/* libFLAC - Free Lossless Audio Codec library
- * Copyright (C) 2000,2001,2002,2003,2004 Josh Coalson
+ * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007 Josh Coalson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
#include <math.h>
+#include <string.h>
+#include "private/bitmath.h"
#include "private/fixed.h"
#include "FLAC/assert.h"
#endif
#define local_abs(x) ((unsigned)((x)<0? -(x) : (x)))
+#ifdef FLAC__INTEGER_ONLY_LIBRARY
+/* rbps stands for residual bits per sample
+ *
+ * (ln(2) * err)
+ * rbps = log (-----------)
+ * 2 ( n )
+ */
+static FLAC__fixedpoint local__compute_rbps_integerized(FLAC__uint32 err, FLAC__uint32 n)
+{
+ FLAC__uint32 rbps;
+ unsigned bits; /* the number of bits required to represent a number */
+ int fracbits; /* the number of bits of rbps that comprise the fractional part */
+
+ FLAC__ASSERT(sizeof(rbps) == sizeof(FLAC__fixedpoint));
+ FLAC__ASSERT(err > 0);
+ FLAC__ASSERT(n > 0);
+
+ FLAC__ASSERT(n <= FLAC__MAX_BLOCK_SIZE);
+ if(err <= n)
+ return 0;
+ /*
+ * The above two things tell us 1) n fits in 16 bits; 2) err/n > 1.
+ * These allow us later to know we won't lose too much precision in the
+ * fixed-point division (err<<fracbits)/n.
+ */
+
+ fracbits = (8*sizeof(err)) - (FLAC__bitmath_ilog2(err)+1);
+
+ err <<= fracbits;
+ err /= n;
+ /* err now holds err/n with fracbits fractional bits */
+
+ /*
+ * Whittle err down to 16 bits max. 16 significant bits is enough for
+ * our purposes.
+ */
+ FLAC__ASSERT(err > 0);
+ bits = FLAC__bitmath_ilog2(err)+1;
+ if(bits > 16) {
+ err >>= (bits-16);
+ fracbits -= (bits-16);
+ }
+ rbps = (FLAC__uint32)err;
+
+ /* Multiply by fixed-point version of ln(2), with 16 fractional bits */
+ rbps *= FLAC__FP_LN2;
+ fracbits += 16;
+ FLAC__ASSERT(fracbits >= 0);
+
+ /* FLAC__fixedpoint_log2 requires fracbits%4 to be 0 */
+ {
+ const int f = fracbits & 3;
+ if(f) {
+ rbps >>= f;
+ fracbits -= f;
+ }
+ }
+
+ rbps = FLAC__fixedpoint_log2(rbps, fracbits, (unsigned)(-1));
+
+ if(rbps == 0)
+ return 0;
+
+ /*
+ * The return value must have 16 fractional bits. Since the whole part
+ * of the base-2 log of a 32 bit number must fit in 5 bits, and fracbits
+ * must be >= -3, these assertion allows us to be able to shift rbps
+ * left if necessary to get 16 fracbits without losing any bits of the
+ * whole part of rbps.
+ *
+ * There is a slight chance due to accumulated error that the whole part
+ * will require 6 bits, so we use 6 in the assertion. Really though as
+ * long as it fits in 13 bits (32 - (16 - (-3))) we are fine.
