| /* libFLAC - Free Lossless Audio Codec library |
| * 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 |
| * 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. |
| */ |
| |
| #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" |
| |
| #ifndef M_LN2 |
| /* math.h in VC++ doesn't seem to have this (how Microsoft is that?) */ |
| #define M_LN2 0.69314718055994530942 |
| #endif |
| |
| #ifdef min |
| #undef min |
| #endif |
| #define min(x,y) ((x) < (y)? (x) : (y)) |
| |
| #ifdef local_abs |
| #undef local_abs |
| #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__int32 last_error_2 = last_error_1 - (data[-2] - data[-3]); |
| FLAC__int32 last_error_3 = last_error_2 - (data[-2] - 2*data[-3] + data[-4]); |
| FLAC__int32 error, save; |
| FLAC__uint32 total_error_0 = 0, total_error_1 = 0, total_error_2 = 0, total_error_3 = 0, total_error_4 = 0; |
| unsigned i, order; |
| |
| for(i = 0; i < data_len; i++) { |
| error = data[i] ; total_error_0 += local_abs(error); save = error; |
| error -= last_error_0; total_error_1 += local_abs(error); last_error_0 = save; save = error; |
| error -= last_error_1; total_error_2 += local_abs(error); last_error_1 = save; save = error; |
| error -= last_error_2; total_error_3 += local_abs(error); last_error_2 = save; save = error; |
| error -= last_error_3; total_error_4 += local_abs(error); last_error_3 = save; |
| } |
| |
| if(total_error_0 < min(min(min(total_error_1, total_error_2), total_error_3), total_error_4)) |
| order = 0; |
| else if(total_error_1 < min(min(total_error_2, total_error_3), total_error_4)) |
| order = 1; |
| else if(total_error_2 < min(total_error_3, total_error_4)) |
| order = 2; |
| else if(total_error_3 < total_error_4) |
| order = 3; |
| else |
| order = 4; |
| |
| /* Estimate the expected number of bits per residual signal sample. */ |
| /* 'total_error*' is linearly related to the variance of the residual */ |
| /* signal, so we use it directly to compute E(|x|) */ |
| FLAC__ASSERT(data_len > 0 || total_error_0 == 0); |
| FLAC__ASSERT(data_len > 0 || total_error_1 == 0); |
| 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__int32 last_error_2 = last_error_1 - (data[-2] - data[-3]); |
| FLAC__int32 last_error_3 = last_error_2 - (data[-2] - 2*data[-3] + data[-4]); |
| FLAC__int32 error, save; |
| /* total_error_* are 64-bits to avoid overflow when encoding |
| * erratic signals when the bits-per-sample and blocksize are |
| * large. |
| */ |
| FLAC__uint64 total_error_0 = 0, total_error_1 = 0, total_error_2 = 0, total_error_3 = 0, total_error_4 = 0; |
| unsigned i, order; |
| |
| for(i = 0; i < data_len; i++) { |
| error = data[i] ; total_error_0 += local_abs(error); save = error; |
| error -= last_error_0; total_error_1 += local_abs(error); last_error_0 = save; save = error; |
| error -= last_error_1; total_error_2 += local_abs(error); last_error_1 = save; save = error; |
| error -= last_error_2; total_error_3 += local_abs(error); last_error_2 = save; save = error; |
| error -= last_error_3; total_error_4 += local_abs(error); last_error_3 = save; |
| } |
| |
| if(total_error_0 < min(min(min(total_error_1, total_error_2), total_error_3), total_error_4)) |
| order = 0; |
| else if(total_error_1 < min(min(total_error_2, total_error_3), total_error_4)) |
| order = 1; |
| else if(total_error_2 < min(total_error_3, total_error_4)) |
| order = 2; |
| else if(total_error_3 < total_error_4) |
| order = 3; |
| else |
| order = 4; |
| |
| /* Estimate the expected number of bits per residual signal sample. */ |
| /* 'total_error*' is linearly related to the variance of the residual */ |
| /* signal, so we use it directly to compute E(|x|) */ |
| FLAC__ASSERT(data_len > 0 || total_error_0 == 0); |
| FLAC__ASSERT(data_len > 0 || total_error_1 == 0); |
| 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 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)(FLAC__int64)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)(FLAC__int64)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0); |
| #else |
| 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); |
| #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; |
| } |
| |
| void FLAC__fixed_compute_residual(const FLAC__int32 data[], unsigned data_len, unsigned order, FLAC__int32 residual[]) |
| { |
| const int idata_len = (int)data_len; |
| int i; |
| |
| switch(order) { |
| case 0: |
| 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++) |
| residual[i] = data[i] - data[i-1]; |
| break; |
| case 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++) |
| #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++) |
| #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); |
| } |
| } |
| |
| void FLAC__fixed_restore_signal(const FLAC__int32 residual[], unsigned data_len, unsigned order, FLAC__int32 data[]) |
| { |
| int i, idata_len = (int)data_len; |
| |
| switch(order) { |
| case 0: |
| 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++) |
| data[i] = residual[i] + data[i-1]; |
| break; |
| case 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++) |
| #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++) |
| #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); |
| } |
| } |
