[farsight2/master] Clearly explain what the blocking id is for

[Olivier Crête]

---
 gst/fsrtpconference/fs-rtp-session.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/gst/fsrtpconference/fs-rtp-session.c b/gst/fsrtpconference/fs-rtp-session.c
index e96f14e..aefcdc2 100644
--- a/gst/fsrtpconference/fs-rtp-session.c
+++ b/gst/fsrtpconference/fs-rtp-session.c
@@ -105,7 +105,10 @@ struct _FsRtpSessionPrivate
   FsCodec *current_send_codec;
   FsCodec *requested_send_codec;
 
-  /* Protected by the session mutex */
+  /* This is the id of the pad probe used to blocked the stream
+   * while the codec is changed
+   * Protected by the session mutex
+   */
   gulong send_blocking_id;
 
   /* These lists are protected by the session mutex */
-- 
1.5.6.5