diff --git a/README.md b/README.md
index ec907f4..d340dc8 100644
--- a/README.md
+++ b/README.md
@@ -65,15 +65,14 @@ Voici le script qui réalise la copie depuis le serveur de l'application web :
 
 SNAPSHOTS_DIRECTORY="$HOME/web/motion/snapshots/"
 
-rsync -avz --exclude lastsnap.jpg pi@terrarium:/var/lib/motioneye/Camera1/ "$SNAPSHOTS_DIRECTORY"
+rsync -avz --exclude lastsnap.jpg $1 --delete pi@terrarium:/var/lib/motioneye/Camera1/ "$SNAPSHOTS_DIRECTORY"
 
 for PARENT in "$SNAPSHOTS_DIRECTORY"*; do
-	for MOVIE in "$PARENT"/*.mp4; do
-		THUMB="$(echo "$MOVIE" | sed 's/.mp4/.jpg/')"
+  for MOVIE in "$PARENT"/*.mp4; do
+    THUMB="$(echo "$MOVIE" | sed 's/.mp4/.jpg/')"
+    MIDDLE=$(ffprobe "$MOVIE" 2>&1 | grep Duration: | egrep -o "[0-9]*:[0-9]*:[0-9]*.[0-9]*" | awk -F ':' '{print ($3+$2*60+$1*3600)/2}')
 
-		if [ ! -f "$THUMB" ]; then
-			ffmpeg -i "$MOVIE" -vcodec mjpeg -vframes 1 -an -f rawvideo -s 300x168 -ss 1 "$THUMB"
-		fi
-	done
+    ffmpeg -i "$MOVIE" -vcodec mjpeg -vframes 1 -an -f rawvideo -s 300x168 -ss $MIDDLE "$THUMB"
+  done
 done
 ```