def cut_video_stream(stream, start, end, fmt):
    """ cut video stream from `start` to `end` time

    Parameters
    ----------
    stream : bytes
        video file content
    start : float
        start time
    end : float
        end time

    Returns
    -------
    result : bytes
        content of cut video

    """
    with TemporaryDirectory() as tmp:
        in_file = Path(tmp) / f"in{fmt}"
        out_file = Path(tmp) / f"out{fmt}"

        in_file.write_bytes(stream)

        try:
            ret = subprocess.run(
                [
                    "ffmpeg",
                    "-ss",
                    f"{start}",
                    "-i",
                    f"{in_file}",
                    "-to",
                    f"{end}",
                    "-c",
                    "copy",
                    f"{out_file}",
                ],
                capture_output=True,
            )
        except FileNotFoundError:
            result = stream
        else:
            if ret.returncode:
                result = stream
            else:
                result = out_file.read_bytes()

    return result
cut video stream from `start` to `end` time

    Parameters
    ----------
    stream : bytes
        video file content
    start : float
        start time
    end : float
        end time

    Returns
    -------
    result : bytes
        content of cut video