the idle handler from the mainloop */
135 stop_feed (GstElement * playbin, App * app)
137 if (app->sourceid != 0) {
138 GST_DEBUG ("stop feeding");
139 g_source_remove (app->sourceid);
144 /* this callback is called when playbin2 has constructed a source object to read
145 * from. Since we provided the appsrc:// uri to playbin2, this will be the
146 * appsrc that we must handle. We set up some signals to start and stop pushing
147 * data into appsrc */
149 found_source (GObject * object, GObject * orig, GParamSpec * pspec, App * app)
151 /* get a handle to the appsrc */
152 g_object_get (orig, pspec->name, &app->appsrc, NULL);
154 GST_DEBUG ("got appsrc %p", app->appsrc);
156 /* we can set the length in appsrc. This allows some elements to estimate the
157 * total duration of the stream. It's a good idea to set the property when you
158 * can but it's not required. */
159 g_object_set (app->appsrc, "size", (gint64) app->length, NULL);
161 /* configure the appsrc, we will push data into the appsrc from the
163 g_signal_connect (app->appsrc, "need-data", G_CALLBACK (start_feed), app);
164 g_signal_connect (app->appsrc, "enough-data", G_CALLBACK (stop_feed), app);
168 bus_message (GstBus * bus, GstMessage * message, App * app)
170 GST_DEBUG ("got message %s",
171 gst_message_type_get_name (GST_MESSAGE_TYPE (message)));
173 switch (GST_MESSAGE_TYPE (message)) {
174 case GST_MESSAGE_ERROR:
175 g_error ("received error");
176 g_main_loop_quit (app->loop);
178 case GST_MESSAGE_EOS:
179 g_main_loop_quit (app->loop);
188 main (int argc, char *argv[])
191 GError *error = NULL;
194 gst_init (&argc, &argv);
196 GST_DEBUG_CATEGORY_INIT (appsrc_playbin_debug, "appsrc-playbin", 0,
197 "appsrc playbin example");
200 g_print ("usage: %s <filename>\n", argv[0]);
204 /* try to open the file as an mmapped file */
205 app->file = g_mapped_file_new (argv[1], FALSE, &error);
207 g_print ("failed to open file: %s\n", error->message);
208 g_error_free (error);
211 /* get some vitals, this will be used to read data from the mmapped file and
212 * feed it to appsrc. */
213 app->length = g_mapped_file_get_length (app->file);
214 app->data = (guint8 *) g_mapped_file_get_contents (app->file);
217 /* create a mainloop to get messages and to handle the idle handler that will
218 * feed data to appsrc. */
219 app->loop = g_main_loop_new (NULL, TRUE);
221 app->playbin = gst_element_factory_make ("playbin2", NULL);
222 g_assert (app->playbin);
224 bus = gst_pipeline_get_bus (GST_PIPELINE (app->playbin));
226 /* add watch for messages */
227 gst_bus_add_watch (bus, (GstBusFunc) bus_message, app);
229 /* set to read from appsrc */
230 g_object_set (app->playbin, "uri", "appsrc://", NULL);
232 /* get notification when the source is created so that we get a handle to it
233 * and can configure it */
234 g_signal_connect (app->playbin, "deep-notify::source",
235 (GCallback) found_source, app);
237 /* go to playing and wait in a mainloop. */
238 gst_element_set_state (app->playbin, GST_STATE_PLAYING);
240 /* this mainloop is stopped when we receive an error or EOS */
241 g_main_loop_run (app->loop);
243 GST_DEBUG ("stopping");
245 gst_element_set_state (app->playbin, GST_STATE_NULL);
248 g_mapped_file_unref (app->file);
250 gst_object_unref (bus);
251 g_main_loop_unref (app->loop);