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