Beispiel #1
0
static void search_for_ms(AACEncContext *s, ChannelElement *cpe,
                          const float lambda)
{
    int start = 0, i, w, w2, g;
    float M[128], S[128];
    float *L34 = s->scoefs, *R34 = s->scoefs + 128, *M34 = s->scoefs + 128*2, *S34 = s->scoefs + 128*3;
    SingleChannelElement *sce0 = &cpe->ch[0];
    SingleChannelElement *sce1 = &cpe->ch[1];
    if (!cpe->common_window)
        return;
    for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
        for (g = 0;  g < sce0->ics.num_swb; g++) {
            if (!cpe->ch[0].zeroes[w*16+g] && !cpe->ch[1].zeroes[w*16+g]) {
                float dist1 = 0.0f, dist2 = 0.0f;
                for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
                    FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
                    FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
                    float minthr = FFMIN(band0->threshold, band1->threshold);
                    float maxthr = FFMAX(band0->threshold, band1->threshold);
                    for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
                        M[i] = (sce0->coeffs[start+w2*128+i]
                              + sce1->coeffs[start+w2*128+i]) * 0.5;
                        S[i] =  M[i]
                              - sce1->coeffs[start+w2*128+i];
                    }
                    abs_pow34_v(L34, sce0->coeffs+start+w2*128, sce0->ics.swb_sizes[g]);
                    abs_pow34_v(R34, sce1->coeffs+start+w2*128, sce0->ics.swb_sizes[g]);
                    abs_pow34_v(M34, M,                         sce0->ics.swb_sizes[g]);
                    abs_pow34_v(S34, S,                         sce0->ics.swb_sizes[g]);
                    dist1 += quantize_band_cost(s, sce0->coeffs + start + w2*128,
                                                L34,
                                                sce0->ics.swb_sizes[g],
                                                sce0->sf_idx[(w+w2)*16+g],
                                                sce0->band_type[(w+w2)*16+g],
                                                lambda / band0->threshold, INFINITY, NULL);
                    dist1 += quantize_band_cost(s, sce1->coeffs + start + w2*128,
                                                R34,
                                                sce1->ics.swb_sizes[g],
                                                sce1->sf_idx[(w+w2)*16+g],
                                                sce1->band_type[(w+w2)*16+g],
                                                lambda / band1->threshold, INFINITY, NULL);
                    dist2 += quantize_band_cost(s, M,
                                                M34,
                                                sce0->ics.swb_sizes[g],
                                                sce0->sf_idx[(w+w2)*16+g],
                                                sce0->band_type[(w+w2)*16+g],
                                                lambda / maxthr, INFINITY, NULL);
                    dist2 += quantize_band_cost(s, S,
                                                S34,
                                                sce1->ics.swb_sizes[g],
                                                sce1->sf_idx[(w+w2)*16+g],
                                                sce1->band_type[(w+w2)*16+g],
                                                lambda / minthr, INFINITY, NULL);
                }
                cpe->ms_mask[w*16+g] = dist2 < dist1;
            }
            start += sce0->ics.swb_sizes[g];
        }
    }
}
struct AACISError ff_aac_is_encoding_err(AACEncContext *s, ChannelElement *cpe,
                                         int start, int w, int g, float ener0,
                                         float ener1, float ener01,
                                         int use_pcoeffs, int phase)
{
    int i, w2;
    SingleChannelElement *sce0 = &cpe->ch[0];
    SingleChannelElement *sce1 = &cpe->ch[1];
    float *L = use_pcoeffs ? sce0->pcoeffs : sce0->coeffs;
    float *R = use_pcoeffs ? sce1->pcoeffs : sce1->coeffs;
    float *L34 = &s->scoefs[256*0], *R34 = &s->scoefs[256*1];
    float *IS  = &s->scoefs[256*2], *I34 = &s->scoefs[256*3];
    float dist1 = 0.0f, dist2 = 0.0f;
    struct AACISError is_error = {0};

    for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
        FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
        FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
        int is_band_type, is_sf_idx = FFMAX(1, sce0->sf_idx[(w+w2)*16+g]-4);
        float e01_34 = phase*pow(ener1/ener0, 3.0/4.0);
        float maxval, dist_spec_err = 0.0f;
        float minthr = FFMIN(band0->threshold, band1->threshold);
        for (i = 0; i < sce0->ics.swb_sizes[g]; i++)
            IS[i] = (L[start+(w+w2)*128+i] + phase*R[start+(w+w2)*128+i])*sqrt(ener0/ener01);
        abs_pow34_v(L34, &L[start+(w+w2)*128], sce0->ics.swb_sizes[g]);
        abs_pow34_v(R34, &R[start+(w+w2)*128], sce0->ics.swb_sizes[g]);
        abs_pow34_v(I34, IS,                   sce0->ics.swb_sizes[g]);
        maxval = find_max_val(1, sce0->ics.swb_sizes[g], I34);
        is_band_type = find_min_book(maxval, is_sf_idx);
        dist1 += quantize_band_cost(s, &L[start + (w+w2)*128], L34,
                                    sce0->ics.swb_sizes[g],
                                    sce0->sf_idx[(w+w2)*16+g],
                                    sce0->band_type[(w+w2)*16+g],
                                    s->lambda / band0->threshold, INFINITY, NULL, 0);
        dist1 += quantize_band_cost(s, &R[start + (w+w2)*128], R34,
                                    sce1->ics.swb_sizes[g],
                                    sce1->sf_idx[(w+w2)*16+g],
                                    sce1->band_type[(w+w2)*16+g],
                                    s->lambda / band1->threshold, INFINITY, NULL, 0);
        dist2 += quantize_band_cost(s, IS, I34, sce0->ics.swb_sizes[g],
                                    is_sf_idx, is_band_type,
                                    s->lambda / minthr, INFINITY, NULL, 0);
        for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
            dist_spec_err += (L34[i] - I34[i])*(L34[i] - I34[i]);
            dist_spec_err += (R34[i] - I34[i]*e01_34)*(R34[i] - I34[i]*e01_34);
        }
        dist_spec_err *= s->lambda / minthr;
        dist2 += dist_spec_err;
    }

    is_error.pass = dist2 <= dist1;
    is_error.phase = phase;
    is_error.error = fabsf(dist1 - dist2);
    is_error.dist1 = dist1;
    is_error.dist2 = dist2;

    return is_error;
}
Beispiel #3
0
static void search_for_quantizers_faac(AVCodecContext *avctx, AACEncContext *s,
                                       SingleChannelElement *sce,
                                       const float lambda)
{
    int start = 0, i, w, w2, g;
    float uplim[128], maxq[128];
    int minq, maxsf;
    float distfact = ((sce->ics.num_windows > 1) ? 85.80 : 147.84) / lambda;
    int last = 0, lastband = 0, curband = 0;
    float avg_energy = 0.0;
    if (sce->ics.num_windows == 1) {
        start = 0;
        for (i = 0; i < 1024; i++) {
            if (i - start >= sce->ics.swb_sizes[curband]) {
                start += sce->ics.swb_sizes[curband];
                curband++;
            }
            if (sce->coeffs[i]) {
                avg_energy += sce->coeffs[i] * sce->coeffs[i];
                last = i;
                lastband = curband;
            }
        }
    } else {
        for (w = 0; w < 8; w++) {
            const float *coeffs = sce->coeffs + w*128;
            start = 0;
            for (i = 0; i < 128; i++) {
                if (i - start >= sce->ics.swb_sizes[curband]) {
                    start += sce->ics.swb_sizes[curband];
                    curband++;
                }
                if (coeffs[i]) {
                    avg_energy += coeffs[i] * coeffs[i];
                    last = FFMAX(last, i);
                    lastband = FFMAX(lastband, curband);
                }
            }
        }
    }
    last++;
    avg_energy /= last;
    if (avg_energy == 0.0f) {
        for (i = 0; i < FF_ARRAY_ELEMS(sce->sf_idx); i++)
            sce->sf_idx[i] = SCALE_ONE_POS;
        return;
    }
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = w*128;
        for (g = 0; g < sce->ics.num_swb; g++) {
            float *coefs   = sce->coeffs + start;
            const int size = sce->ics.swb_sizes[g];
            int start2 = start, end2 = start + size, peakpos = start;
            float maxval = -1, thr = 0.0f, t;
            maxq[w*16+g] = 0.0f;
            if (g > lastband) {
                maxq[w*16+g] = 0.0f;
                start += size;
                for (w2 = 0; w2 < sce->ics.group_len[w]; w2++)
                    memset(coefs + w2*128, 0, sizeof(coefs[0])*size);
                continue;
            }
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                for (i = 0; i < size; i++) {
                    float t = coefs[w2*128+i]*coefs[w2*128+i];
                    maxq[w*16+g] = FFMAX(maxq[w*16+g], fabsf(coefs[w2*128 + i]));
                    thr += t;
                    if (sce->ics.num_windows == 1 && maxval < t) {
                        maxval  = t;
                        peakpos = start+i;
                    }
                }
            }
            if (sce->ics.num_windows == 1) {
                start2 = FFMAX(peakpos - 2, start2);
                end2   = FFMIN(peakpos + 3, end2);
            } else {
                start2 -= start;
                end2   -= start;
            }
            start += size;
            thr = pow(thr / (avg_energy * (end2 - start2)), 0.3 + 0.1*(lastband - g) / lastband);
            t   = 1.0 - (1.0 * start2 / last);
            uplim[w*16+g] = distfact / (1.4 * thr + t*t*t + 0.075);
        }
    }
    memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
    abs_pow34_v(s->scoefs, sce->coeffs, 1024);
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = w*128;
        for (g = 0;  g < sce->ics.num_swb; g++) {
            const float *coefs  = sce->coeffs + start;
            const float *scaled = s->scoefs   + start;
            const int size      = sce->ics.swb_sizes[g];
            int scf, prev_scf, step;
            int min_scf = -1, max_scf = 256;
            float curdiff;
            if (maxq[w*16+g] < 21.544) {
                sce->zeroes[w*16+g] = 1;
                start += size;
                continue;
            }
            sce->zeroes[w*16+g] = 0;
            scf  = prev_scf = av_clip(SCALE_ONE_POS - SCALE_DIV_512 - log2f(1/maxq[w*16+g])*16/3, 60, 218);
            step = 16;
            for (;;) {
                float dist = 0.0f;
                int quant_max;

