2 Copyright (C) 2003 Paul Brossier
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 This object implements a phase vocoder. The spectral frames are computed
25 using a HanningZ window and a swapped version of the signal to simplify the
26 phase relationships across frames. The window sizes and overlap are specified
27 at creation time. Multiple channels are fully supported.
38 /** phasevocoder object */
39 typedef struct _aubio_pvoc_t aubio_pvoc_t;
41 /** create phase vocoder object
43 \param win_s size of analysis buffer (and length the FFT transform)
44 \param hop_s step size between two consecutive analysis
45 \param channels number of channels
48 aubio_pvoc_t * new_aubio_pvoc (uint_t win_s, uint_t hop_s, uint_t channels);
49 /** delete phase vocoder object
51 \param pv phase vocoder object as returned by new_aubio_pvoc
54 void del_aubio_pvoc(aubio_pvoc_t *pv);
56 /** compute spectral frame
58 This function accepts an input vector of size [channels]x[hop_s]. The
59 analysis buffer is rotated and filled with the new data. After windowing of
60 this signal window, the Fourier transform is computed and returned in
61 fftgrain as two vectors, magnitude and phase.
63 \param pv phase vocoder object as returned by new_aubio_pvoc
64 \param in new input signal (hop_s long)
65 \param fftgrain output spectral frame
68 void aubio_pvoc_do(aubio_pvoc_t *pv, fvec_t *in, cvec_t * fftgrain);
69 /** compute signal from spectral frame
71 This function takes an input spectral frame fftgrain of size
72 [channels]x[buf_s] and computes its inverse Fourier transform. Overlap-add
73 synthesis is then computed using the previously synthetised frames, and the
76 \param pv phase vocoder object as returned by new_aubio_pvoc
77 \param fftgrain input spectral frame
78 \param out output signal (hop_s long)
81 void aubio_pvoc_rdo(aubio_pvoc_t *pv, cvec_t * fftgrain, fvec_t *out);
85 \param pv phase vocoder to get the window size from
88 uint_t aubio_pvoc_get_win(aubio_pvoc_t* pv);
91 \param pv phase vocoder to get the hop size from
94 uint_t aubio_pvoc_get_hop(aubio_pvoc_t* pv);
95 /** get channel number
97 \param pv phase vocoder to get the number of channels from
100 uint_t aubio_pvoc_get_channels(aubio_pvoc_t* pv);