qv4l2: do nothing if querystd does not detect a standard.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

diff --git a/utils/qv4l2/general-tab.cpp b/utils/qv4l2/general-tab.cpp
index 4c052b5..2b6eec5 100644 (file)
--- a/utils/qv4l2/general-tab.cpp
+++ b/utils/qv4l2/general-tab.cpp
@@ -753,7 +753,12 @@ void GeneralTab::qryStdClicked()
 {
        v4l2_std_id std;
 
-       if (query_std(std)) {
+       if (!query_std(std))
+               return;
+
+       if (std == V4L2_STD_ALL) {
+               info("No standard detected\n");
+       } else {
                s_std(std);
                updateStandard();
        }