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Diffstat (limited to 'drivers/speex/lpc.c')
| -rw-r--r-- | drivers/speex/lpc.c | 201 |
1 files changed, 0 insertions, 201 deletions
diff --git a/drivers/speex/lpc.c b/drivers/speex/lpc.c deleted file mode 100644 index 6304efaa53..0000000000 --- a/drivers/speex/lpc.c +++ /dev/null @@ -1,201 +0,0 @@ -/* - Copyright 1992, 1993, 1994 by Jutta Degener and Carsten Bormann, - Technische Universitaet Berlin - - Any use of this software is permitted provided that this notice is not - removed and that neither the authors nor the Technische Universitaet Berlin - are deemed to have made any representations as to the suitability of this - software for any purpose nor are held responsible for any defects of - this software. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. - - As a matter of courtesy, the authors request to be informed about uses - this software has found, about bugs in this software, and about any - improvements that may be of general interest. - - Berlin, 28.11.1994 - Jutta Degener - Carsten Bormann - - - Code modified by Jean-Marc Valin - - Speex License: - - 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. -*/ - - -#include "config.h" - - -#include "lpc.h" - -#ifdef BFIN_ASM -#include "lpc_bfin.h" -#endif - -/* LPC analysis - * - * The next two functions calculate linear prediction coefficients - * and/or the related reflection coefficients from the first P_MAX+1 - * values of the autocorrelation function. - */ - -/* Invented by N. Levinson in 1947, modified by J. Durbin in 1959. - */ - -/* returns minimum mean square error */ -spx_word32_t _spx_lpc( -spx_coef_t *lpc, /* out: [0...p-1] LPC coefficients */ -const spx_word16_t *ac, /* in: [0...p] autocorrelation values */ -int p -) -{ - int i, j; - spx_word16_t r; - spx_word16_t error = ac[0]; - - if (ac[0] == 0) - { - for (i = 0; i < p; i++) - lpc[i] = 0; - return 0; - } - - for (i = 0; i < p; i++) { - - /* Sum up this iteration's reflection coefficient */ - spx_word32_t rr = NEG32(SHL32(EXTEND32(ac[i + 1]),13)); - for (j = 0; j < i; j++) - rr = SUB32(rr,MULT16_16(lpc[j],ac[i - j])); -#ifdef FIXED_POINT - r = DIV32_16(rr+PSHR32(error,1),ADD16(error,8)); -#else - r = rr/(error+.003*ac[0]); -#endif - /* Update LPC coefficients and total error */ - lpc[i] = r; - for (j = 0; j < i>>1; j++) - { - spx_word16_t tmp = lpc[j]; - lpc[j] = MAC16_16_P13(lpc[j],r,lpc[i-1-j]); - lpc[i-1-j] = MAC16_16_P13(lpc[i-1-j],r,tmp); - } - if (i & 1) - lpc[j] = MAC16_16_P13(lpc[j],lpc[j],r); - - error = SUB16(error,MULT16_16_Q13(r,MULT16_16_Q13(error,r))); - } - return error; -} - - -#ifdef FIXED_POINT - -/* Compute the autocorrelation - * ,--, - * ac(i) = > x(n) * x(n-i) for all n - * `--' - * for lags between 0 and lag-1, and x == 0 outside 0...n-1 - */ - -#ifndef OVERRIDE_SPEEX_AUTOCORR -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 d; - int i, j; - spx_word32_t ac0=1; - int shift, ac_shift; - - for (j=0;j<n;j++) - ac0 = ADD32(ac0,SHR32(MULT16_16(x[j],x[j]),8)); - ac0 = ADD32(ac0,n); - shift = 8; - while (shift && ac0<0x40000000) - { - shift--; - ac0 <<= 1; - } - ac_shift = 18; - while (ac_shift && ac0<0x40000000) - { - ac_shift--; - ac0 <<= 1; - } - - - for (i=0;i<lag;i++) - { - d=0; - for (j=i;j<n;j++) - { - d = ADD32(d,SHR32(MULT16_16(x[j],x[j-i]), shift)); - } - - ac[i] = SHR32(d, ac_shift); - } -} -#endif - - -#else - - - -/* Compute the autocorrelation - * ,--, - * ac(i) = > x(n) * x(n-i) for all n - * `--' - * for lags between 0 and lag-1, and x == 0 outside 0...n-1 - */ -void _spx_autocorr( -const spx_word16_t *x, /* in: [0...n-1] samples x */ -float *ac, /* out: [0...lag-1] ac values */ -int lag, -int n -) -{ - float d; - int i; - while (lag--) - { - for (i = lag, d = 0; i < n; i++) - d += x[i] * x[i-lag]; - ac[lag] = d; - } - ac[0] += 10; -} - -#endif - - |