/* * 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 #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->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, 0); } 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 */