1 /* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2000,2001,2002,2003,2004,2005 Josh Coalson
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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.
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.
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.
32 #ifndef FLAC__PRIVATE__LPC_H
33 #define FLAC__PRIVATE__LPC_H
39 #include "private/float.h"
40 #include "FLAC/format.h"
42 #ifndef FLAC__INTEGER_ONLY_LIBRARY
45 * FLAC__lpc_window_data()
46 * --------------------------------------------------------------------
47 * Applies the given window to the data.
51 * IN window[0,data_len-1]
55 void FLAC__lpc_window_data(const FLAC__real in[], const FLAC__real window[], FLAC__real out[], unsigned data_len);
58 * FLAC__lpc_compute_autocorrelation()
59 * --------------------------------------------------------------------
60 * Compute the autocorrelation for lags between 0 and lag-1.
61 * Assumes data[] outside of [0,data_len-1] == 0.
62 * Asserts that lag > 0.
64 * IN data[0,data_len-1]
66 * IN 0 < lag <= data_len
69 void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
71 # ifdef FLAC__CPU_IA32
72 # ifdef FLAC__HAS_NASM
73 void FLAC__lpc_compute_autocorrelation_asm_ia32(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
74 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_4(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
75 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_8(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
76 void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_12(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
77 void FLAC__lpc_compute_autocorrelation_asm_ia32_3dnow(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
83 * FLAC__lpc_compute_lp_coefficients()
84 * --------------------------------------------------------------------
85 * Computes LP coefficients for orders 1..max_order.
86 * Do not call if autoc[0] == 0.0. This means the signal is zero
87 * and there is no point in calculating a predictor.
89 * IN autoc[0,max_order] autocorrelation values
90 * IN 0 < max_order <= FLAC__MAX_LPC_ORDER max LP order to compute
91 * OUT lp_coeff[0,max_order-1][0,max_order-1] LP coefficients for each order
93 * *** lp_coeff[0,max_order-1][max_order,FLAC__MAX_LPC_ORDER-1] are untouched
94 * OUT error[0,max_order-1] error for each order
96 * Example: if max_order is 9, the LP coefficients for order 9 will be
97 * in lp_coeff[8][0,8], the LP coefficients for order 8 will be
98 * in lp_coeff[7][0,7], etc.
100 void FLAC__lpc_compute_lp_coefficients(const FLAC__real autoc[], unsigned max_order, FLAC__real lp_coeff[][FLAC__MAX_LPC_ORDER], FLAC__double error[]);
103 * FLAC__lpc_quantize_coefficients()
104 * --------------------------------------------------------------------
105 * Quantizes the LP coefficients. NOTE: precision + bits_per_sample
106 * must be less than 32 (sizeof(FLAC__int32)*8).
108 * IN lp_coeff[0,order-1] LP coefficients
110 * IN FLAC__MIN_QLP_COEFF_PRECISION < precision
111 * desired precision (in bits, including sign
112 * bit) of largest coefficient
113 * OUT qlp_coeff[0,order-1] quantized coefficients
114 * OUT shift # of bits to shift right to get approximated
115 * LP coefficients. NOTE: could be negative.
116 * RETURN 0 => quantization OK
117 * 1 => coefficients require too much shifting for *shift to
118 * fit in the LPC subframe header. 'shift' is unset.
119 * 2 => coefficients are all zero, which is bad. 'shift' is
122 int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int *shift);
125 * FLAC__lpc_compute_residual_from_qlp_coefficients()
126 * --------------------------------------------------------------------
127 * Compute the residual signal obtained from sutracting the predicted
128 * signal from the original.
130 * IN data[-order,data_len-1] original signal (NOTE THE INDICES!)
131 * IN data_len length of original signal
132 * IN qlp_coeff[0,order-1] quantized LP coefficients
133 * IN order > 0 LP order
134 * IN lp_quantization quantization of LP coefficients in bits
135 * OUT residual[0,data_len-1] residual signal
137 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[]);
138 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[]);
140 # ifdef FLAC__CPU_IA32
141 # ifdef FLAC__HAS_NASM
142 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[]);
143 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[]);
148 #endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */
151 * FLAC__lpc_restore_signal()
152 * --------------------------------------------------------------------
153 * Restore the original signal by summing the residual and the
156 * IN residual[0,data_len-1] residual signal
157 * IN data_len length of original signal
158 * IN qlp_coeff[0,order-1] quantized LP coefficients
159 * IN order > 0 LP order
160 * IN lp_quantization quantization of LP coefficients in bits
161 * *** IMPORTANT: the caller must pass in the historical samples:
162 * IN data[-order,-1] previously-reconstructed historical samples
163 * OUT data[0,data_len-1] original signal
165 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[]);
166 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[]);
168 # ifdef FLAC__CPU_IA32
169 # ifdef FLAC__HAS_NASM
170 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[]);
171 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[]);
172 # endif /* FLAC__HAS_NASM */
173 # elif defined FLAC__CPU_PPC
174 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[]);
175 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[]);
176 # endif/* FLAC__CPU_IA32 || FLAC__CPU_PPC */
177 #endif /* FLAC__NO_ASM */
179 #ifndef FLAC__INTEGER_ONLY_LIBRARY
182 * FLAC__lpc_compute_expected_bits_per_residual_sample()
183 * --------------------------------------------------------------------
184 * Compute the expected number of bits per residual signal sample
185 * based on the LP error (which is related to the residual variance).
187 * IN lpc_error >= 0.0 error returned from calculating LP coefficients
188 * IN total_samples > 0 # of samples in residual signal
189 * RETURN expected bits per sample
191 FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__double lpc_error, unsigned total_samples);
192 FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(FLAC__double lpc_error, FLAC__double error_scale);
195 * FLAC__lpc_compute_best_order()
196 * --------------------------------------------------------------------
197 * Compute the best order from the array of signal errors returned
198 * during coefficient computation.
200 * IN lpc_error[0,max_order-1] >= 0.0 error returned from calculating LP coefficients
201 * IN max_order > 0 max LP order
202 * IN total_samples > 0 # of samples in residual signal
203 * IN bits_per_signal_sample # of bits per sample in the original signal
204 * RETURN [1,max_order] best order
206 unsigned FLAC__lpc_compute_best_order(const FLAC__double lpc_error[], unsigned max_order, unsigned total_samples, unsigned bits_per_signal_sample);
208 #endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */