1/*********************************************************************** 2Copyright (c) 2006-2011, Skype Limited. All rights reserved. 3Redistribution and use in source and binary forms, with or without 4modification, are permitted provided that the following conditions 5are met: 6- Redistributions of source code must retain the above copyright notice, 7this list of conditions and the following disclaimer. 8- Redistributions in binary form must reproduce the above copyright 9notice, this list of conditions and the following disclaimer in the 10documentation and/or other materials provided with the distribution. 11- Neither the name of Internet Society, IETF or IETF Trust, nor the 12names of specific contributors, may be used to endorse or promote 13products derived from this software without specific prior written 14permission. 15THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 19LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25POSSIBILITY OF SUCH DAMAGE. 26***********************************************************************/ 27 28#ifdef HAVE_CONFIG_H 29#include "config.h" 30#endif 31#ifdef FIXED_POINT 32#include "main_FIX.h" 33#else 34#include "main_FLP.h" 35#endif 36#include "tuning_parameters.h" 37 38/* High-pass filter with cutoff frequency adaptation based on pitch lag statistics */ 39void silk_HP_variable_cutoff( 40 silk_encoder_state_Fxx state_Fxx[] /* I/O Encoder states */ 41) 42{ 43 opus_int quality_Q15; 44 opus_int32 pitch_freq_Hz_Q16, pitch_freq_log_Q7, delta_freq_Q7; 45 silk_encoder_state *psEncC1 = &state_Fxx[ 0 ].sCmn; 46 47 /* Adaptive cutoff frequency: estimate low end of pitch frequency range */ 48 if( psEncC1->prevSignalType == TYPE_VOICED ) { 49 /* difference, in log domain */ 50 pitch_freq_Hz_Q16 = silk_DIV32_16( silk_LSHIFT( silk_MUL( psEncC1->fs_kHz, 1000 ), 16 ), psEncC1->prevLag ); 51 pitch_freq_log_Q7 = silk_lin2log( pitch_freq_Hz_Q16 ) - ( 16 << 7 ); 52 53 /* adjustment based on quality */ 54 quality_Q15 = psEncC1->input_quality_bands_Q15[ 0 ]; 55 pitch_freq_log_Q7 = silk_SMLAWB( pitch_freq_log_Q7, silk_SMULWB( silk_LSHIFT( -quality_Q15, 2 ), quality_Q15 ), 56 pitch_freq_log_Q7 - ( silk_lin2log( SILK_FIX_CONST( VARIABLE_HP_MIN_CUTOFF_HZ, 16 ) ) - ( 16 << 7 ) ) ); 57 58 /* delta_freq = pitch_freq_log - psEnc->variable_HP_smth1; */ 59 delta_freq_Q7 = pitch_freq_log_Q7 - silk_RSHIFT( psEncC1->variable_HP_smth1_Q15, 8 ); 60 if( delta_freq_Q7 < 0 ) { 61 /* less smoothing for decreasing pitch frequency, to track something close to the minimum */ 62 delta_freq_Q7 = silk_MUL( delta_freq_Q7, 3 ); 63 } 64 65 /* limit delta, to reduce impact of outliers in pitch estimation */ 66 delta_freq_Q7 = silk_LIMIT_32( delta_freq_Q7, -SILK_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ), SILK_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ) ); 67 68 /* update smoother */ 69 psEncC1->variable_HP_smth1_Q15 = silk_SMLAWB( psEncC1->variable_HP_smth1_Q15, 70 silk_SMULBB( psEncC1->speech_activity_Q8, delta_freq_Q7 ), SILK_FIX_CONST( VARIABLE_HP_SMTH_COEF1, 16 ) ); 71 72 /* limit frequency range */ 73 psEncC1->variable_HP_smth1_Q15 = silk_LIMIT_32( psEncC1->variable_HP_smth1_Q15, 74 silk_LSHIFT( silk_lin2log( VARIABLE_HP_MIN_CUTOFF_HZ ), 8 ), 75 silk_LSHIFT( silk_lin2log( VARIABLE_HP_MAX_CUTOFF_HZ ), 8 ) ); 76 } 77} 78