Improved error handling

.ci/install.sh

@@ -23,8 +23,7 @@ if [[ $(uname) != CYGWIN* ]]; then
     sudo apt-get -qq install libfreetype6-dev liblcms2-dev python3-tk\
                              ghostscript libjpeg-turbo-progs libopenjp2-7-dev\
                              cmake meson imagemagick libharfbuzz-dev libfribidi-dev\
-                             sway wl-clipboard libopenblas-dev\
-                             ninja-build build-essential nasm
+                             sway wl-clipboard libopenblas-dev nasm
 fi
 
 python3 -m pip install --upgrade pip

.github/workflows/wheels-dependencies.sh

@@ -114,7 +114,7 @@ function install_rav1e {
 
     curl -sLo - \
         https://github.com/xiph/rav1e/releases/download/v$RAV1E_VERSION/librav1e-$RAV1E_VERSION-$suffix.tar.gz \
-        | tar -C $BUILD_PREFIX --exclude LICENSE --exclude LICENSE --exclude '*.so' --exclude '*.dylib' -zxf -
+        | tar -C $BUILD_PREFIX --exclude LICENSE --exclude '*.so' --exclude '*.dylib' -zxf -
 
     if [ -z "$IS_MACOS" ]; then
         sed -i 's/-lgcc_s/-lgcc_eh/g' "${BUILD_PREFIX}/lib/pkgconfig/rav1e.pc"
@@ -133,20 +133,19 @@ EOF
 }
 
 function build_libavif {
+    if [ -e libavif-stamp ]; then return; fi
     install_rav1e
     python3 -m pip install meson ninja
 
     if [[ "$PLAT" == "x86_64" ]]; then
         build_simple nasm 2.16.03 https://www.nasm.us/pub/nasm/releasebuilds/2.16.03/
     fi
 
-    local cmake=$(get_modern_cmake)
     local out_dir=$(fetch_unpack https://github.com/AOMediaCodec/libavif/archive/refs/tags/v$LIBAVIF_VERSION.tar.gz libavif-$LIBAVIF_VERSION.tar.gz)
-
     (cd $out_dir \
-        && $cmake \
+        && cmake \
             -DCMAKE_INSTALL_PREFIX=$BUILD_PREFIX \
-            -DCMAKE_INSTALL_NAME_DIR=$BUILD_PREFIX/lib \
+            -DCMAKE_INSTALL_LIBDIR=$BUILD_PREFIX/lib \
             -DCMAKE_BUILD_TYPE=Release \
             -DBUILD_SHARED_LIBS=OFF \
             -DAVIF_LIBSHARPYUV=LOCAL \
@@ -159,11 +158,7 @@ function build_libavif {
             -DCMAKE_MODULE_PATH=/tmp/cmake/Modules \
             . \
         && make install)
-
-    if [[ "$MB_ML_LIBC" == "manylinux" ]]; then
-        cp /usr/local/lib64/libavif.a /usr/local/lib
-        cp /usr/local/lib64/pkgconfig/libavif.pc /usr/local/lib/pkgconfig
-    fi
+    touch libavif-stamp
 }
 
 function build {

Tests/check_wheel.py

@@ -18,7 +18,7 @@ def test_wheel_modules() -> None:
     except ImportError:
         expected_modules.remove("tkinter")
 
-    # libavif is not available on windows for x86 and ARM64 architectures
+    # libavif is not available on Windows for x86 and ARM64 architectures
     if sys.platform == "win32":
         if platform.machine() == "ARM64" or struct.calcsize("P") == 4:
             expected_modules.remove("avif")

Tests/test_file_avif.py

@@ -127,8 +127,6 @@ def test_unsupported_open(self, monkeypatch: pytest.MonkeyPatch) -> None:
 @skip_unless_feature("avif")
 class TestFileAvif:
     def test_version(self) -> None:
-        _avif.AvifCodecVersions()
-
         version = features.version_module("avif")
         assert version is not None
         assert re.search(r"\d+\.\d+\.\d+$", version)

docs/handbook/image-file-formats.rst

@@ -1370,17 +1370,16 @@ The :py:meth:`~PIL.Image.Image.save` method supports the following options:
     YUV range, either "full" or "limited". Defaults to "full"
 
 **codec**
-    AV1 codec to use for encoding. Possible values are "aom", "rav1e", and
-    "svt", depending on what codecs were compiled with libavif. Defaults to
-    "auto", which will choose the first available codec in the order of the
-    preceding list.
+    AV1 codec to use for encoding. Specific values are "aom", "rav1e", and
+    "svt", presuming the chosen codec is available. Defaults to "auto", which
+    will choose the first available codec in the order of the preceding list.
 
