Fix all the type errors mypy complains about

av/audio/stream.pyi

@@ -12,5 +12,5 @@ class AudioStream(Stream):
     format: AudioFormat
     codec_context: AudioCodecContext
 
-    def encode(self, frame: AudioFrame | None = None) -> list[Packet]: ...
+    def encode(self, frame: AudioFrame | None = None) -> list[Packet]: ...  # type: ignore[override]
     def decode(self, packet: Packet | None = None) -> list[AudioFrame]: ...

av/format.pyi

@@ -1,3 +1,5 @@
+__all__ = ("ContainerFormat", "formats_available")
+
 from .enum import EnumFlag
 
 class Flags(EnumFlag):

av/sidedata/motionvectors.pyi

@@ -1,11 +1,16 @@
-from typing import Any, Sequence
+from typing import Any, Sequence, overload
 
 import numpy as np
 
 from .sidedata import SideData
 
-class MotionVectors(SideData, Sequence[Any]):
-    def __getitem__(self, index: int) -> MotionVector: ...
+class MotionVectors(SideData, Sequence[MotionVector]):
+    @overload
+    def __getitem__(self, index: int): ...
+    @overload
+    def __getitem__(self, index: slice): ...
+    @overload
+    def __getitem__(self, index: int | slice): ...
     def __len__(self) -> int: ...
     def to_ndarray(self) -> np.ndarray[Any, Any]: ...
 

av/sidedata/sidedata.pyi

@@ -1,4 +1,5 @@
 from collections.abc import Mapping
+from typing import Iterator, Sequence, overload
 
 from av.buffer import Buffer
 from av.enum import EnumItem
@@ -27,5 +28,13 @@ class SideData(Buffer):
     type: Type
     DISPLAYMATRIX: int
 
-class SideDataContainer(Mapping[str, int]):
+class SideDataContainer(Mapping):
     frame: Frame
+    def __len__(self) -> int: ...
+    def __iter__(self) -> Iterator[SideData]: ...
+    @overload
+    def __getitem__(self, key: int) -> SideData: ...
+    @overload
+    def __getitem__(self, key: slice) -> Sequence[SideData]: ...
+    @overload
+    def __getitem__(self, key: int | slice) -> SideData | Sequence[SideData]: ...

av/video/stream.pyi

@@ -24,5 +24,5 @@ class VideoStream(Stream):
     thread_count: int
     thread_type: Any
 
-    def encode(self, frame: VideoFrame | None = None) -> list[Packet]: ...
+    def encode(self, frame: VideoFrame | None = None) -> list[Packet]: ...  # type: ignore[override]
     def decode(self, packet: Packet | None = None) -> list[VideoFrame]: ...