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Diffstat (limited to 'gr-vocoder/lib/codec2/lpc.h')
| -rw-r--r-- | gr-vocoder/lib/codec2/lpc.h | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/gr-vocoder/lib/codec2/lpc.h b/gr-vocoder/lib/codec2/lpc.h new file mode 100644 index 000000000..ead05e1ba --- /dev/null +++ b/gr-vocoder/lib/codec2/lpc.h @@ -0,0 +1,42 @@ +/*---------------------------------------------------------------------------*\ + + FILE........: lpc.h + AUTHOR......: David Rowe + DATE CREATED: 24/8/09 + + Linear Prediction functions written in C. + +\*---------------------------------------------------------------------------*/ + +/* + Copyright (C) 2009 David Rowe + + All rights reserved. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License version 2.1, as + published by the Free Software Foundation. This program is + distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public + License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. +*/ + +#ifndef __LPC__ +#define __LPC__ + +#define LPC_MAX_ORDER 20 + +void hanning_window(float Sn[], float Wn[], int Nsam); +void autocorrelate(float Sn[], float Rn[], int Nsam, int order); +void autocorrelate_freq(float Pw[], float w[], float R[], int Nsam, int order); +void levinson_durbin(float R[], float lpcs[], int order); +void inverse_filter(float Sn[], float a[], int Nsam, float res[], int order); +void synthesis_filter(float res[], float a[], int Nsam, int order, float Sn_[]); +void find_aks(float Sn[], float a[], int Nsam, int order, float *E); +void weight(float ak[], float gamma, int order, float akw[]); + +#endif |