michael@0: /*********************************************************************** michael@0: Copyright (c) 2006-2011, Skype Limited. All rights reserved. michael@0: Redistribution and use in source and binary forms, with or without michael@0: modification, are permitted provided that the following conditions michael@0: are met: michael@0: - Redistributions of source code must retain the above copyright notice, michael@0: this list of conditions and the following disclaimer. michael@0: - Redistributions in binary form must reproduce the above copyright michael@0: notice, this list of conditions and the following disclaimer in the michael@0: documentation and/or other materials provided with the distribution. michael@0: - Neither the name of Internet Society, IETF or IETF Trust, nor the michael@0: names of specific contributors, may be used to endorse or promote michael@0: products derived from this software without specific prior written michael@0: permission. michael@0: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" michael@0: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE michael@0: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE michael@0: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE michael@0: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR michael@0: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF michael@0: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS michael@0: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN michael@0: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) michael@0: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE michael@0: POSSIBILITY OF SUCH DAMAGE. michael@0: ***********************************************************************/ michael@0: michael@0: #ifdef HAVE_CONFIG_H michael@0: #include "config.h" michael@0: #endif michael@0: michael@0: #include "SigProc_FIX.h" michael@0: #include "define.h" michael@0: #include "tuning_parameters.h" michael@0: #include "pitch.h" michael@0: michael@0: #define MAX_FRAME_SIZE 384 /* subfr_length * nb_subfr = ( 0.005 * 16000 + 16 ) * 4 = 384 */ michael@0: michael@0: #define QA 25 michael@0: #define N_BITS_HEAD_ROOM 2 michael@0: #define MIN_RSHIFTS -16 michael@0: #define MAX_RSHIFTS (32 - QA) michael@0: michael@0: /* Compute reflection coefficients from input signal */ michael@0: void silk_burg_modified( michael@0: opus_int32 *res_nrg, /* O Residual energy */ michael@0: opus_int *res_nrg_Q, /* O Residual energy Q value */ michael@0: opus_int32 A_Q16[], /* O Prediction coefficients (length order) */ michael@0: const opus_int16 x[], /* I Input signal, length: nb_subfr * ( D + subfr_length ) */ michael@0: const opus_int32 minInvGain_Q30, /* I Inverse of max prediction gain */ michael@0: const opus_int subfr_length, /* I Input signal subframe length (incl. D preceding samples) */ michael@0: const opus_int nb_subfr, /* I Number of subframes stacked in x */ michael@0: const opus_int D, /* I Order */ michael@0: int arch /* I Run-time architecture */ michael@0: ) michael@0: { michael@0: opus_int k, n, s, lz, rshifts, rshifts_extra, reached_max_gain; michael@0: opus_int32 C0, num, nrg, rc_Q31, invGain_Q30, Atmp_QA, Atmp1, tmp1, tmp2, x1, x2; michael@0: const opus_int16 *x_ptr; michael@0: opus_int32 C_first_row[ SILK_MAX_ORDER_LPC ]; michael@0: opus_int32 C_last_row[ SILK_MAX_ORDER_LPC ]; michael@0: opus_int32 Af_QA[ SILK_MAX_ORDER_LPC ]; michael@0: opus_int32 CAf[ SILK_MAX_ORDER_LPC + 1 ]; michael@0: opus_int32 CAb[ SILK_MAX_ORDER_LPC + 1 ]; michael@0: opus_int32 xcorr[ SILK_MAX_ORDER_LPC ]; michael@0: michael@0: silk_assert( subfr_length * nb_subfr <= MAX_FRAME_SIZE ); michael@0: michael@0: /* Compute autocorrelations, added over subframes */ michael@0: silk_sum_sqr_shift( &C0, &rshifts, x, nb_subfr * subfr_length ); michael@0: if( rshifts > MAX_RSHIFTS ) { michael@0: C0 = silk_LSHIFT32( C0, rshifts - MAX_RSHIFTS ); michael@0: silk_assert( C0 > 0 ); michael@0: rshifts = MAX_RSHIFTS; michael@0: } else { michael@0: lz = silk_CLZ32( C0 ) - 1; michael@0: rshifts_extra = N_BITS_HEAD_ROOM - lz; michael@0: if( rshifts_extra > 0 ) { michael@0: rshifts_extra = silk_min( rshifts_extra, MAX_RSHIFTS - rshifts ); michael@0: C0 = silk_RSHIFT32( C0, rshifts_extra ); michael@0: } else { michael@0: rshifts_extra = silk_max( rshifts_extra, MIN_RSHIFTS - rshifts ); michael@0: C0 = silk_LSHIFT32( C0, -rshifts_extra ); michael@0: } michael@0: rshifts += rshifts_extra; michael@0: } michael@0: CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ) + 1; /* Q(-rshifts) */ michael@0: silk_memset( C_first_row, 0, SILK_MAX_ORDER_LPC * sizeof( opus_int32 ) ); michael@0: if( rshifts > 0 ) { michael@0: for( s = 0; s < nb_subfr; s++ ) { michael@0: x_ptr = x + s * subfr_length; michael@0: for( n = 1; n < D + 1; n++ ) { michael@0: C_first_row[ n - 1 ] += (opus_int32)silk_RSHIFT64( michael@0: silk_inner_prod16_aligned_64( x_ptr, x_ptr + n, subfr_length - n ), rshifts ); michael@0: } michael@0: } michael@0: } else { michael@0: for( s = 0; s < nb_subfr; s++ ) { michael@0: int i; michael@0: opus_int32 d; michael@0: x_ptr = x + s * subfr_length; michael@0: celt_pitch_xcorr(x_ptr, x_ptr + 1, xcorr, subfr_length - D, D, arch ); michael@0: for( n = 1; n < D + 1; n++ ) { michael@0: for ( i = n + subfr_length - D, d = 0; i < subfr_length; i++ ) michael@0: d = MAC16_16( d, x_ptr[ i ], x_ptr[ i - n ] ); michael@0: xcorr[ n - 1 ] += d; michael@0: } michael@0: for( n = 1; n < D + 1; n++ ) { michael@0: C_first_row[ n - 1 ] += silk_LSHIFT32( xcorr[ n - 1 ], -rshifts ); michael@0: } michael@0: } michael@0: } michael@0: silk_memcpy( C_last_row, C_first_row, SILK_MAX_ORDER_LPC * sizeof( opus_int32 ) ); michael@0: michael@0: /* Initialize */ michael@0: CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ) + 1; /* Q(-rshifts) */ michael@0: michael@0: invGain_Q30 = (opus_int32)1 << 30; michael@0: reached_max_gain = 0; michael@0: for( n = 0; n < D; n++ ) { michael@0: /* Update first row of correlation matrix (without first element) */ michael@0: /* Update last row of correlation matrix (without last element, stored in reversed order) */ michael@0: /* Update C * Af */ michael@0: /* Update C * flipud(Af) (stored in reversed order) */ michael@0: if( rshifts > -2 ) { michael@0: for( s = 0; s < nb_subfr; s++ ) { michael@0: x_ptr = x + s * subfr_length; michael@0: x1 = -silk_LSHIFT32( (opus_int32)x_ptr[ n ], 16 - rshifts ); /* Q(16-rshifts) */ michael@0: x2 = -silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], 16 - rshifts ); /* Q(16-rshifts) */ michael@0: tmp1 = silk_LSHIFT32( (opus_int32)x_ptr[ n ], QA - 16 ); /* Q(QA-16) */ michael@0: tmp2 = silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], QA - 16 ); /* Q(QA-16) */ michael@0: for( k = 0; k < n; k++ ) { michael@0: C_first_row[ k ] = silk_SMLAWB( C_first_row[ k ], x1, x_ptr[ n - k - 1 ] ); /* Q( -rshifts ) */ michael@0: C_last_row[ k ] = silk_SMLAWB( C_last_row[ k ], x2, x_ptr[ subfr_length - n + k ] ); /* Q( -rshifts ) */ michael@0: Atmp_QA = Af_QA[ k ]; michael@0: tmp1 = silk_SMLAWB( tmp1, Atmp_QA, x_ptr[ n - k - 1 ] ); /* Q(QA-16) */ michael@0: tmp2 = silk_SMLAWB( tmp2, Atmp_QA, x_ptr[ subfr_length - n + k ] ); /* Q(QA-16) */ michael@0: } michael@0: tmp1 = silk_LSHIFT32( -tmp1, 32 - QA - rshifts ); /* Q(16-rshifts) */ michael@0: tmp2 = silk_LSHIFT32( -tmp2, 32 - QA - rshifts ); /* Q(16-rshifts) */ michael@0: for( k = 0; k <= n; k++ ) { michael@0: CAf[ k ] = silk_SMLAWB( CAf[ k ], tmp1, x_ptr[ n - k ] ); /* Q( -rshift ) */ michael@0: CAb[ k ] = silk_SMLAWB( CAb[ k ], tmp2, x_ptr[ subfr_length - n + k - 1 ] ); /* Q( -rshift ) */ michael@0: } michael@0: } michael@0: } else { michael@0: for( s = 0; s < nb_subfr; s++ ) { michael@0: x_ptr = x + s * subfr_length; michael@0: x1 = -silk_LSHIFT32( (opus_int32)x_ptr[ n ], -rshifts ); /* Q( -rshifts ) */ michael@0: x2 = -silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], -rshifts ); /* Q( -rshifts ) */ michael@0: tmp1 = silk_LSHIFT32( (opus_int32)x_ptr[ n ], 17 ); /* Q17 */ michael@0: tmp2 = silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], 17 ); /* Q17 */ michael@0: for( k = 0; k < n; k++ ) { michael@0: C_first_row[ k ] = silk_MLA( C_first_row[ k ], x1, x_ptr[ n - k - 1 ] ); /* Q( -rshifts ) */ michael@0: C_last_row[ k ] = silk_MLA( C_last_row[ k ], x2, x_ptr[ subfr_length - n + k ] ); /* Q( -rshifts ) */ michael@0: Atmp1 = silk_RSHIFT_ROUND( Af_QA[ k ], QA - 17 ); /* Q17 */ michael@0: tmp1 = silk_MLA( tmp1, x_ptr[ n - k - 1 ], Atmp1 ); /* Q17 */ michael@0: tmp2 = silk_MLA( tmp2, x_ptr[ subfr_length - n + k ], Atmp1 ); /* Q17 */ michael@0: } michael@0: tmp1 = -tmp1; /* Q17 */ michael@0: tmp2 = -tmp2; /* Q17 */ michael@0: for( k = 0; k <= n; k++ ) { michael@0: CAf[ k ] = silk_SMLAWW( CAf[ k ], tmp1, michael@0: silk_LSHIFT32( (opus_int32)x_ptr[ n - k ], -rshifts - 1 ) ); /* Q( -rshift ) */ michael@0: CAb[ k ] = silk_SMLAWW( CAb[ k ], tmp2, michael@0: silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n + k - 1 ], -rshifts - 1 ) ); /* Q( -rshift ) */ michael@0: } michael@0: } michael@0: } michael@0: michael@0: /* Calculate nominator and denominator for the next order reflection (parcor) coefficient */ michael@0: tmp1 = C_first_row[ n ]; /* Q( -rshifts ) */ michael@0: tmp2 = C_last_row[ n ]; /* Q( -rshifts ) */ michael@0: num = 0; /* Q( -rshifts ) */ michael@0: nrg = silk_ADD32( CAb[ 0 ], CAf[ 0 ] ); /* Q( 1-rshifts ) */ michael@0: for( k = 0; k < n; k++ ) { michael@0: Atmp_QA = Af_QA[ k ]; michael@0: lz = silk_CLZ32( silk_abs( Atmp_QA ) ) - 1; michael@0: lz = silk_min( 32 - QA, lz ); michael@0: Atmp1 = silk_LSHIFT32( Atmp_QA, lz ); /* Q( QA + lz ) */ michael@0: michael@0: tmp1 = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( C_last_row[ n - k - 1 ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ michael@0: tmp2 = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( C_first_row[ n - k - 1 ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ michael@0: num = silk_ADD_LSHIFT32( num, silk_SMMUL( CAb[ n - k ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ michael@0: nrg = silk_ADD_LSHIFT32( nrg, silk_SMMUL( silk_ADD32( CAb[ k + 1 ], CAf[ k + 1 ] ), michael@0: Atmp1 ), 32 - QA - lz ); /* Q( 1-rshifts ) */ michael@0: } michael@0: CAf[ n + 1 ] = tmp1; /* Q( -rshifts ) */ michael@0: CAb[ n + 1 ] = tmp2; /* Q( -rshifts ) */ michael@0: num = silk_ADD32( num, tmp2 ); /* Q( -rshifts ) */ michael@0: num = silk_LSHIFT32( -num, 1 ); /* Q( 1-rshifts ) */ michael@0: michael@0: /* Calculate the next order reflection (parcor) coefficient */ michael@0: if( silk_abs( num ) < nrg ) { michael@0: rc_Q31 = silk_DIV32_varQ( num, nrg, 31 ); michael@0: } else { michael@0: rc_Q31 = ( num > 0 ) ? silk_int32_MAX : silk_int32_MIN; michael@0: } michael@0: michael@0: /* Update inverse