update cam script

scripts/cam

@@ -3,6 +3,7 @@
 output=$(v4l2-ctl --device=/dev/video4 --list-ctrls)
 brightness=$(echo "$output" | grep "brightness" | grep -oP 'value=\K\d+')
 contrast=$(echo "$output" | grep "contrast" | grep -oP 'value=\K\d+')
+zoom=$(echo "$output" | grep "zoom_absolute" | grep -oP 'value=\K\d+')
 
 CMD="v4l2-ctl --device=/dev/video4 --set-ctrl="
 
@@ -21,7 +22,14 @@ case $1 in
       bash -c "${CMD}contrast=$((contrast - 2))"
     fi
     ;;
+  z)  # Zoom
+    if [ "$2" = 'u' ]; then
+      bash -c "${CMD}zoom_absolute=$((zoom + 25))"
+    elif [ "$2" = 'd' ]; then
+      bash -c "${CMD}zoom_absolute=$((zoom - 25))"
+    fi
+    ;;
   *)
-    echo "Usage: $0 [b|c] [u|d]"
+    echo "Usage: $0 [b|c|z] [u|d]"
     ;;
 esac