/* * AAC encoder trellis codebook selector * 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 encoder trellis codebook selector * @author Konstantin Shishkov */ /** * This file contains a template for the codebook_trellis_rate selector function. * It needs to be provided, externally, as an already included declaration, * the following functions from aacenc_quantization/util.h. They're not included * explicitly here to make it possible to provide alternative implementations: *  - quantize_band_cost_bits *  - abs_pow34_v */ #ifndef AVCODEC_AACCODER_TRELLIS_H#define AVCODEC_AACCODER_TRELLIS_H #include <float.h>#include "libavutil/mathematics.h"#include "avcodec.h"#include "put_bits.h"#include "aac.h"#include "aacenc.h"#include "aactab.h"#include "aacenctab.h" /** * structure used in optimal codebook search */typedef struct TrellisBandCodingPath {    int prev_idx; ///< pointer to the previous path point    float cost;   ///< path cost    int run;} TrellisBandCodingPath;  static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce,                                  int win, int group_len, const float lambda){    TrellisBandCodingPath 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_minbits = INFINITY;    int next_mincb = 0;     s->aacdsp.abs_pow34(s->scoefs, sce->coeffs, 1024);    start = win*128;    for (cb = 0; cb < CB_TOT_ALL; 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 < CB_TOT_ALL; 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];            startcb = aac_cb_in_map[startcb];            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 < CB_TOT_ALL; cb++) {                float cost_stay_here, cost_get_here;                float bits = 0.0f;                if (cb >= 12 && sce->band_type[win*16+swb] != aac_cb_out_map[cb]) {                    path[swb+1][cb].cost = 61450;                    path[swb+1][cb].prev_idx = -1;                    path[swb+1][cb].run = 0;                    continue;                }                for (w = 0; w < group_len; w++) {                    bits += quantize_band_cost_bits(s, &sce->coeffs[start + w*128],                                               &s->scoefs[start + w*128], size,                                               sce->sf_idx[win*16+swb],                                               aac_cb_out_map[cb],                                               0, INFINITY, NULL, 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 < 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);    }}  #endif /* AVCODEC_AACCODER_TRELLIS_H */