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/* * AAC coefficients encoder * Copyright (C) 2008-2009 Konstantin Shishkov * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * AAC coefficients encoder */ /*********************************** *              TODOs: * speedup quantizer selection * add sane pulse detection ***********************************/ #include "libavutil/libm.h" // brought forward to work around cygwin header breakage #include <float.h> #include "libavutil/mathematics.h"#include "mathops.h"#include "avcodec.h"#include "put_bits.h"#include "aac.h"#include "aacenc.h"#include "aactab.h"#include "aacenctab.h"#include "aacenc_utils.h"#include "aacenc_quantization.h" #include "aacenc_is.h"#include "aacenc_tns.h" #include "libavcodec/aaccoder_twoloop.h" /* Parameter of f(x) = a*(lambda/100), defines the maximum fourier spread * beyond which no PNS is used (since the SFBs contain tone rather than noise) */#define NOISE_SPREAD_THRESHOLD 0.9f /* Parameter of f(x) = a*(100/lambda), defines how much PNS is allowed to * replace low energy non zero bands */#define NOISE_LAMBDA_REPLACE 1.948f #include "libavcodec/aaccoder_trellis.h" typedef float (*quantize_and_encode_band_func)(struct AACEncContext *s, PutBitContext *pb,                                               const float *in, float *quant, const float *scaled,                                               int size, int scale_idx, int cb,                                               const float lambda, const float uplim,                                               int *bits, float *energy); /** * Calculate rate distortion cost for quantizing with given codebook * * @return quantization distortion */static av_always_inline float quantize_and_encode_band_cost_template(                                struct AACEncContext *s,                                PutBitContext *pb, const float *in, float *out,                                const float *scaled, int size, int scale_idx,                                int cb, const float lambda, const float uplim,                                int *bits, float *energy, int BT_ZERO, int BT_UNSIGNED,                                int BT_PAIR, int BT_ESC, int BT_NOISE, int BT_STEREO,                                const float ROUNDING){    const int q_idx = POW_SF2_ZERO - scale_idx + SCALE_ONE_POS - SCALE_DIV_512;    const float Q   = ff_aac_pow2sf_tab [q_idx];    const float Q34 = ff_aac_pow34sf_tab[q_idx];    const float IQ  = ff_aac_pow2sf_tab [POW_SF2_ZERO + scale_idx - SCALE_ONE_POS + SCALE_DIV_512];    const float CLIPPED_ESCAPE = 165140.0f*IQ;    float cost = 0;    float qenergy = 0;    const int dim = BT_PAIR ? 2 : 4;    int resbits = 0;    int off;     if (BT_ZERO || BT_NOISE || BT_STEREO) {        for (int i = 0; i < size; i++)            cost += in[i]*in[i];        if (bits)            *bits = 0;        if (energy)            *energy = qenergy;        if (out) {            for (int i = 0; i < size; i += dim)                for (int j = 0; j < dim; j++)                    out[i+j] = 0.0f;        }        return cost * lambda;    }    if (!scaled) {        s->aacdsp.abs_pow34(s->scoefs, in, size);        scaled = s->scoefs;    }    s->aacdsp.quant_bands(s->qcoefs, in, scaled, size, !BT_UNSIGNED, aac_cb_maxval[cb], Q34, ROUNDING);    if (BT_UNSIGNED) {        off = 0;    } else {        off = aac_cb_maxval[cb];    }    for (int i = 0; i < size; i += dim) {        const float *vec;        int *quants = s->qcoefs + i;        int curidx = 0;        int curbits;        float quantized, rd = 0.0f;        for (int j = 0; j < dim; j++) {            curidx *= aac_cb_range[cb];            curidx += quants[j] + off;        }        curbits =  ff_aac_spectral_bits[cb-1][curidx];        vec     = &ff_aac_codebook_vectors[cb-1][curidx*dim];        if (BT_UNSIGNED) {            for (int j = 0; j < dim; j++) {                float t = fabsf(in[i+j]);                float di;                if (BT_ESC && vec[j] == 64.0f) { //FIXME: slow                    if (t >= CLIPPED_ESCAPE) {                        quantized = CLIPPED_ESCAPE;                        curbits += 21;                    } else {                        int c = av_clip_uintp2(quant(t, Q, ROUNDING), 13);                        quantized = c*cbrtf(c)*IQ;                        curbits += av_log2(c)*2 - 4 + 1;                    }                } else {                    quantized = vec[j]*IQ;                }                di = t - quantized;                if (out)                    out[i+j] = in[i+j] >= 0 ? quantized : -quantized;                if (vec[j] != 0.0f)                    