perf: convert static animated WebP to PNG

sticker/lib/util.py

@@ -15,6 +15,7 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 from functools import partial
 from io import BytesIO
+import numpy as np
 import os.path
 import subprocess
 import json
@@ -48,7 +49,7 @@ def guess_mime(data: bytes) -> str:
     return mime or "image/png"
 
 
-def video_to_webp(data: bytes) -> bytes:
+def _video_to_webp(data: bytes) -> bytes:
     mime = guess_mime(data)
     ext = mimetypes.guess_extension(mime)
     with tempfile.NamedTemporaryFile(suffix=ext) as video:
@@ -74,9 +75,9 @@ def video_to_webp(data: bytes) -> bytes:
             return webp.read()
 
 
-def video_to_gif(data: bytes, mime: str) -> bytes:
+def video_to_webp(data: bytes) -> bytes:
+    mime = guess_mime(data)
     ext = mimetypes.guess_extension(mime)
-    if mime.startswith("video/"):
     # run ffmpeg to fix duration
     with tempfile.NamedTemporaryFile(suffix=ext) as temp:
         temp.write(data)
@@ -89,17 +90,47 @@ def video_to_gif(data: bytes, mime: str) -> bytes:
                 raise RuntimeError(f"Run ffmpeg failed with code {result.returncode}, Error occurred:\n{result.stderr}")
             temp_fixed.seek(0)
             data = temp_fixed.read()
-    data = video_to_webp(data)
-    with tempfile.NamedTemporaryFile(suffix=ext) as temp:
-        temp.write(data)
-        temp.flush()
-        with tempfile.NamedTemporaryFile(suffix=".gif") as gif:
+    return _video_to_webp(data)
+
+
+def webp_to_others(data: bytes, mimetype: str) -> bytes:
+    with tempfile.NamedTemporaryFile(suffix=".webp") as webp:
+        webp.write(data)
+        webp.flush()
+        ext = mimetypes.guess_extension(mimetype)
+        with tempfile.NamedTemporaryFile(suffix=ext) as img:
             print(".", end="", flush=True)
-            im = Image.open(temp.name)
+            im = Image.open(webp.name)
             im.info.pop('background', None)
-            im.save(gif.name, save_all=True, lossless=True, quality=100, method=6)
-            gif.seek(0)
-            return gif.read()
+            im.save(img.name, save_all=True, lossless=True, quality=100, method=6)
+            img.seek(0)
+            return img.read()
+
+
+def is_uniform_animated_webp(data: bytes) -> bool:
+    img = Image.open(BytesIO(data))
+    if img.n_frames <= 1:
+        return False
+
+    first_frame = np.array(img)
+    for frame_number in range(1, img.n_frames):
+        img.seek(frame_number)
+        current_frame = np.array(img)
+        if not np.array_equal(first_frame, current_frame):
+            return False
+
+    return True
+
+
+def webp_to_gif_or_png(data: bytes) -> bytes:
+    # check if the webp is animated
+    image: Image.Image = Image.open(BytesIO(data))
+    is_animated = getattr(image, "is_animated", False)
+    if is_animated and is_uniform_animated_webp(data):
+        return webp_to_others(data, "image/gif")
+    else:
+        # convert to png
+        return webp_to_others(data, "image/png")
 
 
 def opermize_gif(data: bytes) -> bytes:
@@ -118,9 +149,6 @@ 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()
-    suffix = mimetypes.guess_extension(mimetype)
-    if suffix:
-        suffix = suffix[1:]
     # Determine if the image is a GIF
     is_animated = getattr(image, "is_animated", False)
     if is_animated:
@@ -138,6 +166,9 @@ def _convert_image(data: bytes, mimetype: str) -> (bytes, int, int):
         # Get the size of the first frame to determine resizing
         w, h = frames[0].size
     else:
+        suffix = mimetypes.guess_extension(mimetype)
+        if suffix:
+            suffix = suffix[1:]
         image = image.convert("RGBA")
         image.save(new_file, format=suffix)
         w, h = image.size
@@ -155,9 +186,8 @@ def _convert_image(data: bytes, mimetype: str) -> (bytes, int, int):
 def _convert_sticker(data: bytes) -> (bytes, str, int, int):
     mimetype = guess_mime(data)
     if mimetype.startswith("video/"):
-        data = video_to_gif(data, mimetype)
+        data = video_to_webp(data)
         print(".", end="", flush=True)
-        mimetype = "image/gif"
     elif mimetype.startswith("application/gzip"):
         print(".", end="", flush=True)
         # unzip file
@@ -168,7 +198,7 @@ def _convert_sticker(data: bytes) -> (bytes, str, int, int):
             suffix = mimetypes.guess_extension(mimetype)
             with tempfile.NamedTemporaryFile(suffix=suffix) as temp:
                 temp.write(data)
-                with tempfile.NamedTemporaryFile(suffix=".gif") as gif:
+                with tempfile.NamedTemporaryFile(suffix=".webp") as gif:
                     # run lottie_convert.py input output
                     print(".", end="", flush=True)
                     import subprocess
@@ -179,7 +209,10 @@ def _convert_sticker(data: bytes) -> (bytes, str, int, int):
                         raise RuntimeError(f"Run {cmd} failed with code {retcode}, Error occurred:\n{result.stderr}")
                     gif.seek(0)
                     data = gif.read()
-                    mimetype = "image/gif"
+    mimetype = guess_mime(data)
+    if mimetype == "image/webp":
+        data = webp_to_gif_or_png(data)
+        mimetype = guess_mime(data)
     rlt = _convert_image(data, mimetype)
     data = rlt[0]
     if mimetype == "image/gif":