Use Python 3.12 generics and type aliases in stubs

av/audio/__init__.pyi

@@ -4,7 +4,7 @@ from .frame import AudioFrame as AudioFrame
 from .stream import AudioStream as AudioStream
 
 # FFmpeg 9.0 encoders and the codec descriptor aliases that resolve to them.
-_AudioCodecName = Literal[
+type _AudioCodecName = Literal[
     "aac",
     "aac_at",
     "aac_mf",

av/audio/frame.pyi

@@ -10,7 +10,7 @@ from .layout import AudioLayout
 from .plane import AudioPlane
 
 format_dtypes: dict[str, str]
-_SupportedNDarray = (
+type _SupportedNDarray = (
     npt.NDArray[np.float64]
     | npt.NDArray[np.float32]
     | npt.NDArray[np.int32]

av/packet.pyi

@@ -1,7 +1,7 @@
 from collections.abc import Buffer as _BufferLike
 from collections.abc import Iterator
 from fractions import Fraction
-from typing import Generic, Literal, TypeVar, final, overload
+from typing import Literal, final, overload
 
 from av.audio.frame import AudioFrame
 from av.audio.stream import AudioStream
@@ -80,15 +80,12 @@ class PacketSideData(Buffer):
 def packet_sidedata_type_to_literal(dtype: int) -> PktSideDataT: ...
 def packet_sidedata_type_from_literal(dtype: PktSideDataT) -> int: ...
 
-# TypeVar for stream types - bound to Stream so it can be any stream type
-_StreamT = TypeVar("_StreamT", bound=Stream)
-
 @final
-class Packet(Buffer, Generic[_StreamT]):
+class Packet[StreamT: Stream](Buffer):
     @property
-    def stream(self) -> _StreamT | None: ...
+    def stream(self) -> StreamT | None: ...
     @stream.setter
-    def stream(self, value: _StreamT) -> None: ...
+    def stream(self, value: StreamT) -> None: ...
     stream_index: int
     @property
     def time_base(self) -> AVRational: ...

av/rational.pyi

@@ -3,7 +3,7 @@ from fractions import Fraction
 from numbers import Rational
 from typing import final, overload
 
-_Comparable = AVRational | Rational | Decimal | float
+type _Comparable = AVRational | Rational | Decimal | float
 
 @final
 class AVRational:

av/sidedata/sidedata.pyi

@@ -1,6 +1,6 @@
 from collections.abc import Iterator, Mapping, Sequence
 from enum import Enum
-from typing import Literal, Self, TypeVar, overload
+from typing import Literal, Self, overload
 
 from typing_extensions import disjoint_base
 
@@ -10,8 +10,6 @@ from av.frame import Frame
 from .encparams import VideoEncParams
 from .motionvectors import MotionVectors
 
-_T = TypeVar("_T")
-
 class Type(Enum):
     _value_: int
     PANSCAN = ...
@@ -47,8 +45,8 @@ class Type(Enum):
     THREE_D_REFERENCE_DISPLAYS = ...
     EXIF = ...
 
-_MotionVectorsKey = Literal["MOTION_VECTORS", Type.MOTION_VECTORS]
-_VideoEncParamsKey = Literal["VIDEO_ENC_PARAMS", Type.VIDEO_ENC_PARAMS]
+type _MotionVectorsKey = Literal["MOTION_VECTORS", Type.MOTION_VECTORS]
+type _VideoEncParamsKey = Literal["VIDEO_ENC_PARAMS", Type.VIDEO_ENC_PARAMS]
 
 @disjoint_base
 class SideData(Buffer):
@@ -69,6 +67,6 @@ class SideDataContainer(Mapping[Type, SideData]):
     @overload
     def get(self, key: str | int | Type, /) -> SideData | None: ...
     @overload
-    def get(
-        self, key: str | int | Type, default: SideData | _T, /
-    ) -> SideData | _T: ...
+    def get[T](
+        self, key: str | int | Type, default: SideData | T, /
+    ) -> SideData | T: ...

av/subtitles/__init__.pyi

@@ -1,7 +1,7 @@
 from typing import Literal
 
 # FFmpeg 9.0 encoders and the codec descriptor aliases that resolve to them.
-_SubtitleCodecName = Literal[
+type _SubtitleCodecName = Literal[
     "ass",
     "dvb_subtitle",
     "dvbsub",

av/video/__init__.pyi

@@ -4,7 +4,7 @@ from .frame import VideoFrame as VideoFrame
 from .stream import VideoStream as VideoStream
 
 # FFmpeg 9.0 encoders and the codec descriptor aliases that resolve to them.
-_VideoCodecName = Literal[
+type _VideoCodecName = Literal[
     "a64_multi",
     "a64_multi5",
     "a64multi",

av/video/frame.pyi

@@ -12,7 +12,7 @@ from .format import VideoFormat
 from .plane import VideoPlane
 from .reformatter import ColorPrimaries, ColorTrc
 
-_SupportedNDarray = (
+type _SupportedNDarray = (
     npt.NDArray[np.uint8]
     | npt.NDArray[np.uint16]
     | npt.NDArray[np.float16]
@@ -78,8 +78,6 @@ class VideoFrame(Frame):
     @property
     def sw_format(self) -> VideoFormat | None: ...
     @property
-    def time(self) -> float | None: ...
-    @property
     def width(self) -> int: ...
     @property
     def height(self) -> int: ...

tests/common.py

@@ -21,12 +21,10 @@
 
 if TYPE_CHECKING:
     from collections.abc import Callable
-    from typing import Any, TypeVar
+    from typing import Any
 
     from PIL.Image import Image
 
-    T = TypeVar("T")
-
 
 __all__ = ("fate_suite",)
 
@@ -84,7 +82,7 @@ def sandboxed(
 
 
 # Decorator for running a test in the sandbox directory
-def run_in_sandbox(func: Callable[..., T]) -> Callable[..., T]:
+def run_in_sandbox[T](func: Callable[..., T]) -> Callable[..., T]:
     @functools.wraps(func)
     def _inner(self: Any, *args: Any, **kwargs: Any) -> T:
         current_dir = os.getcwd()