                for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                    int b;
                    dist += quantize_band_cost(s, coefs + w2*128,
                                               scaled + w2*128,
                                               sce->ics.swb_sizes[g],
                                               scf,
                                               ESC_BT,
                                               lambda,
                                               INFINITY,
                                               &b);
                    dist -= b;
                }
                dist *= 1.0f / 512.0f / lambda;
                quant_max = quant(maxq[w*16+g], ff_aac_pow2sf_tab[POW_SF2_ZERO - scf + SCALE_ONE_POS - SCALE_DIV_512]);
                if (quant_max >= 8191) { // too much, return to the previous quantizer
                    sce->sf_idx[w*16+g] = prev_scf;
                    break;
                }
                prev_scf = scf;
                curdiff = fabsf(dist - uplim[w*16+g]);
                if (curdiff <= 1.0f)
                    step = 0;
                else
                    step = log2f(curdiff);
                if (dist > uplim[w*16+g])
                    step = -step;
                scf += step;
                scf = av_clip_uint8(scf);
                step = scf - prev_scf;
                if (FFABS(step) <= 1 || (step > 0 && scf >= max_scf) || (step < 0 && scf <= min_scf)) {
                    sce->sf_idx[w*16+g] = av_clip(scf, min_scf, max_scf);
                    break;
                }
                if (step > 0)
                    min_scf = prev_scf;
                else
                    max_scf = prev_scf;
            }
            start += size;
        }
    }
    minq = sce->sf_idx[0] ? sce->sf_idx[0] : INT_MAX;
    for (i = 1; i < 128; i++) {
        if (!sce->sf_idx[i])
            sce->sf_idx[i] = sce->sf_idx[i-1];
        else
            minq = FFMIN(minq, sce->sf_idx[i]);
    }
    if (minq == INT_MAX)
        minq = 0;
    minq = FFMIN(minq, SCALE_MAX_POS);
    maxsf = FFMIN(minq + SCALE_MAX_DIFF, SCALE_MAX_POS);
    for (i = 126; i >= 0; i--) {
        if (!sce->sf_idx[i])
            sce->sf_idx[i] = sce->sf_idx[i+1];
        sce->sf_idx[i] = av_clip(sce->sf_idx[i], minq, maxsf);
    }
}
Beispiel #4
0
/**
 * two-loop quantizers search taken from ISO 13818-7 Appendix C
 */
static void search_for_quantizers_twoloop(AVCodecContext *avctx,
                                          AACEncContext *s,
                                          SingleChannelElement *sce,
                                          const float lambda)
{
    int start = 0, i, w, w2, g;
    int destbits = avctx->bit_rate * 1024.0 / avctx->sample_rate / avctx->channels;
    float dists[128], uplims[128];
    float maxvals[128];
    int fflag, minscaler;
    int its  = 0;
    int allz = 0;
    float minthr = INFINITY;

    //XXX: some heuristic to determine initial quantizers will reduce search time
    memset(dists, 0, sizeof(dists));
    //determine zero bands and upper limits
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        for (g = 0;  g < sce->ics.num_swb; g++) {
            int nz = 0;
            float uplim = 0.0f;
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                uplim += band->threshold;
                if (band->energy <= band->threshold || band->threshold == 0.0f) {
                    sce->zeroes[(w+w2)*16+g] = 1;
                    continue;
                }
                nz = 1;
            }
            uplims[w*16+g] = uplim *512;
            sce->zeroes[w*16+g] = !nz;
            if (nz)
                minthr = FFMIN(minthr, uplim);
            allz |= nz;
        }
    }
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        for (g = 0;  g < sce->ics.num_swb; g++) {
            if (sce->zeroes[w*16+g]) {
                sce->sf_idx[w*16+g] = SCALE_ONE_POS;
                continue;
            }
            sce->sf_idx[w*16+g] = SCALE_ONE_POS + FFMIN(log2f(uplims[w*16+g]/minthr)*4,59);
        }
    }

    if (!allz)
        return;
    abs_pow34_v(s->scoefs, sce->coeffs, 1024);

    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = w*128;
        for (g = 0;  g < sce->ics.num_swb; g++) {
            const float *scaled = s->scoefs + start;
            maxvals[w*16+g] = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], scaled);
            start += sce->ics.swb_sizes[g];
        }
    }

    //perform two-loop search
    //outer loop - improve quality
    do {
        int tbits, qstep;
        minscaler = sce->sf_idx[0];
        //inner loop - quantize spectrum to fit into given number of bits
        qstep = its ? 1 : 32;
        do {
            int prev = -1;
            tbits = 0;
            fflag = 0;
            for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
                start = w*128;
                for (g = 0;  g < sce->ics.num_swb; g++) {
                    const float *coefs = sce->coeffs + start;
                    const float *scaled = s->scoefs + start;
                    int bits = 0;
                    int cb;
                    float dist = 0.0f;

                    if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) {
                        start += sce->ics.swb_sizes[g];
                        continue;
                    }
                    minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]);
                    cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]);
                    for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                        int b;
                        dist += quantize_band_cost(s, coefs + w2*128,
                                                   scaled + w2*128,
                                                   sce->ics.swb_sizes[g],
                                                   sce->sf_idx[w*16+g],
                                                   cb,
                                                   1.0f,
                                                   INFINITY,
                                                   &b);
                        bits += b;
                    }
                    dists[w*16+g] = dist - bits;
                    if (prev != -1) {
                        bits += ff_aac_scalefactor_bits[sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO];
                    }
                    tbits += bits;
                    start += sce->ics.swb_sizes[g];
                    prev = sce->sf_idx[w*16+g];
                }
            }
            if (tbits > destbits) {
                for (i = 0; i < 128; i++)
                    if (sce->sf_idx[i] < 218 - qstep)
                        sce->sf_idx[i] += qstep;
            } else {
                for (i = 0; i < 128; i++)
                    if (sce->sf_idx[i] > 60 - qstep)
                        sce->sf_idx[i] -= qstep;
            }
            qstep >>= 1;
            if (!qstep && tbits > destbits*1.02 && sce->sf_idx[0] < 217)
                qstep = 1;
        } while (qstep);

        fflag = 0;
        minscaler = av_clip(minscaler, 60, 255 - SCALE_MAX_DIFF);
        for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
            for (g = 0; g < sce->ics.num_swb; g++) {
                int prevsc = sce->sf_idx[w*16+g];
                if (dists[w*16+g] > uplims[w*16+g] && sce->sf_idx[w*16+g] > 60) {
                    if (find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]-1))
                        sce->sf_idx[w*16+g]--;
                    else //Try to make sure there is some energy in every band
                        sce->sf_idx[w*16+g]-=2;
                }
                sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler, minscaler + SCALE_MAX_DIFF);
                sce->sf_idx[w*16+g] = FFMIN(sce->sf_idx[w*16+g], 219);
                if (sce->sf_idx[w*16+g] != prevsc)
                    fflag = 1;
                sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]);
            }
        }
        its++;
    } while (fflag && its < 10);
}
Beispiel #5
0
static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
                                       SingleChannelElement *sce,
                                       const float lambda)
{
    int q, w, w2, g, start = 0;
    int i, j;
    int idx;
    TrellisPath paths[TRELLIS_STAGES][TRELLIS_STATES];
    int bandaddr[TRELLIS_STAGES];
    int minq;
    float mincost;
    float q0f = FLT_MAX, q1f = 0.0f, qnrgf = 0.0f;
    int q0, q1, qcnt = 0;

    for (i = 0; i < 1024; i++) {
        float t = fabsf(sce->coeffs[i]);
        if (t > 0.0f) {
            q0f = FFMIN(q0f, t);
            q1f = FFMAX(q1f, t);
            qnrgf += t*t;
            qcnt++;
        }
    }

    if (!qcnt) {
        memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
        memset(sce->zeroes, 1, sizeof(sce->zeroes));
        return;
    }

    //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
    q0 = coef2minsf(q0f);
    //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
    q1 = coef2maxsf(q1f);
    //av_log(NULL, AV_LOG_ERROR, "q0 %d, q1 %d\n", q0, q1);
    if (q1 - q0 > 60) {
        int q0low  = q0;
        int q1high = q1;
        //minimum scalefactor index is when maximum nonzero coefficient after quantizing is not clipped
        int qnrg = av_clip_uint8(log2f(sqrtf(qnrgf/qcnt))*4 - 31 + SCALE_ONE_POS - SCALE_DIV_512);
        q1 = qnrg + 30;
        q0 = qnrg - 30;
        //av_log(NULL, AV_LOG_ERROR, "q0 %d, q1 %d\n", q0, q1);
        if (q0 < q0low) {
            q1 += q0low - q0;
            q0  = q0low;
        } else if (q1 > q1high) {
            q0 -= q1 - q1high;
            q1  = q1high;
        }
    }
    //av_log(NULL, AV_LOG_ERROR, "q0 %d, q1 %d\n", q0, q1);

    for (i = 0; i < TRELLIS_STATES; i++) {
        paths[0][i].cost    = 0.0f;
        paths[0][i].prev    = -1;
    }
    for (j = 1; j < TRELLIS_STAGES; j++) {
        for (i = 0; i < TRELLIS_STATES; i++) {
            paths[j][i].cost    = INFINITY;
            paths[j][i].prev    = -2;
        }
    }
    idx = 1;
    abs_pow34_v(s->scoefs, sce->coeffs, 1024);
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = w*128;
        for (g = 0; g < sce->ics.num_swb; g++) {
            const float *coefs = sce->coeffs + start;
            float qmin, qmax;
            int nz = 0;

            bandaddr[idx] = w * 16 + g;
            qmin = INT_MAX;
            qmax = 0.0f;
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                if (band->energy <= band->threshold || band->threshold == 0.0f) {
                    sce->zeroes[(w+w2)*16+g] = 1;
                    continue;
                }
                sce->zeroes[(w+w2)*16+g] = 0;
                nz = 1;
                for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
                    float t = fabsf(coefs[w2*128+i]);
                    if (t > 0.0f)
                        qmin = FFMIN(qmin, t);
                    qmax = FFMAX(qmax, t);
                }
            }
            if (nz) {
                int minscale, maxscale;
                float minrd = INFINITY;
                float maxval;
                //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
                minscale = coef2minsf(qmin);
                //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
                maxscale = coef2maxsf(qmax);
                minscale = av_clip(minscale - q0, 0, TRELLIS_STATES - 1);
                maxscale = av_clip(maxscale - q0, 0, TRELLIS_STATES);
                maxval = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], s->scoefs+start);
                for (q = minscale; q < maxscale; q++) {
                    float dist = 0;
                    int cb = find_min_book(maxval, sce->sf_idx[w*16+g]);
                    for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                        FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                        dist += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
                                                   q + q0, cb, lambda / band->threshold, INFINITY, NULL);
                    }
                    minrd = FFMIN(minrd, dist);

                    for (i = 0; i < q1 - q0; i++) {
                        float cost;
                        cost = paths[idx - 1][i].cost + dist
                               + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO];
                        if (cost < paths[idx][q].cost) {
                            paths[idx][q].cost    = cost;
                            paths[idx][q].prev    = i;
                        }
                    }
                }
            } else {
                for (q = 0; q < q1 - q0; q++) {
                    paths[idx][q].cost = paths[idx - 1][q].cost + 1;
                    paths[idx][q].prev = q;
                }
            }
            sce->zeroes[w*16+g] = !nz;
            start += sce->ics.swb_sizes[g];
            idx++;
        }
    }
    idx--;
    mincost = paths[idx][0].cost;
    minq    = 0;
    for (i = 1; i < TRELLIS_STATES; i++) {
        if (paths[idx][i].cost < mincost) {
            mincost = paths[idx][i].cost;
            minq = i;
        }
    }
    while (idx) {
        sce->sf_idx[bandaddr[idx]] = minq + q0;
        minq = paths[idx][minq].prev;
        idx--;
    }
    //set the same quantizers inside window groups
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
        for (g = 0;  g < sce->ics.num_swb; g++)
            for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
                sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
}
Beispiel #6
0
static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce,
                                  int win, int group_len, const float lambda)
{
    BandCodingPath path[120][12];
    int w, swb, cb, start, size;
    int i, j;
    const int max_sfb  = sce->ics.max_sfb;
    const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
    const int run_esc  = (1 << run_bits) - 1;
    int idx, ppos, count;
    int stackrun[120], stackcb[120], stack_len;
    float next_minrd = INFINITY;
    int next_mincb = 0;

