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4349 | Serge | 1 | /* |
2 | * audio encoder psychoacoustic model |
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3 | * Copyright (C) 2008 Konstantin Shishkov |
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4 | * |
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5 | * This file is part of FFmpeg. |
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6 | * |
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7 | * FFmpeg is free software; you can redistribute it and/or |
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8 | * modify it under the terms of the GNU Lesser General Public |
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9 | * License as published by the Free Software Foundation; either |
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10 | * version 2.1 of the License, or (at your option) any later version. |
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11 | * |
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12 | * FFmpeg is distributed in the hope that it will be useful, |
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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15 | * Lesser General Public License for more details. |
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16 | * |
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17 | * You should have received a copy of the GNU Lesser General Public |
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18 | * License along with FFmpeg; if not, write to the Free Software |
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19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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20 | */ |
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21 | |||
22 | #include |
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23 | |||
24 | #include "avcodec.h" |
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25 | #include "psymodel.h" |
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26 | #include "iirfilter.h" |
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27 | #include "libavutil/mem.h" |
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28 | |||
29 | extern const FFPsyModel ff_aac_psy_model; |
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30 | |||
31 | av_cold int ff_psy_init(FFPsyContext *ctx, AVCodecContext *avctx, int num_lens, |
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32 | const uint8_t **bands, const int* num_bands, |
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33 | int num_groups, const uint8_t *group_map) |
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34 | { |
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35 | int i, j, k = 0; |
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36 | |||
37 | ctx->avctx = avctx; |
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38 | ctx->ch = av_mallocz(sizeof(ctx->ch[0]) * avctx->channels * 2); |
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39 | ctx->group = av_mallocz(sizeof(ctx->group[0]) * num_groups); |
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40 | ctx->bands = av_malloc (sizeof(ctx->bands[0]) * num_lens); |
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41 | ctx->num_bands = av_malloc (sizeof(ctx->num_bands[0]) * num_lens); |
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42 | memcpy(ctx->bands, bands, sizeof(ctx->bands[0]) * num_lens); |
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43 | memcpy(ctx->num_bands, num_bands, sizeof(ctx->num_bands[0]) * num_lens); |
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44 | |||
45 | /* assign channels to groups (with virtual channels for coupling) */ |
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46 | for (i = 0; i < num_groups; i++) { |
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47 | /* NOTE: Add 1 to handle the AAC chan_config without modification. |
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48 | * This has the side effect of allowing an array of 0s to map |
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49 | * to one channel per group. |
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50 | */ |
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51 | ctx->group[i].num_ch = group_map[i] + 1; |
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52 | for (j = 0; j < ctx->group[i].num_ch * 2; j++) |
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53 | ctx->group[i].ch[j] = &ctx->ch[k++]; |
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54 | } |
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55 | |||
56 | switch (ctx->avctx->codec_id) { |
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57 | case AV_CODEC_ID_AAC: |
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58 | ctx->model = &ff_aac_psy_model; |
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59 | break; |
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60 | } |
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61 | if (ctx->model->init) |
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62 | return ctx->model->init(ctx); |
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63 | return 0; |
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64 | } |
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65 | |||
66 | FFPsyChannelGroup *ff_psy_find_group(FFPsyContext *ctx, int channel) |
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67 | { |
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68 | int i = 0, ch = 0; |
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69 | |||
70 | while (ch <= channel) |
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71 | ch += ctx->group[i++].num_ch; |
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72 | |||
73 | return &ctx->group[i-1]; |
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74 | } |
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75 | |||
76 | av_cold void ff_psy_end(FFPsyContext *ctx) |
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77 | { |
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78 | if (ctx->model && ctx->model->end) |
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79 | ctx->model->end(ctx); |
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80 | av_freep(&ctx->bands); |
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81 | av_freep(&ctx->num_bands); |
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82 | av_freep(&ctx->group); |
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83 | av_freep(&ctx->ch); |
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84 | } |
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85 | |||
86 | typedef struct FFPsyPreprocessContext{ |
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87 | AVCodecContext *avctx; |
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88 | float stereo_att; |
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89 | struct FFIIRFilterCoeffs *fcoeffs; |
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90 | struct FFIIRFilterState **fstate; |
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91 | struct FFIIRFilterContext fiir; |
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92 | }FFPsyPreprocessContext; |
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93 | |||
94 | #define FILT_ORDER 4 |
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95 | |||
96 | av_cold struct FFPsyPreprocessContext* ff_psy_preprocess_init(AVCodecContext *avctx) |
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97 | { |
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98 | FFPsyPreprocessContext *ctx; |
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99 | int i; |
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100 | float cutoff_coeff = 0; |
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101 | ctx = av_mallocz(sizeof(FFPsyPreprocessContext)); |
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102 | ctx->avctx = avctx; |
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103 | |||
104 | if (avctx->cutoff > 0) |
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105 | cutoff_coeff = 2.0 * avctx->cutoff / avctx->sample_rate; |
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106 | |||
107 | if (!cutoff_coeff && avctx->codec_id == AV_CODEC_ID_AAC) |
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108 | cutoff_coeff = 2.0 * AAC_CUTOFF(avctx) / avctx->sample_rate; |
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109 | |||
110 | if (cutoff_coeff && cutoff_coeff < 0.98) |
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111 | ctx->fcoeffs = ff_iir_filter_init_coeffs(avctx, FF_FILTER_TYPE_BUTTERWORTH, |
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112 | FF_FILTER_MODE_LOWPASS, FILT_ORDER, |
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113 | cutoff_coeff, 0.0, 0.0); |
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114 | if (ctx->fcoeffs) { |
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115 | ctx->fstate = av_mallocz(sizeof(ctx->fstate[0]) * avctx->channels); |
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116 | for (i = 0; i < avctx->channels; i++) |
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117 | ctx->fstate[i] = ff_iir_filter_init_state(FILT_ORDER); |
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118 | } |
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119 | |||
120 | ff_iir_filter_init(&ctx->fiir); |
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121 | |||
122 | return ctx; |
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123 | } |
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124 | |||
125 | void ff_psy_preprocess(struct FFPsyPreprocessContext *ctx, float **audio, int channels) |
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126 | { |
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127 | int ch; |
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128 | int frame_size = ctx->avctx->frame_size; |
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129 | FFIIRFilterContext *iir = &ctx->fiir; |
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130 | |||
131 | if (ctx->fstate) { |
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132 | for (ch = 0; ch < channels; ch++) |
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133 | iir->filter_flt(ctx->fcoeffs, ctx->fstate[ch], frame_size, |
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134 | &audio[ch][frame_size], 1, &audio[ch][frame_size], 1); |
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135 | } |
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136 | } |
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137 | |||
138 | av_cold void ff_psy_preprocess_end(struct FFPsyPreprocessContext *ctx) |
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139 | { |
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140 | int i; |
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141 | ff_iir_filter_free_coeffs(ctx->fcoeffs); |
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142 | if (ctx->fstate) |
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143 | for (i = 0; i < ctx->avctx->channels; i++) |
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144 | ff_iir_filter_free_state(ctx->fstate[i]); |
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145 | av_freep(&ctx->fstate); |
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146 | av_free(ctx); |
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147 | }>>>>=>>> |