prediction gain */ michael@0: tmp1 = ( (opus_int32)1 << 30 ) - silk_SMMUL( rc_Q31, rc_Q31 ); michael@0: tmp1 = silk_LSHIFT( silk_SMMUL( invGain_Q30, tmp1 ), 2 ); michael@0: if( tmp1 <= minInvGain_Q30 ) { michael@0: /* Max prediction gain exceeded; set reflection coefficient such that max prediction gain is exactly hit */ michael@0: tmp2 = ( (opus_int32)1 << 30 ) - silk_DIV32_varQ( minInvGain_Q30, invGain_Q30, 30 ); /* Q30 */ michael@0: rc_Q31 = silk_SQRT_APPROX( tmp2 ); /* Q15 */ michael@0: /* Newton-Raphson iteration */ michael@0: rc_Q31 = silk_RSHIFT32( rc_Q31 + silk_DIV32( tmp2, rc_Q31 ), 1 ); /* Q15 */ michael@0: rc_Q31 = silk_LSHIFT32( rc_Q31, 16 ); /* Q31 */ michael@0: if( num < 0 ) { michael@0: /* Ensure adjusted reflection coefficients has the original sign */ michael@0: rc_Q31 = -rc_Q31; michael@0: } michael@0: invGain_Q30 = minInvGain_Q30; michael@0: reached_max_gain = 1; michael@0: } else { michael@0: invGain_Q30 = tmp1; michael@0: } michael@0: michael@0: /* Update the AR coefficients */ michael@0: for( k = 0; k < (n + 1) >> 1; k++ ) { michael@0: tmp1 = Af_QA[ k ]; /* QA */ michael@0: tmp2 = Af_QA[ n - k - 1 ]; /* QA */ michael@0: Af_QA[ k ] = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 ); /* QA */ michael@0: Af_QA[ n - k - 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 ); /* QA */ michael@0: } michael@0: Af_QA[ n ] = silk_RSHIFT32( rc_Q31, 31 - QA ); /* QA */ michael@0: michael@0: if( reached_max_gain ) { michael@0: /* Reached max prediction gain; set remaining coefficients to zero and exit loop */ michael@0: for( k = n + 1; k < D; k++ ) { michael@0: Af_QA[ k ] = 0; michael@0: } michael@0: break; michael@0: } michael@0: michael@0: /* Update C * Af and C * Ab */ michael@0: for( k = 0; k <= n + 1; k++ ) { michael@0: tmp1 = CAf[ k ]; /* Q( -rshifts ) */ michael@0: tmp2 = CAb[ n - k + 1 ]; /* Q( -rshifts ) */ michael@0: CAf[ k ] = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 ); /* Q( -rshifts ) */ michael@0: CAb[ n - k + 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 ); /* Q( -rshifts ) */ michael@0: } michael@0: } michael@0: michael@0: if( reached_max_gain ) { michael@0: for( k = 0; k < D; k++ ) { michael@0: /* Scale coefficients */ michael@0: A_Q16[ k ] = -silk_RSHIFT_ROUND( Af_QA[ k ], QA - 16 ); michael@0: } michael@0: /* Subtract energy of preceding samples from C0 */ michael@0: if( rshifts > 0 ) { michael@0: for( s = 0; s < nb_subfr; s++ ) { michael@0: x_ptr = x + s * subfr_length; michael@0: C0 -= (opus_int32)silk_RSHIFT64( silk_inner_prod16_aligned_64( x_ptr, x_ptr, D ), rshifts ); michael@0: } michael@0: } else { michael@0: for( s = 0; s < nb_subfr; s++ ) { michael@0: x_ptr = x + s * subfr_length; michael@0: C0 -= silk_LSHIFT32( silk_inner_prod_aligned( x_ptr, x_ptr, D ), -rshifts ); michael@0: } michael@0: } michael@0: /* Approximate residual energy */ michael@0: *res_nrg = silk_LSHIFT( silk_SMMUL( invGain_Q30, C0 ), 2 ); michael@0: *res_nrg_Q = -rshifts; michael@0: } else { michael@0: /* Return residual energy */ michael@0: nrg = CAf[ 0 ]; /* Q( -rshifts ) */ michael@0: tmp1 = (opus_int32)1 << 16; /* Q16 */ michael@0: for( k = 0; k < D; k++ ) { michael@0: Atmp1 = silk_RSHIFT_ROUND( Af_QA[ k ], QA - 16 ); /* Q16 */ michael@0: nrg = silk_SMLAWW( nrg, CAf[ k + 1 ], Atmp1 ); /* Q( -rshifts ) */ michael@0: tmp1 = silk_SMLAWW( tmp1, Atmp1, Atmp1 ); /* Q16 */ michael@0: A_Q16[ k ] = -Atmp1; michael@0: } michael@0: *res_nrg = silk_SMLAWW( nrg, silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ), -tmp1 );/* Q( -rshifts ) */ michael@0: *res_nrg_Q = -rshifts; michael@0: } michael@0: }