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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ***********************************************************************/ #include "SKP_Silk_main_FIX.h" #include "SKP_Silk_tuning_parameters.h" #if HIGH_PASS_INPUT #define SKP_RADIANS_CONSTANT_Q19 1482 // 0.45f * 2.0f * 3.14159265359 / 1000 #define SKP_LOG2_VARIABLE_HP_MIN_FREQ_Q7 809 // log(80) in Q7 /* High-pass filter with cutoff frequency adaptation based on pitch lag statistics */ void SKP_Silk_HP_variable_cutoff_FIX( SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */ SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control FIX */ SKP_int16 *out, /* O high-pass filtered output signal */ const SKP_int16 *in /* I input signal */ ) { SKP_int quality_Q15; SKP_int32 B_Q28[ 3 ], A_Q28[ 2 ]; SKP_int32 Fc_Q19, r_Q28, r_Q22; SKP_int32 pitch_freq_Hz_Q16, pitch_freq_log_Q7, delta_freq_Q7; /*********************************************/ /* Estimate Low End of Pitch Frequency Range */ /*********************************************/ if( psEnc->sCmn.prev_sigtype == SIG_TYPE_VOICED ) { /* difference, in log domain */ pitch_freq_Hz_Q16 = SKP_DIV32_16( SKP_LSHIFT( SKP_MUL( psEnc->sCmn.fs_kHz, 1000 ), 16 ), psEnc->sCmn.prevLag ); pitch_freq_log_Q7 = SKP_Silk_lin2log( pitch_freq_Hz_Q16 ) - ( 16 << 7 ); //0x70 /* adjustment based on quality */ quality_Q15 = psEncCtrl->input_quality_bands_Q15[ 0 ]; pitch_freq_log_Q7 = SKP_SUB32( pitch_freq_log_Q7, SKP_SMULWB( SKP_SMULWB( SKP_LSHIFT( quality_Q15, 2 ), quality_Q15 ), pitch_freq_log_Q7 - SKP_LOG2_VARIABLE_HP_MIN_FREQ_Q7 ) ); pitch_freq_log_Q7 = SKP_ADD32( pitch_freq_log_Q7, SKP_RSHIFT( SKP_FIX_CONST( 0.6, 15 ) - quality_Q15, 9 ) ); //delta_freq = pitch_freq_log - psEnc->variable_HP_smth1; delta_freq_Q7 = pitch_freq_log_Q7 - SKP_RSHIFT( psEnc->variable_HP_smth1_Q15, 8 ); if( delta_freq_Q7 < 0 ) { /* less smoothing for decreasing pitch frequency, to track something close to the minimum */ delta_freq_Q7 = SKP_MUL( delta_freq_Q7, 3 ); } /* limit delta, to reduce impact of outliers */ delta_freq_Q7 = SKP_LIMIT_32( delta_freq_Q7, -SKP_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ), SKP_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ) ); /* update smoother */ psEnc->variable_HP_smth1_Q15 = SKP_SMLAWB( psEnc->variable_HP_smth1_Q15, SKP_MUL( SKP_LSHIFT( psEnc->speech_activity_Q8, 1 ), delta_freq_Q7 ), SKP_FIX_CONST( VARIABLE_HP_SMTH_COEF1, 16 ) ); } /* second smoother */ psEnc->variable_HP_smth2_Q15 = SKP_SMLAWB( psEnc->variable_HP_smth2_Q15, psEnc->variable_HP_smth1_Q15 - psEnc->variable_HP_smth2_Q15, SKP_FIX_CONST( VARIABLE_HP_SMTH_COEF2, 16 ) ); /* convert from log scale to Hertz */ psEncCtrl->pitch_freq_low_Hz = SKP_Silk_log2lin( SKP_RSHIFT( psEnc->variable_HP_smth2_Q15, 8 ) ); /* limit frequency range */ psEncCtrl->pitch_freq_low_Hz = SKP_LIMIT_32( psEncCtrl->pitch_freq_low_Hz, SKP_FIX_CONST( VARIABLE_HP_MIN_FREQ, 0 ), SKP_FIX_CONST( VARIABLE_HP_MAX_FREQ, 0 ) ); /********************************/ /* Compute Filter Coefficients */ /********************************/ /* compute cut-off frequency, in radians */ //Fc_num = (SKP_float)( 0.45f * 2.0f * 3.14159265359 * psEncCtrl->pitch_freq_low_Hz ); //Fc_denom = (SKP_float)( 1e3f * psEnc->sCmn.fs_kHz ); SKP_assert( psEncCtrl->pitch_freq_low_Hz <= SKP_int32_MAX / SKP_RADIANS_CONSTANT_Q19 ); Fc_Q19 = SKP_DIV32_16( SKP_SMULBB( SKP_RADIANS_CONSTANT_Q19, psEncCtrl->pitch_freq_low_Hz ), psEnc->sCmn.fs_kHz ); // range: 3704 - 27787, 11-15 bits SKP_assert( Fc_Q19 >= 3704 ); SKP_assert( Fc_Q19 <= 27787 ); r_Q28 = SKP_FIX_CONST( 1.0, 28 ) - SKP_MUL( SKP_FIX_CONST( 0.92, 9 ), Fc_Q19 ); SKP_assert( r_Q28 >= 255347779 ); SKP_assert( r_Q28 <= 266690872 ); /* b = r * [ 1; -2; 1 ]; */ /* a = [ 1; -2 * r * ( 1 - 0.5 * Fc^2 ); r^2 ]; */ B_Q28[ 0 ] = r_Q28; B_Q28[ 1 ] = SKP_LSHIFT( -r_Q28, 1 ); B_Q28[ 2 ] = r_Q28; // -r * ( 2 - Fc * Fc ); r_Q22 = SKP_RSHIFT( r_Q28, 6 ); A_Q28[ 0 ] = SKP_SMULWW( r_Q22, SKP_SMULWW( Fc_Q19, Fc_Q19 ) - SKP_FIX_CONST( 2.0, 22 ) ); A_Q28[ 1 ] = SKP_SMULWW( r_Q22, r_Q22 ); /********************************/ /* High-Pass Filter */ /********************************/ SKP_Silk_biquad_alt( in, B_Q28, A_Q28, psEnc->sCmn.In_HP_State, out, psEnc->sCmn.frame_length ); } #endif // HIGH_PASS_INPUT