static int decode_exp_vlc(WMACodecContext *s, int ch)

{

    int last_exp, n, code;

    const uint16_t *ptr;

    float v, max_scale;

    uint32_t *q, *q_end, iv;

    const float *ptab = pow_tab + 60;

    const uint32_t *iptab = (const uint32_t*)ptab;



    ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];

    q = (uint32_t *)s->exponents[ch];

    q_end = q + s->block_len;

    max_scale = 0;

    if (s->version == 1) {

        last_exp = get_bits(&s->gb, 5) + 10;

        v = ptab[last_exp];

        iv = iptab[last_exp];

        max_scale = v;

        n = *ptr++;

        switch (n & 3) do {

        case 0: *q++ = iv;

        case 3: *q++ = iv;

        case 2: *q++ = iv;

        case 1: *q++ = iv;

        } while ((n -= 4) > 0);

    }else

        last_exp = 36;



    while (q < q_end) {

        code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);

        if (code < 0){

            av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");

            return -1;

        }

        /* NOTE: this offset is the same as MPEG4 AAC ! */

        last_exp += code - 60;

        if ((unsigned)last_exp + 60 > FF_ARRAY_ELEMS(pow_tab)) {

            av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",

                   last_exp);

            return -1;

        }

        v = ptab[last_exp];

        iv = iptab[last_exp];

        if (v > max_scale)

            max_scale = v;

        n = *ptr++;

        switch (n & 3) do {

        case 0: *q++ = iv;

        case 3: *q++ = iv;

        case 2: *q++ = iv;

        case 1: *q++ = iv;

        } while ((n -= 4) > 0);

    }

    s->max_exponent[ch] = max_scale;

    return 0;

}
