1 | /* |
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2 | Copyright (C) 2018 Paul Brossier <piem@aubio.org> |
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3 | |
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4 | This file is part of aubio. |
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5 | |
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6 | aubio is free software: you can redistribute it and/or modify |
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7 | it under the terms of the GNU General Public License as published by |
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8 | the Free Software Foundation, either version 3 of the License, or |
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9 | (at your option) any later version. |
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10 | |
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11 | aubio is distributed in the hope that it will be useful, |
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12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | GNU General Public License for more details. |
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15 | |
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16 | You should have received a copy of the GNU General Public License |
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17 | along with aubio. If not, see <http://www.gnu.org/licenses/>. |
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18 | |
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19 | */ |
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20 | |
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21 | #include "aubio_priv.h" |
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22 | #include "fvec.h" |
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23 | #include "fmat.h" |
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24 | #include "spectral/dct.h" |
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25 | |
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26 | typedef struct _aubio_dct_plain_t aubio_dct_plain_t; |
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27 | |
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28 | struct _aubio_dct_plain_t { |
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29 | uint_t size; |
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30 | fmat_t *dct_coeffs; /** DCT type II orthonormal transform, size * size */ |
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31 | fmat_t *idct_coeffs; /** DCT type III orthonormal transform, size * size */ |
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32 | }; |
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33 | |
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34 | aubio_dct_plain_t * new_aubio_dct_plain (uint_t size) { |
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35 | aubio_dct_plain_t * s = AUBIO_NEW(aubio_dct_plain_t); |
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36 | uint_t i, j; |
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37 | smpl_t scaling; |
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38 | if (aubio_is_power_of_two (size) == 1 && size > 16) { |
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39 | AUBIO_WRN("dct_plain: using plain dct but size %d is a power of two", size); |
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40 | } |
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41 | |
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42 | s->size = size; |
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43 | |
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44 | s->dct_coeffs = new_fmat (size, size); |
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45 | s->idct_coeffs = new_fmat (size, size); |
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46 | |
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47 | /* compute DCT type-II transformation matrix |
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48 | dct_coeffs[j][i] = cos ( j * (i+.5) * PI / n_filters ) |
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49 | */ |
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50 | scaling = SQRT (2. / size); |
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51 | for (i = 0; i < size; i++) { |
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52 | for (j = 1; j < size; j++) { |
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53 | s->dct_coeffs->data[j][i] = |
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54 | scaling * COS (j * (i + 0.5) * PI / size ); |
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55 | } |
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56 | s->dct_coeffs->data[0][i] = 1. / SQRT (size); |
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57 | } |
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58 | |
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59 | /* compute DCT type-III transformation matrix |
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60 | idct_coeffs[j][i] = cos ( i * (j+.5) * PI / n_filters ) |
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61 | */ |
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62 | scaling = SQRT (2. / size); |
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63 | for (j = 0; j < size; j++) { |
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64 | for (i = 1; i < size; i++) { |
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65 | s->idct_coeffs->data[j][i] = |
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66 | scaling * COS (i * (j + 0.5) * PI / size ); |
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67 | } |
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68 | s->idct_coeffs->data[j][0] = 1. / SQRT (size); |
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69 | } |
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70 | return s; |
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71 | } |
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72 | |
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73 | void del_aubio_dct_plain (aubio_dct_plain_t *s) { |
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74 | del_fmat(s->dct_coeffs); |
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75 | del_fmat(s->idct_coeffs); |
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76 | AUBIO_FREE(s); |
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77 | } |
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78 | |
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79 | void aubio_dct_plain_do(aubio_dct_plain_t *s, const fvec_t *input, fvec_t *output) { |
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80 | if (input->length != output->length || input->length != s->size) { |
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81 | AUBIO_WRN("dct_plain: using input length %d, but output length = %d and size = %d", |
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82 | input->length, output->length, s->size); |
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83 | } |
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84 | fmat_vecmul(s->dct_coeffs, input, output); |
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85 | } |
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86 | |
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87 | void aubio_dct_plain_rdo(aubio_dct_plain_t *s, const fvec_t *input, fvec_t *output) { |
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88 | if (input->length != output->length || input->length != s->size) { |
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89 | AUBIO_WRN("dct_plain: using input length %d, but output length = %d and size = %d", |
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90 | input->length, output->length, s->size); |
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91 | } |
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92 | fmat_vecmul(s->idct_coeffs, input, output); |
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93 | } |
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