specrec.c

the mpeg2/4 aac decoder

        REAL_CONST(0)
    };
    real_t x1, x2;
#endif
    int16_t sgn = 1;

    if (q < 0)
    {
        q = -q;
        sgn = -1;
    }

    if (q < IQ_TABLE_SIZE)
    {
//#define IQUANT_PRINT
#ifdef IQUANT_PRINT
        //printf("0x%.8X\n", sgn * tab[q]);
        printf("%d\n", sgn * tab[q]);
#endif
        return sgn * tab[q];
    }

#ifndef BIG_IQ_TABLE
    if (q >= 8192)
    {
        *error = 17;
        return 0;
    }

    /* linear interpolation */
    x1 = tab[q>>3];
    x2 = tab[(q>>3) + 1];
    return sgn * 16 * (MUL_R(errcorr[q&7],(x2-x1)) + x1);
#else
    *error = 17;
    return 0;
#endif

#else
    if (q < 0)
    {
        /* tab contains a value for all possible q [0,8192] */
        if (-q < IQ_TABLE_SIZE)
            return -tab[-q];

        *error = 17;
        return 0;
    } else {
        /* tab contains a value for all possible q [0,8192] */
        if (q < IQ_TABLE_SIZE)
            return tab[q];

        *error = 17;
        return 0;
    }
#endif
}

#ifndef FIXED_POINT
ALIGN static const real_t pow2sf_tab[] = {
    2.9802322387695313E-008, 5.9604644775390625E-008, 1.1920928955078125E-007,
    2.384185791015625E-007, 4.76837158203125E-007, 9.5367431640625E-007,
    1.9073486328125E-006, 3.814697265625E-006, 7.62939453125E-006,
    1.52587890625E-005, 3.0517578125E-005, 6.103515625E-005,
    0.0001220703125, 0.000244140625, 0.00048828125,
    0.0009765625, 0.001953125, 0.00390625,
    0.0078125, 0.015625, 0.03125,
    0.0625, 0.125, 0.25,
    0.5, 1.0, 2.0,
    4.0, 8.0, 16.0, 32.0,
    64.0, 128.0, 256.0,
    512.0, 1024.0, 2048.0,
    4096.0, 8192.0, 16384.0,
    32768.0, 65536.0, 131072.0,
    262144.0, 524288.0, 1048576.0,
    2097152.0, 4194304.0, 8388608.0,
    16777216.0, 33554432.0, 67108864.0,
    134217728.0, 268435456.0, 536870912.0,
    1073741824.0, 2147483648.0, 4294967296.0,
    8589934592.0, 17179869184.0, 34359738368.0,
    68719476736.0, 137438953472.0, 274877906944.0
};
#endif

/* quant_to_spec: perform dequantisation and scaling
 * and in case of short block it also does the deinterleaving
 */
/*
  For ONLY_LONG_SEQUENCE windows (num_window_groups = 1,
  window_group_length[0] = 1) the spectral data is in ascending spectral
  order.
  For the EIGHT_SHORT_SEQUENCE window, the spectral order depends on the
  grouping in the following manner:
  - Groups are ordered sequentially
  - Within a group, a scalefactor band consists of the spectral data of all
    grouped SHORT_WINDOWs for the associated scalefactor window band. To
    clarify via example, the length of a group is in the range of one to eight
    SHORT_WINDOWs.
  - If there are eight groups each with length one (num_window_groups = 8,
    window_group_length[0..7] = 1), the result is a sequence of eight spectra,
    each in ascending spectral order.
  - If there is only one group with length eight (num_window_groups = 1,
    window_group_length[0] = 8), the result is that spectral data of all eight
    SHORT_WINDOWs is interleaved by scalefactor window bands.
  - Within a scalefactor window band, the coefficients are in ascending
    spectral order.
*/
static uint8_t quant_to_spec(NeAACDecHandle hDecoder,
                             ic_stream *ics, int16_t *quant_data,
                             real_t *spec_data, uint16_t frame_len)
{
    ALIGN static const real_t pow2_table[] =
    {
        COEF_CONST(1.0),
        COEF_CONST(1.1892071150027210667174999705605), /* 2^0.25 */
        COEF_CONST(1.4142135623730950488016887242097), /* 2^0.5 */
        COEF_CONST(1.6817928305074290860622509524664) /* 2^0.75 */
    };
    const real_t *tab = iq_table;

    uint8_t g, sfb, win;
    uint16_t width, bin, k, gindex, wa, wb;
    uint8_t error = 0; /* Init error flag */
#ifndef FIXED_POINT
    real_t scf;
#endif

    k = 0;
    gindex = 0;

    for (g = 0; g < ics->num_window_groups; g++)
    {
        uint16_t j = 0;
        uint16_t gincrease = 0;
        uint16_t win_inc = ics->swb_offset[ics->num_swb];

        for (sfb = 0; sfb < ics->num_swb; sfb++)
        {
            int32_t exp, frac;

            width = ics->swb_offset[sfb+1] - ics->swb_offset[sfb];

