manual: talk about playsink

Talk about playsink and give an example of its usage.

1 files changed, 200 insertions, 5 deletions

diff --git a/docs/manual/highlevel-playback.xml b/docs/manual/highlevel-playback.xml
index c4526d28ce..27d2d1ff9d 100644
--- a/docs/manual/highlevel-playback.xml
+++ b/docs/manual/highlevel-playback.xml
@@ -193,9 +193,12 @@ main (gint   argc,
       responsible for reporting the error to the user.
     </para>
     <programlisting><!-- example-begin decodebin.c a -->
-#include &lt;gst/gst.h&gt;
+<![CDATA[
+#include <gst/gst.h>
+]]>
 <!-- example-end decodebin.c a -->
-[.. my_bus_callback goes here ..]<!-- example-begin decodebin.c b --><!--
+[.. my_bus_callback goes here ..]<!-- example-begin decodebin.c b -->
+<!--
 static gboolean
 my_bus_callback (GstBus     *bus,
 		 GstMessage *message,
@@ -230,6 +233,7 @@ my_bus_callback (GstBus     *bus,
 }
 --><!-- example-end decodebin.c b -->
 <!-- example-begin decodebin.c c -->
+<![CDATA[
 GstElement *pipeline, *audio;
 
 static void
@@ -274,12 +278,12 @@ main (gint   argc,
   GstBus *bus;
 
   /* init GStreamer */
-  gst_init (&amp;argc, &amp;argv);
+  gst_init (&argc, &argv);
   loop = g_main_loop_new (NULL, FALSE);
 
   /* make sure we have input */
   if (argc != 2) {
-    g_print ("Usage: %s &lt;filename&gt;\n", argv[0]);
+    g_print ("Usage: %s <filename>\n", argv[0]);
     return -1;
   }
 
@@ -319,8 +323,8 @@ main (gint   argc,
 
   return 0;
 }
+]]>
     <!-- example-end decodebin.c c --></programlisting>
-
     <para>
       Decodebin, similar to playbin, supports the following features:
     </para>
@@ -419,4 +423,195 @@ main (gint   argc,
       ! audioconvert ! audioresample ! autoaudiosink</command>.
     </para>
   </sect1>
+
+  <sect1 id="section-components-playsink">
+    <title>Playsink</title>
+    <para>
+      The playsink element is a powerful sink element. It has request pads
+      for raw decoded audio, video and text and it will configure itself to
+      play the media streams. It has the following features:
+    </para>
+    <itemizedlist>
+      <listitem>
+        <para>
+          It exposes GstStreamVolume, GstVideoOverlay, GstNavigation and
+          GstColorBalance interfaces and automatically plugs software
+          elements to implement the interfaces when needed.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It will automatically plug conversion elements.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Can optionally render visualizations when there is no video input.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Configurable sink elements.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Configurable audio/video sync offset to fine-tune synchronization
+          in badly muxed files.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Support for taking a snapshot of the last video frame.
+        </para>
+      </listitem>
+    </itemizedlist>
+    <para>
+      Below is an example of how you can use playsink. We use a uridecodebin
+      element to decode into raw audio and video streams which we then link
+      to the playsink request pads. We only link the first audio and video
+      pads, you could use an input-selector to link all pads.
+    </para>
+    <programlisting>
+<!-- example-begin playsink.c a -->
+<![CDATA[
+#include <gst/gst.h>
+]]>
+<!-- example-end playsink.c a -->
+[.. my_bus_callback goes here ..]
+<!-- example-begin playsink.c b -->
+<!--
+static gboolean
+my_bus_callback (GstBus     *bus,
+		 GstMessage *message,
+		 gpointer    data)
+{
+  GMainLoop *loop = data;
+
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ERROR: {
+      GError *err;
+      gchar *debug;
+
+      gst_message_parse_error (message, &amp;err, &amp;debug);
+      g_print ("Error: %s\n", err-&gt;message);
+      g_error_free (err);
+      g_free (debug);
+
+      g_main_loop_quit (loop);
+      break;
+    }
+    case GST_MESSAGE_EOS:
+      /* end-of-stream */
+      g_main_loop_quit (loop);
+      break;
+    default:
+      /* unhandled message */
+      break;
+  }
+
+  /* remove message from the queue */
+  return TRUE;
+}
+-->
+<!-- example-end playsink.c b -->
+<!-- example-begin playsink.c c -->
+<![CDATA[
+GstElement *pipeline, *sink;
+
+static void
+cb_pad_added (GstElement *dec,
+	      GstPad     *pad,
+	      gpointer    data)
+{
+  GstCaps *caps;
+  GstStructure *str;
+  const gchar *name;
+  GstPadTemplate *templ;
+  GstElementClass *klass;
+
+  /* check media type */
+  caps = gst_pad_query_caps (pad, NULL);
+  str = gst_caps_get_structure (caps, 0);
+  name = gst_structure_get_name (str);
+
+  klass = GST_ELEMENT_GET_CLASS (sink);
+
+  if (g_str_has_prefix (name, "audio")) {
+    templ = gst_element_class_get_pad_template (klass, "audio_sink");
+  } else if (g_str_has_prefix (name, "video")) {
+    templ = gst_element_class_get_pad_template (klass, "video_sink");
+  } else if (g_str_has_prefix (name, "text")) {
+    templ = gst_element_class_get_pad_template (klass, "text_sink");
+  } else {
+    templ = NULL;
+  }
+
+  if (templ) {
+    GstPad *sinkpad;
+
+    sinkpad = gst_element_request_pad (sink, templ, NULL, NULL);
+
+    if (!gst_pad_is_linked (sinkpad))
+      gst_pad_link (pad, sinkpad);
+
+    gst_object_unref (sinkpad);
+  }
+}
+
+gint
+main (gint   argc,
+      gchar *argv[])
+{
+  GMainLoop *loop;
+  GstElement *dec;
+  GstBus *bus;
+
+  /* init GStreamer */
+  gst_init (&argc, &argv);
+  loop = g_main_loop_new (NULL, FALSE);
+
+  /* make sure we have input */
+  if (argc != 2) {
+    g_print ("Usage: %s <uri>\n", argv[0]);
+    return -1;
+  }
+
+  /* setup */
+  pipeline = gst_pipeline_new ("pipeline");
+
+  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
+  gst_bus_add_watch (bus, my_bus_callback, loop);
+  gst_object_unref (bus);
+
+  dec = gst_element_factory_make ("uridecodebin", "source");
+  g_object_set (G_OBJECT (dec), "uri", argv[1], NULL);
+  g_signal_connect (dec, "pad-added", G_CALLBACK (cb_pad_added), NULL);
+
+  /* create audio output */
+  sink = gst_element_factory_make ("playsink", "sink");
+  gst_util_set_object_arg (G_OBJECT (sink), "flags",  
+      "soft-colorbalance+soft-volume+vis+text+audio+video");
+  gst_bin_add_many (GST_BIN (pipeline), dec, sink, NULL);
+
+  /* run */
+  gst_element_set_state (pipeline, GST_STATE_PLAYING);
+  g_main_loop_run (loop);
+
+  /* cleanup */
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+  gst_object_unref (GST_OBJECT (pipeline));
+
+  return 0;
+}
+]]>
+<!-- example-end playsink.c c -->
+    </programlisting>
+    <para>
+      This example will show audio and video depending on what you
+      give it. Try this example on an audio file and you will see that
+      it shows visualizations. You can change the visualization at runtime by
+      changing the vis-plugin property.
+    </para>
+  </sect1>
 </chapter>