1 /* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2000-2009 Josh Coalson
3 * Copyright (C) 2011-2013 Xiph.Org Foundation
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
12 * - Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * - Neither the name of the Xiph.org Foundation nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
24 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 #ifndef FLAC__PRIVATE__LPC_H
34 #define FLAC__PRIVATE__LPC_H
40 #include "private/float.h"
41 #include "FLAC/format.h"
43 #ifndef FLAC__INTEGER_ONLY_LIBRARY
46 * FLAC__lpc_window_data()
47 * --------------------------------------------------------------------
48 * Applies the given window to the data.
49 * OPT: asm implementation
52 * IN window[0,data_len-1]
56 void FLAC__lpc_window_data(const FLAC__int32 in[], const FLAC__real window[], FLAC__real out[], unsigned data_len);
59 * FLAC__lpc_compute_autocorrelation()
60 * --------------------------------------------------------------------
61 * Compute the autocorrelation for lags between 0 and lag-1.
62 * Assumes data[] outside of [0,data_len-1] == 0.
63 * Asserts that lag > 0.
65 * IN data[0,data_len-1]
67 * IN 0 < lag <= data_len
70 void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
72 # ifdef FLAC__CPU_IA32
73 # ifdef FLAC__HAS_NASM
74 void FLAC__lpc_compute_autocorrelation_asm_ia32(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
75 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_4(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
76 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_8(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
77 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_12(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
78 void FLAC__lpc_compute_autocorrelation_asm_ia32_3dnow(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
84 * FLAC__lpc_compute_lp_coefficients()
85 * --------------------------------------------------------------------
86 * Computes LP coefficients for orders 1..max_order.
87 * Do not call if autoc[0] == 0.0. This means the signal is zero
88 * and there is no point in calculating a predictor.
90 * IN autoc[0,max_order] autocorrelation values
91 * IN 0 < max_order <= FLAC__MAX_LPC_ORDER max LP order to compute
92 * OUT lp_coeff[0,max_order-1][0,max_order-1] LP coefficients for each order
94 * *** lp_coeff[0,max_order-1][max_order,FLAC__MAX_LPC_ORDER-1] are untouched
95 * OUT error[0,max_order-1] error for each order (more
96 * specifically, the variance of
97 * the error signal times # of
98 * samples in the signal)
100 * Example: if max_order is 9, the LP coefficients for order 9 will be
101 * in lp_coeff[8][0,8], the LP coefficients for order 8 will be
102 * in lp_coeff[7][0,7], etc.
104 void FLAC__lpc_compute_lp_coefficients(const FLAC__real autoc[], unsigned *max_order, FLAC__real lp_coeff[][FLAC__MAX_LPC_ORDER], FLAC__double error[]);
107 * FLAC__lpc_quantize_coefficients()
108 * --------------------------------------------------------------------
109 * Quantizes the LP coefficients. NOTE: precision + bits_per_sample
110 * must be less than 32 (sizeof(FLAC__int32)*8).
112 * IN lp_coeff[0,order-1] LP coefficients
114 * IN FLAC__MIN_QLP_COEFF_PRECISION < precision
115 * desired precision (in bits, including sign
116 * bit) of largest coefficient
117 * OUT qlp_coeff[0,order-1] quantized coefficients
118 * OUT shift # of bits to shift right to get approximated
119 * LP coefficients. NOTE: could be negative.
120 * RETURN 0 => quantization OK
121 * 1 => coefficients require too much shifting for *shift to
122 * fit in the LPC subframe header. 'shift' is unset.
123 * 2 => coefficients are all zero, which is bad. 'shift' is
126 int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int *shift);
129 * FLAC__lpc_compute_residual_from_qlp_coefficients()
130 * --------------------------------------------------------------------
131 * Compute the residual signal obtained from sutracting the predicted
132 * signal from the original.
134 * IN data[-order,data_len-1] original signal (NOTE THE INDICES!)
135 * IN data_len length of original signal
136 * IN qlp_coeff[0,order-1] quantized LP coefficients
137 * IN order > 0 LP order
138 * IN lp_quantization quantization of LP coefficients in bits
139 * OUT residual[0,data_len-1] residual signal
141 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[]);
142 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[]);
144 # ifdef FLAC__CPU_IA32
145 # ifdef FLAC__HAS_NASM
146 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[]);
147 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[]);
152 #endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */
155 * FLAC__lpc_restore_signal()
156 * --------------------------------------------------------------------
157 * Restore the original signal by summing the residual and the
160 * IN residual[0,data_len-1] residual signal
161 * IN data_len length of original signal
162 * IN qlp_coeff[0,order-1] quantized LP coefficients
163 * IN order > 0 LP order
164 * IN lp_quantization quantization of LP coefficients in bits
165 * *** IMPORTANT: the caller must pass in the historical samples:
166 * IN data[-order,-1] previously-reconstructed historical samples
167 * OUT data[0,data_len-1] original signal
169 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[]);
170 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[]);
172 # ifdef FLAC__CPU_IA32
173 # ifdef FLAC__HAS_NASM
174 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[]);
175 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[]);
176 # endif /* FLAC__HAS_NASM */
177 # elif defined FLAC__CPU_PPC
178 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[]);
179 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[]);
180 # endif/* FLAC__CPU_IA32 || FLAC__CPU_PPC */
181 #endif /* FLAC__NO_ASM */
183 #ifndef FLAC__INTEGER_ONLY_LIBRARY
186 * FLAC__lpc_compute_expected_bits_per_residual_sample()
187 * --------------------------------------------------------------------
188 * Compute the expected number of bits per residual signal sample
189 * based on the LP error (which is related to the residual variance).
191 * IN lpc_error >= 0.0 error returned from calculating LP coefficients
192 * IN total_samples > 0 # of samples in residual signal
193 * RETURN expected bits per sample
195 FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__double lpc_error, unsigned total_samples);
196 FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(FLAC__double lpc_error, FLAC__double error_scale);
199 * FLAC__lpc_compute_best_order()
200 * --------------------------------------------------------------------
201 * Compute the best order from the array of signal errors returned
202 * during coefficient computation.
204 * IN lpc_error[0,max_order-1] >= 0.0 error returned from calculating LP coefficients
205 * IN max_order > 0 max LP order
206 * IN total_samples > 0 # of samples in residual signal
207 * IN overhead_bits_per_order # of bits overhead for each increased LP order
208 * (includes warmup sample size and quantized LP coefficient)
209 * RETURN [1,max_order] best order
211 unsigned FLAC__lpc_compute_best_order(const FLAC__double lpc_error[], unsigned max_order, unsigned total_samples, unsigned overhead_bits_per_order);
213 #endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */