/* * AAC coefficients encoder * Copyright (C) 2008-2009 Konstantin Shishkov * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; 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 "avcodec.h" #include "put_bits.h" #include "aac.h" #include "aacenc.h" #include "aactab.h" /** bits needed to code codebook run value for long windows */ static const uint8_t run_value_bits_long[64] = { 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 15 }; /** bits needed to code codebook run value for short windows */ static const uint8_t run_value_bits_short[16] = { 3, 3, 3, 3, 3, 3, 3, 6, 6, 6, 6, 6, 6, 6, 6, 9 }; static const uint8_t *run_value_bits[2] = { run_value_bits_long, run_value_bits_short }; /** * Quantize one coefficient. * @return absolute value of the quantized coefficient * @see 3GPP TS26.403 5.6.2 "Scalefactor determination" */ static av_always_inline int quant(float coef, const float Q) { float a = coef * Q; return sqrtf(a * sqrtf(a)) + 0.4054; } static void quantize_bands(int *out, const float *in, const float *scaled, int size, float Q34, int is_signed, int maxval) { int i; double qc; for (i = 0; i < size; i++) { qc = scaled[i] * Q34; out[i] = (int)FFMIN(qc + 0.4054, (double)maxval); if (is_signed && in[i] < 0.0f) { out[i] = -out[i]; } } } static void abs_pow34_v(float *out, const float *in, const int size) { #ifndef USE_REALLY_FULL_SEARCH int i; for (i = 0; i < size; i++) { float a = fabsf(in[i]); out[i] = sqrtf(a * sqrtf(a)); } #endif /* USE_REALLY_FULL_SEARCH */ } static const uint8_t aac_cb_range [12] = {0, 3, 3, 3, 3, 9, 9, 8, 8, 13, 13, 17}; static const uint8_t aac_cb_maxval[12] = {0, 1, 1, 2, 2, 4, 4, 7, 7, 12, 12, 16}; /** * 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, const float *scaled, int size, int scale_idx, int cb, const float lambda, const float uplim, int *bits, int BT_ZERO, int BT_UNSIGNED, int BT_PAIR, int BT_ESC) { 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; int i, j; float cost = 0; const int dim = BT_PAIR ? 2 : 4; int resbits = 0; const int range = aac_cb_range[cb]; const int maxval = aac_cb_maxval[cb]; int off; if (BT_ZERO) { for (i = 0; i < size; i++) cost += in[i]*in[i]; if (bits) *bits = 0; return cost * lambda; } if (!scaled) { abs_pow34_v(s->scoefs, in, size); scaled = s->scoefs; } quantize_bands(s->qcoefs, in, scaled, size, Q34, !BT_UNSIGNED, maxval); if (BT_UNSIGNED) { off = 0; } else { off = maxval; } for (i = 0; i < size; i += dim) { const float *vec; int *quants = s->qcoefs + i; int curidx = 0; int curbits; float rd = 0.0f; for (j = 0; j < dim; j++) { curidx *= range; 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 (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) { 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[j]*IQ; } if (vec[j] != 0.0f) curbits++; rd += di*di; } } else { for (j = 0; j < dim; j++) { float di = in[i+j] - vec[j]*IQ; rd += di*di; } } 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 (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 (j = 0; j < 2; j++) { if (ff_aac_codebook_vectors[cb-1][curidx*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)); } } } } } if (bits) *bits = resbits; return cost; } #define QUANTIZE_AND_ENCODE_BAND_COST_FUNC(NAME, BT_ZERO, BT_UNSIGNED, BT_PAIR, BT_ESC) \ static float quantize_and_encode_band_cost_ ## NAME( \ struct AACEncContext *s, \ PutBitContext *pb, const float *in, \ const float *scaled, int size, int scale_idx, \ int cb, const float lambda, const float uplim, \ int *bits) { \ return quantize_and_encode_band_cost_template( \ s, pb, in, scaled, size, scale_idx, \ BT_ESC ? ESC_BT : cb, lambda, uplim, bits, \ BT_ZERO, BT_UNSIGNED, BT_PAIR, BT_ESC); \ } QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ZERO, 1, 0, 0, 0) QUANTIZE_AND_ENCODE_BAND_COST_FUNC(SQUAD, 0, 0, 0, 0) QUANTIZE_AND_ENCODE_BAND_COST_FUNC(UQUAD, 0, 1, 0, 0) QUANTIZE_AND_ENCODE_BAND_COST_FUNC(SPAIR, 0, 0, 1, 0) QUANTIZE_AND_ENCODE_BAND_COST_FUNC(UPAIR, 0, 1, 1, 0) QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ESC, 0, 1, 1, 1) static float (*const quantize_and_encode_band_cost_arr[])( struct AACEncContext *s, PutBitContext *pb, const float *in, const float *scaled, int size, int scale_idx, int cb, const float lambda, const float uplim, int *bits) = { 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, }; #define quantize_and_encode_band_cost( \ s, pb, in, scaled, size, scale_idx, cb, \ lambda, uplim, bits) \ quantize_and_encode_band_cost_arr[cb]( \ s, pb, in, scaled, size, scale_idx, cb, \ lambda, uplim, bits) 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) { return quantize_and_encode_band_cost(s, NULL, in, scaled, size, scale_idx, cb, lambda, uplim, bits); } static void quantize_and_encode_band(struct AACEncContext *s, PutBitContext *pb, const float *in, int size, int scale_idx, int cb, const float lambda) { quantize_and_encode_band_cost(s, pb, in, NULL, size, scale_idx, cb, lambda, INFINITY, NULL); } static float find_max_val(int group_len, int swb_size, const float *scaled) { float maxval = 0.0f; int w2, i; for (w2 = 0; w2 < group_len; w2++) { for (i = 0; i < swb_size; i++) { maxval = FFMAX(maxval, scaled[w2*128+i]); } } return maxval; } static int find_min_book(float maxval, int sf) { float Q = ff_aac_pow2sf_tab[POW_SF2_ZERO - sf + SCALE_ONE_POS - SCALE_DIV_512]; float Q34 = sqrtf(Q * sqrtf(Q)); int qmaxval, cb; qmaxval = maxval * Q34 + 0.4054f; if (qmaxval == 0) cb = 0; else if (qmaxval == 1) cb = 1; else if (qmaxval == 2) cb = 3; else if (qmaxval <= 4) cb = 5; else if (qmaxval <= 7) cb = 7; else if (qmaxval <= 12) cb = 9; else cb = 11; return cb; } /** * 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, 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++) { 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.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], 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); } } 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_minbits = 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_minbits + 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_minbits = 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 minbits = next_minbits; int mincb = next_mincb; int startcb = sce->band_type[win*16+swb]; next_minbits = 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 bits = 0.0f; for (w = 0; w < group_len; w++) { bits += 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 + bits; cost_get_here = minbits + bits + 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_minbits) { next_minbits = 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); } } /** Return the minimum scalefactor where the quantized coef does not clip. */ static av_always_inline uint8_t coef2minsf(float coef) { return av_clip_uint8(log2f(coef)*4 - 69 + SCALE_ONE_POS - SCALE_DIV_512); } /** Return the maximum scalefactor where the quantized coef is not zero. */ static av_always_inline uint8_t coef2maxsf(float coef) { return av_clip_uint8(log2f(coef)*4 + 6 + SCALE_ONE_POS - SCALE_DIV_512); } typedef struct TrellisPath { float cost; int prev; } TrellisPath; #define TRELLIS_STAGES 121 #define TRELLIS_STATES (SCALE_MAX_DIFF+1) 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); 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; if (q0 < q0low) { q1 += q0low - q0; q0 = q0low; } else if (q1 > q1high) { q0 -= q1 - q1high; q1 = q1high; } } 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]; } /** * 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); float dists[128] = { 0 }, uplims[128]; 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); //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]) { 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); } 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); } } static void search_for_quantizers_fast(AVCodecContext *avctx, AACEncContext *s, SingleChannelElement *sce, const float lambda) { int i, w, w2, g; int minq = 255; memset(sce->sf_idx, 0, sizeof(sce->sf_idx)); 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 = 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) { sce->sf_idx[(w+w2)*16+g] = 218; sce->zeroes[(w+w2)*16+g] = 1; } else { sce->sf_idx[(w+w2)*16+g] = av_clip(SCALE_ONE_POS - SCALE_DIV_512 + log2f(band->threshold), 80, 218); sce->zeroes[(w+w2)*16+g] = 0; } minq = FFMIN(minq, sce->sf_idx[(w+w2)*16+g]); } } } for (i = 0; i < 128; i++) { sce->sf_idx[i] = 140; //av_clip(sce->sf_idx[i], minq, minq + SCALE_MAX_DIFF - 1); } //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]; } 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]; } } } AACCoefficientsEncoder ff_aac_coders[] = { { search_for_quantizers_faac, encode_window_bands_info, quantize_and_encode_band, search_for_ms, }, { search_for_quantizers_anmr, encode_window_bands_info, quantize_and_encode_band, search_for_ms, }, { search_for_quantizers_twoloop, codebook_trellis_rate, quantize_and_encode_band, search_for_ms, }, { search_for_quantizers_fast, encode_window_bands_info, quantize_and_encode_band, search_for_ms, }, };