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#include "stack_alloc.h" 342bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 352bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/* Convert Left/Right stereo signal to adaptive Mid/Side representation */ 362bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianvoid silk_stereo_LR_to_MS( 372bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian stereo_enc_state *state, /* I/O State */ 382bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int16 x1[], /* I/O Left input signal, becomes mid signal */ 392bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int16 x2[], /* I/O Right input signal, becomes side signal */ 402bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int8 ix[ 2 ][ 3 ], /* O Quantization indices */ 412bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int8 *mid_only_flag, /* O Flag: only mid signal coded */ 422bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 mid_side_rates_bps[], /* O Bitrates for mid and side signals */ 432bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 total_rate_bps, /* I Total bitrate */ 442bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int prev_speech_act_Q8, /* I Speech activity level in previous frame */ 452bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int toMono, /* I Last frame before a stereo->mono transition */ 462bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int fs_kHz, /* I Sample rate (kHz) */ 472bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int frame_length /* I Number of samples */ 482bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian) 492bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian{ 502bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int n, is10msFrame, denom_Q16, delta0_Q13, delta1_Q13; 512bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 sum, diff, smooth_coef_Q16, pred_Q13[ 2 ], pred0_Q13, pred1_Q13; 522bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int32 LP_ratio_Q14, HP_ratio_Q14, frac_Q16, frac_3_Q16, min_mid_rate_bps, width_Q14, w_Q24, deltaw_Q24; 532bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian VARDECL( opus_int16, side ); 542bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian VARDECL( opus_int16, LP_mid ); 552bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian VARDECL( opus_int16, HP_mid ); 562bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian VARDECL( opus_int16, LP_side ); 572bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian VARDECL( opus_int16, HP_side ); 582bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian opus_int16 *mid = &x1[ -2 ]; 592bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian SAVE_STACK; 602bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 612bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian ALLOC( side, frame_length + 2, opus_int16 ); 622bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Convert to basic mid/side signals */ 632bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( n = 0; n < frame_length + 2; n++ ) { 642bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = x1[ n - 2 ] + (opus_int32)x2[ n - 2 ]; 652bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian diff = x1[ n - 2 ] - (opus_int32)x2[ n - 2 ]; 662bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid[ n ] = (opus_int16)silk_RSHIFT_ROUND( sum, 1 ); 672bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian side[ n ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( diff, 1 ) ); 682bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 692bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 702bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Buffering */ 712bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_memcpy( mid, state->sMid, 2 * sizeof( opus_int16 ) ); 722bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_memcpy( side, state->sSide, 2 * sizeof( opus_int16 ) ); 732bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_memcpy( state->sMid, &mid[ frame_length ], 2 * sizeof( opus_int16 ) ); 742bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_memcpy( state->sSide, &side[ frame_length ], 2 * sizeof( opus_int16 ) ); 752bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 762bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* LP and HP filter mid signal */ 772bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian ALLOC( LP_mid, frame_length, opus_int16 ); 782bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian ALLOC( HP_mid, frame_length, opus_int16 ); 792bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( n = 0; n < frame_length; n++ ) { 802bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = silk_RSHIFT_ROUND( silk_ADD_LSHIFT( mid[ n ] + mid[ n + 2 ], mid[ n + 1 ], 1 ), 2 ); 812bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian LP_mid[ n ] = sum; 822bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian HP_mid[ n ] = mid[ n + 1 ] - sum; 832bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 842bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 852bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* LP and HP filter side signal */ 862bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian ALLOC( LP_side, frame_length, opus_int16 ); 872bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian ALLOC( HP_side, frame_length, opus_int16 ); 882bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( n = 0; n < frame_length; n++ ) { 892bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = silk_RSHIFT_ROUND( silk_ADD_LSHIFT( side[ n ] + side[ n + 2 ], side[ n + 1 ], 1 ), 2 ); 902bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian LP_side[ n ] = sum; 912bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian HP_side[ n ] = side[ n + 1 ] - sum; 922bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 932bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 942bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Find energies and predictors */ 952bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian is10msFrame = frame_length == 10 * fs_kHz; 962bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian smooth_coef_Q16 = is10msFrame ? 972bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian SILK_FIX_CONST( STEREO_RATIO_SMOOTH_COEF / 2, 16 ) : 982bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian SILK_FIX_CONST( STEREO_RATIO_SMOOTH_COEF, 16 ); 992bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian smooth_coef_Q16 = silk_SMULWB( silk_SMULBB( prev_speech_act_Q8, prev_speech_act_Q8 ), smooth_coef_Q16 ); 1002bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1012bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 0 ] = silk_stereo_find_predictor( &LP_ratio_Q14, LP_mid, LP_side, &state->mid_side_amp_Q0[ 0 ], frame_length, smooth_coef_Q16 ); 1022bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 1 ] = silk_stereo_find_predictor( &HP_ratio_Q14, HP_mid, HP_side, &state->mid_side_amp_Q0[ 2 ], frame_length, smooth_coef_Q16 ); 1032bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Ratio of the norms of residual and mid signals */ 1042bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian frac_Q16 = silk_SMLABB( HP_ratio_Q14, LP_ratio_Q14, 3 ); 1052bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian frac_Q16 = silk_min( frac_Q16, SILK_FIX_CONST( 1, 16 ) ); 1062bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1072bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Determine bitrate distribution between mid and side, and possibly reduce stereo width */ 1082bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian total_rate_bps -= is10msFrame ? 1200 : 600; /* Subtract approximate bitrate for coding stereo parameters */ 1092bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if( total_rate_bps < 1 ) { 1102bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian total_rate_bps = 1; 1112bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 1122bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian min_mid_rate_bps = silk_SMLABB( 2000, fs_kHz, 900 ); 1132bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_assert( min_mid_rate_bps < 32767 ); 1142bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Default bitrate distribution: 8 parts for Mid and (5+3*frac) parts for Side. so: mid_rate = ( 8 / ( 13 + 3 * frac ) ) * total_ rate */ 1152bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian frac_3_Q16 = silk_MUL( 3, frac_Q16 ); 1162bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_side_rates_bps[ 0 ] = silk_DIV32_varQ( total_rate_bps, SILK_FIX_CONST( 8 + 5, 16 ) + frac_3_Q16, 16+3 ); 1172bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* If Mid bitrate below minimum, reduce stereo width */ 1182bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if( mid_side_rates_bps[ 0 ] < min_mid_rate_bps ) { 1192bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_side_rates_bps[ 0 ] = min_mid_rate_bps; 1202bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_side_rates_bps[ 1 ] = total_rate_bps - mid_side_rates_bps[ 0 ]; 1212bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* width = 4 * ( 2 * side_rate - min_rate ) / ( ( 1 + 3 * frac ) * min_rate ) */ 1222bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian width_Q14 = silk_DIV32_varQ( silk_LSHIFT( mid_side_rates_bps[ 1 ], 1 ) - min_mid_rate_bps, 1232bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_SMULWB( SILK_FIX_CONST( 1, 16 ) + frac_3_Q16, min_mid_rate_bps ), 14+2 ); 1242bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian width_Q14 = silk_LIMIT( width_Q14, 0, SILK_FIX_CONST( 1, 14 ) ); 1252bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else { 1262bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_side_rates_bps[ 1 ] = total_rate_bps - mid_side_rates_bps[ 0 ]; 1272bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian width_Q14 = SILK_FIX_CONST( 1, 14 ); 1282bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 1292bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1302bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Smoother */ 1312bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian state->smth_width_Q14 = (opus_int16)silk_SMLAWB( state->smth_width_Q14, width_Q14 - state->smth_width_Q14, smooth_coef_Q16 ); 1322bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1332bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* At very low bitrates or for inputs that are nearly amplitude panned, switch to panned-mono coding */ 1342bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian *mid_only_flag = 0; 1352bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if( toMono ) { 1362bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Last frame before stereo->mono transition; collapse stereo width */ 1372bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian width_Q14 = 0; 1382bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 0 ] = 0; 1392bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 1 ] = 0; 1402bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_stereo_quant_pred( pred_Q13, ix ); 1412bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else if( state->width_prev_Q14 == 0 && 1422bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian ( 8 * total_rate_bps < 13 * min_mid_rate_bps || silk_SMULWB( frac_Q16, state->smth_width_Q14 ) < SILK_FIX_CONST( 0.05, 14 ) ) ) 1432bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian { 1442bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Code as panned-mono; previous frame already had zero width */ 1452bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Scale down and quantize predictors */ 1462bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 ); 1472bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 ); 1482bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_stereo_quant_pred( pred_Q13, ix ); 1492bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Collapse stereo width */ 1502bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian width_Q14 = 0; 1512bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 0 ] = 0; 1522bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 1 ] = 0; 1532bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_side_rates_bps[ 0 ] = total_rate_bps; 1542bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_side_rates_bps[ 1 ] = 0; 1552bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian *mid_only_flag = 1; 1562bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else if( state->width_prev_Q14 != 0 && 1572bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian ( 8 * total_rate_bps < 11 * min_mid_rate_bps || silk_SMULWB( frac_Q16, state->smth_width_Q14 ) < SILK_FIX_CONST( 0.02, 14 ) ) ) 1582bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian { 1592bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Transition to zero-width stereo */ 1602bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Scale down and quantize predictors */ 