def METHOD_NAME(h, f):
    if not h.startswith(b'Creative Voice File\032'):
        return None
    sbseek = get_short_le(h[20:22])
    rate = 0
    if 0 <= sbseek < 500 and h[sbseek] == 1:
        ratecode = 256 - h[sbseek+4]
        if ratecode:
            rate = int(1000000.0 / ratecode)
    return 'voc', rate, 1, -1, 8