fix: is_uniform_animated_webp

sticker/lib/util.py

@@ -148,14 +148,15 @@ def webp_to_others(data: bytes, mimetype: str) -> bytes:
 
 
 def is_uniform_animated_webp(data: bytes) -> bool:
-    img = Image.open(BytesIO(data))
+    with Image.open(BytesIO(data)) as img:
         if img.n_frames <= 1:
-        return False
+            return True
+
+        img_iter = ImageSequence.Iterator(img)
+        first_frame = np.array(img_iter[0].convert("RGBA"))
 
-    first_frame = np.array(img)
-    for frame_number in range(1, img.n_frames):
-        img.seek(frame_number)
-        current_frame = np.array(img)
+        for frame in img_iter:
+            current_frame = np.array(frame.convert("RGBA"))
             if not np.array_equal(first_frame, current_frame):
                 return False
 
@@ -163,8 +164,8 @@ def is_uniform_animated_webp(data: bytes) -> bool:
 
 
 def webp_to_gif_or_png(data: bytes) -> bytes:
+    with Image.open(BytesIO(data)) as image:
         # check if the webp is animated
-    image: Image.Image = Image.open(BytesIO(data))
         is_animated = getattr(image, "is_animated", False)
         if is_animated and not is_uniform_animated_webp(data):
             return webp_to_others(data, "image/gif")
@@ -187,8 +188,8 @@ def opermize_gif(data: bytes) -> bytes:
 
 
 def _convert_image(data: bytes, mimetype: str) -> (bytes, int, int):
-    image: Image.Image = Image.open(BytesIO(data))
-    new_file = BytesIO()
+    with Image.open(BytesIO(data)) as image:
+        with BytesIO() as new_file:
             # Determine if the image is a GIF
             is_animated = getattr(image, "is_animated", False)
             if is_animated: