ref: 853823f435cd30ffb52d90cd49b4cfdba42121d4
dir: /sys/src/cmd/audio/libFLAC/private/lpc.h/
/* libFLAC - Free Lossless Audio Codec library * Copyright (C) 2000,2001,2002,2003,2004 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. */ #ifndef FLAC__PRIVATE__LPC_H #define FLAC__PRIVATE__LPC_H #include "FLAC/format.h" #ifdef HAVE_CONFIG_H #include <config.h> #endif /* * FLAC__lpc_compute_autocorrelation() * -------------------------------------------------------------------- * Compute the autocorrelation for lags between 0 and lag-1. * Assumes data[] outside of [0,data_len-1] == 0. * Asserts that lag > 0. * * IN data[0,data_len-1] * IN data_len * IN 0 < lag <= data_len * OUT autoc[0,lag-1] */ void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); #ifndef FLAC__NO_ASM #ifdef FLAC__CPU_IA32 #ifdef FLAC__HAS_NASM void FLAC__lpc_compute_autocorrelation_asm_ia32(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_4(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_8(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); void FLAC__lpc_compute_autocorrelation_asm_ia32_sse_lag_12(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); void FLAC__lpc_compute_autocorrelation_asm_ia32_3dnow(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[]); #endif #endif /* * FLAC__lpc_compute_lp_coefficients() * -------------------------------------------------------------------- * Computes LP coefficients for orders 1..max_order. * Do not call if autoc[0] == 0.0. This means the signal is zero * and there is no point in calculating a predictor. * * IN autoc[0,max_order] autocorrelation values * IN 0 < max_order <= FLAC__MAX_LPC_ORDER max LP order to compute * OUT lp_coeff[0,max_order-1][0,max_order-1] LP coefficients for each order * *** IMPORTANT: * *** lp_coeff[0,max_order-1][max_order,FLAC__MAX_LPC_ORDER-1] are untouched * OUT error[0,max_order-1] error for each order * * Example: if max_order is 9, the LP coefficients for order 9 will be * in lp_coeff[8][0,8], the LP coefficients for order 8 will be * in lp_coeff[7][0,7], etc. */ void FLAC__lpc_compute_lp_coefficients(const FLAC__real autoc[], unsigned max_order, FLAC__real lp_coeff[][FLAC__MAX_LPC_ORDER], FLAC__real error[]); /* * FLAC__lpc_quantize_coefficients() * -------------------------------------------------------------------- * Quantizes the LP coefficients. NOTE: precision + bits_per_sample * must be less than 32 (sizeof(FLAC__int32)*8). * * IN lp_coeff[0,order-1] LP coefficients * IN order LP order * IN FLAC__MIN_QLP_COEFF_PRECISION < precision * desired precision (in bits, including sign * bit) of largest coefficient * OUT qlp_coeff[0,order-1] quantized coefficients * OUT shift # of bits to shift right to get approximated * LP coefficients. NOTE: could be negative. * RETURN 0 => quantization OK * 1 => coefficients require too much shifting for *shift to * fit in the LPC subframe header. 'shift' is unset. * 2 => coefficients are all zero, which is bad. 'shift' is * unset. */ int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int *shift); /* * FLAC__lpc_compute_residual_from_qlp_coefficients() * -------------------------------------------------------------------- * Compute the residual signal obtained from sutracting the predicted * signal from the original. * * IN data[-order,data_len-1] original signal (NOTE THE INDICES!) * IN data_len length of original signal * IN qlp_coeff[0,order-1] quantized LP coefficients * IN order > 0 LP order * IN lp_quantization quantization of LP coefficients in bits * OUT residual[0,data_len-1] residual signal */ 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[]); 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[]); #ifndef FLAC__NO_ASM #ifdef FLAC__CPU_IA32 #ifdef FLAC__HAS_NASM 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[]); 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[]); #endif #endif #endif /* * FLAC__lpc_restore_signal() * -------------------------------------------------------------------- * Restore the original signal by summing the residual and the * predictor. * * IN residual[0,data_len-1] residual signal * IN data_len length of original signal * IN qlp_coeff[0,order-1] quantized LP coefficients * IN order > 0 LP order * IN lp_quantization quantization of LP coefficients in bits * *** IMPORTANT: the caller must pass in the historical samples: * IN data[-order,-1] previously-reconstructed historical samples * OUT data[0,data_len-1] original signal */ 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[]); 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[]); #ifndef FLAC__NO_ASM #ifdef FLAC__CPU_IA32 #ifdef FLAC__HAS_NASM 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[]); 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[]); #endif #elif defined FLAC__CPU_PPC 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[]); 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[]); #endif #endif #endif /* * FLAC__lpc_compute_expected_bits_per_residual_sample() * -------------------------------------------------------------------- * Compute the expected number of bits per residual signal sample * based on the LP error (which is related to the residual variance). * * IN lpc_error >= 0.0 error returned from calculating LP coefficients * IN total_samples > 0 # of samples in residual signal * RETURN expected bits per sample */ FLAC__real FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__real lpc_error, unsigned total_samples); FLAC__real FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(FLAC__real lpc_error, double error_scale); /* * FLAC__lpc_compute_best_order() * -------------------------------------------------------------------- * Compute the best order from the array of signal errors returned * during coefficient computation. * * IN lpc_error[0,max_order-1] >= 0.0 error returned from calculating LP coefficients * IN max_order > 0 max LP order * IN total_samples > 0 # of samples in residual signal * IN bits_per_signal_sample # of bits per sample in the original signal * RETURN [1,max_order] best order */ unsigned FLAC__lpc_compute_best_order(const FLAC__real lpc_error[], unsigned max_order, unsigned total_samples, unsigned bits_per_signal_sample); #endif