Support loop_count when writing animations

tests/test_webp.py

@@ -105,6 +105,32 @@ def test_anim_simple(self):
                 expected = np.asarray(img, dtype=np.uint8)
                 assert_array_equal(actual, expected)
 
+    def test_anim_loop_count(self):
+        imgs = []
+        width = 256
+        height = 64
+        for i in range(4):
+            img = Image.new('RGBA', (width, height))
+            draw = ImageDraw.Draw(img)
+            draw.rectangle((0, 0, width-1, height-1), fill=(0, 0, 255))
+            x = i * (width/4)
+            draw.rectangle((x, 0, x + (width/4-1), height-1), fill=(255, 0, 0))
+            imgs.append(img)
+
+        with TemporaryDirectory() as tmpdir:
+            file_name = os.path.join(tmpdir, 'anim.webp')
+
+            webp.save_images(imgs, file_name, fps=4, loop_count=2, lossless=True)
+
+            with open(file_name, 'rb') as f:
+                webp_data = webp.WebPData.from_buffer(f.read())
+                dec_opts = webp.WebPAnimDecoderOptions.new(
+                    use_threads=True, color_mode=webp.WebPColorMode.RGBA)
+                dec = webp.WebPAnimDecoder.new(webp_data, dec_opts)
+                assert dec.anim_info.loop_count == 2
+                assert dec.anim_info.width == width
+                assert dec.anim_info.height == height
+
     # WebP combines adjacent duplicate frames and adjusts timestamps
     # accordingly, resulting in unevenly spaced frames. By specifying the fps
     # while loading we can return evenly spaced frames.

webp/__init__.py

@@ -360,6 +360,14 @@ class WebPAnimEncoderOptions:
     def __init__(self, ptr: Any) -> None:
         self.ptr = ptr
 
+    @property
+    def loop_count(self) -> int:
+        return self.ptr.anim_params.loop_count
+
+    @loop_count.setter
+    def loop_count(self, loop_count: int) -> None:
+        self.ptr.anim_params.loop_count = loop_count
+
     @property
     def minimize_size(self) -> bool:
         return self.ptr.minimize_size != 0
@@ -475,6 +483,10 @@ def width(self) -> int:
     def height(self) -> int:
         return self.ptr.canvas_height
 
+    @property
+    def loop_count(self) -> int:
+        return self.ptr.loop_count
+
     @staticmethod
     def new() -> "WebPAnimInfo":
         ptr = ffi.new('WebPAnimInfo*')
@@ -582,9 +594,12 @@ def _mimwrite_pics(
         pics: List[WebPPicture],
         *args: Any,
         fps: float = 30.0,
+        loop_count: Optional[int] = None,
         **kwargs: Any
         ) -> None:
     enc_opts = WebPAnimEncoderOptions.new()
+    if loop_count is not None:
+        enc_opts.loop_count = loop_count
     enc = WebPAnimEncoder.new(pics[0].ptr.width, pics[0].ptr.height, enc_opts)
     config = WebPConfig.new(**kwargs)
     for i, pic in enumerate(pics):
@@ -602,6 +617,7 @@ def mimwrite(
         arrs: "List[np.ndarray[Any, np.dtype[np.uint8]]]",
         *args: Any,
         fps: float = 30.0,
+        loop_count: Optional[int] = None,
         pilmode: Optional[str] = None,
         **kwargs: Any) -> None:
     """Encode a sequence of PIL Images with WebP and save to file.
@@ -610,10 +626,14 @@ def mimwrite(
         file_path (str): File to save to.
         imgs (list of np.ndarray): Image data to save.
         fps (float): Animation speed in frames per second.
+        loop_count (int, optional): Number of times to repeat the animation.
+            0 = infinite.
+        pilmode (str, optional): Image color mode (RGBA or RGB). Will be
+            inferred from the images if not specified.
         kwargs: Keyword arguments for encoder settings (see `WebPConfig.new`).
     """
     pics = [WebPPicture.from_numpy(arr, pilmode=pilmode) for arr in arrs]
-    _mimwrite_pics(file_path, pics, fps=fps, **kwargs)
+    _mimwrite_pics(file_path, pics, fps=fps, loop_count=loop_count, **kwargs)
 
 
 def mimread(

webp_build/cdef.h

@@ -142,7 +142,14 @@ struct WebPMemoryWriter {
 };
 typedef struct WebPMemoryWriter WebPMemoryWriter;
 
+struct WebPMuxAnimParams {
+  uint32_t bgcolor;
+  int loop_count;
+};
+typedef struct WebPMuxAnimParams WebPMuxAnimParams;
+
 struct WebPAnimEncoderOptions {
+  WebPMuxAnimParams anim_params;
   int minimize_size;
   int kmin;
   int kmax;