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 "main.h" 332bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 342bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/* Find least-squares prediction gain for one signal based on another and quantize it */ 352bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianopus_int32 silk_stereo_find_predictor( /* O Returns predictor in Q13 */ 362bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 *ratio_Q14, /* O Ratio of residual and mid energies */ 372bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian const opus_int16 x[], /* I Basis signal */ 382bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian const opus_int16 y[], /* I Target signal */ 392bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 mid_res_amp_Q0[], /* I/O Smoothed mid, residual norms */ 402bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int length, /* I Number of samples */ 412bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int smooth_coef_Q16 /* I Smoothing coefficient */ 422bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian) 432bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian{ 442bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int scale, scale1, scale2; 452bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 nrgx, nrgy, corr, pred_Q13, pred2_Q10; 462bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 472bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Find predictor */ 482bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_sum_sqr_shift( &nrgx, &scale1, x, length ); 492bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_sum_sqr_shift( &nrgy, &scale2, y, length ); 502bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian scale = silk_max_int( scale1, scale2 ); 512bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian scale = scale + ( scale & 1 ); /* make even */ 522bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian nrgy = silk_RSHIFT32( nrgy, scale - scale2 ); 532bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian nrgx = silk_RSHIFT32( nrgx, scale - scale1 ); 542bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian nrgx = silk_max_int( nrgx, 1 ); 552bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian corr = silk_inner_prod_aligned_scale( x, y, scale, length ); 562bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13 = silk_DIV32_varQ( corr, nrgx, 13 ); 572bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13 = silk_LIMIT( pred_Q13, -(1 << 14), 1 << 14 ); 582bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred2_Q10 = silk_SMULWB( pred_Q13, pred_Q13 ); 592bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 602bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Faster update for signals with large prediction parameters */ 612bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian smooth_coef_Q16 = (opus_int)silk_max_int( smooth_coef_Q16, silk_abs( pred2_Q10 ) ); 622bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 632bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Smoothed mid and residual norms */ 642bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_assert( smooth_coef_Q16 < 32768 ); 652bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian scale = silk_RSHIFT( scale, 1 ); 662bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_res_amp_Q0[ 0 ] = silk_SMLAWB( mid_res_amp_Q0[ 0 ], silk_LSHIFT( silk_SQRT_APPROX( nrgx ), scale ) - mid_res_amp_Q0[ 0 ], 672bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian smooth_coef_Q16 ); 682bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Residual energy = nrgy - 2 * pred * corr + pred^2 * nrgx */ 692bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian nrgy = silk_SUB_LSHIFT32( nrgy, silk_SMULWB( corr, pred_Q13 ), 3 + 1 ); 702bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian nrgy = silk_ADD_LSHIFT32( nrgy, silk_SMULWB( nrgx, pred2_Q10 ), 6 ); 712bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_res_amp_Q0[ 1 ] = silk_SMLAWB( mid_res_amp_Q0[ 1 ], silk_LSHIFT( silk_SQRT_APPROX( nrgy ), scale ) - mid_res_amp_Q0[ 1 ], 722bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian smooth_coef_Q16 ); 732bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 742bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Ratio of smoothed residual and mid norms */ 752bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian *ratio_Q14 = silk_DIV32_varQ( mid_res_amp_Q0[ 1 ], silk_max( mid_res_amp_Q0[ 0 ], 1 ), 14 ); 762bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian *ratio_Q14 = silk_LIMIT( *ratio_Q14, 0, 32767 ); 772bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 782bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian return pred_Q13; 792bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian} 80