161 lines
7.7 KiB
C
161 lines
7.7 KiB
C
/***********************************************************************
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Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, (subject to the limitations in the disclaimer below)
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are permitted provided that the following conditions are met:
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- Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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- Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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- Neither the name of Skype Limited, nor the names of specific
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contributors, may be used to endorse or promote products derived from
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this software without specific prior written permission.
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NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
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BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
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BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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***********************************************************************/
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/* *
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* File Name: SKP_Silk_resampler_private_down_FIR.c *
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* *
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* Description: Hybrid IIR/FIR polyphase implementation of resampling *
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* *
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* Copyright 2010 (c), Skype Limited *
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* All rights reserved. *
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* */
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#include "SKP_Silk_SigProc_FIX.h"
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#include "SKP_Silk_resampler_private.h"
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SKP_INLINE SKP_int16 *SKP_Silk_resampler_private_down_FIR_INTERPOL0(
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SKP_int16 *out, SKP_int32 *buf2, const SKP_int16 *FIR_Coefs, SKP_int32 max_index_Q16, SKP_int32 index_increment_Q16){
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SKP_int32 index_Q16, res_Q6;
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SKP_int32 *buf_ptr;
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for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
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/* Integer part gives pointer to buffered input */
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buf_ptr = buf2 + SKP_RSHIFT( index_Q16, 16 );
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/* Inner product */
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res_Q6 = SKP_SMULWB( SKP_ADD32( buf_ptr[ 0 ], buf_ptr[ 11 ] ), FIR_Coefs[ 0 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 1 ], buf_ptr[ 10 ] ), FIR_Coefs[ 1 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 2 ], buf_ptr[ 9 ] ), FIR_Coefs[ 2 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 3 ], buf_ptr[ 8 ] ), FIR_Coefs[ 3 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 4 ], buf_ptr[ 7 ] ), FIR_Coefs[ 4 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 5 ], buf_ptr[ 6 ] ), FIR_Coefs[ 5 ] );
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/* Scale down, saturate and store in output array */
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*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q6, 6 ) );
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}
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return out;
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}
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SKP_INLINE SKP_int16 *SKP_Silk_resampler_private_down_FIR_INTERPOL1(
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SKP_int16 *out, SKP_int32 *buf2, const SKP_int16 *FIR_Coefs, SKP_int32 max_index_Q16, SKP_int32 index_increment_Q16, SKP_int32 FIR_Fracs){
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SKP_int32 index_Q16, res_Q6;
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SKP_int32 *buf_ptr;
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SKP_int32 interpol_ind;
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const SKP_int16 *interpol_ptr;
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for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
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/* Integer part gives pointer to buffered input */
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buf_ptr = buf2 + SKP_RSHIFT( index_Q16, 16 );
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/* Fractional part gives interpolation coefficients */
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interpol_ind = SKP_SMULWB( index_Q16 & 0xFFFF, FIR_Fracs );
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/* Inner product */
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interpol_ptr = &FIR_Coefs[ RESAMPLER_DOWN_ORDER_FIR / 2 * interpol_ind ];
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res_Q6 = SKP_SMULWB( buf_ptr[ 0 ], interpol_ptr[ 0 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 1 ], interpol_ptr[ 1 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 2 ], interpol_ptr[ 2 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 3 ], interpol_ptr[ 3 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 4 ], interpol_ptr[ 4 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 5 ], interpol_ptr[ 5 ] );
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interpol_ptr = &FIR_Coefs[ RESAMPLER_DOWN_ORDER_FIR / 2 * ( FIR_Fracs - 1 - interpol_ind ) ];
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 11 ], interpol_ptr[ 0 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 10 ], interpol_ptr[ 1 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 9 ], interpol_ptr[ 2 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 8 ], interpol_ptr[ 3 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 7 ], interpol_ptr[ 4 ] );
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res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 6 ], interpol_ptr[ 5 ] );
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/* Scale down, saturate and store in output array */
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*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q6, 6 ) );
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}
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return out;
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}
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/* Resample with a 2x downsampler (optional), a 2nd order AR filter followed by FIR interpolation */
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void SKP_Silk_resampler_private_down_FIR(
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void *SS, /* I/O: Resampler state */
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SKP_int16 out[], /* O: Output signal */
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const SKP_int16 in[], /* I: Input signal */
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SKP_int32 inLen /* I: Number of input samples */
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)
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{
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SKP_Silk_resampler_state_struct *S = (SKP_Silk_resampler_state_struct *)SS;
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SKP_int32 nSamplesIn;
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SKP_int32 max_index_Q16, index_increment_Q16;
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SKP_int16 buf1[ RESAMPLER_MAX_BATCH_SIZE_IN / 2 ];
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SKP_int32 buf2[ RESAMPLER_MAX_BATCH_SIZE_IN + RESAMPLER_DOWN_ORDER_FIR ];
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const SKP_int16 *FIR_Coefs;
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/* Copy buffered samples to start of buffer */
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SKP_memcpy( buf2, S->sFIR, RESAMPLER_DOWN_ORDER_FIR * sizeof( SKP_int32 ) );
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FIR_Coefs = &S->Coefs[ 2 ];
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/* Iterate over blocks of frameSizeIn input samples */
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index_increment_Q16 = S->invRatio_Q16;
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while( 1 ) {
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nSamplesIn = SKP_min( inLen, S->batchSize );
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if( S->input2x == 1 ) {
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/* Downsample 2x */
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SKP_Silk_resampler_down2( S->sDown2, buf1, in, nSamplesIn );
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nSamplesIn = SKP_RSHIFT32( nSamplesIn, 1 );
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/* Second-order AR filter (output in Q8) */
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SKP_Silk_resampler_private_AR2( S->sIIR, &buf2[ RESAMPLER_DOWN_ORDER_FIR ], buf1, S->Coefs, nSamplesIn );
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} else {
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/* Second-order AR filter (output in Q8) */
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SKP_Silk_resampler_private_AR2( S->sIIR, &buf2[ RESAMPLER_DOWN_ORDER_FIR ], in, S->Coefs, nSamplesIn );
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}
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max_index_Q16 = SKP_LSHIFT32( nSamplesIn, 16 );
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/* Interpolate filtered signal */
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if( S->FIR_Fracs == 1 ) {
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out = SKP_Silk_resampler_private_down_FIR_INTERPOL0(out, buf2, FIR_Coefs, max_index_Q16, index_increment_Q16);
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} else {
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out = SKP_Silk_resampler_private_down_FIR_INTERPOL1(out, buf2, FIR_Coefs, max_index_Q16, index_increment_Q16, S->FIR_Fracs);
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}
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in += nSamplesIn << S->input2x;
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inLen -= nSamplesIn << S->input2x;
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if( inLen > S->input2x ) {
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/* More iterations to do; copy last part of filtered signal to beginning of buffer */
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SKP_memcpy( buf2, &buf2[ nSamplesIn ], RESAMPLER_DOWN_ORDER_FIR * sizeof( SKP_int32 ) );
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} else {
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break;
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}
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}
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/* Copy last part of filtered signal to the state for the next call */
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SKP_memcpy( S->sFIR, &buf2[ nSamplesIn ], RESAMPLER_DOWN_ORDER_FIR * sizeof( SKP_int32 ) );
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}
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