curbits++;                qenergy += quantized*quantized;                rd += di*di;            }        } else {            for (int j = 0; j < dim; j++) {                quantized = vec[j]*IQ;                qenergy += quantized*quantized;                if (out)                    out[i+j] = quantized;                rd += (in[i+j] - quantized)*(in[i+j] - quantized);            }        }        cost    += rd * lambda + curbits;        resbits += curbits;        if (cost >= uplim)            return uplim;        if (pb) {            put_bits(pb, ff_aac_spectral_bits[cb-1][curidx], ff_aac_spectral_codes[cb-1][curidx]);            if (BT_UNSIGNED)                for (int j = 0; j < dim; j++)                    if (ff_aac_codebook_vectors[cb-1][curidx*dim+j] != 0.0f)                        put_bits(pb, 1, in[i+j] < 0.0f);            if (BT_ESC) {                for (int j = 0; j < 2; j++) {                    if (ff_aac_codebook_vectors[cb-1][curidx*2+j] == 64.0f) {                        int coef = av_clip_uintp2(quant(fabsf(in[i+j]), Q, ROUNDING), 13);                        int len = av_log2(coef);                         put_bits(pb, len - 4 + 1, (1 << (len - 4 + 1)) - 2);                        put_sbits(pb, len, coef);                    }                }            }        }    }     if (bits)        *bits = resbits;    if (energy)        *energy = qenergy;    return cost;} static inline float quantize_and_encode_band_cost_NONE(struct AACEncContext *s, PutBitContext *pb,                                                const float *in, float *quant, const float *scaled,                                                int size, int scale_idx, int cb,                                                const float lambda, const float uplim,                                                int *bits, float *energy) {    av_assert0(0);    return 0.0f;} #define QUANTIZE_AND_ENCODE_BAND_COST_FUNC(NAME, BT_ZERO, BT_UNSIGNED, BT_PAIR, BT_ESC, BT_NOISE, BT_STEREO, ROUNDING) \static float quantize_and_encode_band_cost_ ## NAME(                                         \                                struct AACEncContext *s,                                     \                                PutBitContext *pb, const float *in, float *quant,            \                                const float *scaled, int size, int scale_idx,                \                                int cb, const float lambda, const float uplim,               \                                int *bits, float *energy) {                                  \    return quantize_and_encode_band_cost_template(                                           \                                s, pb, in, quant, scaled, size, scale_idx,                   \                                BT_ESC ? ESC_BT : cb, lambda, uplim, bits, energy,           \                                BT_ZERO, BT_UNSIGNED, BT_PAIR, BT_ESC, BT_NOISE, BT_STEREO,  \                                ROUNDING);                                                   \} QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ZERO,  1, 0, 0, 0, 0, 0, ROUND_STANDARD)QUANTIZE_AND_ENCODE_BAND_COST_FUNC(SQUAD, 0, 0, 0, 0, 0, 0, ROUND_STANDARD)QUANTIZE_AND_ENCODE_BAND_COST_FUNC(UQUAD, 0, 1, 0, 0, 0, 0, ROUND_STANDARD)QUANTIZE_AND_ENCODE_BAND_COST_FUNC(SPAIR, 0, 0, 1, 0, 0, 0, ROUND_STANDARD)QUANTIZE_AND_ENCODE_BAND_COST_FUNC(UPAIR, 0, 1, 1, 0, 0, 0, ROUND_STANDARD)QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ESC,   0, 1, 1, 1, 0, 0, ROUND_STANDARD)QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ESC_RTZ, 0, 1, 1, 1, 0, 0, ROUND_TO_ZERO)QUANTIZE_AND_ENCODE_BAND_COST_FUNC(NOISE, 0, 0, 0, 0, 1, 0, ROUND_STANDARD)QUANTIZE_AND_ENCODE_BAND_COST_FUNC(STEREO,0, 0, 0, 0, 0, 1, ROUND_STANDARD) static const quantize_and_encode_band_func quantize_and_encode_band_cost_arr[] ={    quantize_and_encode_band_cost_ZERO,    quantize_and_encode_band_cost_SQUAD,    quantize_and_encode_band_cost_SQUAD,    quantize_and_encode_band_cost_UQUAD,    quantize_and_encode_band_cost_UQUAD,    quantize_and_encode_band_cost_SPAIR,    quantize_and_encode_band_cost_SPAIR,    quantize_and_encode_band_cost_UPAIR,    quantize_and_encode_band_cost_UPAIR,    quantize_and_encode_band_cost_UPAIR,    quantize_and_encode_band_cost_UPAIR,    quantize_and_encode_band_cost_ESC,    quantize_and_encode_band_cost_NONE,     /* CB 12 doesn't exist */    quantize_and_encode_band_cost_NOISE,    quantize_and_encode_band_cost_STEREO,    quantize_and_encode_band_cost_STEREO,}; static const quantize_and_encode_band_func quantize_and_encode_band_cost_rtz_arr[] ={    quantize_and_encode_band_cost_ZERO,    quantize_and_encode_band_cost_SQUAD,    quantize_and_encode_band_cost_SQUAD,    quantize_and_encode_band_cost_UQUAD,    quantize_and_encode_band_cost_UQUAD,    quantize_and_encode_band_cost_SPAIR,    quantize_and_encode_band_cost_SPAIR,    quantize_and_encode_band_cost_UPAIR,    quantize_and_encode_band_cost_UPAIR,    quantize_and_encode_band_cost_UPAIR,    quantize_and_encode_band_cost_UPAIR,    quantize_and_encode_band_cost_ESC_RTZ,    quantize_and_encode_band_cost_NONE,     /* CB 12 doesn't exist */    quantize_and_encode_band_cost_NOISE,    quantize_and_encode_band_cost_STEREO,    quantize_and_encode_band_cost_STEREO,}; float ff_quantize_and_encode_band_cost(struct AACEncContext *s, PutBitContext *pb,                                       const float *in, float *quant, const float *scaled,                                       int size, int scale_idx, int cb,                                       const float lambda, const float uplim,                                       int *bits, float *energy){    return quantize_and_encode_band_cost_arr[cb](s, pb, in, quant, scaled, size,                                                 scale_idx, cb, lambda, uplim,                                                 bits, energy);} static inline void quantize_and_encode_band(struct AACEncContext *s, PutBitContext *pb,                                            const float *in, float *out, int size, int scale_idx,                                            int cb, const float lambda, int rtz){    (rtz ? quantize_and_encode_band_cost_rtz_arr : quantize_and_encode_band_cost_arr)[cb](s, pb, in, out, NULL, size, scale_idx, cb,                                     lambda, INFINITY, NULL, NULL);} /** * 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; typedef struct TrellisPath {    float cost;    int prev;} TrellisPath; #define TRELLIS_STAGES 121#define TRELLIS_STATES (SCALE_MAX_DIFF+1) static void set_special_band_scalefactors(AACEncContext *s, SingleChannelElement *sce){    int w, g;    int prevscaler_n = -255, prevscaler_i = 0;    int bands = 0;     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])                continue;            if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {                sce->sf_idx[w*16+g] = av_clip(roundf(log2f(sce->is_ener[w*16+g])*2), -155, 100);                bands++;            } else if (sce->band_type[w*16+g] == NOISE_BT) {                sce->sf_idx[w*16+g] = av_clip(3+ceilf(log2f(sce->pns_ener[w*16+g])*2), -100, 155);                if (prevscaler_n == -255)                    prevscaler_n = sce->sf_idx[w*16+g];                bands++;            }        }    }     if (!bands)        return;     /* Clip the scalefactor indices */    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])                continue;            if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {                sce->sf_idx[w*16+g] = prevscaler_i = av_clip(sce->sf_idx[w*16+g], prevscaler_i - SCALE_MAX_DIFF, prevscaler_i + SCALE_MAX_DIFF);            } else if (sce->band_type[w*16+g] == NOISE_BT) {                sce->sf_idx[w*16+g] = prevscaler_n = av_clip(sce->sf_idx[w*16+g], prevscaler_n - SCALE_MAX_DIFF, prevscaler_n + SCALE_MAX_DIFF);            }        }    }} static void search_for_quantizers_fast(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->ch_layout.nb_channels * (lambda / 120.f);    float dists[128] = { 0 }, uplims[128] = { 0 };    float maxvals[128];    int fflag, minscaler;    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);    //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;            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->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;    s->aacdsp.abs_pow34(s->scoefs, sce->coeffs, 1024);    ff_quantize_band_cost_cache_init(s);     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;            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_cached(s, w + w2, g,                                                          coefs + w2*128,                                                          scaled + w2*128,                                                          sce->ics.swb_sizes[g],                                                          sce->sf_idx[w*16+g],                                                          cb, 1.0f, INFINITY,                                                          &b, NULL, 0);                        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);} 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);

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