+ */
+ FLAC__ASSERT((int)FLAC__bitmath_ilog2(rbps)+1 <= fracbits + 6);
+ FLAC__ASSERT(fracbits >= -3);
+
+ /* now shift the decimal point into place */
+ if(fracbits < 16)
+ return rbps << (16-fracbits);
+ else if(fracbits > 16)
+ return rbps >> (fracbits-16);
+ else
+ return rbps;
+}
+
+static FLAC__fixedpoint local__compute_rbps_wide_integerized(FLAC__uint64 err, FLAC__uint32 n)
+{
+ FLAC__uint32 rbps;
+ unsigned bits; /* the number of bits required to represent a number */
+ int fracbits; /* the number of bits of rbps that comprise the fractional part */
+
+ FLAC__ASSERT(sizeof(rbps) == sizeof(FLAC__fixedpoint));
+ FLAC__ASSERT(err > 0);
+ FLAC__ASSERT(n > 0);
+
+ FLAC__ASSERT(n <= FLAC__MAX_BLOCK_SIZE);
+ if(err <= n)
+ return 0;
+ /*
+ * The above two things tell us 1) n fits in 16 bits; 2) err/n > 1.
+ * These allow us later to know we won't lose too much precision in the
+ * fixed-point division (err<<fracbits)/n.
+ */
+
+ fracbits = (8*sizeof(err)) - (FLAC__bitmath_ilog2_wide(err)+1);
+
+ err <<= fracbits;
+ err /= n;
+ /* err now holds err/n with fracbits fractional bits */
+
+ /*
+ * Whittle err down to 16 bits max. 16 significant bits is enough for
+ * our purposes.
+ */
+ FLAC__ASSERT(err > 0);
+ bits = FLAC__bitmath_ilog2_wide(err)+1;
+ if(bits > 16) {
+ err >>= (bits-16);
+ fracbits -= (bits-16);
+ }
+ rbps = (FLAC__uint32)err;
+
+ /* Multiply by fixed-point version of ln(2), with 16 fractional bits */
+ rbps *= FLAC__FP_LN2;
+ fracbits += 16;
+ FLAC__ASSERT(fracbits >= 0);
+
+ /* FLAC__fixedpoint_log2 requires fracbits%4 to be 0 */
+ {
+ const int f = fracbits & 3;
+ if(f) {
+ rbps >>= f;
+ fracbits -= f;
+ }
+ }
+
+ rbps = FLAC__fixedpoint_log2(rbps, fracbits, (unsigned)(-1));
+
+ if(rbps == 0)
+ return 0;
+
+ /*
+ * The return value must have 16 fractional bits. Since the whole part
+ * of the base-2 log of a 32 bit number must fit in 5 bits, and fracbits
+ * must be >= -3, these assertion allows us to be able to shift rbps
+ * left if necessary to get 16 fracbits without losing any bits of the
+ * whole part of rbps.
+ *
+ * There is a slight chance due to accumulated error that the whole part
+ * will require 6 bits, so we use 6 in the assertion. Really though as
+ * long as it fits in 13 bits (32 - (16 - (-3))) we are fine.
+ */
+ FLAC__ASSERT((int)FLAC__bitmath_ilog2(rbps)+1 <= fracbits + 6);
+ FLAC__ASSERT(fracbits >= -3);
+
+ /* now shift the decimal point into place */
+ if(fracbits < 16)
+ return rbps << (16-fracbits);
+ else if(fracbits > 16)
+ return rbps >> (fracbits-16);
+ else
+ return rbps;
+}
+#endif
+
+#ifndef FLAC__INTEGER_ONLY_LIBRARY
unsigned FLAC__fixed_compute_best_predictor(const FLAC__int32 data[], unsigned data_len, FLAC__float residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
+#else
+unsigned FLAC__fixed_compute_best_predictor(const FLAC__int32 data[], unsigned data_len, FLAC__fixedpoint residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
+#endif
{
FLAC__int32 last_error_0 = data[-1];
FLAC__int32 last_error_1 = data[-1] - data[-2];
FLAC__ASSERT(data_len > 0 || total_error_2 == 0);
FLAC__ASSERT(data_len > 0 || total_error_3 == 0);
FLAC__ASSERT(data_len > 0 || total_error_4 == 0);
+#ifndef FLAC__INTEGER_ONLY_LIBRARY
residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ? log(M_LN2 * (FLAC__double)total_error_0 / (FLAC__double)data_len) / M_LN2 : 0.0);
residual_bits_per_sample[1] = (FLAC__float)((total_error_1 > 0) ? log(M_LN2 * (FLAC__double)total_error_1 / (FLAC__double)data_len) / M_LN2 : 0.0);
residual_bits_per_sample[2] = (FLAC__float)((total_error_2 > 0) ? log(M_LN2 * (FLAC__double)total_error_2 / (FLAC__double)data_len) / M_LN2 : 0.0);
residual_bits_per_sample[3] = (FLAC__float)((total_error_3 > 0) ? log(M_LN2 * (FLAC__double)total_error_3 / (FLAC__double)data_len) / M_LN2 : 0.0);
residual_bits_per_sample[4] = (FLAC__float)((total_error_4 > 0) ? log(M_LN2 * (FLAC__double)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0);
+#else
+ residual_bits_per_sample[0] = (total_error_0 > 0) ? local__compute_rbps_integerized(total_error_0, data_len) : 0;
+ residual_bits_per_sample[1] = (total_error_1 > 0) ? local__compute_rbps_integerized(total_error_1, data_len) : 0;
+ residual_bits_per_sample[2] = (total_error_2 > 0) ? local__compute_rbps_integerized(total_error_2, data_len) : 0;
+ residual_bits_per_sample[3] = (total_error_3 > 0) ? local__compute_rbps_integerized(total_error_3, data_len) : 0;
+ residual_bits_per_sample[4] = (total_error_4 > 0) ? local__compute_rbps_integerized(total_error_4, data_len) : 0;
+#endif
return order;
}
+#ifndef FLAC__INTEGER_ONLY_LIBRARY
unsigned FLAC__fixed_compute_best_predictor_wide(const FLAC__int32 data[], unsigned data_len, FLAC__float residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
+#else
+unsigned FLAC__fixed_compute_best_predictor_wide(const FLAC__int32 data[], unsigned data_len, FLAC__fixedpoint residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
+#endif
{
FLAC__int32 last_error_0 = data[-1];
FLAC__int32 last_error_1 = data[-1] - data[-2];
FLAC__ASSERT(data_len > 0 || total_error_2 == 0);
FLAC__ASSERT(data_len > 0 || total_error_3 == 0);
FLAC__ASSERT(data_len > 0 || total_error_4 == 0);
+#ifndef FLAC__INTEGER_ONLY_LIBRARY
#if defined _MSC_VER || defined __MINGW32__
- /* with VC++ you have to spoon feed it the casting */
+ /* with MSVC you have to spoon feed it the casting */
residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_0 / (FLAC__double)data_len) / M_LN2 : 0.0);
residual_bits_per_sample[1] = (FLAC__float)((total_error_1 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_1 / (FLAC__double)data_len) / M_LN2 : 0.0);
residual_bits_per_sample[2] = (FLAC__float)((total_error_2 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_2 / (FLAC__double)data_len) / M_LN2 : 0.0);
residual_bits_per_sample[3] = (FLAC__float)((total_error_3 > 0) ? log(M_LN2 * (FLAC__double)total_error_3 / (FLAC__double)data_len) / M_LN2 : 0.0);
residual_bits_per_sample[4] = (FLAC__float)((total_error_4 > 0) ? log(M_LN2 * (FLAC__double)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0);
#endif
+#else
+ residual_bits_per_sample[0] = (total_error_0 > 0) ? local__compute_rbps_wide_integerized(total_error_0, data_len) : 0;
+ residual_bits_per_sample[1] = (total_error_1 > 0) ? local__compute_rbps_wide_integerized(total_error_1, data_len) : 0;
