Packet decode return type is SubtitleSet which is too narrow.

[ntjohnson1]

Right now demux returns Packet which doesn't have any typing specification based on the type of Stream it holds.

PyAV/av/packet.pyi

Line 85 in efe1e4c

def decode(self) -> list[SubtitleSet]: ...

Repro:

def test_decoded_time_base(self) -> None:
        container = av.open(fate_suite("h264/interlaced_crop.mp4"))
        stream = container.streams.video[0]

        assert stream.time_base == Fraction(1, 25)

        video_frame: av.VideoFrame | None = None

        for packet in container.demux(stream): # < - Typing returns Packet
            for frame in packet.decode(): < - Typing returns Subtitle Set (runtime returns video frame)
                video_frame = frame
                assert not isinstance(frame, SubtitleSet)
                assert packet.time_base == frame.time_base
                assert stream.time_base == frame.time_base
                return