12bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/*********************************************************************** 22bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianCopyright (c) 2006-2011, Skype Limited. All rights reserved. 32bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianRedistribution and use in source and binary forms, with or without 42bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianmodification, are permitted provided that the following conditions 52bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianare met: 62bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian- Redistributions of source code must retain the above copyright notice, 72bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianthis list of conditions and the following disclaimer. 82bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian- Redistributions in binary form must reproduce the above copyright 92bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramaniannotice, this list of conditions and the following disclaimer in the 102bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramaniandocumentation and/or other materials provided with the distribution. 112bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian- Neither the name of Internet Society, IETF or IETF Trust, nor the 122bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramaniannames of specific contributors, may be used to endorse or promote 132bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianproducts derived from this software without specific prior written 142bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianpermission. 152bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianTHIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 162bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianAND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 172bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianIMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 182bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 192bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianLIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 202bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianCONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 212bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianSUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 222bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianINTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 232bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianCONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 242bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 252bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianPOSSIBILITY OF SUCH DAMAGE. 262bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian***********************************************************************/ 272bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 282bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#ifdef HAVE_CONFIG_H 292bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#include "config.h" 302bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#endif 312bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 322bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#include "SigProc_FIX.h" 332bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 342bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/* Faster than schur64(), but much less accurate. */ 352bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/* uses SMLAWB(), requiring armv5E and higher. */ 362bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianopus_int32 silk_schur( /* O Returns residual energy */ 372bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int16 *rc_Q15, /* O reflection coefficients [order] Q15 */ 382bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian const opus_int32 *c, /* I correlations [order+1] */ 392bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian const opus_int32 order /* I prediction order */ 402bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian) 412bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian{ 422bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int k, n, lz; 432bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ]; 442bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 Ctmp1, Ctmp2, rc_tmp_Q15; 452bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 462bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 ); 472bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 482bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Get number of leading zeros */ 492bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian lz = silk_CLZ32( c[ 0 ] ); 502bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 512bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Copy correlations and adjust level to Q30 */ 522bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if( lz < 2 ) { 532bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* lz must be 1, so shift one to the right */ 542bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( k = 0; k < order + 1; k++ ) { 552bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian C[ k ][ 0 ] = C[ k ][ 1 ] = silk_RSHIFT( c[ k ], 1 ); 562bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 572bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else if( lz > 2 ) { 582bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Shift to the left */ 592bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian lz -= 2; 602bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( k = 0; k < order + 1; k++ ) { 612bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian C[ k ][ 0 ] = C[ k ][ 1 ] = silk_LSHIFT( c[ k ], lz ); 622bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 632bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else { 642bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* No need to shift */ 652bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( k = 0; k < order + 1; k++ ) { 662bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ]; 672bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 682bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 692bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 702bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( k = 0; k < order; k++ ) { 712bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Check that we won't be getting an unstable rc, otherwise stop here. */ 722bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if (silk_abs_int32(C[ k + 1 ][ 0 ]) >= C[ 0 ][ 1 ]) { 732bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if ( C[ k + 1 ][ 0 ] > 0 ) { 742bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian rc_Q15[ k ] = -SILK_FIX_CONST( .99f, 15 ); 752bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else { 762bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian rc_Q15[ k ] = SILK_FIX_CONST( .99f, 15 ); 772bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 782bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian k++; 792bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian break; 802bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 812bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 822bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Get reflection coefficient */ 832bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian rc_tmp_Q15 = -silk_DIV32_16( C[ k + 1 ][ 0 ], silk_max_32( silk_RSHIFT( C[ 0 ][ 1 ], 15 ), 1 ) ); 842bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 852bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Clip (shouldn't happen for properly conditioned inputs) */ 862bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian rc_tmp_Q15 = silk_SAT16( rc_tmp_Q15 ); 872bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 882bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Store */ 892bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian rc_Q15[ k ] = (opus_int16)rc_tmp_Q15; 902bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 912bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Update correlations */ 922bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( n = 0; n < order - k; n++ ) { 932bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian Ctmp1 = C[ n + k + 1 ][ 0 ]; 942bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian Ctmp2 = C[ n ][ 1 ]; 952bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian C[ n + k + 1 ][ 0 ] = silk_SMLAWB( Ctmp1, silk_LSHIFT( Ctmp2, 1 ), rc_tmp_Q15 ); 962bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian C[ n ][ 1 ] = silk_SMLAWB( Ctmp2, silk_LSHIFT( Ctmp1, 1 ), rc_tmp_Q15 ); 972bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 982bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 992bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1002bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for(; k < order; k++ ) { 1012bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian rc_Q15[ k ] = 0; 1022bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 1032bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1042bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* return residual energy */ 1052bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian return silk_max_32( 1, C[ 0 ][ 1 ] ); 1062bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian} 107