ref: 7c67888988b1e48bbcbd3190b9324407e319b0b5
dir: /silk/resampler_private_AR2.c/
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#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "SigProc_FIX.h"
#include "resampler_private.h"
/* Second order AR filter with single delay elements */
void silk_resampler_private_AR2(
opus_int32 S[], /* I/O State vector [ 2 ] */
opus_int32 out_Q8[], /* O Output signal */
const opus_int16 in[], /* I Input signal */
const opus_int16 A_Q14[], /* I AR coefficients, Q14 */
opus_int32 len /* I Signal length */
)
{
opus_int32 k;
opus_int32 out32;
for( k = 0; k < len; k++ ) {
out32 = silk_ADD_LSHIFT32( S[ 0 ], (opus_int32)in[ k ], 8 );
out_Q8[ k ] = out32;
out32 = silk_LSHIFT( out32, 2 );
S[ 0 ] = silk_SMLAWB( S[ 1 ], out32, A_Q14[ 0 ] );
S[ 1 ] = silk_SMULWB( out32, A_Q14[ 1 ] );
}
}