ref: ef1339a8301a0e52dce4a09d0febb8c8bf7074da
dir: /src/libflac/lpc.c/
/* libFLAC - Free Lossless Audio Codec library * Copyright (C) 2000-2009 Josh Coalson * Copyright (C) 2011-2016 Xiph.Org Foundation * * 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 <math.h> #include "FLAC/format.h" #include "share/compat.h" #include "private/bitmath.h" #include "private/lpc.h" #include "private/macros.h" /* OPT: #undef'ing this may improve the speed on some architectures */ #define FLAC__LPC_UNROLLED_FILTER_LOOPS #if defined(_MSC_VER) && (_MSC_VER < 1800) #include <float.h> static inline long int lround(double x) { return (long)(x + _copysign(0.5, x)); } #endif void FLAC__lpc_window_data(const FLAC__int32 in[], const FLAC__real window[], FLAC__real out[], uint32_t data_len) { uint32_t i; for(i = 0; i < data_len; i++) out[i] = in[i] * window[i]; } void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], uint32_t data_len, uint32_t lag, FLAC__real autoc[]) { /* * this version tends to run faster because of better data locality * ('data_len' is usually much larger than 'lag') */ FLAC__real d; uint32_t sample, coeff; const uint32_t limit = data_len - lag; for(coeff = 0; coeff < lag; coeff++) autoc[coeff] = 0.0; for(sample = 0; sample <= limit; sample++) { d = data[sample]; for(coeff = 0; coeff < lag; coeff++) autoc[coeff] += d * data[sample+coeff]; } for(; sample < data_len; sample++) { d = data[sample]; for(coeff = 0; coeff < data_len - sample; coeff++) autoc[coeff] += d * data[sample+coeff]; } } void FLAC__lpc_compute_lp_coefficients(const FLAC__real autoc[], uint32_t *max_order, FLAC__real lp_coeff[][FLAC__MAX_LPC_ORDER], double error[]) { uint32_t i, j; double r, err, lpc[FLAC__MAX_LPC_ORDER]; err = autoc[0]; for(i = 0; i < *max_order; i++) { /* Sum up this iteration's reflection coefficient. */ r = -autoc[i+1]; for(j = 0; j < i; j++) r -= lpc[j] * autoc[i-j]; r /= err; /* Update LPC coefficients and total error. */ lpc[i]=r; for(j = 0; j < (i>>1); j++) { double tmp = lpc[j]; lpc[j] += r * lpc[i-1-j]; lpc[i-1-j] += r * tmp; } if(i & 1) lpc[j] += lpc[j] * r; err *= (1.0 - r * r); /* save this order */ for(j = 0; j <= i; j++) lp_coeff[i][j] = (FLAC__real)(-lpc[j]); /* negate FIR filter coeff to get predictor coeff */ error[i] = err; /* see SF bug https://sourceforge.net/p/flac/bugs/234/ */ if(err == 0.0) { *max_order = i+1; return; } } } int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], uint32_t order, uint32_t precision, FLAC__int32 qlp_coeff[], int *shift) { uint32_t i; double cmax; FLAC__int32 qmax, qmin; /* drop one bit for the sign; from here on out we consider only |lp_coeff[i]| */ precision--; qmax = 1 << precision; qmin = -qmax; qmax--; /* calc cmax = max( |lp_coeff[i]| ) */ cmax = 0.0; for(i = 0; i < order; i++) { const double d = fabs(lp_coeff[i]); if(d > cmax) cmax = d; } if(cmax <= 0.0) { /* => coefficients are all 0, which means our constant-detect didn't work */ return 2; } else { const int max_shiftlimit = (1 << (FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN-1)) - 1; const int min_shiftlimit = -max_shiftlimit - 1; int log2cmax; (void)frexp(cmax, &log2cmax); log2cmax--; *shift = (int)precision - log2cmax - 1; if(*shift > max_shiftlimit) *shift = max_shiftlimit; else if(*shift < min_shiftlimit) return 1; } if(*shift >= 0) { double error = 0.0; FLAC__int32 q; for(i = 0; i < order; i++) { error += lp_coeff[i] * (1 << *shift); q = lround(error); if(q > qmax) q = qmax; else if(q < qmin) q = qmin; error -= q; qlp_coeff[i] = q; } } /* negative shift is very rare but due to design flaw, negative shift is * not allowed in the decoder, so it must be handled specially by scaling * down coeffs */ else { const int nshift = -(*shift); double error = 0.0; FLAC__int32 q; for(i = 0; i < order; i++) { error += lp_coeff[i] / (1 << nshift); q = lround(error); if(q > qmax) q = qmax; else if(q < qmin) q = qmin; error -= q; qlp_coeff[i] = q; } *shift = 0; } return 0; } #if defined(_MSC_VER) // silence MSVC warnings about __restrict modifier #pragma warning ( disable : 4028 ) #endif void FLAC__lpc_compute_residual_from_qlp_coefficients(const FLAC__int32 * flac_restrict data, uint32_t data_len, const FLAC__int32 * flac_restrict qlp_coeff, uint32_t order, int lp_quantization, FLAC__int32 * flac_restrict residual) #if !defined(FLAC__LPC_UNROLLED_FILTER_LOOPS) { FLAC__int64 sumo; uint32_t i, j; FLAC__int32 sum; const FLAC__int32 *history; FLAC__ASSERT(order > 0); for(i = 0; i < data_len; i++) { sumo = 0; sum = 0; history = data; for(j = 0; j < order; j++) { sum += qlp_coeff[j] * (*(--history)); sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history); if(sumo > 2147483647ll || sumo < -2147483648ll) fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%" PRId64 "\n",i,j,qlp_coeff[j],*history,sumo); } *(residual++) = *(data++) - (sum >> lp_quantization); } } #else /* fully unrolled version for normal use */ { int i; FLAC__int32 sum; /* * We do unique versions up to 12th order since that's the subset limit. * Also they are roughly ordered to match frequency of occurrence to * minimize branching. */ if(order <= 12) { if(order > 8) { if(order > 10) { if(order == 12) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[11] * data[i-12]; sum += qlp_coeff[10] * data[i-11]; sum += qlp_coeff[9] * data[i-10]; sum += qlp_coeff[8] * data[i-9]; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } else { /* order == 11 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[10] * data[i-11]; sum += qlp_coeff[9] * data[i-10]; sum += qlp_coeff[8] * data[i-9]; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } } else { if(order == 10) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[9] * data[i-10]; sum += qlp_coeff[8] * data[i-9]; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } else { /* order == 9 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[8] * data[i-9]; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } } } else if(order > 4) { if(order > 6) { if(order == 8) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } else { /* order == 7 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } } else { if(order == 6) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } else { /* order == 5 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } } } else { if(order > 2) { if(order == 4) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } else { /* order == 3 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } } else { if(order == 2) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; residual[i] = data[i] - (sum >> lp_quantization); } } else { /* order == 1 */ for(i = 0; i < (int)data_len; i++) residual[i] = data[i] - ((qlp_coeff[0] * data[i-1]) >> lp_quantization); } } } } else { /* order > 12 */ for(i = 0; i < (int)data_len; i++) { sum = 0; switch(order) { default: case 32: sum += qlp_coeff[31] * data[i-32]; /* Falls through. */ case 31: sum += qlp_coeff[30] * data[i-31]; /* Falls through. */ case 30: sum += qlp_coeff[29] * data[i-30]; /* Falls through. */ case 29: sum += qlp_coeff[28] * data[i-29]; /* Falls through. */ case 28: sum += qlp_coeff[27] * data[i-28]; /* Falls through. */ case 27: sum += qlp_coeff[26] * data[i-27]; /* Falls through. */ case 26: sum += qlp_coeff[25] * data[i-26]; /* Falls through. */ case 25: sum += qlp_coeff[24] * data[i-25]; /* Falls through. */ case 24: sum += qlp_coeff[23] * data[i-24]; /* Falls through. */ case 23: sum += qlp_coeff[22] * data[i-23]; /* Falls through. */ case 22: sum += qlp_coeff[21] * data[i-22]; /* Falls through. */ case 21: sum += qlp_coeff[20] * data[i-21]; /* Falls through. */ case 20: sum += qlp_coeff[19] * data[i-20]; /* Falls through. */ case 19: sum += qlp_coeff[18] * data[i-19]; /* Falls through. */ case 18: sum += qlp_coeff[17] * data[i-18]; /* Falls through. */ case 17: sum += qlp_coeff[16] * data[i-17]; /* Falls through. */ case 16: sum += qlp_coeff[15] * data[i-16]; /* Falls through. */ case 15: sum += qlp_coeff[14] * data[i-15]; /* Falls through. */ case 14: sum += qlp_coeff[13] * data[i-14]; /* Falls through. */ case 13: sum += qlp_coeff[12] * data[i-13]; sum += qlp_coeff[11] * data[i-12]; sum += qlp_coeff[10] * data[i-11]; sum += qlp_coeff[ 9] * data[i-10]; sum += qlp_coeff[ 8] * data[i- 9]; sum += qlp_coeff[ 7] * data[i- 8]; sum += qlp_coeff[ 6] * data[i- 7]; sum += qlp_coeff[ 5] * data[i- 6]; sum += qlp_coeff[ 4] * data[i- 5]; sum += qlp_coeff[ 3] * data[i- 4]; sum += qlp_coeff[ 2] * data[i- 3]; sum += qlp_coeff[ 1] * data[i- 2]; sum += qlp_coeff[ 0] * data[i- 1]; } residual[i] = data[i] - (sum >> lp_quantization); } } } #endif void FLAC__lpc_compute_residual_from_qlp_coefficients_wide(const FLAC__int32 * flac_restrict data, uint32_t data_len, const FLAC__int32 * flac_restrict qlp_coeff, uint32_t order, int lp_quantization, FLAC__int32 * flac_restrict residual) #if !defined(FLAC__LPC_UNROLLED_FILTER_LOOPS) { uint32_t i, j; FLAC__int64 sum; const FLAC__int32 *history; FLAC__ASSERT(order > 0); for(i = 0; i < data_len; i++) { sum = 0; history = data; for(j = 0; j < order; j++) sum += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*(--history)); if(FLAC__bitmath_silog2(sum >> lp_quantization) > 32) { fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, sum=%" PRId64 "\n", i, (sum >> lp_quantization)); break; } if(FLAC__bitmath_silog2((FLAC__int64)(*data) - (sum >> lp_quantization)) > 32) { fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, data=%d, sum=%" PRId64 ", residual=%" PRId64 "\n", i, *data, (int64_t)(sum >> lp_quantization), ((FLAC__int64)(*data) - (sum >> lp_quantization))); break; } *(residual++) = *(data++) - (FLAC__int32)(sum >> lp_quantization); } } #else /* fully unrolled version for normal use */ { int i; FLAC__int64 sum; /* * We do unique versions up to 12th order since that's the subset limit. * Also they are roughly ordered to match frequency of occurrence to * minimize branching. */ if(order <= 12) { if(order > 8) { if(order > 10) { if(order == 12) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[11] * (FLAC__int64)data[i-12]; sum += qlp_coeff[10] * (FLAC__int64)data[i-11]; sum += qlp_coeff[9] * (FLAC__int64)data[i-10]; sum += qlp_coeff[8] * (FLAC__int64)data[i-9]; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 11 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[10] * (FLAC__int64)data[i-11]; sum += qlp_coeff[9] * (FLAC__int64)data[i-10]; sum += qlp_coeff[8] * (FLAC__int64)data[i-9]; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } } else { if(order == 10) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[9] * (FLAC__int64)data[i-10]; sum += qlp_coeff[8] * (FLAC__int64)data[i-9]; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 9 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[8] * (FLAC__int64)data[i-9]; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } } } else if(order > 4) { if(order > 6) { if(order == 8) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 7 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } } else { if(order == 6) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 5 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } } } else { if(order > 2) { if(order == 4) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 3 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } } else { if(order == 2) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 1 */ for(i = 0; i < (int)data_len; i++) residual[i] = data[i] - (FLAC__int32)((qlp_coeff[0] * (FLAC__int64)data[i-1]) >> lp_quantization); } } } } else { /* order > 12 */ for(i = 0; i < (int)data_len; i++) { sum = 0; switch(order) { default: case 32: sum += qlp_coeff[31] * (FLAC__int64)data[i-32]; /* Falls through. */ case 31: sum += qlp_coeff[30] * (FLAC__int64)data[i-31]; /* Falls through. */ case 30: sum += qlp_coeff[29] * (FLAC__int64)data[i-30]; /* Falls through. */ case 29: sum += qlp_coeff[28] * (FLAC__int64)data[i-29]; /* Falls through. */ case 28: sum += qlp_coeff[27] * (FLAC__int64)data[i-28]; /* Falls through. */ case 27: sum += qlp_coeff[26] * (FLAC__int64)data[i-27]; /* Falls through. */ case 26: sum += qlp_coeff[25] * (FLAC__int64)data[i-26]; /* Falls through. */ case 25: sum += qlp_coeff[24] * (FLAC__int64)data[i-25]; /* Falls through. */ case 24: sum += qlp_coeff[23] * (FLAC__int64)data[i-24]; /* Falls through. */ case 23: sum += qlp_coeff[22] * (FLAC__int64)data[i-23]; /* Falls through. */ case 22: sum += qlp_coeff[21] * (FLAC__int64)data[i-22]; /* Falls through. */ case 21: sum += qlp_coeff[20] * (FLAC__int64)data[i-21]; /* Falls through. */ case 20: sum += qlp_coeff[19] * (FLAC__int64)data[i-20]; /* Falls through. */ case 19: sum += qlp_coeff[18] * (FLAC__int64)data[i-19]; /* Falls through. */ case 18: sum += qlp_coeff[17] * (FLAC__int64)data[i-18]; /* Falls through. */ case 17: sum += qlp_coeff[16] * (FLAC__int64)data[i-17]; /* Falls through. */ case 16: sum += qlp_coeff[15] * (FLAC__int64)data[i-16]; /* Falls through. */ case 15: sum += qlp_coeff[14] * (FLAC__int64)data[i-15]; /* Falls through. */ case 14: sum += qlp_coeff[13] * (FLAC__int64)data[i-14]; /* Falls through. */ case 13: sum += qlp_coeff[12] * (FLAC__int64)data[i-13]; sum += qlp_coeff[11] * (FLAC__int64)data[i-12]; sum += qlp_coeff[10] * (FLAC__int64)data[i-11]; sum += qlp_coeff[ 9] * (FLAC__int64)data[i-10]; sum += qlp_coeff[ 8] * (FLAC__int64)data[i- 9]; sum += qlp_coeff[ 7] * (FLAC__int64)data[i- 8]; sum += qlp_coeff[ 6] * (FLAC__int64)data[i- 7]; sum += qlp_coeff[ 5] * (FLAC__int64)data[i- 6]; sum += qlp_coeff[ 4] * (FLAC__int64)data[i- 5]; sum += qlp_coeff[ 3] * (FLAC__int64)data[i- 4]; sum += qlp_coeff[ 2] * (FLAC__int64)data[i- 3]; sum += qlp_coeff[ 1] * (FLAC__int64)data[i- 2]; sum += qlp_coeff[ 0] * (FLAC__int64)data[i- 1]; } residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization); } } } #endif void FLAC__lpc_restore_signal(const FLAC__int32 * flac_restrict residual, uint32_t data_len, const FLAC__int32 * flac_restrict qlp_coeff, uint32_t order, int lp_quantization, FLAC__int32 * flac_restrict data) #if !defined(FLAC__LPC_UNROLLED_FILTER_LOOPS) { FLAC__int64 sumo; uint32_t i, j; FLAC__int32 sum; const FLAC__int32 *r = residual, *history; FLAC__ASSERT(order > 0); for(i = 0; i < data_len; i++) { sumo = 0; sum = 0; history = data; for(j = 0; j < order; j++) { sum += qlp_coeff[j] * (*(--history)); sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history); if(sumo > 2147483647ll || sumo < -2147483648ll) fprintf(stderr,"FLAC__lpc_restore_signal: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%" PRId64 "\n",i,j,qlp_coeff[j],*history,sumo); } *(data++) = *(r++) + (sum >> lp_quantization); } } #else /* fully unrolled version for normal use */ { int i; FLAC__int32 sum; /* * We do unique versions up to 12th order since that's the subset limit. * Also they are roughly ordered to match frequency of occurrence to * minimize branching. */ if(order <= 12) { if(order > 8) { if(order > 10) { if(order == 12) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[11] * data[i-12]; sum += qlp_coeff[10] * data[i-11]; sum += qlp_coeff[9] * data[i-10]; sum += qlp_coeff[8] * data[i-9]; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } else { /* order == 11 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[10] * data[i-11]; sum += qlp_coeff[9] * data[i-10]; sum += qlp_coeff[8] * data[i-9]; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } } else { if(order == 10) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[9] * data[i-10]; sum += qlp_coeff[8] * data[i-9]; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } else { /* order == 9 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[8] * data[i-9]; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } } } else if(order > 4) { if(order > 6) { if(order == 8) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[7] * data[i-8]; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } else { /* order == 7 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[6] * data[i-7]; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } } else { if(order == 6) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[5] * data[i-6]; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } else { /* order == 5 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[4] * data[i-5]; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } } } else { if(order > 2) { if(order == 4) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[3] * data[i-4]; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } else { /* order == 3 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[2] * data[i-3]; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } } else { if(order == 2) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[1] * data[i-2]; sum += qlp_coeff[0] * data[i-1]; data[i] = residual[i] + (sum >> lp_quantization); } } else { /* order == 1 */ for(i = 0; i < (int)data_len; i++) data[i] = residual[i] + ((qlp_coeff[0] * data[i-1]) >> lp_quantization); } } } } else { /* order > 12 */ for(i = 0; i < (int)data_len; i++) { sum = 0; switch(order) { default: case 32: sum += qlp_coeff[31] * data[i-32]; /* Falls through. */ case 31: sum += qlp_coeff[30] * data[i-31]; /* Falls through. */ case 30: sum += qlp_coeff[29] * data[i-30]; /* Falls through. */ case 29: sum += qlp_coeff[28] * data[i-29]; /* Falls through. */ case 28: sum += qlp_coeff[27] * data[i-28]; /* Falls through. */ case 27: sum += qlp_coeff[26] * data[i-27]; /* Falls through. */ case 26: sum += qlp_coeff[25] * data[i-26]; /* Falls through. */ case 25: sum += qlp_coeff[24] * data[i-25]; /* Falls through. */ case 24: sum += qlp_coeff[23] * data[i-24]; /* Falls through. */ case 23: sum += qlp_coeff[22] * data[i-23]; /* Falls through. */ case 22: sum += qlp_coeff[21] * data[i-22]; /* Falls through. */ case 21: sum += qlp_coeff[20] * data[i-21]; /* Falls through. */ case 20: sum += qlp_coeff[19] * data[i-20]; /* Falls through. */ case 19: sum += qlp_coeff[18] * data[i-19]; /* Falls through. */ case 18: sum += qlp_coeff[17] * data[i-18]; /* Falls through. */ case 17: sum += qlp_coeff[16] * data[i-17]; /* Falls through. */ case 16: sum += qlp_coeff[15] * data[i-16]; /* Falls through. */ case 15: sum += qlp_coeff[14] * data[i-15]; /* Falls through. */ case 14: sum += qlp_coeff[13] * data[i-14]; /* Falls through. */ case 13: sum += qlp_coeff[12] * data[i-13]; sum += qlp_coeff[11] * data[i-12]; sum += qlp_coeff[10] * data[i-11]; sum += qlp_coeff[ 9] * data[i-10]; sum += qlp_coeff[ 8] * data[i- 9]; sum += qlp_coeff[ 7] * data[i- 8]; sum += qlp_coeff[ 6] * data[i- 7]; sum += qlp_coeff[ 5] * data[i- 6]; sum += qlp_coeff[ 4] * data[i- 5]; sum += qlp_coeff[ 3] * data[i- 4]; sum += qlp_coeff[ 2] * data[i- 3]; sum += qlp_coeff[ 1] * data[i- 2]; sum += qlp_coeff[ 0] * data[i- 1]; } data[i] = residual[i] + (sum >> lp_quantization); } } } #endif void FLAC__lpc_restore_signal_wide(const FLAC__int32 * flac_restrict residual, uint32_t data_len, const FLAC__int32 * flac_restrict qlp_coeff, uint32_t order, int lp_quantization, FLAC__int32 * flac_restrict data) #if !defined(FLAC__LPC_UNROLLED_FILTER_LOOPS) { uint32_t i, j; FLAC__int64 sum; const FLAC__int32 *r = residual, *history; FLAC__ASSERT(order > 0); for(i = 0; i < data_len; i++) { sum = 0; history = data; for(j = 0; j < order; j++) sum += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*(--history)); if(FLAC__bitmath_silog2(sum >> lp_quantization) > 32) { fprintf(stderr,"FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, sum=%" PRId64 "\n", i, (sum >> lp_quantization)); break; } if(FLAC__bitmath_silog2((FLAC__int64)(*r) + (sum >> lp_quantization)) > 32) { fprintf(stderr,"FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, residual=%d, sum=%" PRId64 ", data=%" PRId64 "\n", i, *r, (sum >> lp_quantization), ((FLAC__int64)(*r) + (sum >> lp_quantization))); break; } *(data++) = *(r++) + (FLAC__int32)(sum >> lp_quantization); } } #else /* fully unrolled version for normal use */ { int i; FLAC__int64 sum; /* * We do unique versions up to 12th order since that's the subset limit. * Also they are roughly ordered to match frequency of occurrence to * minimize branching. */ if(order <= 12) { if(order > 8) { if(order > 10) { if(order == 12) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[11] * (FLAC__int64)data[i-12]; sum += qlp_coeff[10] * (FLAC__int64)data[i-11]; sum += qlp_coeff[9] * (FLAC__int64)data[i-10]; sum += qlp_coeff[8] * (FLAC__int64)data[i-9]; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 11 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[10] * (FLAC__int64)data[i-11]; sum += qlp_coeff[9] * (FLAC__int64)data[i-10]; sum += qlp_coeff[8] * (FLAC__int64)data[i-9]; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } } else { if(order == 10) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[9] * (FLAC__int64)data[i-10]; sum += qlp_coeff[8] * (FLAC__int64)data[i-9]; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 9 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[8] * (FLAC__int64)data[i-9]; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } } } else if(order > 4) { if(order > 6) { if(order == 8) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[7] * (FLAC__int64)data[i-8]; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 7 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[6] * (FLAC__int64)data[i-7]; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } } else { if(order == 6) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[5] * (FLAC__int64)data[i-6]; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 5 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[4] * (FLAC__int64)data[i-5]; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } } } else { if(order > 2) { if(order == 4) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[3] * (FLAC__int64)data[i-4]; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 3 */ for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[2] * (FLAC__int64)data[i-3]; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } } else { if(order == 2) { for(i = 0; i < (int)data_len; i++) { sum = 0; sum += qlp_coeff[1] * (FLAC__int64)data[i-2]; sum += qlp_coeff[0] * (FLAC__int64)data[i-1]; data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } else { /* order == 1 */ for(i = 0; i < (int)data_len; i++) data[i] = residual[i] + (FLAC__int32)((qlp_coeff[0] * (FLAC__int64)data[i-1]) >> lp_quantization); } } } } else { /* order > 12 */ for(i = 0; i < (int)data_len; i++) { sum = 0; switch(order) { default: case 32: sum += qlp_coeff[31] * (FLAC__int64)data[i-32]; /* Falls through. */ case 31: sum += qlp_coeff[30] * (FLAC__int64)data[i-31]; /* Falls through. */ case 30: sum += qlp_coeff[29] * (FLAC__int64)data[i-30]; /* Falls through. */ case 29: sum += qlp_coeff[28] * (FLAC__int64)data[i-29]; /* Falls through. */ case 28: sum += qlp_coeff[27] * (FLAC__int64)data[i-28]; /* Falls through. */ case 27: sum += qlp_coeff[26] * (FLAC__int64)data[i-27]; /* Falls through. */ case 26: sum += qlp_coeff[25] * (FLAC__int64)data[i-26]; /* Falls through. */ case 25: sum += qlp_coeff[24] * (FLAC__int64)data[i-25]; /* Falls through. */ case 24: sum += qlp_coeff[23] * (FLAC__int64)data[i-24]; /* Falls through. */ case 23: sum += qlp_coeff[22] * (FLAC__int64)data[i-23]; /* Falls through. */ case 22: sum += qlp_coeff[21] * (FLAC__int64)data[i-22]; /* Falls through. */ case 21: sum += qlp_coeff[20] * (FLAC__int64)data[i-21]; /* Falls through. */ case 20: sum += qlp_coeff[19] * (FLAC__int64)data[i-20]; /* Falls through. */ case 19: sum += qlp_coeff[18] * (FLAC__int64)data[i-19]; /* Falls through. */ case 18: sum += qlp_coeff[17] * (FLAC__int64)data[i-18]; /* Falls through. */ case 17: sum += qlp_coeff[16] * (FLAC__int64)data[i-17]; /* Falls through. */ case 16: sum += qlp_coeff[15] * (FLAC__int64)data[i-16]; /* Falls through. */ case 15: sum += qlp_coeff[14] * (FLAC__int64)data[i-15]; /* Falls through. */ case 14: sum += qlp_coeff[13] * (FLAC__int64)data[i-14]; /* Falls through. */ case 13: sum += qlp_coeff[12] * (FLAC__int64)data[i-13]; sum += qlp_coeff[11] * (FLAC__int64)data[i-12]; sum += qlp_coeff[10] * (FLAC__int64)data[i-11]; sum += qlp_coeff[ 9] * (FLAC__int64)data[i-10]; sum += qlp_coeff[ 8] * (FLAC__int64)data[i- 9]; sum += qlp_coeff[ 7] * (FLAC__int64)data[i- 8]; sum += qlp_coeff[ 6] * (FLAC__int64)data[i- 7]; sum += qlp_coeff[ 5] * (FLAC__int64)data[i- 6]; sum += qlp_coeff[ 4] * (FLAC__int64)data[i- 5]; sum += qlp_coeff[ 3] * (FLAC__int64)data[i- 4]; sum += qlp_coeff[ 2] * (FLAC__int64)data[i- 3]; sum += qlp_coeff[ 1] * (FLAC__int64)data[i- 2]; sum += qlp_coeff[ 0] * (FLAC__int64)data[i- 1]; } data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization); } } } #endif #if defined(_MSC_VER) #pragma warning ( default : 4028 ) #endif double FLAC__lpc_compute_expected_bits_per_residual_sample(double lpc_error, uint32_t total_samples) { double error_scale; error_scale = 0.5 / (double)total_samples; return FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error, error_scale); } double FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(double lpc_error, double error_scale) { if(lpc_error > 0.0) { double bps = (double)0.5 * log(error_scale * lpc_error) / M_LN2; if(bps >= 0.0) return bps; else return 0.0; } else if(lpc_error < 0.0) { /* error should not be negative but can happen due to inadequate floating-point resolution */ return 1e32; } else { return 0.0; } } uint32_t FLAC__lpc_compute_best_order(const double lpc_error[], uint32_t max_order, uint32_t total_samples, uint32_t overhead_bits_per_order) { uint32_t order, indx, best_index; /* 'index' the index into lpc_error; index==order-1 since lpc_error[0] is for order==1, lpc_error[1] is for order==2, etc */ double bits, best_bits, error_scale; error_scale = 0.5 / (double)total_samples; best_index = 0; best_bits = (uint32_t)(-1); for(indx = 0, order = 1; indx < max_order; indx++, order++) { bits = FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error[indx], error_scale) * (double)(total_samples - order) + (double)(order * overhead_bits_per_order); if(bits < best_bits) { best_index = indx; best_bits = bits; } } return best_index+1; /* +1 since indx of lpc_error[] is order-1 */ }