1612bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 ); 1622bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 ); 1632bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_stereo_quant_pred( pred_Q13, ix ); 1642bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Collapse stereo width */ 1652bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian width_Q14 = 0; 1662bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 0 ] = 0; 1672bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 1 ] = 0; 1682bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else if( state->smth_width_Q14 > SILK_FIX_CONST( 0.95, 14 ) ) { 1692bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Full-width stereo coding */ 1702bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_stereo_quant_pred( pred_Q13, ix ); 1712bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian width_Q14 = SILK_FIX_CONST( 1, 14 ); 1722bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else { 1732bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Reduced-width stereo coding; scale down and quantize predictors */ 1742bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 ); 1752bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 ); 1762bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian silk_stereo_quant_pred( pred_Q13, ix ); 1772bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian width_Q14 = state->smth_width_Q14; 1782bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 1792bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1802bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Make sure to keep on encoding until the tapered output has been transmitted */ 1812bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if( *mid_only_flag == 1 ) { 1822bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian state->silent_side_len += frame_length - STEREO_INTERP_LEN_MS * fs_kHz; 1832bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if( state->silent_side_len < LA_SHAPE_MS * fs_kHz ) { 1842bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian *mid_only_flag = 0; 1852bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else { 1862bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Limit to avoid wrapping around */ 1872bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian state->silent_side_len = 10000; 1882bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 1892bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } else { 1902bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian state->silent_side_len = 0; 1912bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 1922bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1932bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian if( *mid_only_flag == 0 && mid_side_rates_bps[ 1 ] < 1 ) { 1942bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_side_rates_bps[ 1 ] = 1; 1952bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian mid_side_rates_bps[ 0 ] = silk_max_int( 1, total_rate_bps - mid_side_rates_bps[ 1 ]); 1962bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 1972bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 1982bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian /* Interpolate predictors and subtract prediction from side channel */ 1992bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred0_Q13 = -state->pred_prev_Q13[ 0 ]; 2002bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred1_Q13 = -state->pred_prev_Q13[ 1 ]; 2012bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian w_Q24 = silk_LSHIFT( state->width_prev_Q14, 10 ); 2022bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian denom_Q16 = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz ); 2032bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian delta0_Q13 = -silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 ); 2042bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian delta1_Q13 = -silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 ); 2052bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian deltaw_Q24 = silk_LSHIFT( silk_SMULWB( width_Q14 - state->width_prev_Q14, denom_Q16 ), 10 ); 2062bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) { 2072bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred0_Q13 += delta0_Q13; 2082bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred1_Q13 += delta1_Q13; 2092bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian w_Q24 += deltaw_Q24; 2102bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = silk_LSHIFT( silk_ADD_LSHIFT( mid[ n ] + mid[ n + 2 ], mid[ n + 1 ], 1 ), 9 ); /* Q11 */ 2112bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = silk_SMLAWB( silk_SMULWB( w_Q24, side[ n + 1 ] ), sum, pred0_Q13 ); /* Q8 */ 2122bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)mid[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ 2132bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian x2[ n - 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); 2142bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 2152bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian 2162bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred0_Q13 = -pred_Q13[ 0 ]; 2172bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian pred1_Q13 = -pred_Q13[ 1 ]; 2182bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian w_Q24 = silk_LSHIFT( width_Q14, 10 ); 2192bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) { 2202bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = silk_LSHIFT( silk_ADD_LSHIFT( mid[ n ] + mid[ n + 2 ], mid[ n + 1 ], 1 ), 9 ); /* Q11 */ 2212bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = silk_SMLAWB( silk_SMULWB( w_Q24, side[ n + 1 ] ), sum, pred0_Q13 ); /* Q8 */ 2222bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)mid[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ 2232bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian x2[ n - 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); 2242bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian } 2252bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian state->pred_prev_Q13[ 0 ] = (opus_int16)pred_Q13[ 0 ]; 2262bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian state->pred_prev_Q13[ 1 ] = (opus_int16)pred_Q13[ 1 ]; 2272bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian state->width_prev_Q14 = (opus_int16)width_Q14; 2282bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian RESTORE_STACK; 2292bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian} 230