lpc.h (10085B)
1 /* libFLAC - Free Lossless Audio Codec library 2 * Copyright (C) 2000,2001,2002,2003,2004,2005 Josh Coalson 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * - Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * - Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * - Neither the name of the Xiph.org Foundation nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR 23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef FLAC__PRIVATE__LPC_H 33 #define FLAC__PRIVATE__LPC_H 34 35 #ifdef HAVE_CONFIG_H 36 #include <config.h> 37 #endif 38 39 #include "private/float.h" 40 #include "FLAC/format.h" 41 42 #ifndef FLAC__INTEGER_ONLY_LIBRARY 43 44 /* 45 * FLAC__lpc_compute_autocorrelation() 46 * -------------------------------------------------------------------- 47 * Compute the autocorrelation for lags between 0 and lag-1. 48 * Assumes data[] outside of [0,data_len-1] == 0. 49 * Asserts that lag > 0. 50 * 51 * IN data[0,data_len-1] 52 * IN data_len 53 * IN 0 < lag <= data_len 54 * OUT autoc[0,lag-1] 55 */ 56 void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); 57 #ifndef FLAC__NO_ASM 58 # ifdef FLAC__CPU_IA32 59 # ifdef FLAC__HAS_NASM 60 void FLAC__lpc_compute_autocorrelation_asm_ia32(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); 61 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_4(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); 62 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_8(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); 63 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_12(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); 64 void FLAC__lpc_compute_autocorrelation_asm_ia32_3dnow(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); 65 # endif 66 # endif 67 #endif 68 69 /* 70 * FLAC__lpc_compute_lp_coefficients() 71 * -------------------------------------------------------------------- 72 * Computes LP coefficients for orders 1..max_order. 73 * Do not call if autoc[0] == 0.0. This means the signal is zero 74 * and there is no point in calculating a predictor. 75 * 76 * IN autoc[0,max_order] autocorrelation values 77 * IN 0 < max_order <= FLAC__MAX_LPC_ORDER max LP order to compute 78 * OUT lp_coeff[0,max_order-1][0,max_order-1] LP coefficients for each order 79 * *** IMPORTANT: 80 * *** lp_coeff[0,max_order-1][max_order,FLAC__MAX_LPC_ORDER-1] are untouched 81 * OUT error[0,max_order-1] error for each order 82 * 83 * Example: if max_order is 9, the LP coefficients for order 9 will be 84 * in lp_coeff[8][0,8], the LP coefficients for order 8 will be 85 * in lp_coeff[7][0,7], etc. 86 */ 87 void FLAC__lpc_compute_lp_coefficients(const FLAC__real autoc[], unsigned max_order, FLAC__real lp_coeff[][FLAC__MAX_LPC_ORDER], FLAC__double error[]); 88 89 /* 90 * FLAC__lpc_quantize_coefficients() 91 * -------------------------------------------------------------------- 92 * Quantizes the LP coefficients. NOTE: precision + bits_per_sample 93 * must be less than 32 (sizeof(FLAC__int32)*8). 94 * 95 * IN lp_coeff[0,order-1] LP coefficients 96 * IN order LP order 97 * IN FLAC__MIN_QLP_COEFF_PRECISION < precision 98 * desired precision (in bits, including sign 99 * bit) of largest coefficient 100 * OUT qlp_coeff[0,order-1] quantized coefficients 101 * OUT shift # of bits to shift right to get approximated 102 * LP coefficients. NOTE: could be negative. 103 * RETURN 0 => quantization OK 104 * 1 => coefficients require too much shifting for *shift to 105 * fit in the LPC subframe header. 'shift' is unset. 106 * 2 => coefficients are all zero, which is bad. 'shift' is 107 * unset. 108 */ 109 int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int *shift); 110 111 /* 112 * FLAC__lpc_compute_residual_from_qlp_coefficients() 113 * -------------------------------------------------------------------- 114 * Compute the residual signal obtained from sutracting the predicted 115 * signal from the original. 116 * 117 * IN data[-order,data_len-1] original signal (NOTE THE INDICES!) 118 * IN data_len length of original signal 119 * IN qlp_coeff[0,order-1] quantized LP coefficients 120 * IN order > 0 LP order 121 * IN lp_quantization quantization of LP coefficients in bits 122 * OUT residual[0,data_len-1] residual signal 123 */ 124 void FLAC__lpc_compute_residual_from_qlp_coefficients(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[]); 125 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[]); 126 #ifndef FLAC__NO_ASM 127 # ifdef FLAC__CPU_IA32 128 # ifdef FLAC__HAS_NASM 129 void FLAC__lpc_compute_residual_from_qlp_coefficients_asm_ia32(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[]); 130 void FLAC__lpc_compute_residual_from_qlp_coefficients_asm_ia32_mmx(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[]); 131 # endif 132 # endif 133 #endif 134 135 #endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */ 136 137 /* 138 * FLAC__lpc_restore_signal() 139 * -------------------------------------------------------------------- 140 * Restore the original signal by summing the residual and the 141 * predictor. 142 * 143 * IN residual[0,data_len-1] residual signal 144 * IN data_len length of original signal 145 * IN qlp_coeff[0,order-1] quantized LP coefficients 146 * IN order > 0 LP order 147 * IN lp_quantization quantization of LP coefficients in bits 148 * *** IMPORTANT: the caller must pass in the historical samples: 149 * IN data[-order,-1] previously-reconstructed historical samples 150 * OUT data[0,data_len-1] original signal 151 */ 152 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[]); 153 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[]); 154 #ifndef FLAC__NO_ASM 155 # ifdef FLAC__CPU_IA32 156 # ifdef FLAC__HAS_NASM 157 void FLAC__lpc_restore_signal_asm_ia32(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[]); 158 void FLAC__lpc_restore_signal_asm_ia32_mmx(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[]); 159 # endif /* FLAC__HAS_NASM */ 160 # elif defined FLAC__CPU_PPC 161 void FLAC__lpc_restore_signal_asm_ppc_altivec_16(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[]); 162 void FLAC__lpc_restore_signal_asm_ppc_altivec_16_order8(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[]); 163 # endif/* FLAC__CPU_IA32 || FLAC__CPU_PPC */ 164 #endif /* FLAC__NO_ASM */ 165 166 #ifndef FLAC__INTEGER_ONLY_LIBRARY 167 168 /* 169 * FLAC__lpc_compute_expected_bits_per_residual_sample() 170 * -------------------------------------------------------------------- 171 * Compute the expected number of bits per residual signal sample 172 * based on the LP error (which is related to the residual variance). 173 * 174 * IN lpc_error >= 0.0 error returned from calculating LP coefficients 175 * IN total_samples > 0 # of samples in residual signal 176 * RETURN expected bits per sample 177 */ 178 FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__double lpc_error, unsigned total_samples); 179 FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(FLAC__double lpc_error, FLAC__double error_scale); 180 181 /* 182 * FLAC__lpc_compute_best_order() 183 * -------------------------------------------------------------------- 184 * Compute the best order from the array of signal errors returned 185 * during coefficient computation. 186 * 187 * IN lpc_error[0,max_order-1] >= 0.0 error returned from calculating LP coefficients 188 * IN max_order > 0 max LP order 189 * IN total_samples > 0 # of samples in residual signal 190 * IN bits_per_signal_sample # of bits per sample in the original signal 191 * RETURN [1,max_order] best order 192 */ 193 unsigned FLAC__lpc_compute_best_order(const FLAC__double lpc_error[], unsigned max_order, unsigned total_samples, unsigned bits_per_signal_sample); 194 195 #endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */ 196 197 #endif