    abs_pow34_v(s->scoefs, sce->coeffs, 1024);
    start = win*128;
    for (cb = 0; cb < 12; cb++) {
        path[0][cb].cost     = run_bits+4;
        path[0][cb].prev_idx = -1;
        path[0][cb].run      = 0;
    }
    for (swb = 0; swb < max_sfb; swb++) {
        size = sce->ics.swb_sizes[swb];
        if (sce->zeroes[win*16 + swb]) {
            float cost_stay_here = path[swb][0].cost;
            float cost_get_here  = next_minrd + run_bits + 4;
            if (   run_value_bits[sce->ics.num_windows == 8][path[swb][0].run]
                != run_value_bits[sce->ics.num_windows == 8][path[swb][0].run+1])
                cost_stay_here += run_bits;
            if (cost_get_here < cost_stay_here) {
                path[swb+1][0].prev_idx = next_mincb;
                path[swb+1][0].cost     = cost_get_here;
                path[swb+1][0].run      = 1;
            } else {
                path[swb+1][0].prev_idx = 0;
                path[swb+1][0].cost     = cost_stay_here;
                path[swb+1][0].run      = path[swb][0].run + 1;
            }
            next_minrd = path[swb+1][0].cost;
            next_mincb = 0;
            for (cb = 1; cb < 12; cb++) {
                path[swb+1][cb].cost = 61450;
                path[swb+1][cb].prev_idx = -1;
                path[swb+1][cb].run = 0;
            }
        } else {
            float minrd = next_minrd;
            int mincb = next_mincb;
            int startcb = sce->band_type[win*16+swb];
            next_minrd = INFINITY;
            next_mincb = 0;
            for (cb = 0; cb < startcb; cb++) {
                path[swb+1][cb].cost = 61450;
                path[swb+1][cb].prev_idx = -1;
                path[swb+1][cb].run = 0;
            }
            for (cb = startcb; cb < 12; cb++) {
                float cost_stay_here, cost_get_here;
                float rd = 0.0f;
                for (w = 0; w < group_len; w++) {
                    rd += quantize_band_cost(s, sce->coeffs + start + w*128,
                                             s->scoefs + start + w*128, size,
                                             sce->sf_idx[(win+w)*16+swb], cb,
                                             0, INFINITY, NULL);
                }
                cost_stay_here = path[swb][cb].cost + rd;
                cost_get_here  = minrd              + rd + run_bits + 4;
                if (   run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
                    != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
                    cost_stay_here += run_bits;
                if (cost_get_here < cost_stay_here) {
                    path[swb+1][cb].prev_idx = mincb;
                    path[swb+1][cb].cost     = cost_get_here;
                    path[swb+1][cb].run      = 1;
                } else {
                    path[swb+1][cb].prev_idx = cb;
                    path[swb+1][cb].cost     = cost_stay_here;
                    path[swb+1][cb].run      = path[swb][cb].run + 1;
                }
                if (path[swb+1][cb].cost < next_minrd) {
                    next_minrd = path[swb+1][cb].cost;
                    next_mincb = cb;
                }
            }
        }
        start += sce->ics.swb_sizes[swb];
    }

    //convert resulting path from backward-linked list
    stack_len = 0;
    idx       = 0;
    for (cb = 1; cb < 12; cb++)
        if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
            idx = cb;
    ppos = max_sfb;
    while (ppos > 0) {
        assert(idx >= 0);
        cb = idx;
        stackrun[stack_len] = path[ppos][cb].run;
        stackcb [stack_len] = cb;
        idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
        ppos -= path[ppos][cb].run;
        stack_len++;
    }
    //perform actual band info encoding
    start = 0;
    for (i = stack_len - 1; i >= 0; i--) {
        put_bits(&s->pb, 4, stackcb[i]);
        count = stackrun[i];
        memset(sce->zeroes + win*16 + start, !stackcb[i], count);
        //XXX: memset when band_type is also uint8_t
        for (j = 0; j < count; j++) {
            sce->band_type[win*16 + start] =  stackcb[i];
            start++;
        }
        while (count >= run_esc) {
            put_bits(&s->pb, run_bits, run_esc);
            count -= run_esc;
        }
        put_bits(&s->pb, run_bits, count);
    }
}
Beispiel #7
0
/**
 * Encode band info for single window group bands.
 */
static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce,
                                     int win, int group_len, const float lambda)
{
    BandCodingPath path[120][CB_TOT_ALL];
    int w, swb, cb, start, size;
    int i, j;
    const int max_sfb  = sce->ics.max_sfb;
    const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
    const int run_esc  = (1 << run_bits) - 1;
    int idx, ppos, count;
    int stackrun[120], stackcb[120], stack_len;
    float next_minrd = INFINITY;
    int next_mincb = 0;

    abs_pow34_v(s->scoefs, sce->coeffs, 1024);
    start = win*128;
    for (cb = 0; cb < CB_TOT_ALL; cb++) {
        path[0][cb].cost     = 0.0f;
        path[0][cb].prev_idx = -1;
        path[0][cb].run      = 0;
    }
    for (swb = 0; swb < max_sfb; swb++) {
        size = sce->ics.swb_sizes[swb];
        if (sce->zeroes[win*16 + swb]) {
            for (cb = 0; cb < CB_TOT_ALL; cb++) {
                path[swb+1][cb].prev_idx = cb;
                path[swb+1][cb].cost     = path[swb][cb].cost;
                path[swb+1][cb].run      = path[swb][cb].run + 1;
            }
        } else {
            float minrd = next_minrd;
            int mincb = next_mincb;
            next_minrd = INFINITY;
            next_mincb = 0;
            for (cb = 0; cb < CB_TOT_ALL; cb++) {
                float cost_stay_here, cost_get_here;
                float rd = 0.0f;
                if (cb >= 12 && sce->band_type[win*16+swb] < aac_cb_out_map[cb] ||
                    cb  < aac_cb_in_map[sce->band_type[win*16+swb]] && sce->band_type[win*16+swb] > aac_cb_out_map[cb]) {
                    path[swb+1][cb].prev_idx = -1;
                    path[swb+1][cb].cost     = INFINITY;
                    path[swb+1][cb].run      = path[swb][cb].run + 1;
                    continue;
                }
                for (w = 0; w < group_len; w++) {
                    FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(win+w)*16+swb];
                    rd += quantize_band_cost(s, &sce->coeffs[start + w*128],
                                             &s->scoefs[start + w*128], size,
                                             sce->sf_idx[(win+w)*16+swb], aac_cb_out_map[cb],
                                             lambda / band->threshold, INFINITY, NULL, NULL, 0);
                }
                cost_stay_here = path[swb][cb].cost + rd;
                cost_get_here  = minrd              + rd + run_bits + 4;
                if (   run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
                    != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
                    cost_stay_here += run_bits;
                if (cost_get_here < cost_stay_here) {
                    path[swb+1][cb].prev_idx = mincb;
                    path[swb+1][cb].cost     = cost_get_here;
                    path[swb+1][cb].run      = 1;
                } else {
                    path[swb+1][cb].prev_idx = cb;
                    path[swb+1][cb].cost     = cost_stay_here;
                    path[swb+1][cb].run      = path[swb][cb].run + 1;
                }
                if (path[swb+1][cb].cost < next_minrd) {
                    next_minrd = path[swb+1][cb].cost;
                    next_mincb = cb;
                }
            }
        }
        start += sce->ics.swb_sizes[swb];
    }

    //convert resulting path from backward-linked list
    stack_len = 0;
    idx       = 0;
    for (cb = 1; cb < CB_TOT_ALL; cb++)
        if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
            idx = cb;
    ppos = max_sfb;
    while (ppos > 0) {
        av_assert1(idx >= 0);
        cb = idx;
        stackrun[stack_len] = path[ppos][cb].run;
        stackcb [stack_len] = cb;
        idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
        ppos -= path[ppos][cb].run;
        stack_len++;
    }
    //perform actual band info encoding
    start = 0;
    for (i = stack_len - 1; i >= 0; i--) {
        cb = aac_cb_out_map[stackcb[i]];
        put_bits(&s->pb, 4, cb);
        count = stackrun[i];
        memset(sce->zeroes + win*16 + start, !cb, count);
        //XXX: memset when band_type is also uint8_t
        for (j = 0; j < count; j++) {
            sce->band_type[win*16 + start] = cb;
            start++;
        }
        while (count >= run_esc) {
            put_bits(&s->pb, run_bits, run_esc);
            count -= run_esc;
        }
        put_bits(&s->pb, run_bits, count);
    }
}
Beispiel #8
0
static void search_for_ms(AACEncContext *s, ChannelElement *cpe)
{
    int start = 0, i, w, w2, g, sid_sf_boost, prev_mid, prev_side;
    uint8_t nextband0[128], nextband1[128];
    float M[128], S[128];
    float *L34 = s->scoefs, *R34 = s->scoefs + 128, *M34 = s->scoefs + 128*2, *S34 = s->scoefs + 128*3;
    const float lambda = s->lambda;
    const float mslambda = FFMIN(1.0f, lambda / 120.f);
    SingleChannelElement *sce0 = &cpe->ch[0];
    SingleChannelElement *sce1 = &cpe->ch[1];
    if (!cpe->common_window)
        return;

    /** Scout out next nonzero bands */
    ff_init_nextband_map(sce0, nextband0);
    ff_init_nextband_map(sce1, nextband1);

    prev_mid = sce0->sf_idx[0];
    prev_side = sce1->sf_idx[0];
    for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
        start = 0;
        for (g = 0; g < sce0->ics.num_swb; g++) {
            float bmax = bval2bmax(g * 17.0f / sce0->ics.num_swb) / 0.0045f;
            if (!cpe->is_mask[w*16+g])
                cpe->ms_mask[w*16+g] = 0;
            if (!sce0->zeroes[w*16+g] && !sce1->zeroes[w*16+g] && !cpe->is_mask[w*16+g]) {
                float Mmax = 0.0f, Smax = 0.0f;

                /* Must compute mid/side SF and book for the whole window group */
                for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
                    for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
                        M[i] = (sce0->coeffs[start+(w+w2)*128+i]
                              + sce1->coeffs[start+(w+w2)*128+i]) * 0.5;
                        S[i] =  M[i]
                              - sce1->coeffs[start+(w+w2)*128+i];
                    }
                    abs_pow34_v(M34, M, sce0->ics.swb_sizes[g]);
                    abs_pow34_v(S34, S, sce0->ics.swb_sizes[g]);
                    for (i = 0; i < sce0->ics.swb_sizes[g]; i++ ) {
                        Mmax = FFMAX(Mmax, M34[i]);
                        Smax = FFMAX(Smax, S34[i]);
                    }
                }

                for (sid_sf_boost = 0; sid_sf_boost < 4; sid_sf_boost++) {
                    float dist1 = 0.0f, dist2 = 0.0f;
                    int B0 = 0, B1 = 0;
                    int minidx;
                    int mididx, sididx;
                    int midcb, sidcb;

                    minidx = FFMIN(sce0->sf_idx[w*16+g], sce1->sf_idx[w*16+g]);
                    mididx = av_clip(minidx, 0, SCALE_MAX_POS - SCALE_DIV_512);
                    sididx = av_clip(minidx - sid_sf_boost * 3, 0, SCALE_MAX_POS - SCALE_DIV_512);
                    if (sce0->band_type[w*16+g] != NOISE_BT && sce1->band_type[w*16+g] != NOISE_BT
                        && (   !ff_sfdelta_can_replace(sce0, nextband0, prev_mid, mididx, w*16+g)
                            || !ff_sfdelta_can_replace(sce1, nextband1, prev_side, sididx, w*16+g))) {
                        /* scalefactor range violation, bad stuff, will decrease quality unacceptably */
                        continue;
                    }

                    midcb = find_min_book(Mmax, mididx);
                    sidcb = find_min_book(Smax, sididx);

