How to use the av.Packet function in av

frame_count,
                codec_name if codec_name != 'mjpeg' else 'jpg',
            ))
            path_list.append(path)
            with open(path, 'wb') as f:
                f.write(new_packet)
            frame_count += 1
            if frame_count > 5:
                break

        ctx = av.Codec(codec_name, 'r').create()

        for path in path_list:
            with open(path, 'rb') as f:
                size = os.fstat(f.fileno()).st_size
                packet = Packet(size)
                size = f.readinto(packet)
                frame = ctx.decode(packet)[0]
                self.assertEqual(frame.width, width)
                self.assertEqual(frame.height, height)
                self.assertEqual(frame.format.name, pix_fmt)

def iter_raw_frames(path, packet_sizes, ctx):
    with open(path, 'rb') as f:
        for i, size in enumerate(packet_sizes):
            packet = Packet(size)
            read_size = f.readinto(packet)
            assert size
            assert read_size == size
            if not read_size:
                break
            for frame in ctx.decode(packet):
                yield frame
        while True:
            try:
                frames = ctx.decode(None)
            except EOFError:
                break
            for frame in frames:
                yield frame
            if not frames:
                break

def decode(self, encoded_frame: JitterFrame) -> List[Frame]:
        try:
            packet = av.Packet(encoded_frame.data)
            packet.pts = encoded_frame.timestamp
            packet.time_base = VIDEO_TIME_BASE
            frames = self.codec.decode(packet)
        except av.AVError as e:
            logger.warning("failed to decode, skipping package: " + str(e))
            return []

        return frames