diff options
Diffstat (limited to 'src/opus-1.0.2/silk/LP_variable_cutoff.c')
| -rw-r--r-- | src/opus-1.0.2/silk/LP_variable_cutoff.c | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/src/opus-1.0.2/silk/LP_variable_cutoff.c b/src/opus-1.0.2/silk/LP_variable_cutoff.c deleted file mode 100644 index d0912a64..00000000 --- a/src/opus-1.0.2/silk/LP_variable_cutoff.c +++ /dev/null @@ -1,135 +0,0 @@ -/*********************************************************************** -Copyright (c) 2006-2011, Skype Limited. All rights reserved. -Redistribution and use in source and binary forms, with or without -modification, are permitted provided that the following conditions -are met: -- Redistributions of source code must retain the above copyright notice, -this list of conditions and the following disclaimer. -- Redistributions in binary form must reproduce the above copyright -notice, this list of conditions and the following disclaimer in the -documentation and/or other materials provided with the distribution. -- Neither the name of Internet Society, IETF or IETF Trust, nor the -names of specific contributors, may be used to endorse or promote -products derived from this software without specific prior written -permission. -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. -***********************************************************************/ - -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif - -/* - Elliptic/Cauer filters designed with 0.1 dB passband ripple, - 80 dB minimum stopband attenuation, and - [0.95 : 0.15 : 0.35] normalized cut off frequencies. -*/ - -#include "main.h" - -/* Helper function, interpolates the filter taps */ -static inline void silk_LP_interpolate_filter_taps( - opus_int32 B_Q28[ TRANSITION_NB ], - opus_int32 A_Q28[ TRANSITION_NA ], - const opus_int ind, - const opus_int32 fac_Q16 -) -{ - opus_int nb, na; - - if( ind < TRANSITION_INT_NUM - 1 ) { - if( fac_Q16 > 0 ) { - if( fac_Q16 < 32768 ) { /* fac_Q16 is in range of a 16-bit int */ - /* Piece-wise linear interpolation of B and A */ - for( nb = 0; nb < TRANSITION_NB; nb++ ) { - B_Q28[ nb ] = silk_SMLAWB( - silk_Transition_LP_B_Q28[ ind ][ nb ], - silk_Transition_LP_B_Q28[ ind + 1 ][ nb ] - - silk_Transition_LP_B_Q28[ ind ][ nb ], - fac_Q16 ); - } - for( na = 0; na < TRANSITION_NA; na++ ) { - A_Q28[ na ] = silk_SMLAWB( - silk_Transition_LP_A_Q28[ ind ][ na ], - silk_Transition_LP_A_Q28[ ind + 1 ][ na ] - - silk_Transition_LP_A_Q28[ ind ][ na ], - fac_Q16 ); - } - } else { /* ( fac_Q16 - ( 1 << 16 ) ) is in range of a 16-bit int */ - silk_assert( fac_Q16 - ( 1 << 16 ) == silk_SAT16( fac_Q16 - ( 1 << 16 ) ) ); - /* Piece-wise linear interpolation of B and A */ - for( nb = 0; nb < TRANSITION_NB; nb++ ) { - B_Q28[ nb ] = silk_SMLAWB( - silk_Transition_LP_B_Q28[ ind + 1 ][ nb ], - silk_Transition_LP_B_Q28[ ind + 1 ][ nb ] - - silk_Transition_LP_B_Q28[ ind ][ nb ], - fac_Q16 - ( (opus_int32)1 << 16 ) ); - } - for( na = 0; na < TRANSITION_NA; na++ ) { - A_Q28[ na ] = silk_SMLAWB( - silk_Transition_LP_A_Q28[ ind + 1 ][ na ], - silk_Transition_LP_A_Q28[ ind + 1 ][ na ] - - silk_Transition_LP_A_Q28[ ind ][ na ], - fac_Q16 - ( (opus_int32)1 << 16 ) ); - } - } - } else { - silk_memcpy( B_Q28, silk_Transition_LP_B_Q28[ ind ], TRANSITION_NB * sizeof( opus_int32 ) ); - silk_memcpy( A_Q28, silk_Transition_LP_A_Q28[ ind ], TRANSITION_NA * sizeof( opus_int32 ) ); - } - } else { - silk_memcpy( B_Q28, silk_Transition_LP_B_Q28[ TRANSITION_INT_NUM - 1 ], TRANSITION_NB * sizeof( opus_int32 ) ); - silk_memcpy( A_Q28, silk_Transition_LP_A_Q28[ TRANSITION_INT_NUM - 1 ], TRANSITION_NA * sizeof( opus_int32 ) ); - } -} - -/* Low-pass filter with variable cutoff frequency based on */ -/* piece-wise linear interpolation between elliptic filters */ -/* Start by setting psEncC->mode <> 0; */ -/* Deactivate by setting psEncC->mode = 0; */ -void silk_LP_variable_cutoff( - silk_LP_state *psLP, /* I/O LP filter state */ - opus_int16 *frame, /* I/O Low-pass filtered output signal */ - const opus_int frame_length /* I Frame length */ -) -{ - opus_int32 B_Q28[ TRANSITION_NB ], A_Q28[ TRANSITION_NA ], fac_Q16 = 0; - opus_int ind = 0; - - silk_assert( psLP->transition_frame_no >= 0 && psLP->transition_frame_no <= TRANSITION_FRAMES ); - - /* Run filter if needed */ - if( psLP->mode != 0 ) { - /* Calculate index and interpolation factor for interpolation */ -#if( TRANSITION_INT_STEPS == 64 ) - fac_Q16 = silk_LSHIFT( TRANSITION_FRAMES - psLP->transition_frame_no, 16 - 6 ); -#else - fac_Q16 = silk_DIV32_16( silk_LSHIFT( TRANSITION_FRAMES - psLP->transition_frame_no, 16 ), TRANSITION_FRAMES ); -#endif - ind = silk_RSHIFT( fac_Q16, 16 ); - fac_Q16 -= silk_LSHIFT( ind, 16 ); - - silk_assert( ind >= 0 ); - silk_assert( ind < TRANSITION_INT_NUM ); - - /* Interpolate filter coefficients */ - silk_LP_interpolate_filter_taps( B_Q28, A_Q28, ind, fac_Q16 ); - - /* Update transition frame number for next frame */ - psLP->transition_frame_no = silk_LIMIT( psLP->transition_frame_no + psLP->mode, 0, TRANSITION_FRAMES ); - - /* ARMA low-pass filtering */ - silk_assert( TRANSITION_NB == 3 && TRANSITION_NA == 2 ); - silk_biquad_alt( frame, B_Q28, A_Q28, psLP->In_LP_State, frame, frame_length, 1); - } -} |