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- #ifdef HAVE_CONFIG_H
- #include "config.h"
- #endif
- #include "SigProc_FIX.h"
- #include "resampler_rom.h"
- void silk_resampler_down2(
- opus_int32 *S,
- opus_int16 *out,
- const opus_int16 *in,
- opus_int32 inLen
- )
- {
- opus_int32 k, len2 = silk_RSHIFT32( inLen, 1 );
- opus_int32 in32, out32, Y, X;
- silk_assert( silk_resampler_down2_0 > 0 );
- silk_assert( silk_resampler_down2_1 < 0 );
-
- for( k = 0; k < len2; k++ ) {
-
- in32 = silk_LSHIFT( (opus_int32)in[ 2 * k ], 10 );
-
- Y = silk_SUB32( in32, S[ 0 ] );
- X = silk_SMLAWB( Y, Y, silk_resampler_down2_1 );
- out32 = silk_ADD32( S[ 0 ], X );
- S[ 0 ] = silk_ADD32( in32, X );
-
- in32 = silk_LSHIFT( (opus_int32)in[ 2 * k + 1 ], 10 );
-
- Y = silk_SUB32( in32, S[ 1 ] );
- X = silk_SMULWB( Y, silk_resampler_down2_0 );
- out32 = silk_ADD32( out32, S[ 1 ] );
- out32 = silk_ADD32( out32, X );
- S[ 1 ] = silk_ADD32( in32, X );
-
- out[ k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( out32, 11 ) );
- }
- }
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