def output_meta(face_meta, output_path, overwrite=True):
    """ Output face metadata into a .csv file

    Parameters
    ----------
    face_meta : dict of {int : dict of {str: float}}}
        Mapping *<face_id>* to a :class:`dict`, which contains the metadata and face detection and
        age estimation results of the output faces.
        Each result is a :class:`dict` with fields frame_id, min_x, min_y, width, height, confidence and estimated_age
    output_path : Path
        Path to the output face metadata file
    overwrite : bool
        True if overwriting the existing file at :attr:`output_path`, default True

    Returns
    -------
    success : bool
        Whether the video file is generated
    """

    if output_path.exists() and not overwrite:
        return False

    with open(str(output_path), 'w') as fout:
        fout.write('FaceID,FrameID,Min_X,Min_Y,Width,Height,Confidence,EstimatedAge\n')
        for face_id, info in face_meta.items():
            fout.write('{},{},{},{},{},{},{},{}\n'.format(face_id, info['frame_id'],
                                                          info['min_x'], info['min_y'],
                                                          info['width'], info['height'],
                                                          info['confidence'], info['estimated_age']))
    return True