add missing alpha filter on the logo

src/render/mod.rs

@@ -414,10 +414,16 @@ impl<'a> Renderer<'a> {
 		});
 
 		// overlay the logo
+		let logoalpha = "logoalpha";
+		ffmpeg.add_filter(Filter::Alpha {
+			input: logo.into(),
+			alpha: 0.5,
+			output: logoalpha.into()
+		});
 		let overlay = "overlay";
 		ffmpeg.add_filter(Filter::Overlay {
 			video_input: concat.into(),
-			overlay_input: logo.into(),
+			overlay_input: logoalpha.into(),
 			x: "main_w-overlay_w-130".into(),
 			y: "main_h-overlay_h-65".into(),
 			output: overlay.into()