                    /* No CB can be zero */
                    midcb = FFMAX(1,midcb);
                    sidcb = FFMAX(1,sidcb);

                    for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
                        FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
                        FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
                        float minthr = FFMIN(band0->threshold, band1->threshold);
                        int b1,b2,b3,b4;
                        for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
                            M[i] = (sce0->coeffs[start+(w+w2)*128+i]
                                  + sce1->coeffs[start+(w+w2)*128+i]) * 0.5;
                            S[i] =  M[i]
                                  - sce1->coeffs[start+(w+w2)*128+i];
                        }

                        abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
                        abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
                        abs_pow34_v(M34, M,                         sce0->ics.swb_sizes[g]);
                        abs_pow34_v(S34, S,                         sce0->ics.swb_sizes[g]);
                        dist1 += quantize_band_cost(s, &sce0->coeffs[start + (w+w2)*128],
                                                    L34,
                                                    sce0->ics.swb_sizes[g],
                                                    sce0->sf_idx[w*16+g],
                                                    sce0->band_type[w*16+g],
                                                    lambda / band0->threshold, INFINITY, &b1, NULL, 0);
                        dist1 += quantize_band_cost(s, &sce1->coeffs[start + (w+w2)*128],
                                                    R34,
                                                    sce1->ics.swb_sizes[g],
                                                    sce1->sf_idx[w*16+g],
                                                    sce1->band_type[w*16+g],
                                                    lambda / band1->threshold, INFINITY, &b2, NULL, 0);
                        dist2 += quantize_band_cost(s, M,
                                                    M34,
                                                    sce0->ics.swb_sizes[g],
                                                    mididx,
                                                    midcb,
                                                    lambda / minthr, INFINITY, &b3, NULL, 0);
                        dist2 += quantize_band_cost(s, S,
                                                    S34,
                                                    sce1->ics.swb_sizes[g],
                                                    sididx,
                                                    sidcb,
                                                    mslambda / (minthr * bmax), INFINITY, &b4, NULL, 0);
                        B0 += b1+b2;
                        B1 += b3+b4;
                        dist1 -= b1+b2;
                        dist2 -= b3+b4;
                    }
                    cpe->ms_mask[w*16+g] = dist2 <= dist1 && B1 < B0;
                    if (cpe->ms_mask[w*16+g]) {
                        if (sce0->band_type[w*16+g] != NOISE_BT && sce1->band_type[w*16+g] != NOISE_BT) {
                            sce0->sf_idx[w*16+g] = mididx;
                            sce1->sf_idx[w*16+g] = sididx;
                            sce0->band_type[w*16+g] = midcb;
                            sce1->band_type[w*16+g] = sidcb;
                        } else if ((sce0->band_type[w*16+g] != NOISE_BT) ^ (sce1->band_type[w*16+g] != NOISE_BT)) {
                            /* ms_mask unneeded, and it confuses some decoders */
                            cpe->ms_mask[w*16+g] = 0;
                        }
                        break;
                    } else if (B1 > B0) {
                        /* More boost won't fix this */
                        break;
                    }
                }
            }
            if (!sce0->zeroes[w*16+g] && sce0->band_type[w*16+g] < RESERVED_BT)
                prev_mid = sce0->sf_idx[w*16+g];
            if (!sce1->zeroes[w*16+g] && !cpe->is_mask[w*16+g] && sce1->band_type[w*16+g] < RESERVED_BT)
                prev_side = sce1->sf_idx[w*16+g];
            start += sce0->ics.swb_sizes[g];
        }
    }
}
Beispiel #9
0
static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
{
    FFPsyBand *band;
    int w, g, w2, i;
    int wlen = 1024 / sce->ics.num_windows;
    int bandwidth, cutoff;
    float *PNS = &s->scoefs[0*128], *PNS34 = &s->scoefs[1*128];
    float *NOR34 = &s->scoefs[3*128];
    uint8_t nextband[128];
    const float lambda = s->lambda;
    const float freq_mult = avctx->sample_rate*0.5f/wlen;
    const float thr_mult = NOISE_LAMBDA_REPLACE*(100.0f/lambda);
    const float spread_threshold = FFMIN(0.75f, NOISE_SPREAD_THRESHOLD*FFMAX(0.5f, lambda/100.f));
    const float dist_bias = av_clipf(4.f * 120 / lambda, 0.25f, 4.0f);
    const float pns_transient_energy_r = FFMIN(0.7f, lambda / 140.f);

    int refbits = avctx->bit_rate * 1024.0 / avctx->sample_rate
        / ((avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : avctx->channels)
        * (lambda / 120.f);

    /** Keep this in sync with twoloop's cutoff selection */
    float rate_bandwidth_multiplier = 1.5f;
    int prev = -1000, prev_sf = -1;
    int frame_bit_rate = (avctx->flags & CODEC_FLAG_QSCALE)
        ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024)
        : (avctx->bit_rate / avctx->channels);

    frame_bit_rate *= 1.15f;

    if (avctx->cutoff > 0) {
        bandwidth = avctx->cutoff;
    } else {
        bandwidth = FFMAX(3000, AAC_CUTOFF_FROM_BITRATE(frame_bit_rate, 1, avctx->sample_rate));
    }

    cutoff = bandwidth * 2 * wlen / avctx->sample_rate;

    memcpy(sce->band_alt, sce->band_type, sizeof(sce->band_type));
    ff_init_nextband_map(sce, nextband);
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        int wstart = w*128;
        for (g = 0; g < sce->ics.num_swb; g++) {
            int noise_sfi;
            float dist1 = 0.0f, dist2 = 0.0f, noise_amp;
            float pns_energy = 0.0f, pns_tgt_energy, energy_ratio, dist_thresh;
            float sfb_energy = 0.0f, threshold = 0.0f, spread = 2.0f;
            float min_energy = -1.0f, max_energy = 0.0f;
            const int start = wstart+sce->ics.swb_offset[g];
            const float freq = (start-wstart)*freq_mult;
            const float freq_boost = FFMAX(0.88f*freq/NOISE_LOW_LIMIT, 1.0f);
            if (freq < NOISE_LOW_LIMIT || (start-wstart) >= cutoff) {
                if (!sce->zeroes[w*16+g])
                    prev_sf = sce->sf_idx[w*16+g];
                continue;
            }
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                sfb_energy += band->energy;
                spread     = FFMIN(spread, band->spread);
                threshold  += band->threshold;
                if (!w2) {
                    min_energy = max_energy = band->energy;
                } else {
                    min_energy = FFMIN(min_energy, band->energy);
                    max_energy = FFMAX(max_energy, band->energy);
                }
            }

            /* Ramps down at ~8000Hz and loosens the dist threshold */
            dist_thresh = av_clipf(2.5f*NOISE_LOW_LIMIT/freq, 0.5f, 2.5f) * dist_bias;

            /* PNS is acceptable when all of these are true:
             * 1. high spread energy (noise-like band)
             * 2. near-threshold energy (high PE means the random nature of PNS content will be noticed)
             * 3. on short window groups, all windows have similar energy (variations in energy would be destroyed by PNS)
             *
             * At this stage, point 2 is relaxed for zeroed bands near the noise threshold (hole avoidance is more important)
             */
            if ((!sce->zeroes[w*16+g] && !ff_sfdelta_can_remove_band(sce, nextband, prev_sf, w*16+g)) ||
                ((sce->zeroes[w*16+g] || !sce->band_alt[w*16+g]) && sfb_energy < threshold*sqrtf(1.0f/freq_boost)) || spread < spread_threshold ||
                (!sce->zeroes[w*16+g] && sce->band_alt[w*16+g] && sfb_energy > threshold*thr_mult*freq_boost) ||
                min_energy < pns_transient_energy_r * max_energy ) {
                sce->pns_ener[w*16+g] = sfb_energy;
                if (!sce->zeroes[w*16+g])
                    prev_sf = sce->sf_idx[w*16+g];
                continue;
            }

            pns_tgt_energy = sfb_energy*FFMIN(1.0f, spread*spread);
            noise_sfi = av_clip(roundf(log2f(pns_tgt_energy)*2), -100, 155); /* Quantize */
            noise_amp = -ff_aac_pow2sf_tab[noise_sfi + POW_SF2_ZERO];    /* Dequantize */
            if (prev != -1000) {
                int noise_sfdiff = noise_sfi - prev + SCALE_DIFF_ZERO;
                if (noise_sfdiff < 0 || noise_sfdiff > 2*SCALE_MAX_DIFF) {
                    if (!sce->zeroes[w*16+g])
                        prev_sf = sce->sf_idx[w*16+g];
                    continue;
                }
            }
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                float band_energy, scale, pns_senergy;
                const int start_c = (w+w2)*128+sce->ics.swb_offset[g];
                band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                for (i = 0; i < sce->ics.swb_sizes[g]; i+=2) {
                    double rnd[2];
                    av_bmg_get(&s->lfg, rnd);
                    PNS[i+0] = (float)rnd[0];
                    PNS[i+1] = (float)rnd[1];
                }
                band_energy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
                scale = noise_amp/sqrtf(band_energy);
                s->fdsp->vector_fmul_scalar(PNS, PNS, scale, sce->ics.swb_sizes[g]);
                pns_senergy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
                pns_energy += pns_senergy;
                abs_pow34_v(NOR34, &sce->coeffs[start_c], sce->ics.swb_sizes[g]);
                abs_pow34_v(PNS34, PNS, sce->ics.swb_sizes[g]);
                dist1 += quantize_band_cost(s, &sce->coeffs[start_c],
                                            NOR34,
                                            sce->ics.swb_sizes[g],
                                            sce->sf_idx[(w+w2)*16+g],
                                            sce->band_alt[(w+w2)*16+g],
                                            lambda/band->threshold, INFINITY, NULL, NULL, 0);
                /* Estimate rd on average as 5 bits for SF, 4 for the CB, plus spread energy * lambda/thr */
                dist2 += band->energy/(band->spread*band->spread)*lambda*dist_thresh/band->threshold;
            }
            if (g && sce->band_type[w*16+g-1] == NOISE_BT) {
                dist2 += 5;
            } else {
                dist2 += 9;
            }
            energy_ratio = pns_tgt_energy/pns_energy; /* Compensates for quantization error */
            sce->pns_ener[w*16+g] = energy_ratio*pns_tgt_energy;
            if (sce->zeroes[w*16+g] || !sce->band_alt[w*16+g] || (energy_ratio > 0.85f && energy_ratio < 1.25f && dist2 < dist1)) {
                sce->band_type[w*16+g] = NOISE_BT;
                sce->zeroes[w*16+g] = 0;
                prev = noise_sfi;
            } else {
                if (!sce->zeroes[w*16+g])
                    prev_sf = sce->sf_idx[w*16+g];
            }
        }
    }
}
Beispiel #10
0
static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
                                       SingleChannelElement *sce,
                                       const float lambda)
{
    int q, w, w2, g, start = 0;
    int i, j;
    int idx;
    TrellisPath paths[TRELLIS_STAGES][TRELLIS_STATES];
    int bandaddr[TRELLIS_STAGES];
    int minq;
    float mincost;

    for (i = 0; i < TRELLIS_STATES; i++) {
        paths[0][i].cost    = 0.0f;
        paths[0][i].prev    = -1;
        paths[0][i].min_val = i;
        paths[0][i].max_val = i;
    }
    for (j = 1; j < TRELLIS_STAGES; j++) {
        for (i = 0; i < TRELLIS_STATES; i++) {
            paths[j][i].cost    = INFINITY;
            paths[j][i].prev    = -2;
            paths[j][i].min_val = INT_MAX;
            paths[j][i].max_val = 0;
        }
    }
    idx = 1;
    abs_pow34_v(s->scoefs, sce->coeffs, 1024);
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = w*128;
        for (g = 0; g < sce->ics.num_swb; g++) {
            const float *coefs = sce->coeffs + start;
            float qmin, qmax;
            int nz = 0;

            bandaddr[idx] = w * 16 + g;
            qmin = INT_MAX;
            qmax = 0.0f;
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                FFPsyBand *band = &s->psy.psy_bands[s->cur_channel*PSY_MAX_BANDS+(w+w2)*16+g];
                if (band->energy <= band->threshold || band->threshold == 0.0f) {
                    sce->zeroes[(w+w2)*16+g] = 1;
                    continue;
                }
                sce->zeroes[(w+w2)*16+g] = 0;
                nz = 1;
                for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
                    float t = fabsf(coefs[w2*128+i]);
                    if (t > 0.0f)
                        qmin = FFMIN(qmin, t);
                    qmax = FFMAX(qmax, t);
                }
            }
            if (nz) {
                int minscale, maxscale;
                float minrd = INFINITY;
                //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
                minscale = av_clip_uint8(log2(qmin)*4 - 69 + SCALE_ONE_POS - SCALE_DIV_512);
                //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
                maxscale = av_clip_uint8(log2(qmax)*4 +  6 + SCALE_ONE_POS - SCALE_DIV_512);
                for (q = minscale; q < maxscale; q++) {
                    float dists[12], dist;
                    memset(dists, 0, sizeof(dists));
                    for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                        FFPsyBand *band = &s->psy.psy_bands[s->cur_channel*PSY_MAX_BANDS+(w+w2)*16+g];
                        int cb;
                        for (cb = 0; cb <= ESC_BT; cb++)
                            dists[cb] += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
                                                            q, cb, lambda / band->threshold, INFINITY, NULL);
                    }
                    dist = dists[0];
                    for (i = 1; i <= ESC_BT; i++)
                        dist = FFMIN(dist, dists[i]);
                    minrd = FFMIN(minrd, dist);

                    for (i = FFMAX(q - SCALE_MAX_DIFF, 0); i < FFMIN(q + SCALE_MAX_DIFF, TRELLIS_STATES); i++) {
                        float cost;
                        int minv, maxv;
                        if (isinf(paths[idx - 1][i].cost))
                            continue;
                        cost = paths[idx - 1][i].cost + dist
                               + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO];
                        minv = FFMIN(paths[idx - 1][i].min_val, q);
                        maxv = FFMAX(paths[idx - 1][i].max_val, q);
                        if (cost < paths[idx][q].cost && maxv-minv < SCALE_MAX_DIFF) {
                            paths[idx][q].cost    = cost;
                            paths[idx][q].prev    = i;
                            paths[idx][q].min_val = minv;
                            paths[idx][q].max_val = maxv;
                        }
                    }
                }
            } else {
                for (q = 0; q < TRELLIS_STATES; q++) {
                    if (!isinf(paths[idx - 1][q].cost)) {
                        paths[idx][q].cost = paths[idx - 1][q].cost + 1;
                        paths[idx][q].prev = q;
                        paths[idx][q].min_val = FFMIN(paths[idx - 1][q].min_val, q);
                        paths[idx][q].max_val = FFMAX(paths[idx - 1][q].max_val, q);
                        continue;
                    }
                    for (i = FFMAX(q - SCALE_MAX_DIFF, 0); i < FFMIN(q + SCALE_MAX_DIFF, TRELLIS_STATES); i++) {
                        float cost;
                        int minv, maxv;
                        if (isinf(paths[idx - 1][i].cost))
                            continue;
                        cost = paths[idx - 1][i].cost + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO];
                        minv = FFMIN(paths[idx - 1][i].min_val, q);
                        maxv = FFMAX(paths[idx - 1][i].max_val, q);
                        if (cost < paths[idx][q].cost && maxv-minv < SCALE_MAX_DIFF) {
                            paths[idx][q].cost    = cost;
                            paths[idx][q].prev    = i;
                            paths[idx][q].min_val = minv;
                            paths[idx][q].max_val = maxv;
                        }
                    }
                }
            }
            sce->zeroes[w*16+g] = !nz;
            start += sce->ics.swb_sizes[g];
            idx++;
        }
    }
    idx--;
    mincost = paths[idx][0].cost;
    minq    = 0;
    for (i = 1; i < TRELLIS_STATES; i++) {
        if (paths[idx][i].cost < mincost) {
            mincost = paths[idx][i].cost;
            minq = i;
        }
    }
    while (idx) {
        sce->sf_idx[bandaddr[idx]] = minq;
        minq = paths[idx][minq].prev;
        idx--;
    }
    //set the same quantizers inside window groups
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
        for (g = 0;  g < sce->ics.num_swb; g++)
            for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
                sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
}
Beispiel #11
0
/**
 * Calculate rate distortion cost for quantizing with given codebook
 *
 * @return quantization distortion
 */
static float quantize_band_cost(struct AACEncContext *s, const float *in,
                                const float *scaled, int size, int scale_idx,
                                int cb, const float lambda, const float uplim,
                                int *bits)
{
    const float IQ = ff_aac_pow2sf_tab[200 + scale_idx - SCALE_ONE_POS + SCALE_DIV_512];
    const float  Q = ff_aac_pow2sf_tab[200 - scale_idx + SCALE_ONE_POS - SCALE_DIV_512];
    const float CLIPPED_ESCAPE = 165140.0f*IQ;
    int i, j, k;
    float cost = 0;
    const int dim = cb < FIRST_PAIR_BT ? 4 : 2;
    int resbits = 0;
#ifndef USE_REALLY_FULL_SEARCH
    const float  Q34 = sqrtf(Q * sqrtf(Q));
    const int range  = aac_cb_range[cb];
    const int maxval = aac_cb_maxval[cb];
    int offs[4];
#endif /* USE_REALLY_FULL_SEARCH */

    if (!cb) {
        for (i = 0; i < size; i++)
            cost += in[i]*in[i];
        if (bits)
            *bits = 0;
        return cost * lambda;
    }
#ifndef USE_REALLY_FULL_SEARCH
    offs[0] = 1;
    for (i = 1; i < dim; i++)
        offs[i] = offs[i-1]*range;
    quantize_bands(s->qcoefs, in, scaled, size, Q34, !IS_CODEBOOK_UNSIGNED(cb), maxval);
#endif /* USE_REALLY_FULL_SEARCH */
    for (i = 0; i < size; i += dim) {
        float mincost;
        int minidx  = 0;
        int minbits = 0;
        const float *vec;
#ifndef USE_REALLY_FULL_SEARCH
        int (*quants)[2] = &s->qcoefs[i];
        mincost = 0.0f;
        for (j = 0; j < dim; j++)
            mincost += in[i+j]*in[i+j];
        minidx = IS_CODEBOOK_UNSIGNED(cb) ? 0 : 40;
        minbits = ff_aac_spectral_bits[cb-1][minidx];
        mincost = mincost * lambda + minbits;
        for (j = 0; j < (1<<dim); j++) {
            float rd = 0.0f;
            int curbits;
            int curidx = IS_CODEBOOK_UNSIGNED(cb) ? 0 : 40;
            int same   = 0;
            for (k = 0; k < dim; k++) {
                if ((j & (1 << k)) && quants[k][0] == quants[k][1]) {
                    same = 1;
                    break;
                }
            }
            if (same)
                continue;
            for (k = 0; k < dim; k++)
                curidx += quants[k][!!(j & (1 << k))] * offs[dim - 1 - k];
            curbits =  ff_aac_spectral_bits[cb-1][curidx];
            vec     = &ff_aac_codebook_vectors[cb-1][curidx*dim];
#else
        mincost = INFINITY;
        vec = ff_aac_codebook_vectors[cb-1];
        for (j = 0; j < ff_aac_spectral_sizes[cb-1]; j++, vec += dim) {
            float rd = 0.0f;
            int curbits = ff_aac_spectral_bits[cb-1][j];
#endif /* USE_REALLY_FULL_SEARCH */
            if (IS_CODEBOOK_UNSIGNED(cb)) {
                for (k = 0; k < dim; k++) {
                    float t = fabsf(in[i+k]);
                    float di;
                    if (vec[k] == 64.0f) { //FIXME: slow
                        //do not code with escape sequence small values
                        if (t < 39.0f*IQ) {
                            rd = INFINITY;
                            break;
                        }
                        if (t >= CLIPPED_ESCAPE) {
                            di = t - CLIPPED_ESCAPE;
                            curbits += 21;
                        } else {
                            int c = av_clip(quant(t, Q), 0, 8191);
                            di = t - c*cbrtf(c)*IQ;
                            curbits += av_log2(c)*2 - 4 + 1;
                        }
                    } else {
                        di = t - vec[k]*IQ;
                    }
                    if (vec[k] != 0.0f)
                        curbits++;
                    rd += di*di;
                }
            } else {
                for (k = 0; k < dim; k++) {
                    float di = in[i+k] - vec[k]*IQ;
                    rd += di*di;
                }
            }
            rd = rd * lambda + curbits;
            if (rd < mincost) {
                mincost = rd;
                minidx  = j;
                minbits = curbits;
            }
        }
        cost    += mincost;
        resbits += minbits;
        if (cost >= uplim)
            return uplim;
    }

    if (bits)
        *bits = resbits;
    return cost;
}

static void quantize_and_encode_band(struct AACEncContext *s, PutBitContext *pb,
                                     const float *in, int size, int scale_idx,
                                     int cb, const float lambda)
{
    const float IQ = ff_aac_pow2sf_tab[200 + scale_idx - SCALE_ONE_POS + SCALE_DIV_512];
    const float  Q = ff_aac_pow2sf_tab[200 - scale_idx + SCALE_ONE_POS - SCALE_DIV_512];
    const float CLIPPED_ESCAPE = 165140.0f*IQ;
    const int dim = (cb < FIRST_PAIR_BT) ? 4 : 2;
    int i, j, k;
#ifndef USE_REALLY_FULL_SEARCH
    const float  Q34 = sqrtf(Q * sqrtf(Q));
    const int range  = aac_cb_range[cb];
    const int maxval = aac_cb_maxval[cb];
    int offs[4];
    float *scaled = s->scoefs;
#endif /* USE_REALLY_FULL_SEARCH */

//START_TIMER
    if (!cb)
        return;

#ifndef USE_REALLY_FULL_SEARCH
    offs[0] = 1;
    for (i = 1; i < dim; i++)
        offs[i] = offs[i-1]*range;
    abs_pow34_v(scaled, in, size);
    quantize_bands(s->qcoefs, in, scaled, size, Q34, !IS_CODEBOOK_UNSIGNED(cb), maxval);
#endif /* USE_REALLY_FULL_SEARCH */
    for (i = 0; i < size; i += dim) {
        float mincost;
        int minidx  = 0;
        int minbits = 0;
        const float *vec;
#ifndef USE_REALLY_FULL_SEARCH
        int (*quants)[2] = &s->qcoefs[i];
        mincost = 0.0f;
        for (j = 0; j < dim; j++)
            mincost += in[i+j]*in[i+j];
        minidx = IS_CODEBOOK_UNSIGNED(cb) ? 0 : 40;
        minbits = ff_aac_spectral_bits[cb-1][minidx];
        mincost = mincost * lambda + minbits;
        for (j = 0; j < (1<<dim); j++) {
            float rd = 0.0f;
            int curbits;
            int curidx = IS_CODEBOOK_UNSIGNED(cb) ? 0 : 40;
            int same   = 0;
            for (k = 0; k < dim; k++) {
                if ((j & (1 << k)) && quants[k][0] == quants[k][1]) {
                    same = 1;
                    break;
                }
            }
            if (same)
                continue;
            for (k = 0; k < dim; k++)
                curidx += quants[k][!!(j & (1 << k))] * offs[dim - 1 - k];
            curbits =  ff_aac_spectral_bits[cb-1][curidx];
            vec     = &ff_aac_codebook_vectors[cb-1][curidx*dim];
#else
        vec = ff_aac_codebook_vectors[cb-1];
        mincost = INFINITY;
        for (j = 0; j < ff_aac_spectral_sizes[cb-1]; j++, vec += dim) {
            float rd = 0.0f;
            int curbits = ff_aac_spectral_bits[cb-1][j];
            int curidx  = j;
#endif /* USE_REALLY_FULL_SEARCH */
            if (IS_CODEBOOK_UNSIGNED(cb)) {
                for (k = 0; k < dim; k++) {
                    float t = fabsf(in[i+k]);
                    float di;
                    if (vec[k] == 64.0f) { //FIXME: slow
                        //do not code with escape sequence small values
                        if (t < 39.0f*IQ) {
                            rd = INFINITY;
                            break;
                        }
                        if (t >= CLIPPED_ESCAPE) {
                            di = t - CLIPPED_ESCAPE;
                            curbits += 21;
                        } else {
                            int c = av_clip(quant(t, Q), 0, 8191);
                            di = t - c*cbrtf(c)*IQ;
                            curbits += av_log2(c)*2 - 4 + 1;
                        }
                    } else {
                        di = t - vec[k]*IQ;
                    }
                    if (vec[k] != 0.0f)
                        curbits++;
                    rd += di*di;
                }
            } else {
                for (k = 0; k < dim; k++) {
                    float di = in[i+k] - vec[k]*IQ;
                    rd += di*di;
                }
            }
            rd = rd * lambda + curbits;
            if (rd < mincost) {
                mincost = rd;
                minidx  = curidx;
                minbits = curbits;
            }
        }
        put_bits(pb, ff_aac_spectral_bits[cb-1][minidx], ff_aac_spectral_codes[cb-1][minidx]);
        if (IS_CODEBOOK_UNSIGNED(cb))
            for (j = 0; j < dim; j++)
                if (ff_aac_codebook_vectors[cb-1][minidx*dim+j] != 0.0f)
                    put_bits(pb, 1, in[i+j] < 0.0f);
        if (cb == ESC_BT) {
            for (j = 0; j < 2; j++) {
                if (ff_aac_codebook_vectors[cb-1][minidx*2+j] == 64.0f) {
                    int coef = av_clip(quant(fabsf(in[i+j]), Q), 0, 8191);
                    int len = av_log2(coef);

                    put_bits(pb, len - 4 + 1, (1 << (len - 4 + 1)) - 2);
                    put_bits(pb, len, coef & ((1 << len) - 1));
                }
            }
        }
    }
//STOP_TIMER("quantize_and_encode")
}

/**
 * structure used in optimal codebook search
 */
typedef struct BandCodingPath {
    int prev_idx; ///< pointer to the previous path point
    float cost;   ///< path cost
    int run;
} BandCodingPath;

/**
 * Encode band info for single window group bands.
 */
static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce,
                                     int win, int group_len, const float lambda)
{
    BandCodingPath path[120][12];
    int w, swb, cb, start, start2, size;
    int i, j;
    const int max_sfb  = sce->ics.max_sfb;
    const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
    const int run_esc  = (1 << run_bits) - 1;
    int idx, ppos, count;
    int stackrun[120], stackcb[120], stack_len;
    float next_minrd = INFINITY;
    int next_mincb = 0;

    abs_pow34_v(s->scoefs, sce->coeffs, 1024);
    start = win*128;
    for (cb = 0; cb < 12; cb++) {
        path[0][cb].cost     = 0.0f;
        path[0][cb].prev_idx = -1;
        path[0][cb].run      = 0;
    }
    for (swb = 0; swb < max_sfb; swb++) {
        start2 = start;
        size = sce->ics.swb_sizes[swb];
        if (sce->zeroes[win*16 + swb]) {
            for (cb = 0; cb < 12; cb++) {
                path[swb+1][cb].prev_idx = cb;
                path[swb+1][cb].cost     = path[swb][cb].cost;
                path[swb+1][cb].run      = path[swb][cb].run + 1;
            }
        } else {
            float minrd = next_minrd;
            int mincb = next_mincb;
            next_minrd = INFINITY;
            next_mincb = 0;
            for (cb = 0; cb < 12; cb++) {
                float cost_stay_here, cost_get_here;
                float rd = 0.0f;
                for (w = 0; w < group_len; w++) {
                    FFPsyBand *band = &s->psy.psy_bands[s->cur_channel*PSY_MAX_BANDS+(win+w)*16+swb];
                    rd += quantize_band_cost(s, sce->coeffs + start + w*128,
                                             s->scoefs + start + w*128, size,
                                             sce->sf_idx[(win+w)*16+swb], cb,
                                             lambda / band->threshold, INFINITY, NULL);
                }
                cost_stay_here = path[swb][cb].cost + rd;
                cost_get_here  = minrd              + rd + run_bits + 4;
                if (   run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
                    != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
                    cost_stay_here += run_bits;
                if (cost_get_here < cost_stay_here) {
                    path[swb+1][cb].prev_idx = mincb;
                    path[swb+1][cb].cost     = cost_get_here;
                    path[swb+1][cb].run      = 1;
                } else {
                    path[swb+1][cb].prev_idx = cb;
                    path[swb+1][cb].cost     = cost_stay_here;
                    path[swb+1][cb].run      = path[swb][cb].run + 1;
                }
                if (path[swb+1][cb].cost < next_minrd) {
                    next_minrd = path[swb+1][cb].cost;
                    next_mincb = cb;
                }
            }
        }
        start += sce->ics.swb_sizes[swb];
    }

    //convert resulting path from backward-linked list
    stack_len = 0;
    idx       = 0;
    for (cb = 1; cb < 12; cb++)
        if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
            idx = cb;
    ppos = max_sfb;
    while (ppos > 0) {
        cb = idx;
        stackrun[stack_len] = path[ppos][cb].run;
        stackcb [stack_len] = cb;
        idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
        ppos -= path[ppos][cb].run;
        stack_len++;
    }
    //perform actual band info encoding
    start = 0;
    for (i = stack_len - 1; i >= 0; i--) {
        put_bits(&s->pb, 4, stackcb[i]);
        count = stackrun[i];
        memset(sce->zeroes + win*16 + start, !stackcb[i], count);
        //XXX: memset when band_type is also uint8_t
        for (j = 0; j < count; j++) {
            sce->band_type[win*16 + start] =  stackcb[i];
            start++;
        }
        while (count >= run_esc) {
            put_bits(&s->pb, run_bits, run_esc);
            count -= run_esc;
        }
        put_bits(&s->pb, run_bits, count);
    }
}

typedef struct TrellisPath {
    float cost;
    int prev;
    int min_val;
    int max_val;
} TrellisPath;

#define TRELLIS_STAGES 121
#define TRELLIS_STATES 256

static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
                                       SingleChannelElement *sce,
                                       const float lambda)
{
    int q, w, w2, g, start = 0;
    int i, j;
    int idx;
    TrellisPath paths[TRELLIS_STAGES][TRELLIS_STATES];
    int bandaddr[TRELLIS_STAGES];
    int minq;
    float mincost;

    for (i = 0; i < TRELLIS_STATES; i++) {
        paths[0][i].cost    = 0.0f;
        paths[0][i].prev    = -1;
        paths[0][i].min_val = i;
        paths[0][i].max_val = i;
    }
    for (j = 1; j < TRELLIS_STAGES; j++) {
        for (i = 0; i < TRELLIS_STATES; i++) {
            paths[j][i].cost    = INFINITY;
            paths[j][i].prev    = -2;
            paths[j][i].min_val = INT_MAX;
            paths[j][i].max_val = 0;
        }
    }
    idx = 1;
    abs_pow34_v(s->scoefs, sce->coeffs, 1024);
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = w*128;
        for (g = 0; g < sce->ics.num_swb; g++) {
            const float *coefs = sce->coeffs + start;
            float qmin, qmax;
            int nz = 0;

            bandaddr[idx] = w * 16 + g;
            qmin = INT_MAX;
            qmax = 0.0f;
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                FFPsyBand *band = &s->psy.psy_bands[s->cur_channel*PSY_MAX_BANDS+(w+w2)*16+g];
                if (band->energy <= band->threshold || band->threshold == 0.0f) {
                    sce->zeroes[(w+w2)*16+g] = 1;
                    continue;
                }
                sce->zeroes[(w+w2)*16+g] = 0;
                nz = 1;
                for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
                    float t = fabsf(coefs[w2*128+i]);
                    if (t > 0.0f)
                        qmin = FFMIN(qmin, t);
                    qmax = FFMAX(qmax, t);
                }
            }
            if (nz) {
                int minscale, maxscale;
                float minrd = INFINITY;
                //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
                minscale = av_clip_uint8(log2(qmin)*4 - 69 + SCALE_ONE_POS - SCALE_DIV_512);
                //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
                maxscale = av_clip_uint8(log2(qmax)*4 +  6 + SCALE_ONE_POS - SCALE_DIV_512);
                for (q = minscale; q < maxscale; q++) {
                    float dists[12], dist;
                    memset(dists, 0, sizeof(dists));
                    for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                        FFPsyBand *band = &s->psy.psy_bands[s->cur_channel*PSY_MAX_BANDS+(w+w2)*16+g];
                        int cb;
                        for (cb = 0; cb <= ESC_BT; cb++)
                            dists[cb] += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
                                                            q, cb, lambda / band->threshold, INFINITY, NULL);
                    }
                    dist = dists[0];
                    for (i = 1; i <= ESC_BT; i++)
                        dist = FFMIN(dist, dists[i]);
                    minrd = FFMIN(minrd, dist);

                    for (i = FFMAX(q - SCALE_MAX_DIFF, 0); i < FFMIN(q + SCALE_MAX_DIFF, TRELLIS_STATES); i++) {
                        float cost;
                        int minv, maxv;
                        if (isinf(paths[idx - 1][i].cost))
                            continue;
                        cost = paths[idx - 1][i].cost + dist
                               + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO];
                        minv = FFMIN(paths[idx - 1][i].min_val, q);
                        maxv = FFMAX(paths[idx - 1][i].max_val, q);
                        if (cost < paths[idx][q].cost && maxv-minv < SCALE_MAX_DIFF) {
                            paths[idx][q].cost    = cost;
                            paths[idx][q].prev    = i;
                            paths[idx][q].min_val = minv;
                            paths[idx][q].max_val = maxv;
                        }
                    }
                }
            } else {
                for (q = 0; q < TRELLIS_STATES; q++) {
                    if (!isinf(paths[idx - 1][q].cost)) {
                        paths[idx][q].cost = paths[idx - 1][q].cost + 1;
                        paths[idx][q].prev = q;
                        paths[idx][q].min_val = FFMIN(paths[idx - 1][q].min_val, q);
                        paths[idx][q].max_val = FFMAX(paths[idx - 1][q].max_val, q);
                        continue;
                    }
                    for (i = FFMAX(q - SCALE_MAX_DIFF, 0); i < FFMIN(q + SCALE_MAX_DIFF, TRELLIS_STATES); i++) {
                        float cost;
                        int minv, maxv;
                        if (isinf(paths[idx - 1][i].cost))
                            continue;
                        cost = paths[idx - 1][i].cost + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO];
                        minv = FFMIN(paths[idx - 1][i].min_val, q);
                        maxv = FFMAX(paths[idx - 1][i].max_val, q);
                        if (cost < paths[idx][q].cost && maxv-minv < SCALE_MAX_DIFF) {
                            paths[idx][q].cost    = cost;
                            paths[idx][q].prev    = i;
                            paths[idx][q].min_val = minv;
                            paths[idx][q].max_val = maxv;
                        }
                    }
                }
            }
            sce->zeroes[w*16+g] = !nz;
            start += sce->ics.swb_sizes[g];
            idx++;
        }
    }
    idx--;
    mincost = paths[idx][0].cost;
    minq    = 0;
    for (i = 1; i < TRELLIS_STATES; i++) {
        if (paths[idx][i].cost < mincost) {
            mincost = paths[idx][i].cost;
            minq = i;
        }
    }
    while (idx) {
        sce->sf_idx[bandaddr[idx]] = minq;
        minq = paths[idx][minq].prev;
        idx--;
    }
    //set the same quantizers inside window groups
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
        for (g = 0;  g < sce->ics.num_swb; g++)
            for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
                sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
}
Beispiel #12
0
static void search_for_ms(AACEncContext *s, ChannelElement *cpe)
{
    int start = 0, i, w, w2, g, sid_sf_boost;
    float M[128], S[128];
    float *L34 = s->scoefs, *R34 = s->scoefs + 128, *M34 = s->scoefs + 128*2, *S34 = s->scoefs + 128*3;
    const float lambda = s->lambda;
    const float mslambda = FFMIN(1.0f, lambda / 120.f);
    SingleChannelElement *sce0 = &cpe->ch[0];
    SingleChannelElement *sce1 = &cpe->ch[1];
    if (!cpe->common_window)
        return;
    for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
        int min_sf_idx_mid = SCALE_MAX_POS;
        int min_sf_idx_side = SCALE_MAX_POS;
        for (g = 0; g < sce0->ics.num_swb; g++) {
            if (!sce0->zeroes[w*16+g] && sce0->band_type[w*16+g] < RESERVED_BT)
                min_sf_idx_mid = FFMIN(min_sf_idx_mid, sce0->sf_idx[w*16+g]);
            if (!sce1->zeroes[w*16+g] && sce1->band_type[w*16+g] < RESERVED_BT)
                min_sf_idx_side = FFMIN(min_sf_idx_side, sce1->sf_idx[w*16+g]);
        }

        start = 0;
        for (g = 0;  g < sce0->ics.num_swb; g++) {
            float bmax = bval2bmax(g * 17.0f / sce0->ics.num_swb) / 0.0045f;
            cpe->ms_mask[w*16+g] = 0;
            if (!cpe->ch[0].zeroes[w*16+g] && !cpe->ch[1].zeroes[w*16+g]) {
                float Mmax = 0.0f, Smax = 0.0f;

                /* Must compute mid/side SF and book for the whole window group */
                for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
                    for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
                        M[i] = (sce0->coeffs[start+(w+w2)*128+i]
                              + sce1->coeffs[start+(w+w2)*128+i]) * 0.5;
                        S[i] =  M[i]
                              - sce1->coeffs[start+(w+w2)*128+i];
                    }
                    abs_pow34_v(M34, M, sce0->ics.swb_sizes[g]);
                    abs_pow34_v(S34, S, sce0->ics.swb_sizes[g]);
                    for (i = 0; i < sce0->ics.swb_sizes[g]; i++ ) {
                        Mmax = FFMAX(Mmax, M34[i]);
                        Smax = FFMAX(Smax, S34[i]);
                    }
                }

                for (sid_sf_boost = 0; sid_sf_boost < 4; sid_sf_boost++) {
                    float dist1 = 0.0f, dist2 = 0.0f;
                    int B0 = 0, B1 = 0;
                    int minidx;
                    int mididx, sididx;
                    int midcb, sidcb;

                    minidx = FFMIN(sce0->sf_idx[w*16+g], sce1->sf_idx[w*16+g]);
                    mididx = av_clip(minidx, min_sf_idx_mid, min_sf_idx_mid + SCALE_MAX_DIFF);
                    sididx = av_clip(minidx - sid_sf_boost * 3, min_sf_idx_side, min_sf_idx_side + SCALE_MAX_DIFF);
                    midcb = find_min_book(Mmax, mididx);
                    sidcb = find_min_book(Smax, sididx);

                    if ((mididx > minidx) || (sididx > minidx)) {
                        /* scalefactor range violation, bad stuff, will decrease quality unacceptably */
                        continue;
                    }

                    /* No CB can be zero */
                    midcb = FFMAX(1,midcb);
                    sidcb = FFMAX(1,sidcb);

                    for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
                        FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
                        FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
                        float minthr = FFMIN(band0->threshold, band1->threshold);
                        int b1,b2,b3,b4;
                        for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
                            M[i] = (sce0->coeffs[start+(w+w2)*128+i]
                                  + sce1->coeffs[start+(w+w2)*128+i]) * 0.5;
                            S[i] =  M[i]
                                  - sce1->coeffs[start+(w+w2)*128+i];
                        }

                        abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
                        abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
                        abs_pow34_v(M34, M,                         sce0->ics.swb_sizes[g]);
                        abs_pow34_v(S34, S,                         sce0->ics.swb_sizes[g]);
                        dist1 += quantize_band_cost(s, &sce0->coeffs[start + (w+w2)*128],
                                                    L34,
                                                    sce0->ics.swb_sizes[g],
                                                    sce0->sf_idx[(w+w2)*16+g],
                                                    sce0->band_type[(w+w2)*16+g],
                                                    lambda / band0->threshold, INFINITY, &b1, NULL, 0);
                        dist1 += quantize_band_cost(s, &sce1->coeffs[start + (w+w2)*128],
                                                    R34,
                                                    sce1->ics.swb_sizes[g],
                                                    sce1->sf_idx[(w+w2)*16+g],
                                                    sce1->band_type[(w+w2)*16+g],
                                                    lambda / band1->threshold, INFINITY, &b2, NULL, 0);
                        dist2 += quantize_band_cost(s, M,
                                                    M34,
                                                    sce0->ics.swb_sizes[g],
                                                    sce0->sf_idx[(w+w2)*16+g],
                                                    sce0->band_type[(w+w2)*16+g],
                                                    lambda / minthr, INFINITY, &b3, NULL, 0);
                        dist2 += quantize_band_cost(s, S,
                                                    S34,
                                                    sce1->ics.swb_sizes[g],
                                                    sce1->sf_idx[(w+w2)*16+g],
                                                    sce1->band_type[(w+w2)*16+g],
                                                    mslambda / (minthr * bmax), INFINITY, &b4, NULL, 0);
                        B0 += b1+b2;
                        B1 += b3+b4;
                        dist1 -= B0;
                        dist2 -= B1;
                    }
                    cpe->ms_mask[w*16+g] = dist2 <= dist1 && B1 < B0;
                    if (cpe->ms_mask[w*16+g]) {
                        /* Setting the M/S mask is useful with I/S or PNS, but only the flag */
                        if (!cpe->is_mask[w*16+g] && sce0->band_type[w*16+g] != NOISE_BT && sce1->band_type[w*16+g] != NOISE_BT) {
                            sce0->sf_idx[w*16+g] = mididx;
                            sce1->sf_idx[w*16+g] = sididx;
                            sce0->band_type[w*16+g] = midcb;
                            sce1->band_type[w*16+g] = sidcb;
                        }
                        break;
                    } else if (B1 > B0) {
                        /* More boost won't fix this */
                        break;
                    }
                }
            }
            start += sce0->ics.swb_sizes[g];
        }
    }
}
Beispiel #13
0
/**
 * two-loop quantizers search taken from ISO 13818-7 Appendix C
 */
static void search_for_quantizers_twoloop(AVCodecContext *avctx,
                                          AACEncContext *s,
                                          SingleChannelElement *sce,
                                          const float lambda)
{
    int start = 0, i, w, w2, g;
    int destbits = avctx->bit_rate * 1024.0 / avctx->sample_rate / avctx->channels * (lambda / 120.f);
    const float freq_mult = avctx->sample_rate/(1024.0f/sce->ics.num_windows)/2.0f;
    float dists[128] = { 0 }, uplims[128] = { 0 };
    float maxvals[128];
    int noise_sf[128] = { 0 };
    int fflag, minscaler, minscaler_n;
    int its  = 0;
    int allz = 0;
    float minthr = INFINITY;

    // for values above this the decoder might end up in an endless loop
    // due to always having more bits than what can be encoded.
    destbits = FFMIN(destbits, 5800);
    //XXX: some heuristic to determine initial quantizers will reduce search time
    //determine zero bands and upper limits
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = 0;
        for (g = 0;  g < sce->ics.num_swb; g++) {
            int nz = 0;
            float uplim = 0.0f, energy = 0.0f;
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                uplim += band->threshold;
                energy += band->energy;
                if (band->energy <= band->threshold || band->threshold == 0.0f) {
                    sce->zeroes[(w+w2)*16+g] = 1;
                    continue;
                }
                nz = 1;
            }
            uplims[w*16+g] = uplim *512;
            if (s->options.pns && start*freq_mult > NOISE_LOW_LIMIT && energy < uplim * 1.2f) {
                noise_sf[w*16+g] = av_clip(4+FFMIN(log2f(energy)*2,255), -100, 155);
                sce->band_type[w*16+g] = NOISE_BT;
                nz= 1;
            } else { /** Band type will be determined by the twoloop algorithm */
                sce->band_type[w*16+g] = 0;
            }
            sce->zeroes[w*16+g] = !nz;
            if (nz)
                minthr = FFMIN(minthr, uplim);
            allz |= nz;
            start += sce->ics.swb_sizes[g];
        }
    }
    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        for (g = 0;  g < sce->ics.num_swb; g++) {
            if (sce->zeroes[w*16+g]) {
                sce->sf_idx[w*16+g] = SCALE_ONE_POS;
                continue;
            }
            sce->sf_idx[w*16+g] = SCALE_ONE_POS + FFMIN(log2f(uplims[w*16+g]/minthr)*4,59);
        }
    }

    if (!allz)
        return;
    abs_pow34_v(s->scoefs, sce->coeffs, 1024);

