v4l2: sort formats in the right order so that non-emulated formats are prefered

The format list should be sorted from high ranks to low ranks. In the GSList
sorting function this means the compare needs to return a positive value if
format a has a lower rank than format b.

Among other things this fixes v4l2src to prefer non-emulated formats
to emulated formats when built against libv4l.

diff --git a/sys/v4l2/gstv4l2object.c b/sys/v4l2/gstv4l2object.c
index 37a30e344c705f5912cda79c052e6bbaa1930a4c..c77da5e97a4e462f4e224fce50743a40a7c823b4 100644 (file)
--- a/sys/v4l2/gstv4l2object.c
+++ b/sys/v4l2/gstv4l2object.c
@@ -864,8 +864,8 @@ format_cmp_func (gconstpointer a, gconstpointer b)
   if (fa->pixelformat == fb->pixelformat)
     return 0;
 
-  return gst_v4l2_object_format_get_rank (fa) -
-      gst_v4l2_object_format_get_rank (fb);
+  return gst_v4l2_object_format_get_rank (fb) -
+      gst_v4l2_object_format_get_rank (fa);
 }
 
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