            /* this could be scalefactor for IS or PNS, those can be negative or bigger then 255 */
            /* just ignore them */
            if (ics->scale_factors[g][sfb] < 0 || ics->scale_factors[g][sfb] > 255)
            {
                exp = 0;
                frac = 0;
            } else {
                /* ics->scale_factors[g][sfb] must be between 0 and 255 */
                exp = (ics->scale_factors[g][sfb] /* - 100 */) >> 2;
                /* frac must always be > 0 */
                frac = (ics->scale_factors[g][sfb] /* - 100 */) & 3;
            }

#ifdef FIXED_POINT
            exp -= 25;
            /* IMDCT pre-scaling */
            if (hDecoder->object_type == LD)
            {
                exp -= 6 /*9*/;
            } else {
                if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
                    exp -= 4 /*7*/;
                else
                    exp -= 7 /*10*/;
            }
#endif

            wa = gindex + j;

#ifndef FIXED_POINT
            scf = pow2sf_tab[exp/*+25*/] * pow2_table[frac];
#endif

            for (win = 0; win < ics->window_group_length[g]; win++)
            {
                for (bin = 0; bin < width; bin += 4)
                {
#ifndef FIXED_POINT
                    wb = wa + bin;

                    spec_data[wb+0] = iquant(quant_data[k+0], tab, &error) * scf;
                    spec_data[wb+1] = iquant(quant_data[k+1], tab, &error) * scf;                        
                    spec_data[wb+2] = iquant(quant_data[k+2], tab, &error) * scf;                        
                    spec_data[wb+3] = iquant(quant_data[k+3], tab, &error) * scf;
                        
#else
                    real_t iq0 = iquant(quant_data[k+0], tab, &error);
                    real_t iq1 = iquant(quant_data[k+1], tab, &error);
                    real_t iq2 = iquant(quant_data[k+2], tab, &error);
                    real_t iq3 = iquant(quant_data[k+3], tab, &error);

                    wb = wa + bin;

                    if (exp < 0)
                    {
                        spec_data[wb+0] = iq0 >>= -exp;
                        spec_data[wb+1] = iq1 >>= -exp;
                        spec_data[wb+2] = iq2 >>= -exp;
                        spec_data[wb+3] = iq3 >>= -exp;
                    } else {
                        spec_data[wb+0] = iq0 <<= exp;
                        spec_data[wb+1] = iq1 <<= exp;
                        spec_data[wb+2] = iq2 <<= exp;
                        spec_data[wb+3] = iq3 <<= exp;
                    }
                    if (frac != 0)
                    {
                        spec_data[wb+0] = MUL_C(spec_data[wb+0],pow2_table[frac]);
                        spec_data[wb+1] = MUL_C(spec_data[wb+1],pow2_table[frac]);
                        spec_data[wb+2] = MUL_C(spec_data[wb+2],pow2_table[frac]);
                        spec_data[wb+3] = MUL_C(spec_data[wb+3],pow2_table[frac]);
                    }

//#define SCFS_PRINT
#ifdef SCFS_PRINT
                    printf("%d\n", spec_data[gindex+(win*win_inc)+j+bin+0]);
                    printf("%d\n", spec_data[gindex+(win*win_inc)+j+bin+1]);
                    printf("%d\n", spec_data[gindex+(win*win_inc)+j+bin+2]);
                    printf("%d\n", spec_data[gindex+(win*win_inc)+j+bin+3]);
                    //printf("0x%.8X\n", spec_data[gindex+(win*win_inc)+j+bin+0]);
                    //printf("0x%.8X\n", spec_data[gindex+(win*win_inc)+j+bin+1]);
                    //printf("0x%.8X\n", spec_data[gindex+(win*win_inc)+j+bin+2]);
                    //printf("0x%.8X\n", spec_data[gindex+(win*win_inc)+j+bin+3]);
#endif
#endif

                    gincrease += 4;
                    k += 4;
                }
                wa += win_inc;
            }
            j += width;
        }
        gindex += gincrease;
    }

    return error;
}

static uint8_t allocate_single_channel(NeAACDecHandle hDecoder, uint8_t channel,
                                       uint8_t output_channels)
{
    uint8_t mul = 1;