 **tile_rows** / **tile_cols**
     For tile encoding, the (log 2) number of tile rows and columns to use.
     Valid values are 0-6, default 0.
 
 **alpha_premultiplied**
-    Encode the image with premultiplied alpha, defaults ``False``
+    Encode the image with premultiplied alpha. Defaults to ``False``
 
 **icc_profile**
     The ICC Profile to include in the saved file.

docs/installation/building-from-source.rst

@@ -164,9 +164,11 @@ Many of Pillow's features require external libraries:
     The easiest way to install external libraries is via `Homebrew
     <https://brew.sh/>`_. After you install Homebrew, run::
 
-        brew install libjpeg libraqm libtiff little-cms2 openjpeg webp
+        brew install libavif libjpeg libraqm libtiff little-cms2 openjpeg webp
 
-    To install libavif on macOS use Homebrew to install its build dependencies::
+    If you would like to use libavif with more codecs than just aom, then
+    instead of installing libavif through Homebrew directly, you can use
+    Homebrew to install libavif's build dependencies::
 
         brew install aom dav1d rav1e
 
@@ -224,8 +226,7 @@ Many of Pillow's features require external libraries:
 
         sudo pkg install jpeg-turbo tiff webp lcms2 freetype2 openjpeg harfbuzz fribidi libxcb libavif
 
-    See ``depends/install_raqm_cmake.sh`` to install libraqm and
-    ``depends/install_libavif.sh`` to install libavif.
+    See ``depends/install_raqm_cmake.sh`` to install libraqm.
 
 .. tab:: Android
 

src/PIL/AvifImagePlugin.py

@@ -24,24 +24,26 @@
 def _accept(prefix: bytes) -> bool | str:
     if prefix[4:8] != b"ftyp":
         return False
-    coding_brands = (b"avif", b"avis")
-    container_brands = (b"mif1", b"msf1")
     major_brand = prefix[8:12]
-    if major_brand in coding_brands:
-        if not SUPPORTED:
-            return (
-                "image file could not be identified because AVIF "
-                "support not installed"
-            )
-        return True
-    if major_brand in container_brands:
+    if major_brand in (
+        # coding brands
+        b"avif",
+        b"avis",
         # We accept files with AVIF container brands; we can't yet know if
         # the ftyp box has the correct compatible brands, but if it doesn't
         # then the plugin will raise a SyntaxError which Pillow will catch
         # before moving on to the next plugin that accepts the file.
         #
         # Also, because this file might not actually be an AVIF file, we
         # don't raise an error if AVIF support isn't properly compiled.
+        b"mif1",
+        b"msf1",
+    ):
+        if not SUPPORTED:
+            return (
+                "image file could not be identified because AVIF "
+                "support not installed"
+            )
         return True
     return False
 
@@ -72,6 +74,11 @@ def _open(self) -> None:
             )
             raise SyntaxError(msg)
 
+        if DECODE_CODEC_CHOICE != "auto" and not _avif.decoder_codec_available(
+            DECODE_CODEC_CHOICE
+        ):
+            msg = "Invalid opening codec"
+            raise ValueError(msg)
         self._decoder = _avif.AvifDecoder(
             self.fp.read(),
             DECODE_CODEC_CHOICE,
@@ -104,10 +111,8 @@ def load(self) -> Image.core.PixelAccess | None:
             data, timescale, tsp_in_ts, dur_in_ts = self._decoder.get_frame(
                 self.__frame
             )
-            timestamp = round(1000 * (tsp_in_ts / timescale))
-            duration = round(1000 * (dur_in_ts / timescale))
-            self.info["timestamp"] = timestamp
-            self.info["duration"] = duration
+            self.info["timestamp"] = round(1000 * (tsp_in_ts / timescale))
+            self.info["duration"] = round(1000 * (dur_in_ts / timescale))
             self.__loaded = self.__frame
 
             # Set tile
@@ -153,6 +158,9 @@ def _save(
     speed = info.get("speed", 6)
     max_threads = info.get("max_threads", _get_default_max_threads())
     codec = info.get("codec", "auto")
+    if codec != "auto" and not _avif.encoder_codec_available(codec):
+        msg = "Invalid saving codec"
+        raise ValueError(msg)
     range_ = info.get("range", "full")
     tile_rows_log2 = info.get("tile_rows", 0)
     tile_cols_log2 = info.get("tile_cols", 0)
@@ -199,7 +207,7 @@ def _save(
             )
             raise ValueError(msg)
         advanced = tuple(
-            [(str(k).encode("utf-8"), str(v).encode("utf-8")) for k, v in advanced]
+            (str(k).encode("utf-8"), str(v).encode("utf-8")) for k, v in advanced
         )
 
     # Setup the AVIF encoder