+ residual_bits_per_sample[2] = (total_error_2 > 0) ? local__compute_rbps_wide_integerized(total_error_2, data_len) : 0;
+ residual_bits_per_sample[3] = (total_error_3 > 0) ? local__compute_rbps_wide_integerized(total_error_3, data_len) : 0;
+ residual_bits_per_sample[4] = (total_error_4 > 0) ? local__compute_rbps_wide_integerized(total_error_4, data_len) : 0;
+#endif
return order;
}
switch(order) {
case 0:
- for(i = 0; i < idata_len; i++) {
- residual[i] = data[i];
- }
+ FLAC__ASSERT(sizeof(residual[0]) == sizeof(data[0]));
+ memcpy(residual, data, sizeof(residual[0])*data_len);
break;
case 1:
- for(i = 0; i < idata_len; i++) {
+ for(i = 0; i < idata_len; i++)
residual[i] = data[i] - data[i-1];
- }
break;
case 2:
- for(i = 0; i < idata_len; i++) {
- /* == data[i] - 2*data[i-1] + data[i-2] */
+ for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
residual[i] = data[i] - (data[i-1] << 1) + data[i-2];
- }
+#else
+ residual[i] = data[i] - 2*data[i-1] + data[i-2];
+#endif
break;
case 3:
- for(i = 0; i < idata_len; i++) {
- /* == data[i] - 3*data[i-1] + 3*data[i-2] - data[i-3] */
+ for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
residual[i] = data[i] - (((data[i-1]-data[i-2])<<1) + (data[i-1]-data[i-2])) - data[i-3];
- }
+#else
+ residual[i] = data[i] - 3*data[i-1] + 3*data[i-2] - data[i-3];
+#endif
break;
case 4:
- for(i = 0; i < idata_len; i++) {
- /* == data[i] - 4*data[i-1] + 6*data[i-2] - 4*data[i-3] + data[i-4] */
+ for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
residual[i] = data[i] - ((data[i-1]+data[i-3])<<2) + ((data[i-2]<<2) + (data[i-2]<<1)) + data[i-4];
- }
+#else
+ residual[i] = data[i] - 4*data[i-1] + 6*data[i-2] - 4*data[i-3] + data[i-4];
+#endif
break;
default:
FLAC__ASSERT(0);
switch(order) {
case 0:
- for(i = 0; i < idata_len; i++) {
- data[i] = residual[i];
- }
+ FLAC__ASSERT(sizeof(residual[0]) == sizeof(data[0]));
+ memcpy(data, residual, sizeof(residual[0])*data_len);
break;
case 1:
- for(i = 0; i < idata_len; i++) {
+ for(i = 0; i < idata_len; i++)
data[i] = residual[i] + data[i-1];
- }
break;
case 2:
- for(i = 0; i < idata_len; i++) {
- /* == residual[i] + 2*data[i-1] - data[i-2] */
+ for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
data[i] = residual[i] + (data[i-1]<<1) - data[i-2];
- }
+#else
+ data[i] = residual[i] + 2*data[i-1] - data[i-2];
+#endif
break;
case 3:
- for(i = 0; i < idata_len; i++) {
- /* residual[i] + 3*data[i-1] - 3*data[i-2]) + data[i-3] */
+ for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
data[i] = residual[i] + (((data[i-1]-data[i-2])<<1) + (data[i-1]-data[i-2])) + data[i-3];
- }
+#else
+ data[i] = residual[i] + 3*data[i-1] - 3*data[i-2] + data[i-3];
+#endif
break;
case 4:
- for(i = 0; i < idata_len; i++) {
- /* == residual[i] + 4*data[i-1] - 6*data[i-2] + 4*data[i-3] - data[i-4] */
+ for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
data[i] = residual[i] + ((data[i-1]+data[i-3])<<2) - ((data[i-2]<<2) + (data[i-2]<<1)) - data[i-4];
- }
+#else
+ data[i] = residual[i] + 4*data[i-1] - 6*data[i-2] + 4*data[i-3] - data[i-4];
+#endif
break;
default:
FLAC__ASSERT(0);
projects / platform / upstream / flac.git / blobdiff