1/* 2 * audio encoder psychoacoustic model 3 * Copyright (C) 2008 Konstantin Shishkov 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "avcodec.h" 23#include "psymodel.h" 24#include "iirfilter.h" 25 26extern const FFPsyModel ff_aac_psy_model; 27 28av_cold int ff_psy_init(FFPsyContext *ctx, AVCodecContext *avctx, 29 int num_lens, 30 const uint8_t **bands, const int* num_bands) 31{ 32 ctx->avctx = avctx; 33 ctx->psy_bands = av_mallocz(sizeof(FFPsyBand) * PSY_MAX_BANDS * avctx->channels); 34 ctx->bands = av_malloc (sizeof(ctx->bands[0]) * num_lens); 35 ctx->num_bands = av_malloc (sizeof(ctx->num_bands[0]) * num_lens); 36 memcpy(ctx->bands, bands, sizeof(ctx->bands[0]) * num_lens); 37 memcpy(ctx->num_bands, num_bands, sizeof(ctx->num_bands[0]) * num_lens); 38 switch (ctx->avctx->codec_id) { 39 case CODEC_ID_AAC: 40 ctx->model = &ff_aac_psy_model; 41 break; 42 } 43 if (ctx->model->init) 44 return ctx->model->init(ctx); 45 return 0; 46} 47 48FFPsyWindowInfo ff_psy_suggest_window(FFPsyContext *ctx, 49 const int16_t *audio, const int16_t *la, 50 int channel, int prev_type) 51{ 52 return ctx->model->window(ctx, audio, la, channel, prev_type); 53} 54 55void ff_psy_set_band_info(FFPsyContext *ctx, int channel, 56 const float *coeffs, FFPsyWindowInfo *wi) 57{ 58 ctx->model->analyze(ctx, channel, coeffs, wi); 59} 60 61av_cold void ff_psy_end(FFPsyContext *ctx) 62{ 63 if (ctx->model->end) 64 ctx->model->end(ctx); 65 av_freep(&ctx->bands); 66 av_freep(&ctx->num_bands); 67 av_freep(&ctx->psy_bands); 68} 69 70typedef struct FFPsyPreprocessContext{ 71 AVCodecContext *avctx; 72 float stereo_att; 73 struct FFIIRFilterCoeffs *fcoeffs; 74 struct FFIIRFilterState **fstate; 75}FFPsyPreprocessContext; 76 77#define FILT_ORDER 4 78 79av_cold struct FFPsyPreprocessContext* ff_psy_preprocess_init(AVCodecContext *avctx) 80{ 81 FFPsyPreprocessContext *ctx; 82 int i; 83 float cutoff_coeff = 0; 84 ctx = av_mallocz(sizeof(FFPsyPreprocessContext)); 85 ctx->avctx = avctx; 86 87 if (avctx->cutoff > 0) 88 cutoff_coeff = 2.0 * avctx->cutoff / avctx->sample_rate; 89 90 if (cutoff_coeff) 91 ctx->fcoeffs = ff_iir_filter_init_coeffs(FF_FILTER_TYPE_BUTTERWORTH, FF_FILTER_MODE_LOWPASS, 92 FILT_ORDER, cutoff_coeff, 0.0, 0.0); 93 if (ctx->fcoeffs) { 94 ctx->fstate = av_mallocz(sizeof(ctx->fstate[0]) * avctx->channels); 95 for (i = 0; i < avctx->channels; i++) 96 ctx->fstate[i] = ff_iir_filter_init_state(FILT_ORDER); 97 } 98 return ctx; 99} 100 101void ff_psy_preprocess(struct FFPsyPreprocessContext *ctx, 102 const int16_t *audio, int16_t *dest, 103 int tag, int channels) 104{ 105 int ch, i; 106 if (ctx->fstate) { 107 for (ch = 0; ch < channels; ch++) 108 ff_iir_filter(ctx->fcoeffs, ctx->fstate[tag+ch], ctx->avctx->frame_size, 109 audio + ch, ctx->avctx->channels, 110 dest + ch, ctx->avctx->channels); 111 } else { 112 for (ch = 0; ch < channels; ch++) 113 for (i = 0; i < ctx->avctx->frame_size; i++) 114 dest[i*ctx->avctx->channels + ch] = audio[i*ctx->avctx->channels + ch]; 115 } 116} 117 118av_cold void ff_psy_preprocess_end(struct FFPsyPreprocessContext *ctx) 119{ 120 int i; 121 ff_iir_filter_free_coeffs(ctx->fcoeffs); 122 if (ctx->fstate) 123 for (i = 0; i < ctx->avctx->channels; i++) 124 ff_iir_filter_free_state(ctx->fstate[i]); 125 av_freep(&ctx->fstate); 126} 127 128