gstreamer: controlbindings: add comments for sparse control source

[Stefan Kost]

Module: gstreamer
Branch: master
Commit: 3de656121fb7560f661ce7f0f36540a1d517169c
URL:    http://cgit.freedesktop.org/gstreamer/gstreamer/commit/?id=3de656121fb7560f661ce7f0f36540a1d517169c

Author: Stefan Sauer <ensonic at users.sf.net>
Date:   Wed Apr 25 20:14:13 2012 +0200

controlbindings: add comments for sparse control source

---

 libs/gst/controller/gstdirectcontrolbinding.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/libs/gst/controller/gstdirectcontrolbinding.c b/libs/gst/controller/gstdirectcontrolbinding.c
index 8d102c4..0596489 100644
--- a/libs/gst/controller/gstdirectcontrolbinding.c
+++ b/libs/gst/controller/gstdirectcontrolbinding.c
@@ -413,6 +413,7 @@ gst_direct_control_binding_get_value_array (GstControlBinding * _self,
   if ((res = gst_control_source_get_value_array (self->cs, timestamp,
               interval, n_values, src_val))) {
     for (i = 0; i < n_values; i++) {
+      /* we will only get NAN for sparse control sources, such as triggers */
       if (!isnan (src_val[i])) {
         convert (self, src_val[i], (gpointer) values);
       } else {
@@ -454,6 +455,7 @@ gst_direct_control_binding_get_g_value_array (GstControlBinding * _self,
   if ((res = gst_control_source_get_value_array (self->cs, timestamp,
               interval, n_values, src_val))) {
     for (i = 0; i < n_values; i++) {
+      /* we will only get NAN for sparse control sources, such as triggers */
       if (!isnan (src_val[i])) {
         g_value_init (&values[i], type);
         convert (self, src_val[i], &values[i]);