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Diffstat (limited to 'src/libspeex/lpc.h')
-rw-r--r-- | src/libspeex/lpc.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/libspeex/lpc.h b/src/libspeex/lpc.h new file mode 100644 index 0000000..952ecdd --- /dev/null +++ b/src/libspeex/lpc.h @@ -0,0 +1,53 @@ +/* Copyright (C) 2002 Jean-Marc Valin */ +/** + @file lpc.h + @brief Functions for LPC (Linear Prediction Coefficients) analysis +*/ +/* + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + - Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + - Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + - Neither the name of the Xiph.org Foundation nor the names of its + contributors may be used to endorse or promote products derived from + this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR + CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*/ + +#ifndef LPC_H +#define LPC_H + +#include "arch.h" + +void _spx_autocorr( + const spx_word16_t * x, /* in: [0...n-1] samples x */ + spx_word16_t *ac, /* out: [0...lag-1] ac values */ + int lag, int n); + +spx_word32_t /* returns minimum mean square error */ +_spx_lpc( + spx_coef_t * lpc, /* [0...p-1] LPC coefficients */ + const spx_word16_t * ac, /* in: [0...p] autocorrelation values */ + int p + ); + + +#endif |