Added get_codec_version() (#29)

Co-authored-by: Andrew Murray <radarhere@users.noreply.github.com>

Tests/test_file_avif.py

@@ -94,7 +94,20 @@ class TestFileAvif:
     def test_version(self) -> None:
         version = features.version_module("avif")
         assert version is not None
-        assert re.search(r"\d+\.\d+\.\d+$", version)
+        assert re.search(r"^\d+\.\d+\.\d+$", version)
+
+    def test_codec_version(self) -> None:
+        assert AvifImagePlugin.get_codec_version("unknown") is None
+
+        for codec_name in ("aom", "dav1d", "rav1e", "svt"):
+            codec_version = AvifImagePlugin.get_codec_version(codec_name)
+            if _avif.decoder_codec_available(
+                codec_name
+            ) or _avif.encoder_codec_available(codec_name):
+                assert codec_version is not None
+                assert re.search(r"^v?\d+\.\d+\.\d+(-([a-z\d])+)*$", codec_version)
+            else:
+                assert codec_version is None
 
     def test_read(self) -> None:
         """

src/PIL/AvifImagePlugin.py

@@ -20,6 +20,14 @@ DECODE_CODEC_CHOICE = "auto"
 DEFAULT_MAX_THREADS = 0
 
 
+def get_codec_version(codec_name: str) -> str | None:
+    versions = _avif.codec_versions()
+    for version in versions.split(", "):
+        if version.split(" [")[0] == codec_name:
+            return version.split(":")[-1].split(" ")[0]
+    return None
+
+
 def _accept(prefix: bytes) -> bool | str:
     if prefix[4:8] != b"ftyp":
         return False

src/_avif.c

@@ -182,6 +182,13 @@ _encoder_codec_available(PyObject *self, PyObject *args) {
     return PyBool_FromLong(is_available);
 }
 
+PyObject *
+_codec_versions(PyObject *self, PyObject *args) {
+    char buffer[256];
+    avifCodecVersions(buffer);
+    return PyUnicode_FromString(buffer);
+}
+
 #if AVIF_VERSION >= 80200  // 0.8.2
 static int
 _add_codec_specific_options(avifEncoder *encoder, PyObject *opts) {
@@ -910,6 +917,7 @@ static PyMethodDef avifMethods[] = {
     {"AvifEncoder", AvifEncoderNew, METH_VARARGS},
     {"decoder_codec_available", _decoder_codec_available, METH_VARARGS},
     {"encoder_codec_available", _encoder_codec_available, METH_VARARGS},
+    {"codec_versions", _codec_versions, METH_NOARGS},
     {NULL, NULL}
 };