gecko/media/libopus/celt/celt_lpc.c
Ralph Giles 178bb65cbb Bug 790381 - Update libopus to 1.0.0 release. r=derf
Update files to match the opus-1.0.0 source release.
This corresponds to the spec implementation included
in RFC 6716.

Changes from the previous in-tree version (draft-12):

 - Add extern "C" protection on opus_multistream.h.
 - Align to sizeof(void*) instead of 4 bytes.
 - Copyright header updates for IETF publication.
 - Minor documentation and whitespace fixes.
2012-09-11 13:08:00 -07:00

198 lines
5.2 KiB
C

/* Copyright (c) 2009-2012 IETF Trust, Xiph.Org Foundation. All rights reserved.
Written by Jean-Marc Valin */
/*
This file is extracted from RFC6716. Please see that RFC for additional
information.
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 Internet Society, IETF or IETF Trust, nor the
names of specific 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 COPYRIGHT OWNER
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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "celt_lpc.h"
#include "stack_alloc.h"
#include "mathops.h"
void _celt_lpc(
opus_val16 *_lpc, /* out: [0...p-1] LPC coefficients */
const opus_val32 *ac, /* in: [0...p] autocorrelation values */
int p
)
{
int i, j;
opus_val32 r;
opus_val32 error = ac[0];
#ifdef FIXED_POINT
opus_val32 lpc[LPC_ORDER];
#else
float *lpc = _lpc;
#endif
for (i = 0; i < p; i++)
lpc[i] = 0;
if (ac[0] != 0)
{
for (i = 0; i < p; i++) {
/* Sum up this iteration's reflection coefficient */
opus_val32 rr = 0;
for (j = 0; j < i; j++)
rr += MULT32_32_Q31(lpc[j],ac[i - j]);
rr += SHR32(ac[i + 1],3);
r = -frac_div32(SHL32(rr,3), error);
/* Update LPC coefficients and total error */
lpc[i] = SHR32(r,3);
for (j = 0; j < (i+1)>>1; j++)
{
opus_val32 tmp1, tmp2;
tmp1 = lpc[j];
tmp2 = lpc[i-1-j];
lpc[j] = tmp1 + MULT32_32_Q31(r,tmp2);
lpc[i-1-j] = tmp2 + MULT32_32_Q31(r,tmp1);
}
error = error - MULT32_32_Q31(MULT32_32_Q31(r,r),error);
/* Bail out once we get 30 dB gain */
#ifdef FIXED_POINT
if (error<SHR32(ac[0],10))
break;
#else
if (error<.001f*ac[0])
break;
#endif
}
}
#ifdef FIXED_POINT
for (i=0;i<p;i++)
_lpc[i] = ROUND16(lpc[i],16);
#endif
}
void celt_fir(const opus_val16 *x,
const opus_val16 *num,
opus_val16 *y,
int N,
int ord,
opus_val16 *mem)
{
int i,j;
for (i=0;i<N;i++)
{
opus_val32 sum = SHL32(EXTEND32(x[i]), SIG_SHIFT);
for (j=0;j<ord;j++)
{
sum += MULT16_16(num[j],mem[j]);
}
for (j=ord-1;j>=1;j--)
{
mem[j]=mem[j-1];
}
mem[0] = x[i];
y[i] = ROUND16(sum, SIG_SHIFT);
}
}
void celt_iir(const opus_val32 *x,
const opus_val16 *den,
opus_val32 *y,
int N,
int ord,
opus_val16 *mem)
{
int i,j;
for (i=0;i<N;i++)
{
opus_val32 sum = x[i];
for (j=0;j<ord;j++)
{
sum -= MULT16_16(den[j],mem[j]);
}
for (j=ord-1;j>=1;j--)
{
mem[j]=mem[j-1];
}
mem[0] = ROUND16(sum,SIG_SHIFT);
y[i] = sum;
}
}
void _celt_autocorr(
const opus_val16 *x, /* in: [0...n-1] samples x */
opus_val32 *ac, /* out: [0...lag-1] ac values */
const opus_val16 *window,
int overlap,
int lag,
int n
)
{
opus_val32 d;
int i;
VARDECL(opus_val16, xx);
SAVE_STACK;
ALLOC(xx, n, opus_val16);
celt_assert(n>0);
celt_assert(overlap>=0);
for (i=0;i<n;i++)
xx[i] = x[i];
for (i=0;i<overlap;i++)
{
xx[i] = MULT16_16_Q15(x[i],window[i]);
xx[n-i-1] = MULT16_16_Q15(x[n-i-1],window[i]);
}
#ifdef FIXED_POINT
{
opus_val32 ac0=0;
int shift;
for(i=0;i<n;i++)
ac0 += SHR32(MULT16_16(xx[i],xx[i]),9);
ac0 += 1+n;
shift = celt_ilog2(ac0)-30+10;
shift = (shift+1)/2;
for(i=0;i<n;i++)
xx[i] = VSHR32(xx[i], shift);
}
#endif
while (lag>=0)
{
for (i = lag, d = 0; i < n; i++)
d += xx[i] * xx[i-lag];
ac[lag] = d;
/*printf ("%f ", ac[lag]);*/
lag--;
}
/*printf ("\n");*/
ac[0] += 10;
RESTORE_STACK;
}