1 | /* |
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2 | Copyright (C) 2003-2013 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 | /** \file |
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22 | |
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23 | Phase vocoder object |
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24 | |
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25 | This object implements a phase vocoder. The spectral frames are computed |
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26 | using a HanningZ window and a swapped version of the signal to simplify the |
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27 | phase relationships across frames. The window sizes and overlap are specified |
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28 | at creation time. |
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29 | |
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30 | \example spectral/test-phasevoc.c |
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31 | |
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32 | */ |
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33 | |
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34 | #ifndef AUBIO_PHASEVOC_H |
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35 | #define AUBIO_PHASEVOC_H |
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36 | |
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37 | #ifdef __cplusplus |
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38 | extern "C" { |
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39 | #endif |
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40 | |
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41 | /** phasevocoder object */ |
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42 | typedef struct _aubio_pvoc_t aubio_pvoc_t; |
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43 | |
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44 | /** create phase vocoder object |
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45 | |
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46 | \param win_s size of analysis buffer (and length the FFT transform) |
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47 | \param hop_s step size between two consecutive analysis |
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48 | |
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49 | */ |
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50 | aubio_pvoc_t * new_aubio_pvoc (uint_t win_s, uint_t hop_s); |
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51 | /** delete phase vocoder object |
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52 | |
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53 | \param pv phase vocoder object as returned by new_aubio_pvoc |
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54 | |
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55 | */ |
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56 | void del_aubio_pvoc(aubio_pvoc_t *pv); |
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57 | |
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58 | /** compute spectral frame |
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59 | |
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60 | This function accepts an input vector of size [hop_s]. The |
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61 | analysis buffer is rotated and filled with the new data. After windowing of |
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62 | this signal window, the Fourier transform is computed and returned in |
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63 | fftgrain as two vectors, magnitude and phase. |
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64 | |
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65 | \param pv phase vocoder object as returned by new_aubio_pvoc |
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66 | \param in new input signal (hop_s long) |
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67 | \param fftgrain output spectral frame |
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68 | |
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69 | */ |
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70 | void aubio_pvoc_do(aubio_pvoc_t *pv, const fvec_t *in, cvec_t * fftgrain); |
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71 | /** compute signal from spectral frame |
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72 | |
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73 | This function takes an input spectral frame fftgrain of size |
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74 | [buf_s] and computes its inverse Fourier transform. Overlap-add |
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75 | synthesis is then computed using the previously synthetised frames, and the |
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76 | output stored in out. |
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77 | |
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78 | \param pv phase vocoder object as returned by new_aubio_pvoc |
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79 | \param fftgrain input spectral frame |
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80 | \param out output signal (hop_s long) |
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81 | |
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82 | */ |
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83 | void aubio_pvoc_rdo(aubio_pvoc_t *pv, cvec_t * fftgrain, fvec_t *out); |
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84 | |
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85 | /** get window size |
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86 | |
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87 | \param pv phase vocoder to get the window size from |
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88 | |
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89 | */ |
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90 | uint_t aubio_pvoc_get_win(aubio_pvoc_t* pv); |
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91 | /** get hop size |
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92 | |
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93 | \param pv phase vocoder to get the hop size from |
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94 | |
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95 | */ |
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96 | uint_t aubio_pvoc_get_hop(aubio_pvoc_t* pv); |
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97 | |
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98 | /** set window type |
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99 | |
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100 | \param pv phase vocoder to set the window type |
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101 | \param window_type a string representing a window |
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102 | |
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103 | \return 0 if successful, non-zero otherwise |
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104 | |
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105 | */ |
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106 | uint_t aubio_pvoc_set_window(aubio_pvoc_t *pv, const char_t *window_type); |
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107 | |
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108 | #ifdef __cplusplus |
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109 | } |
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110 | #endif |
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111 | |
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112 | #endif /* AUBIO_PHASEVOC_H */ |
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