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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def libvlc_video_set_aspect_ratio(p_mi, psz_aspect):
    '''Set new video aspect ratio.
    @param p_mi: the media player.
    @param psz_aspect: new video aspect-ratio or NULL to reset to default @note Invalid aspect ratios are ignored.
    '''
    f = _Cfunctions.get('libvlc_video_set_aspect_ratio', None) or \
        _Cfunction('libvlc_video_set_aspect_ratio', ((1,), (1,),), None,
                    None, MediaPlayer, ctypes.c_char_p)
    return f(p_mi, psz_aspect)