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27 
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31 
32 #include "SigProc_FIX.h"
33 #include "resampler_private.h"
34 #include "stack_alloc.h"
35 
silk_resampler_private_IIR_FIR_INTERPOL(opus_int16 * out,opus_int16 * buf,opus_int32 max_index_Q16,opus_int32 index_increment_Q16)36 static OPUS_INLINE opus_int16 *silk_resampler_private_IIR_FIR_INTERPOL(
37     opus_int16  *out,
38     opus_int16  *buf,
39     opus_int32  max_index_Q16,
40     opus_int32  index_increment_Q16
41 )
42 {
43     opus_int32 index_Q16, res_Q15;
44     opus_int16 *buf_ptr;
45     opus_int32 table_index;
46 
47     /* Interpolate upsampled signal and store in output array */
48     for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
49         table_index = silk_SMULWB( index_Q16 & 0xFFFF, 12 );
50         buf_ptr = &buf[ index_Q16 >> 16 ];
51 
52         res_Q15 = silk_SMULBB(          buf_ptr[ 0 ], silk_resampler_frac_FIR_12[      table_index ][ 0 ] );
53         res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 1 ], silk_resampler_frac_FIR_12[      table_index ][ 1 ] );
54         res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 2 ], silk_resampler_frac_FIR_12[      table_index ][ 2 ] );
55         res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 3 ], silk_resampler_frac_FIR_12[      table_index ][ 3 ] );
56         res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 4 ], silk_resampler_frac_FIR_12[ 11 - table_index ][ 3 ] );
57         res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 5 ], silk_resampler_frac_FIR_12[ 11 - table_index ][ 2 ] );
58         res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 6 ], silk_resampler_frac_FIR_12[ 11 - table_index ][ 1 ] );
59         res_Q15 = silk_SMLABB( res_Q15, buf_ptr[ 7 ], silk_resampler_frac_FIR_12[ 11 - table_index ][ 0 ] );
60         *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q15, 15 ) );
61     }
62     return out;
63 }
64 /* Upsample using a combination of allpass-based 2x upsampling and FIR interpolation */
silk_resampler_private_IIR_FIR(void * SS,opus_int16 out[],const opus_int16 in[],opus_int32 inLen)65 void silk_resampler_private_IIR_FIR(
66     void                            *SS,            /* I/O  Resampler state             */
67     opus_int16                      out[],          /* O    Output signal               */
68     const opus_int16                in[],           /* I    Input signal                */
69     opus_int32                      inLen           /* I    Number of input samples     */
70 )
71 {
72     silk_resampler_state_struct *S = (silk_resampler_state_struct *)SS;
73     opus_int32 nSamplesIn;
74     opus_int32 max_index_Q16, index_increment_Q16;
75     VARDECL( opus_int16, buf );
76     SAVE_STACK;
77 
78     ALLOC( buf, 2 * S->batchSize + RESAMPLER_ORDER_FIR_12, opus_int16 );
79 
80     /* Copy buffered samples to start of buffer */
81     silk_memcpy( buf, S->sFIR.i16, RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) );
82 
83     /* Iterate over blocks of frameSizeIn input samples */
84     index_increment_Q16 = S->invRatio_Q16;
85     while( 1 ) {
86         nSamplesIn = silk_min( inLen, S->batchSize );
87 
88         /* Upsample 2x */
89         silk_resampler_private_up2_HQ( S->sIIR, &buf[ RESAMPLER_ORDER_FIR_12 ], in, nSamplesIn );
90 
91         max_index_Q16 = silk_LSHIFT32( nSamplesIn, 16 + 1 );         /* + 1 because 2x upsampling */
92         out = silk_resampler_private_IIR_FIR_INTERPOL( out, buf, max_index_Q16, index_increment_Q16 );
93         in += nSamplesIn;
94         inLen -= nSamplesIn;
95 
96         if( inLen > 0 ) {
97             /* More iterations to do; copy last part of filtered signal to beginning of buffer */
98             silk_memcpy( buf, &buf[ nSamplesIn << 1 ], RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) );
99         } else {
100             break;
101         }
102     }
103 
104     /* Copy last part of filtered signal to the state for the next call */
105     silk_memcpy( S->sFIR.i16, &buf[ nSamplesIn << 1 ], RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) );
106     RESTORE_STACK;
107 }
108