diff --git a/stopmotion.sh b/stopmotion.sh
index 0f6e381..e580ce6 100755
--- a/stopmotion.sh
+++ b/stopmotion.sh
@@ -53,3 +53,60 @@ if [ ! -d "$INPUT" ]; then
   echo "Erreur : le dossier d'images '$INPUT' n'existe pas." >&2
   exit 1
 fi
+
+IMAGES_ABS_DIR=$(cd "$INPUT" && pwd)
+IMAGES=$(LC_ALL=C find "$IMAGES_ABS_DIR" -maxdepth 1 -type f \( -iname '*.jpg' -o -iname '*.jpeg' -o -iname '*.png' -o -iname '*.heic' \) | LC_ALL=C sort)
+if [ -z "$IMAGES" ]; then
+  echo "Erreur : aucune image (jpg, jpeg, png, heic) trouvée dans '$INPUT'." >&2
+  exit 1
+fi
+COUNT=$(printf '%s\n' "$IMAGES" | wc -l | tr -d ' ')
+
+if [ ! -d "$(dirname "$OUTPUT")" ]; then
+  echo "Erreur : le dossier de sortie '$(dirname "$OUTPUT")' n'existe pas." >&2
+  exit 1
+fi
+
+if [ -e "$OUTPUT" ] && [ "$ASSUME_YES" -ne 1 ]; then
+  read -r -p "'$OUTPUT' existe déjà. L'écraser ? [o/N] " reponse
+  case $reponse in
+    o|O|y|Y|oui|Oui) ;;
+    *) echo "Abandon." ; exit 0 ;;
+  esac
+fi
+
+OUT_DIR=$(cd "$(dirname "$OUTPUT")" && pwd)
+OUT_NAME=$(basename "$OUTPUT")
+LIST_FILE=$(mktemp "$OUT_DIR/.stopmotion.XXXXXX")
+trap 'rm -f "$LIST_FILE"' EXIT
+
+quote_ffconcat() {
+  local s=$1
+  s=${s//\\/\\\\}
+  s=${s//\'/\'\\\'\'}
+  printf "file '%s'\n" "$s"
+}
+
+DURATION=$(awk -v f="$FPS" 'BEGIN{printf "%.6f", 1/f}')
+{
+  echo "ffconcat version 1.0"
+  while IFS= read -r img; do
+    quote_ffconcat "$img"
+    printf 'duration %s\n' "$DURATION"
+  done <<< "$IMAGES"
+} > "$LIST_FILE"
+
+if ! ffmpeg -y -hide_banner -loglevel error -stats \
+    -f concat -safe 0 -i "$LIST_FILE" \
+    -vf "scale=${SIZE}:${SIZE}:force_original_aspect_ratio=decrease:force_divisible_by=2" \
+    -r "$FPS" \
+    -c:v libx264 -pix_fmt yuv420p -movflags +faststart \
+    "$OUT_DIR/$OUT_NAME"; then
+  rm -f "$OUT_DIR/$OUT_NAME"
+  echo "Erreur : l'encodage ffmpeg a échoué." >&2
+  exit 1
+fi
+
+DURATION_VIDEO=$(awk -v c="$COUNT" -v f="$FPS" 'BEGIN{printf "%.2f", c/f}')
+SIZE_HUMAN=$(du -h "$OUT_DIR/$OUT_NAME" | cut -f1 | tr -d ' ')
+echo "Vidéo créée : $OUT_NAME ($COUNT images, ${FPS} fps, ${DURATION_VIDEO} s, ${SIZE_HUMAN})"