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_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.
51 * IN data[0,data_len-1]
53 * IN 0 < lag <= data_len
56 void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]);
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[]);
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.
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
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
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.
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[]);
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).
95 * IN lp_coeff[0,order-1] LP coefficients
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
109 int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int *shift);
112 * FLAC__lpc_compute_residual_from_qlp_coefficients()
113 * --------------------------------------------------------------------
114 * Compute the residual signal obtained from sutracting the predicted
115 * signal from the original.
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
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[]);
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[]);
135 #endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */
138 * FLAC__lpc_restore_signal()
139 * --------------------------------------------------------------------
140 * Restore the original signal by summing the residual and the
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
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[]);
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 */
166 #ifndef FLAC__INTEGER_ONLY_LIBRARY
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).
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
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);
182 * FLAC__lpc_compute_best_order()
183 * --------------------------------------------------------------------
184 * Compute the best order from the array of signal errors returned
185 * during coefficient computation.
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
193 unsigned FLAC__lpc_compute_best_order(const FLAC__double lpc_error[], unsigned max_order, unsigned total_samples, unsigned bits_per_signal_sample);
195 #endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */