rtsp-media: Enable seeking query before pipeline is complete

SDP are now provided *before* the pipeline is fully complete. In order
to know whether a media is seekable or not therefore requires asking
the invididual streams.

API: gst_rtsp_stream_seekable

https://bugzilla.gnome.org/show_bug.cgi?id=790674

docs/libs/gst-rtsp-server-sections.txt

@@ -610,6 +610,8 @@ gst_rtsp_stream_update_crypto
 gst_rtsp_stream_set_pt_map
 gst_rtsp_stream_request_aux_sender
 
+gst_rtsp_stream_seekable
+
 GstRTSPStreamTransportFilterFunc
 gst_rtsp_stream_transport_filter
 

gst/rtsp-server/rtsp-media.c

@@ -703,8 +703,20 @@ check_seekable (GstRTSPMedia * media)
 
     gst_query_parse_seeking (query, &format, &seekable, &start, &end);
     priv->seekable = seekable ? G_MAXINT64 : 0;
+  } else if (priv->streams->len) {
+    gboolean seekable = TRUE;
+    guint i, n = priv->streams->len;
+
+    GST_DEBUG_OBJECT (media, "Checking %d streams", n);
+    for (i = 0; i < n; i++) {
+      GstRTSPStream *stream = g_ptr_array_index (priv->streams, i);
+      seekable &= gst_rtsp_stream_seekable (stream);
+    }
+    priv->seekable = seekable ? G_MAXINT64 : -1;
   }
 
+  GST_DEBUG_OBJECT (media, "seekable:%" G_GINT64_FORMAT, priv->seekable);
+
   gst_query_unref (query);
 }
 

gst/rtsp-server/rtsp-stream.c

@@ -4449,6 +4449,58 @@ gst_rtsp_stream_query_stop (GstRTSPStream * stream, gint64 * stop)
   return TRUE;
 }
 
+/**
+ * gst_rtsp_stream_seekable:
+ * @stream: a #GstRTSPStream
+ *
+ * Checks whether the individual @stream is seekable.
+ *
+ * Returns: %TRUE if @stream is seekable, else %FALSE.
+ */
+gboolean
+gst_rtsp_stream_seekable (GstRTSPStream * stream)
+{
+  GstRTSPStreamPrivate *priv;
+  GstPad *pad = NULL;
+  GstQuery *query = NULL;
+  gboolean seekable = FALSE;
+
+  g_return_val_if_fail (GST_IS_RTSP_STREAM (stream), FALSE);
+
+  /* query stop position: if no sinks have been added yet,
+   * we obtain the stop position from the pad otherwise we query the sinks */
+
+  priv = stream->priv;
+
+  g_mutex_lock (&priv->lock);
+  /* depending on the transport type, it should query corresponding sink */
+  if (priv->srcpad) {
+    pad = gst_object_ref (priv->srcpad);
+  } else {
+    g_mutex_unlock (&priv->lock);
+    GST_WARNING_OBJECT (stream, "Pad not available, can't query seekability");
+    goto beach;
+  }
+  g_mutex_unlock (&priv->lock);
+
+  query = gst_query_new_seeking (GST_FORMAT_TIME);
+  if (!gst_pad_query (pad, query)) {
+    GST_WARNING_OBJECT (stream, "seeking query failed");
+    goto beach;
+  }
+  gst_query_parse_seeking (query, NULL, &seekable, NULL, NULL);
+
+beach:
+  if (pad)
+    gst_object_unref (pad);
+  if (query)
+    gst_query_unref (query);
+
+  GST_DEBUG_OBJECT (stream, "Returning %d", seekable);
+
+  return seekable;
+}
+
 /**
  * gst_rtsp_stream_complete_stream:
  * @stream: a #GstRTSPStream

gst/rtsp-server/rtsp-stream.h

@@ -243,6 +243,9 @@ GST_EXPORT
 gboolean          gst_rtsp_stream_query_stop       (GstRTSPStream * stream,
                                                     gint64 * stop);
 
+GST_EXPORT
+gboolean          gst_rtsp_stream_seekable         (GstRTSPStream *stream);
+
 GST_EXPORT
 void              gst_rtsp_stream_set_seqnum_offset          (GstRTSPStream *stream, guint16 seqnum);
 

win32/common/libgstrtspserver.def

@@ -281,6 +281,7 @@ EXPORTS
 	gst_rtsp_stream_remove_transport
 	gst_rtsp_stream_request_aux_sender
 	gst_rtsp_stream_reserve_address
+	gst_rtsp_stream_seekable
 	gst_rtsp_stream_set_address_pool
 	gst_rtsp_stream_set_blocked
 	gst_rtsp_stream_set_buffer_size