2 * audio encoder psychoacoustic model
3 * Copyright (C) 2008 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
24 #include "iirfilter.h"
26 extern const FFPsyModel ff_aac_psy_model;
28 av_cold int ff_psy_init(FFPsyContext *ctx, AVCodecContext *avctx,
30 const uint8_t **bands, const int* num_bands)
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) {
40 ctx->model = &ff_aac_psy_model;
44 return ctx->model->init(ctx);
48 av_cold void ff_psy_end(FFPsyContext *ctx)
52 av_freep(&ctx->bands);
53 av_freep(&ctx->num_bands);
54 av_freep(&ctx->psy_bands);
57 typedef struct FFPsyPreprocessContext{
58 AVCodecContext *avctx;
60 struct FFIIRFilterCoeffs *fcoeffs;
61 struct FFIIRFilterState **fstate;
62 }FFPsyPreprocessContext;
66 av_cold struct FFPsyPreprocessContext* ff_psy_preprocess_init(AVCodecContext *avctx)
68 FFPsyPreprocessContext *ctx;
70 float cutoff_coeff = 0;
71 ctx = av_mallocz(sizeof(FFPsyPreprocessContext));
74 if (avctx->cutoff > 0)
75 cutoff_coeff = 2.0 * avctx->cutoff / avctx->sample_rate;
78 ctx->fcoeffs = ff_iir_filter_init_coeffs(avctx, FF_FILTER_TYPE_BUTTERWORTH,
79 FF_FILTER_MODE_LOWPASS, FILT_ORDER,
80 cutoff_coeff, 0.0, 0.0);
82 ctx->fstate = av_mallocz(sizeof(ctx->fstate[0]) * avctx->channels);
83 for (i = 0; i < avctx->channels; i++)
84 ctx->fstate[i] = ff_iir_filter_init_state(FILT_ORDER);
89 void ff_psy_preprocess(struct FFPsyPreprocessContext *ctx,
90 const int16_t *audio, int16_t *dest,
91 int tag, int channels)
95 for (ch = 0; ch < channels; ch++)
96 ff_iir_filter(ctx->fcoeffs, ctx->fstate[tag+ch], ctx->avctx->frame_size,
97 audio + ch, ctx->avctx->channels,
98 dest + ch, ctx->avctx->channels);
100 for (ch = 0; ch < channels; ch++)
101 for (i = 0; i < ctx->avctx->frame_size; i++)
102 dest[i*ctx->avctx->channels + ch] = audio[i*ctx->avctx->channels + ch];
106 av_cold void ff_psy_preprocess_end(struct FFPsyPreprocessContext *ctx)
109 ff_iir_filter_free_coeffs(ctx->fcoeffs);
111 for (i = 0; i < ctx->avctx->channels; i++)
112 ff_iir_filter_free_state(ctx->fstate[i]);
113 av_freep(&ctx->fstate);