diff --git a/encoder/input.php b/encoder/input.php
index d0149bd..0605e8d 100755
--- a/encoder/input.php
+++ b/encoder/input.php
@@ -381,6 +381,30 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
         </div>
     </div>
 </form>
+<script>
+const controls=["brightness","contrast","saturation","hue"];
+
+function update(){
+  const b=brightness.value;
+  const c=contrast.value;
+  const s=saturation.value;
+  const h=hue.value;
+
+  brightnessVal.textContent=b;
+  contrastVal.textContent=c;
+  saturationVal.textContent=s;
+  hueVal.textContent=h;
+
+  ffmpegOutput.textContent=
+    `-vf "vpp_qsv=format=nv12:brightness=${b}:contrast=${c}:saturation=${s}:hue=${h}"`;
+}
+
+controls.forEach(id=>{
+  document.getElementById(id).addEventListener("input",update);
+});
+
+update();
+</script>
 <?php
 if (!empty($saveError)) echo '<p style="color:red;text-align:center;">' . htmlspecialchars($saveError) . '</p>';
 if (!empty($saveSuccess)) echo '<p style="color:green;text-align:center;">' . htmlspecialchars($saveSuccess) . '</p>';