How to use the scenedetect.video_manager.VideoOpenFailure function in scenedetect

def test_video_open_failure():
    """ Test VideoManager constructor (__init__ method) with invalid filename(s)
    and device IDs to trigger an IOError/VideoOpenFailure exception. """
    # Attempt to open non-existing video files should raise an IOError.
    with pytest.raises(IOError): VideoManager(['fauxfile.mp4'])
    with pytest.raises(IOError): VideoManager(['fauxfile.mp4', 'otherfakefile.mp4'])
    # Attempt to open 99th video device should raise a VideoOpenFailure since
    # the OpenCV VideoCapture open() method will likely fail (unless the test
    # case computer has 100 webcams or more...)
    with pytest.raises(VideoOpenFailure): VideoManager([99])
    # Test device IDs > 100.
    with pytest.raises(VideoOpenFailure): VideoManager([120])
    with pytest.raises(VideoOpenFailure): VideoManager([255])

def test_video_open_failure():
    """ Test VideoManager constructor (__init__ method) with invalid filename(s)
    and device IDs to trigger an IOError/VideoOpenFailure exception. """
    # Attempt to open non-existing video files should raise an IOError.
    with pytest.raises(IOError): VideoManager(['fauxfile.mp4'])
    with pytest.raises(IOError): VideoManager(['fauxfile.mp4', 'otherfakefile.mp4'])
    # Attempt to open 99th video device should raise a VideoOpenFailure since
    # the OpenCV VideoCapture open() method will likely fail (unless the test
    # case computer has 100 webcams or more...)
    with pytest.raises(VideoOpenFailure): VideoManager([99])
    # Test device IDs > 100.
    with pytest.raises(VideoOpenFailure): VideoManager([120])
    with pytest.raises(VideoOpenFailure): VideoManager([255])

elif not all([isinstance(video_file, (str, STRING_TYPE)) for video_file in video_files]):
        raise ValueError("Unexpected element type in video_files list (expected str(s)/int).")
    elif framerate is not None and not isinstance(framerate, float):
        raise TypeError("Expected type float for parameter framerate.")
    # Check if files exist.
    if not is_device and any([not os.path.exists(video_file) for video_file in video_files]):
        raise IOError("Video file(s) not found.")
    cap_list = []

    try:
        cap_list = [cv2.VideoCapture(video_file) for video_file in video_files]
        video_names = [get_video_name(video_file) for video_file in video_files]
        closed_caps = [video_names[i] for i, cap in
                       enumerate(cap_list) if not cap.isOpened()]
        if closed_caps:
            raise VideoOpenFailure(closed_caps)

        cap_framerates = [cap.get(cv2.CAP_PROP_FPS) for cap in cap_list]
        cap_framerate, check_framerate = validate_capture_framerate(
            video_names, cap_framerates, framerate)
        # Store frame sizes as integers (VideoCapture.get() returns float).
        cap_frame_sizes = [(math.trunc(cap.get(cv2.CAP_PROP_FRAME_WIDTH)),
                            math.trunc(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))
                           for cap in cap_list]
        cap_frame_size = cap_frame_sizes[0]

        # If we need to validate the parameters, we check that the FPS and width/height
        # of all open captures is identical (or almost identical in the case of FPS).
        if validate_parameters:
            validate_capture_parameters(
                video_names=video_names, cap_frame_sizes=cap_frame_sizes,
                check_framerate=check_framerate, cap_framerates=cap_framerates)

def _init_video_manager(self, input_list, framerate, downscale):

        self.base_timecode = None

        logging.debug('Initializing VideoManager.')
        video_manager_initialized = False
        try:
            self.video_manager = VideoManager(
                video_files=input_list, framerate=framerate, logger=logging)
            video_manager_initialized = True
            self.base_timecode = self.video_manager.get_base_timecode()
            self.video_manager.set_downscale_factor(downscale)
        except VideoOpenFailure as ex:
            error_strs = [
                'could not open video%s.' % get_plural(ex.file_list),
                'Failed to open the following video file%s:' % get_plural(ex.file_list)]
            error_strs += ['  %s' % file_name[0] for file_name in ex.file_list]
            dll_okay, dll_name = check_opencv_ffmpeg_dll()
            if not dll_okay:
                error_strs += [
                    'Error: OpenCV dependency %s not found.' % dll_name,
                    'Ensure that you installed the Python OpenCV module, and that the',
                    '%s file can be found to enable video support.' % dll_name]
            logging.debug('\n'.join(error_strs[1:]))
            if not dll_okay:
                click.echo(click.style(
                    '\nOpenCV dependency missing, video input/decoding not available.\n', fg='red'))
            raise click.BadParameter('\n'.join(error_strs), param_hint='input video')
        except VideoFramerateUnavailable as ex:

def __init__(self, file_list=None, message=
                 "OpenCV VideoCapture object failed to return True when calling isOpened()."):
        # type: (Iterable[(str, str)], str)
        # Pass message string to base Exception class.
        super(VideoOpenFailure, self).__init__(message)
        # list of (filename: str, filepath: str)
        self.file_list = file_list

def _init_video_manager(self, input_list, framerate, downscale):

        self.base_timecode = None

        logging.debug('Initializing VideoManager.')
        video_manager_initialized = False
        try:
            self.video_manager = VideoManager(
                video_files=input_list, framerate=framerate, logger=logging)
            video_manager_initialized = True
            self.base_timecode = self.video_manager.get_base_timecode()
            self.video_manager.set_downscale_factor(downscale)
        except VideoOpenFailure as ex:
            error_strs = [
                'could not open video%s.' % get_plural(ex.file_list),
                'Failed to open the following video file%s:' % get_plural(ex.file_list)]
            error_strs += ['  %s' % file_name[0] for file_name in ex.file_list]
            dll_okay, dll_name = check_opencv_ffmpeg_dll()
            if not dll_okay:
                error_strs += [
                    'Error: OpenCV dependency %s not found.' % dll_name,
                    'Ensure that you installed the Python OpenCV module, and that the',
                    '%s file can be found to enable video support.' % dll_name]
            logging.debug('\n'.join(error_strs[1:]))
            if not dll_okay:
                click.echo(click.style(
                    '\nOpenCV dependency missing, video input/decoding not available.\n', fg='red'))
            raise click.BadParameter('\n'.join(error_strs), param_hint='input video')
        except VideoFramerateUnavailable as ex: