/* libFLAC - Free Lossless Audio Codec library
- * Copyright (C) 2000,2001 Josh Coalson
+ * Copyright (C) 2000,2001,2002,2003 Josh Coalson
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
*/
#include <math.h>
-#include <stdio.h>
#include "FLAC/assert.h"
#include "FLAC/format.h"
+#include "private/bitmath.h"
#include "private/lpc.h"
+#if defined DEBUG || defined FLAC__OVERFLOW_DETECT || defined FLAC__OVERFLOW_DETECT_VERBOSE
+#include <stdio.h>
+#endif
#ifndef M_LN2
/* math.h in VC++ doesn't seem to have this (how Microsoft is that?) */
#define M_LN2 0.69314718055994530942
#endif
-#define LOCAL_FABS(x) ((x)<0.0? -(x):(x))
-
void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[])
{
/* a readable, but slower, version */
}
}
-int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, unsigned bits_per_sample, FLAC__int32 qlp_coeff[], int *shift)
+int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int *shift)
{
unsigned i;
double d, cmax = -1e32;
const int max_shiftlimit = (1 << (FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN-1)) - 1;
const int min_shiftlimit = -max_shiftlimit - 1;
- FLAC__ASSERT(bits_per_sample > 0);
- FLAC__ASSERT(bits_per_sample <= sizeof(FLAC__int32)*8);
FLAC__ASSERT(precision > 0);
FLAC__ASSERT(precision >= FLAC__MIN_QLP_COEFF_PRECISION);
- FLAC__ASSERT(precision + bits_per_sample < sizeof(FLAC__int32)*8);
-#ifdef NDEBUG
- (void)bits_per_sample; /* silence compiler warning about unused parameter */
-#endif
/* drop one bit for the sign; from here on out we consider only |lp_coeff[i]| */
precision--;
for(i = 0; i < order; i++) {
if(lp_coeff[i] == 0.0)
continue;
- d = LOCAL_FABS(lp_coeff[i]);
+ d = fabs(lp_coeff[i]);
if(d > cmax)
cmax = d;
}
redo_it:
- if(cmax < 0.0) {
+ if(cmax <= 0.0) {
/* => coefficients are all 0, which means our constant-detect didn't work */
return 2;
}
else {
- const int log2cmax = (int)floor(log(cmax) / M_LN2); /* this is a good estimate but may not be precise enough, so we have to check for corner cases later when shifting */
- const int maxshift = (int)precision - log2cmax - 1;
+ int log2cmax;
- *shift = maxshift;
+ (void)frexp(cmax, &log2cmax);
+ log2cmax--;
+ *shift = (int)precision - log2cmax - 1;
if(*shift < min_shiftlimit || *shift > max_shiftlimit) {
- return 1;
+#if 0
+ /*@@@ this does not seem to help at all, but was not extensively tested either: */
+ if(*shift > max_shiftlimit)
+ *shift = max_shiftlimit;
+ else
+#endif
+ return 1;
}
}
for(i = 0; i < order; i++) {
qlp_coeff[i] = (FLAC__int32)floor((double)lp_coeff[i] * (double)(1 << *shift));
- /* check for corner cases mentioned in the comment for log2cmax above */
+ /* double-check the result */
if(qlp_coeff[i] > qmax || qlp_coeff[i] < qmin) {
#ifdef FLAC__OVERFLOW_DETECT
fprintf(stderr,"FLAC__lpc_quantize_coefficients: compensating for overflow, qlp_coeff[%u]=%d, lp_coeff[%u]=%f, cmax=%f, precision=%u, shift=%d, q=%f, f(q)=%f\n", i, qlp_coeff[i], i, lp_coeff[i], cmax, precision, *shift, (double)lp_coeff[i] * (double)(1 << *shift), floor((double)lp_coeff[i] * (double)(1 << *shift)));
}
else { /* (*shift < 0) */
const int nshift = -(*shift);
+#ifdef DEBUG
fprintf(stderr,"FLAC__lpc_quantize_coefficients: negative shift = %d\n", *shift);
+#endif
for(i = 0; i < order; i++) {
qlp_coeff[i] = (FLAC__int32)floor((double)lp_coeff[i] / (double)(1 << nshift));
- /* check for corner cases mentioned in the comment for log2cmax above */
+ /* double-check the result */
if(qlp_coeff[i] > qmax || qlp_coeff[i] < qmin) {
#ifdef FLAC__OVERFLOW_DETECT
fprintf(stderr,"FLAC__lpc_quantize_coefficients: compensating for overflow, qlp_coeff[%u]=%d, lp_coeff[%u]=%f, cmax=%f, precision=%u, shift=%d, q=%f, f(q)=%f\n", i, qlp_coeff[i], i, lp_coeff[i], cmax, precision, *shift, (double)lp_coeff[i] / (double)(1 << nshift), floor((double)lp_coeff[i] / (double)(1 << nshift)));