    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = w*128;
        for (g = 0;  g < sce->ics.num_swb; g++) {
            const float *scaled = s->scoefs + start;
            maxvals[w*16+g] = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], scaled);
            start += sce->ics.swb_sizes[g];
        }
    }

    //perform two-loop search
    //outer loop - improve quality
    do {
        int tbits, qstep;
        minscaler = sce->sf_idx[0];
        minscaler_n = sce->sf_idx[0];
        //inner loop - quantize spectrum to fit into given number of bits
        qstep = its ? 1 : 32;
        do {
            int prev = -1;
            tbits = 0;
            for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
                start = w*128;
                for (g = 0;  g < sce->ics.num_swb; g++) {
                    const float *coefs = sce->coeffs + start;
                    const float *scaled = s->scoefs + start;
                    int bits = 0;
                    int cb;
                    float dist = 0.0f;

                    if (sce->band_type[w*16+g] == NOISE_BT) {
                        minscaler_n = FFMIN(minscaler_n, noise_sf[w*16+g]);
                        start += sce->ics.swb_sizes[g];
                        continue;
                    } else if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) {
                        start += sce->ics.swb_sizes[g];
                        continue;
                    }
                    minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]);
                    cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]);
                    for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                        int b;
                        dist += quantize_band_cost(s, coefs + w2*128,
                                                   scaled + w2*128,
                                                   sce->ics.swb_sizes[g],
                                                   sce->sf_idx[w*16+g],
                                                   cb,
                                                   1.0f,
                                                   INFINITY,
                                                   &b);
                        bits += b;
                    }
                    dists[w*16+g] = dist - bits;
                    if (prev != -1) {
                        bits += ff_aac_scalefactor_bits[sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO];
                    }
                    tbits += bits;
                    start += sce->ics.swb_sizes[g];
                    prev = sce->sf_idx[w*16+g];
                }
            }
            if (tbits > destbits) {
                for (i = 0; i < 128; i++)
                    if (sce->sf_idx[i] < 218 - qstep)
                        sce->sf_idx[i] += qstep;
            } else {
                for (i = 0; i < 128; i++)
                    if (sce->sf_idx[i] > 60 - qstep)
                        sce->sf_idx[i] -= qstep;
            }
            qstep >>= 1;
            if (!qstep && tbits > destbits*1.02 && sce->sf_idx[0] < 217)
                qstep = 1;
        } while (qstep);

        fflag = 0;
        minscaler = av_clip(minscaler, 60, 255 - SCALE_MAX_DIFF);

        for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
            for (g = 0; g < sce->ics.num_swb; g++)
                if (sce->band_type[w*16+g] == NOISE_BT)
                    sce->sf_idx[w*16+g] = av_clip(noise_sf[w*16+g], minscaler_n, minscaler_n + SCALE_MAX_DIFF);

        for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
            for (g = 0; g < sce->ics.num_swb; g++) {
                int prevsc = sce->sf_idx[w*16+g];
                if (sce->band_type[w*16+g] == NOISE_BT)
                    continue;
                if (dists[w*16+g] > uplims[w*16+g] && sce->sf_idx[w*16+g] > 60) {
                    if (find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]-1))
                        sce->sf_idx[w*16+g]--;
                    else //Try to make sure there is some energy in every band
                        sce->sf_idx[w*16+g]-=2;
                }
                sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler, minscaler + SCALE_MAX_DIFF);
                sce->sf_idx[w*16+g] = FFMIN(sce->sf_idx[w*16+g], 219);
                if (sce->sf_idx[w*16+g] != prevsc)
                    fflag = 1;
                sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]);
            }
        }
        its++;
    } while (fflag && its < 10);
}
Beispiel #14
0
static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
{
    FFPsyBand *band;
    int w, g, w2, i, start, count = 0;
    float *PNS = &s->scoefs[0*128], *PNS34 = &s->scoefs[1*128];
    float *NOR34 = &s->scoefs[3*128];
    const float lambda = s->lambda;
    const float freq_mult = avctx->sample_rate/(1024.0f/sce->ics.num_windows)/2.0f;
    const float thr_mult = NOISE_LAMBDA_REPLACE*(100.0f/lambda);
    const float spread_threshold = NOISE_SPREAD_THRESHOLD*(lambda/100.f);

    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        start = 0;
        for (g = 0;  g < sce->ics.num_swb; g++) {
            int noise_sfi, try_pns = 0;
            float dist1 = 0.0f, dist2 = 0.0f, noise_amp;
            float energy = 0.0f, threshold = 0.0f, spread = 0.0f;
            if (start*freq_mult < NOISE_LOW_LIMIT) {
                start += sce->ics.swb_sizes[g];
                continue;
            }
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                energy    += band->energy;
                spread    += band->spread;
                threshold += band->threshold;
            }
            sce->pns_ener[w*16+g] = energy;

            if (sce->zeroes[w*16+g]) {
                try_pns = 1;
            } else if (energy < threshold) {
                try_pns = 1;
            } else if (spread > spread_threshold) {
                try_pns = 0;
            } else if (energy < threshold*thr_mult) {
                try_pns = 1;
            }

            if (!try_pns || !energy) {
                start += sce->ics.swb_sizes[g];
                continue;
            }

            noise_sfi = av_clip(roundf(log2f(energy)*2), -100, 155);  /* Quantize */
            noise_amp = -ff_aac_pow2sf_tab[noise_sfi + POW_SF2_ZERO]; /* Dequantize */
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                float band_energy, scale;
                band = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
                for (i = 0; i < sce->ics.swb_sizes[g]; i++)
                    PNS[i] = s->random_state = lcg_random(s->random_state);
                band_energy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
                scale = noise_amp/sqrtf(band_energy);
                s->fdsp->vector_fmul_scalar(PNS, PNS, scale, sce->ics.swb_sizes[g]);
                abs_pow34_v(NOR34, &sce->coeffs[start+(w+w2)*128], sce->ics.swb_sizes[g]);
                abs_pow34_v(PNS34, PNS, sce->ics.swb_sizes[g]);
                dist1 += quantize_band_cost(s, &sce->coeffs[start + (w+w2)*128],
                                            NOR34,
                                            sce->ics.swb_sizes[g],
                                            sce->sf_idx[(w+w2)*16+g],
                                            sce->band_alt[(w+w2)*16+g],
                                            lambda/band->threshold, INFINITY, NULL, 0);
                dist2 += quantize_band_cost(s, PNS,
                                            PNS34,
                                            sce->ics.swb_sizes[g],
                                            noise_sfi,
                                            NOISE_BT,
                                            lambda/band->threshold, INFINITY, NULL, 0);
            }
            if (dist2 < dist1) {
                sce->band_type[w*16+g] = NOISE_BT;
                sce->zeroes[w*16+g] = 0;
                if (sce->band_type[w*16+g-1] != NOISE_BT && /* Prevent holes */
                    sce->band_type[w*16+g-2] == NOISE_BT) {
                    sce->band_type[w*16+g-1] = NOISE_BT;
                    sce->zeroes[w*16+g-1] = 0;
                }
                count++;
            }
            start += sce->ics.swb_sizes[g];
        }
    }
}
Beispiel #15
0
static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
{
    FFPsyBand *band;
    int w, g, w2, i;
    float *PNS = &s->scoefs[0*128], *PNS34 = &s->scoefs[1*128];
    float *NOR34 = &s->scoefs[3*128];
    const float lambda = s->lambda;
    const float freq_mult = avctx->sample_rate/(1024.0f/sce->ics.num_windows)/2.0f;
    const float thr_mult = NOISE_LAMBDA_REPLACE*(100.0f/lambda);
    const float spread_threshold = NOISE_SPREAD_THRESHOLD*(lambda/100.f);

    if (sce->ics.window_sequence[0] == EIGHT_SHORT_SEQUENCE)
        return;

    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
        for (g = 0;  g < sce->ics.num_swb; g++) {
            int noise_sfi;
            float dist1 = 0.0f, dist2 = 0.0f, noise_amp;
            float pns_energy = 0.0f, energy_ratio, dist_thresh;
            float sfb_energy = 0.0f, threshold = 0.0f, spread = 0.0f;
            const int start = sce->ics.swb_offset[w*16+g];
            const float freq = start*freq_mult;
            const float freq_boost = FFMAX(0.88f*freq/NOISE_LOW_LIMIT, 1.0f);
            if (freq < NOISE_LOW_LIMIT || avctx->cutoff && freq >= avctx->cutoff)
                continue;
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                sfb_energy += band->energy;
                spread     += band->spread;
                threshold  += band->threshold;
            }

            /* Ramps down at ~8000Hz and loosens the dist threshold */
            dist_thresh = FFMIN(2.5f*NOISE_LOW_LIMIT/freq, 1.27f);

            if (sce->zeroes[w*16+g] || spread < spread_threshold ||
                sfb_energy > threshold*thr_mult*freq_boost) {
                sce->pns_ener[w*16+g] = sfb_energy;
                continue;
            }

            noise_sfi = av_clip(roundf(log2f(sfb_energy)*2), -100, 155); /* Quantize */
            noise_amp = -ff_aac_pow2sf_tab[noise_sfi + POW_SF2_ZERO];    /* Dequantize */
            for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                float band_energy, scale;
                const int start_c = sce->ics.swb_offset[(w+w2)*16+g];
                band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
                for (i = 0; i < sce->ics.swb_sizes[g]; i++)
                    PNS[i] = s->random_state = lcg_random(s->random_state);
                band_energy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
                scale = noise_amp/sqrtf(band_energy);
                s->fdsp->vector_fmul_scalar(PNS, PNS, scale, sce->ics.swb_sizes[g]);
                pns_energy += s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
                abs_pow34_v(NOR34, &sce->coeffs[start_c], sce->ics.swb_sizes[g]);
                abs_pow34_v(PNS34, PNS, sce->ics.swb_sizes[g]);
                dist1 += quantize_band_cost(s, &sce->coeffs[start_c],
                                            NOR34,
                                            sce->ics.swb_sizes[g],
                                            sce->sf_idx[(w+w2)*16+g],
                                            sce->band_alt[(w+w2)*16+g],
                                            lambda/band->threshold, INFINITY, NULL, 0);
                dist2 += quantize_band_cost(s, PNS,
                                            PNS34,
                                            sce->ics.swb_sizes[g],
                                            noise_sfi,
                                            NOISE_BT,
                                            lambda/band->threshold, INFINITY, NULL, 0);
            }
            energy_ratio = sfb_energy/pns_energy; /* Compensates for quantization error */
            sce->pns_ener[w*16+g] = energy_ratio*sfb_energy;
            if (energy_ratio > 0.85f && energy_ratio < 1.25f && dist1/dist2 > dist_thresh) {
                sce->band_type[w*16+g] = NOISE_BT;
                sce->zeroes[w*16+g] = 0;
                if (sce->band_type[w*16+g-1] != NOISE_BT && /* Prevent holes */
                    sce->band_type[w*16+g-2] == NOISE_BT) {
                    sce->band_type[w*16+g-1] = NOISE_BT;
                    sce->zeroes[w*16+g-1] = 0;
                }
            }
        }
    }
}