105 lines
5.3 KiB
C
105 lines
5.3 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_IIR_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_IIR_FIR_INTERPOL(
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SKP_int16 * out, SKP_int16 * buf, SKP_int32 max_index_Q16 , SKP_int32 index_increment_Q16 ){
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SKP_int32 index_Q16, res_Q15;
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SKP_int16 *buf_ptr;
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SKP_int32 table_index;
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/* Interpolate upsampled signal and store in output array */
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for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
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table_index = SKP_SMULWB( index_Q16 & 0xFFFF, 144 );
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buf_ptr = &buf[ index_Q16 >> 16 ];
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res_Q15 = SKP_SMULBB( buf_ptr[ 0 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 0 ] );
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res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 1 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 1 ] );
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res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 2 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 2 ] );
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res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 3 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 2 ] );
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res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 4 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 1 ] );
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res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 5 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 0 ] );
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*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q15, 15 ) );
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}
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return out;
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}
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/* Upsample using a combination of allpass-based 2x upsampling and FIR interpolation */
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void SKP_Silk_resampler_private_IIR_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 buf[ 2 * RESAMPLER_MAX_BATCH_SIZE_IN + RESAMPLER_ORDER_FIR_144 ];
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/* Copy buffered samples to start of buffer */
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SKP_memcpy( buf, S->sFIR, RESAMPLER_ORDER_FIR_144 * sizeof( SKP_int32 ) );
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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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/* Upsample 2x */
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S->up2_function( S->sIIR, &buf[ RESAMPLER_ORDER_FIR_144 ], in, nSamplesIn );
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} else {
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/* Fourth-order ARMA filter */
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SKP_Silk_resampler_private_ARMA4( S->sIIR, &buf[ RESAMPLER_ORDER_FIR_144 ], in, S->Coefs, nSamplesIn );
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}
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max_index_Q16 = SKP_LSHIFT32( nSamplesIn, 16 + S->input2x ); /* +1 if 2x upsampling */
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out = SKP_Silk_resampler_private_IIR_FIR_INTERPOL(out, buf, max_index_Q16, index_increment_Q16);
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in += nSamplesIn;
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inLen -= nSamplesIn;
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if( inLen > 0 ) {
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/* More iterations to do; copy last part of filtered signal to beginning of buffer */
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SKP_memcpy( buf, &buf[ nSamplesIn << S->input2x ], RESAMPLER_ORDER_FIR_144 * 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, &buf[nSamplesIn << S->input2x ], RESAMPLER_ORDER_FIR_144 * sizeof( SKP_int32 ) );
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}
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