sum += qlp_coeff[j] * (*(--history));
#ifdef FLAC__OVERFLOW_DETECT
sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history);
- if(sumo > 2147483647ll || sumo < -2147483648ll) {
+#if defined _MSC_VER
+ if(sumo > 2147483647I64 || sumo < -2147483648I64)
+#else
+ if(sumo > 2147483647ll || sumo < -2147483648ll)
+#endif
+ {
fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%lld\n",i,j,qlp_coeff[j],*history,sumo);
}
#endif
*/
}
+void FLAC__lpc_compute_residual_from_qlp_coefficients_wide(const FLAC__int32 data[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[])
+{
+ unsigned i, j;
+ FLAC__int64 sum;
+ const FLAC__int32 *history;
+
+#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
+ fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
+ for(i=0;i<order;i++)
+ fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
+ fprintf(stderr,"\n");
+#endif
+ 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));
+#ifdef FLAC__OVERFLOW_DETECT
+ if(FLAC__bitmath_silog2_wide(sum >> lp_quantization) > 32) {
+ fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, sum=%lld\n", i, sum >> lp_quantization);
+ break;
+ }
+ if(FLAC__bitmath_silog2_wide((FLAC__int64)(*data) - (sum >> lp_quantization)) > 32) {
+ fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, data=%d, sum=%lld, residual=%lld\n", i, *data, sum >> lp_quantization, (FLAC__int64)(*data) - (sum >> lp_quantization));
+ break;
+ }
+#endif
+ *(residual++) = *(data++) - (FLAC__int32)(sum >> lp_quantization);
+ }
+}
+
void FLAC__lpc_restore_signal(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[])
{
#ifdef FLAC__OVERFLOW_DETECT
sum += qlp_coeff[j] * (*(--history));
#ifdef FLAC__OVERFLOW_DETECT
sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history);
- if(sumo > 2147483647ll || sumo < -2147483648ll) {
+#if defined _MSC_VER
+ if(sumo > 2147483647I64 || sumo < -2147483648I64)
+#else
+ if(sumo > 2147483647ll || sumo < -2147483648ll)
+#endif
+ {
fprintf(stderr,"FLAC__lpc_restore_signal: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%lld\n",i,j,qlp_coeff[j],*history,sumo);
}
#endif
*/
}
+void FLAC__lpc_restore_signal_wide(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[])
+{
+ unsigned i, j;
+ FLAC__int64 sum;
+ const FLAC__int32 *history;
+
+#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
+ fprintf(stderr,"FLAC__lpc_restore_signal_wide: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
+ for(i=0;i<order;i++)
+ fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
+ fprintf(stderr,"\n");
+#endif
+ 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));
+#ifdef FLAC__OVERFLOW_DETECT
+ if(FLAC__bitmath_silog2_wide(sum >> lp_quantization) > 32) {
+ fprintf(stderr,"FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, sum=%lld\n", i, sum >> lp_quantization);
+ break;
+ }
+ if(FLAC__bitmath_silog2_wide((FLAC__int64)(*residual) + (sum >> lp_quantization)) > 32) {
+ fprintf(stderr,"FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, residual=%d, sum=%lld, data=%lld\n", i, *residual, sum >> lp_quantization, (FLAC__int64)(*residual) + (sum >> lp_quantization));
+ break;
+ }
+#endif
+ *(data++) = *(residual++) + (FLAC__int32)(sum >> lp_quantization);
+ }
+}
+
FLAC__real FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__real lpc_error, unsigned total_samples)
{
double error_scale;
error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__real)total_samples;
- if(lpc_error > 0.0) {
- FLAC__real bps = (FLAC__real)((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 float resolution */
- return (FLAC__real)1e32;
- }
- else {
- return 0.0;
- }
+ return FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error, error_scale);
}
FLAC__real FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(FLAC__real lpc_error, double error_scale)
projects / platform / upstream / flac.git / blobdiff