More docs and small cleanups

Add some more docs and update the README
Cleanup some method names.
Remove an unneeded idx field in the GstRTSPMediaStream

docs/README

@@ -107,6 +107,7 @@ can build simple server applications with it.
  request URL to a specific stream and its configuration. We explain in the next
  topic how to configure this object.
 
+
 * Making url mappings
 
  Next we need to define what media is attached to a particular URL. What we want
@@ -161,6 +162,102 @@ can build simple server applications with it.
  found in the examples/test-readme.c file.
 
 
+* more on GstRTSPMediaFactory
+
+ The GstRTSPMediaFactory is responsible for creating and caching GstRTSPMedia
+ objects. 
+
+ A freshly created GstRTSPMedia object from the factory initialy only contains a
+ GstElement containing the elements to produce the RTP streams for the media and
+ a GArray of GstRTSPMediaStream objects describing the payloader and its source
+ pad. The media is unprepared in this state.
+
+ Usually the url will determine what kind of pipeline should be created. You can
+ for example use query parameters to configure certain parts of the pipeline or
+ select encoders and payloaders based on some url pattern.
+
+ When dealing with a live stream from, for example, a webcam, it can be
+ interesting to share the pipeline with multiple clients. This must be done when
+ only one instance of the video capture element can be used at a time. In this
+ case, the shared property of GstRTSPMedia must be used to instruct the default
+ GstRTSPMediaFactory implementation to cache the media.
+
+ When all objects created from a factory can be shared, you can set the shared
+ property directly on the factory.
+
+* more on GstRTSPMedia
+
+ After creating the GstRTSPMedia object from the factory, it can be prepared
+ with gst_rtsp_media_prepare(). This method will put those objects in a
+ GstPipeline and will construct and link the streaming elements and the
+ gstrtpbin session manager object.
+
+ The _prepare() method will then preroll the pipeline in order to figure out the
+ caps on the payloaders. After the GstRTSPMedia prerolled it will be in the
+ prepared state and can be used for creating SDP files or for streaming to
+ clients.
+
+ The prepare method will also create 2 UDP ports for each stream that can be
+ used for sending and receiving RTP/RTCP from clients. These port numbers will
+ have to be negotiated with the client in the SETUP requests.
+
+ When preparing a GstRTSPMedia, a multifdsink is also constructed for streaming
+ the stream over TCP^when requested.
+
+
+* the GstRTSPClient object
+
+ When a server detects a new client connection on its port, it will call its
+ accept_client vmethod. The default implementation of this function will create
+ a new GstRTCPClient object, will configure the session pool and media mapper
+ objects in it and will then call the accept function of the client.
+
+ The default GstRTSPClient will accept the connection and will start a new
+ GThread to handle the connection. In RTSP it is usual to keep the connection
+ open between multiple RTSP requests. The client thread will simply block for a
+ new GstRTSPMessage, will dispatch it and will send a response.
+ 
+ We will briefly describe how it deals with some common requests.
+
+ - DESCRIBE:
+
+    locates the GstRTSPMedia for the url, prepares it and asks the sdp helper
+    function to construct an SDP from the caps of the prepared media pipeline.
+    It will also cache the url+media object so that it can be reused later.
+ 
+ - SETUP
+
+    A new GstRTSPSession object will be created from the GstRTSPSessionPool
+    object configured in the GstRTSPClient. This session will contain the
+    configuration of the client regarding the media it is streaming and the
+    ports/transport it negotiated with the server.
+
+    The sessionid is set in the response header. The client will add the
+    sessionid to any further SETUP/PLAY/PAUSE/TEARDOWN request so that we can
+    always find the session again.
+
+    The session configuration for a sessionid will have a link to the prepared
+    GstRTSPMedia object of the stream. The port and transport of the client is
+    stored in the session configuration.
+
+ - PLAY
+
+    The session configuration is retrieved with the sessionid and the client
+    ports are configured in the UDP sinks, then the streaming to the client 
+    is started. 
+
+ - PAUSE
+
+    The session configuration is retrieved with the sessionid and the client
+    ports are removed from the UDP sinks, the streaming to the client 
+    pauses. 
+
+ - TEARDOWN
+
+    The session configuration is released along with its link to the
+    GstRTSPMedia object. When no more clients are refering to the GstRTSPMedia
+    object, it can be released as well.
+
 
 
 

gst/rtsp-server/rtsp-media-factory.c

@@ -418,7 +418,6 @@ default_construct (GstRTSPMediaFactory *factory, const GstRTSPUrl *url)
     stream = g_new0 (GstRTSPMediaStream, 1);
     stream->media = media;
     stream->payloader = pay;
-    stream->idx = media->streams->len;
 
     pad = gst_element_get_static_pad (pay, "src");
 

gst/rtsp-server/rtsp-media-factory.h

@@ -64,11 +64,13 @@ struct _GstRTSPMediaFactory {
 
 /**
  * GstRTSPMediaFactoryClass:
- * @gen_key: convert @url to a key for caching media
- * @get_element: Construct an return a #GstElement thast is a #GstBin containing
- *       the elements to use for the media. The bin should contain payloaders
- *       pay%d for each stream. The default implementation of this functions
- *       returns the bin created from the launch parameter.
+ * @gen_key: convert @url to a key for caching shared #GstRTSPMedia objects.
+ *       The default implementation of this function will use the complete URL
+ *       including the query parameters to return a key.
+ * @get_element: Construct and return a #GstElement that is a #GstBin containing
+ *       the elements to use for streaming the media. The bin should contain
+ *       payloaders pay%d for each stream. The default implementation of this
+ *       function returns the bin created from the launch parameter.
  * @construct: the vmethod that will be called when the factory has to create the
  *       #GstRTSPMedia for @url. The default implementation of this
  *       function calls get_element to retrieve an element and then looks for
@@ -77,7 +79,7 @@ struct _GstRTSPMediaFactory {
  *       implementation will configure the 'shared' property of the media.
  * @handle_message: Handle a bus message for @media created from @factory.
  *
- * the #GstRTSPMediaFactory class structure.
+ * The #GstRTSPMediaFactory class structure.
  */
 struct _GstRTSPMediaFactoryClass {
   GObjectClass  parent_class;
@@ -90,8 +92,6 @@ struct _GstRTSPMediaFactoryClass {
 
   void              (*handle_message) (GstRTSPMediaFactory *factory, GstRTSPMedia *media, 
                                        GstMessage *message);
-
-
 };
 
 GType                 gst_rtsp_media_factory_get_type     (void);

gst/rtsp-server/rtsp-media.c

@@ -386,7 +386,7 @@ caps_notify (GstPad * pad, GParamSpec * unused, GstRTSPMediaStream * stream)
 
 /* prepare the pipeline objects to handle @stream in @media */
 static gboolean
-setup_stream (GstRTSPMediaStream *stream, GstRTSPMedia *media)
+setup_stream (GstRTSPMediaStream *stream, guint idx, GstRTSPMedia *media)
 {
   gchar *name;
   GstPad *pad;
@@ -399,16 +399,16 @@ setup_stream (GstRTSPMediaStream *stream, GstRTSPMedia *media)
   gst_bin_add (GST_BIN_CAST (media->pipeline), stream->udpsrc[1]);
 
   /* hook up the stream to the RTP session elements. */
-  name = g_strdup_printf ("send_rtp_sink_%d", stream->idx);
+  name = g_strdup_printf ("send_rtp_sink_%d", idx);
   stream->send_rtp_sink = gst_element_get_request_pad (media->rtpbin, name);
   g_free (name);
-  name = g_strdup_printf ("send_rtp_src_%d", stream->idx);
+  name = g_strdup_printf ("send_rtp_src_%d", idx);
   stream->send_rtp_src = gst_element_get_static_pad (media->rtpbin, name);
   g_free (name);
-  name = g_strdup_printf ("send_rtcp_src_%d", stream->idx);
+  name = g_strdup_printf ("send_rtcp_src_%d", idx);
   stream->send_rtcp_src = gst_element_get_request_pad (media->rtpbin, name);
   g_free (name);
-  name = g_strdup_printf ("recv_rtcp_sink_%d", stream->idx);
+  name = g_strdup_printf ("recv_rtcp_sink_%d", idx);
   stream->recv_rtcp_sink = gst_element_get_request_pad (media->rtpbin, name);
   g_free (name);
 
@@ -478,7 +478,7 @@ gst_rtsp_media_prepare (GstRTSPMedia *media)
 
     stream = gst_rtsp_media_get_stream (media, i);
 
-    setup_stream (stream, media);
+    setup_stream (stream, i, media);
   }
 
   /* first go to PAUSED */

gst/rtsp-server/rtsp-media.h

@@ -43,7 +43,6 @@ typedef struct _GstRTSPMediaClass GstRTSPMediaClass;
  * GstRTSPMediaStream:
  *
  * @media: the owner #GstRTSPMedia
- * @idx: the stream index
  * @srcpad: the srcpad of the stream
  * @payloader: the payloader of the format
  * @prepared: if the stream is prepared for streaming
@@ -62,8 +61,6 @@ typedef struct _GstRTSPMediaClass GstRTSPMediaClass;
 struct _GstRTSPMediaStream {
   GstRTSPMedia *media;
 
-  guint         idx;
-
   GstPad       *srcpad;
   GstElement   *payloader;
   gboolean      prepared;

gst/rtsp-server/rtsp-server.c

@@ -42,7 +42,7 @@ static void gst_rtsp_server_get_property (GObject *object, guint propid,
 static void gst_rtsp_server_set_property (GObject *object, guint propid,
     const GValue *value, GParamSpec *pspec);
 
-static GstRTSPClient * gst_rtsp_server_accept_client (GstRTSPServer *server,
+static GstRTSPClient * default_accept_client (GstRTSPServer *server,
     GIOChannel *channel);
 
 static void
@@ -99,7 +99,7 @@ gst_rtsp_server_class_init (GstRTSPServerClass * klass)
 	  "The media mapping to use for client session",
           GST_TYPE_RTSP_MEDIA_MAPPING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
-  klass->accept_client = gst_rtsp_server_accept_client;
+  klass->accept_client = default_accept_client;
 }
 
 static void
@@ -438,7 +438,7 @@ bind_failed:
 /* default method for creating a new client object in the server to accept and
  * handle a client connection on this server */
 static GstRTSPClient *
-gst_rtsp_server_accept_client (GstRTSPServer *server, GIOChannel *channel)
+default_accept_client (GstRTSPServer *server, GIOChannel *channel)
 {
   GstRTSPClient *client;
 

gst/rtsp-server/rtsp-server.h

@@ -106,12 +106,12 @@ void                  gst_rtsp_server_set_media_mapping    (GstRTSPServer *serve
 GstRTSPMediaMapping * gst_rtsp_server_get_media_mapping    (GstRTSPServer *server);
 
 gboolean              gst_rtsp_server_io_func              (GIOChannel *channel, GIOCondition condition,
-                                                           GstRTSPServer *server);
+                                                            GstRTSPServer *server);
 
 GIOChannel *          gst_rtsp_server_get_io_channel       (GstRTSPServer *server);
 GSource *             gst_rtsp_server_create_watch         (GstRTSPServer *server);
 guint                 gst_rtsp_server_attach               (GstRTSPServer *server, 
-                                                           GMainContext *context);
+                                                            GMainContext *context);
 
 G_END_DECLS