show delay.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/v4l2cairo.rs b/src/v4l2cairo.rs
index de89df8..795575b 100644
--- a/src/v4l2cairo.rs
+++ b/src/v4l2cairo.rs
@@ -125,8 +125,11 @@ impl cgtk::Overlay for Overlay{
         Ok(())
     }
     fn update(&self, widget: &gtk::Label) -> Result<()>{
+        let delay = Local::now() - &self.timestamp;
         widget.set_label(
-            &self.timestamp.format("%Y/%m/%d %H:%M:%S%.3f").to_string());
+            &format!("{} (delay={}ms)",
+                self.timestamp.format("%Y/%m/%d %H:%M:%S%.3f"),
+                delay.num_milliseconds()));
         Ok(())
     }
 }