def extract_frames(video, outDir):
    """
    Converts the `video` to images.

    Parameters
    ----------
        video : string
            full path to the video file.
        outDir : string
            path to directory to output the extracted images.

    Returns
    -------
        error : string
            Error message if error occurs otherwise blank string.
    """


    error = ""
    IS_WINDOWS = 'Windows' == platform.system()

    if IS_WINDOWS:
        ffmpeg_path = os.path.join(args.ffmpeg_dir, "ffmpeg")
    else:
        ffmpeg_path = "ffmpeg"

    print('{} -i {} -vsync 0 {}/%06d.png'.format(ffmpeg_path, video, outDir))
    retn = os.system('{} -i "{}" -vsync 0 {}/%06d.png'.format(ffmpeg_path, video, outDir))
    if retn:
        error = "Error converting file:{}. Exiting.".format(video)
    return error

    Converts the `video` to images.

    Parameters
    ----------
        video : string
            full path to the video file.
        outDir : string
            path to directory to output the extracted images.

    Returns
    -------
        error : string
            Error message if error occurs otherwise blank string.
    
video_to_slomo.py