#ifdef MAIN_DEC
    /* MAIN object type prediction */
    if (hDecoder->object_type == MAIN)
    {
        /* allocate the state only when needed */
        if (hDecoder->pred_stat[channel] == NULL)
        {
            hDecoder->pred_stat[channel] = (pred_state*)faad_malloc(hDecoder->frameLength * sizeof(pred_state));
            reset_all_predictors(hDecoder->pred_stat[channel], hDecoder->frameLength);
        }
    }
#endif

#ifdef LTP_DEC
    if (is_ltp_ot(hDecoder->object_type))
    {
        /* allocate the state only when needed */
        if (hDecoder->lt_pred_stat[channel] == NULL)
        {
            hDecoder->lt_pred_stat[channel] = (int16_t*)faad_malloc(hDecoder->frameLength*4 * sizeof(int16_t));
            memset(hDecoder->lt_pred_stat[channel], 0, hDecoder->frameLength*4 * sizeof(int16_t));
        }
    }
#endif

    if (hDecoder->time_out[channel] == NULL)
    {
        mul = 1;
#ifdef SBR_DEC
        hDecoder->sbr_alloced[hDecoder->fr_ch_ele] = 0;
        if ((hDecoder->sbr_present_flag == 1) || (hDecoder->forceUpSampling == 1))
        {
            /* SBR requires 2 times as much output data */
            mul = 2;
            hDecoder->sbr_alloced[hDecoder->fr_ch_ele] = 1;
        }
#endif
        hDecoder->time_out[channel] = (real_t*)faad_malloc(mul*hDecoder->frameLength*sizeof(real_t));
        memset(hDecoder->time_out[channel], 0, mul*hDecoder->frameLength*sizeof(real_t));
    }
#if (defined(PS_DEC) || defined(DRM_PS))
    if (output_channels == 2)
    {
        if (hDecoder->time_out[channel+1] == NULL)
        {
            hDecoder->time_out[channel+1] = (real_t*)faad_malloc(mul*hDecoder->frameLength*sizeof(real_t));
            memset(hDecoder->time_out[channel+1], 0, mul*hDecoder->frameLength*sizeof(real_t));
        }
    }
#endif

    if (hDecoder->fb_intermed[channel] == NULL)
    {
        hDecoder->fb_intermed[channel] = (real_t*)faad_malloc(hDecoder->frameLength*sizeof(real_t));
        memset(hDecoder->fb_intermed[channel], 0, hDecoder->frameLength*sizeof(real_t));
    }

#ifdef SSR_DEC
    if (hDecoder->object_type == SSR)
    {
        if (hDecoder->ssr_overlap[channel] == NULL)
        {
            hDecoder->ssr_overlap[channel] = (real_t*)faad_malloc(2*hDecoder->frameLength*sizeof(real_t));
            memset(hDecoder->ssr_overlap[channel], 0, 2*hDecoder->frameLength*sizeof(real_t));
        }
        if (hDecoder->prev_fmd[channel] == NULL)
        {
            uint16_t k;
            hDecoder->prev_fmd[channel] = (real_t*)faad_malloc(2*hDecoder->frameLength*sizeof(real_t));
            for (k = 0; k < 2*hDecoder->frameLength; k++)
                hDecoder->prev_fmd[channel][k] = REAL_CONST(-1);
        }
    }
#endif

    return 0;
}

static uint8_t allocate_channel_pair(NeAACDecHandle hDecoder,
                                     uint8_t channel, uint8_t paired_channel)
{
    uint8_t mul = 1;

#ifdef MAIN_DEC
    /* MAIN object type prediction */
    if (hDecoder->object_type == MAIN)
    {
        /* allocate the state only when needed */
        if (hDecoder->pred_stat[channel] == NULL)
        {
            hDecoder->pred_stat[channel] = (pred_state*)faad_malloc(hDecoder->frameLength * sizeof(pred_state));
            reset_all_predictors(hDecoder->pred_stat[channel], hDecoder->frameLength);
        }
        if (hDecoder->pred_stat[paired_channel] == NULL)
        {
            hDecoder->pred_stat[paired_channel] = (pred_state*)faad_malloc(hDecoder->frameLength * sizeof(pred_state));
            reset_all_predictors(hDecoder->pred_stat[paired_channel], hDecoder->frameLength);
        }
    }
#endif

#ifdef LTP_DEC
    if (is_ltp_ot(hDecoder->object_type))
    {
        /* allocate the state only when needed */
        if (hDecoder->lt_pred_stat[channel] == NULL)
        {
            hDecoder->lt_pred_stat[channel] = (int16_t*)faad_malloc(hDecoder->frameLength*4 * sizeof(int16_t));
            memset(hDecoder->lt_pred_stat[channel], 0, hDecoder->frameLength*4 * sizeof(int16_t));
        }
        if (hDecoder->lt_pred_stat[paired_channel] == NULL)
        {
            hDecoder->lt_pred_stat[paired_channel] = (int16_t*)faad_malloc(hDecoder->frameLength*4 * sizeof(int16_t));
            memset(hDecoder->lt_pred_stat[paired_channel], 0, hDecoder->frameLength*4 * sizeof(int16_t));
        }
    }
#endif

    if (hDecoder->time_out[channel] == NULL)
    {
        mul = 1;
#ifdef SBR_DEC
        hDecoder->sbr_alloced[hDecoder->fr_ch_ele] = 0;
        if ((hDecoder->sbr_present_flag == 1) || (hDecoder->forceUpSampling == 1))
        {
            /* SBR requires 2 times as much output data */
            mul = 2;
            hDecoder->sbr_alloced[hDecoder->fr_ch_ele] = 1;
        }
#endif
        hDecoder->time_out[channel] = (real_t*)faad_malloc(mul*hDecoder->frameLength*sizeof(real_t));
        memset(hDecoder->time_out[channel], 0, mul*hDecoder->frameLength*sizeof(real_t));
    }
    if (hDecoder->time_out[paired_channel] == NULL)
    {
        hDecoder->time_out[paired_channel] = (real_t*)faad_malloc(mul*hDecoder->frameLength*sizeof(real_t));
        memset(hDecoder->time_out[paired_channel], 0, mul*hDecoder->frameLength*sizeof(real_t));
    }

    if (hDecoder->fb_intermed[channel] == NULL)
    {
        hDecoder->fb_intermed[channel] = (real_t*)faad_malloc(hDecoder->frameLength*sizeof(real_t));
        memset(hDecoder->fb_intermed[channel], 0, hDecoder->frameLength*sizeof(real_t));
    }
    if (hDecoder->fb_intermed[paired_channel] == NULL)
    {
        hDecoder->fb_intermed[paired_channel] = (real_t*)faad_malloc(hDecoder->frameLength*sizeof(real_t));
        memset(hDecoder->fb_intermed[paired_channel], 0, hDecoder->frameLength*sizeof(real_t));
    }

#ifdef SSR_DEC
    if (hDecoder->object_type == SSR)
    {
        if (hDecoder->ssr_overlap[cpe->channel] == NULL)
        {
            hDecoder->ssr_overlap[cpe->channel] = (real_t*)faad_malloc(2*hDecoder->frameLength*sizeof(real_t));
            memset(hDecoder->ssr_overlap[cpe->channel], 0, 2*hDecoder->frameLength*sizeof(real_t));
        }
        if (hDecoder->ssr_overlap[cpe->paired_channel] == NULL)
        {
            hDecoder->ssr_overlap[cpe->paired_channel] = (real_t*)faad_malloc(2*hDecoder->frameLength*sizeof(real_t));
            memset(hDecoder->ssr_overlap[cpe->paired_channel], 0, 2*hDecoder->frameLength*sizeof(real_t));
        }
        if (hDecoder->prev_fmd[cpe->channel] == NULL)
        {
            uint16_t k;
            hDecoder->prev_fmd[cpe->channel] = (real_t*)faad_malloc(2*hDecoder->frameLength*sizeof(real_t));
            for (k = 0; k < 2*hDecoder->frameLength; k++)
                hDecoder->prev_fmd[cpe->channel][k] = REAL_CONST(-1);
        }
        if (hDecoder->prev_fmd[cpe->paired_channel] == NULL)
        {
            uint16_t k;
            hDecoder->prev_fmd[cpe->paired_channel] = (real_t*)faad_malloc(2*hDecoder->frameLength*sizeof(real_t));
            for (k = 0; k < 2*hDecoder->frameLength; k++)
                hDecoder->prev_fmd[cpe->paired_channel][k] = REAL_CONST(-1);
        }
    }
#endif