added deprecation note about AVIF support

Signed-off-by: Alexander Piskun <bigcat88@icloud.com>

README.md

@@ -21,8 +21,8 @@
 Python bindings to [libheif](https://github.com/strukturag/libheif) for working with HEIF images and plugin for Pillow.
 
 Features:
- * Decoding of `8`, `10`, `12` bit HEIC and AVIF files.
- * Encoding of `8`, `10`, `12` bit HEIC and AVIF files.
+ * Decoding of `8`, `10`, `12` bit HEIC files.
+ * Encoding of `8`, `10`, `12` bit HEIC files.
  * `EXIF`, `XMP`, `IPTC` read & write support.
  * Support of multiple images in one file and a `PrimaryImage` attribute.
  * Adding & removing `thumbnails`.
@@ -97,15 +97,6 @@ if pillow_heif.is_supported("input.heic"):
     np_array = np.asarray(heif_file)
 ```
 
-### AVIF support
-
-Working with the `AVIF` files as the same as with the `HEIC` files. Just use a separate function to register plugin:
-```python3
-import pillow_heif
-
-pillow_heif.register_avif_opener()
-```
-
 ### Accessing Depth Images
 
 ```python3

docs/pillow-plugin.rst

@@ -50,6 +50,8 @@ AVIF plugin
 
 ``AVIF`` plugin should support all operations and work the same way as ``HEIF`` plugin do.
 
+.. note:: Deprecated, use the `pillow-avif-plugin <https://github.com/fdintino/pillow-avif-plugin>`_ project instead.
+
 Tips & Tricks
 """""""""""""
 

pillow_heif/as_plugin.py

@@ -206,6 +206,13 @@ def register_avif_opener(**kwargs) -> None:
 
     :param kwargs: dictionary with values to set in options. See: :ref:`options`.
     """
+    warn(
+        "The AVIF support in this library is marked as deprecated and will be removed in the next version. "
+        "If you still need AVIF support until it natively appears in Pillow, use the "
+        "https://github.com/fdintino/pillow-avif-plugin project instead.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     if not _pillow_heif.get_lib_info()["AVIF"]:
         warn("This version of `pillow-heif` was built without AVIF support.", stacklevel=1)
         return