def get_exif_data(exif_data, exif_param):
    """
    Return exif parameter from exif data, return None if param not found

    @param:
    - exif_data : all Exif data from file
    - exif_param : EXIF info to retrieve
    """
    try:
        exif_value = exif_data[exif_param].raw_value
        return exif_value if isinstance(exif_value, list) else [exif_value]
    except KeyError:
        return None

    return None