1/***********************************************************************
2Copyright (c) 2006-2011, Skype Limited. All rights reserved.
3Redistribution and use in source and binary forms, with or without
4modification, are permitted provided that the following conditions
5are met:
6- Redistributions of source code must retain the above copyright notice,
7this list of conditions and the following disclaimer.
8- Redistributions in binary form must reproduce the above copyright
9notice, this list of conditions and the following disclaimer in the
10documentation and/or other materials provided with the distribution.
11- Neither the name of Internet Society, IETF or IETF Trust, nor the
12names of specific contributors, may be used to endorse or promote
13products derived from this software without specific prior written
14permission.
15THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25POSSIBILITY OF SUCH DAMAGE.
26***********************************************************************/
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
36static OPUS_INLINE opus_int16 *silk_resampler_private_down_FIR_INTERPOL(
37    opus_int16          *out,
38    opus_int32          *buf,
39    const opus_int16    *FIR_Coefs,
40    opus_int            FIR_Order,
41    opus_int            FIR_Fracs,
42    opus_int32          max_index_Q16,
43    opus_int32          index_increment_Q16
44)
45{
46    opus_int32 index_Q16, res_Q6;
47    opus_int32 *buf_ptr;
48    opus_int32 interpol_ind;
49    const opus_int16 *interpol_ptr;
50
51    switch( FIR_Order ) {
52        case RESAMPLER_DOWN_ORDER_FIR0:
53            for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
54                /* Integer part gives pointer to buffered input */
55                buf_ptr = buf + silk_RSHIFT( index_Q16, 16 );
56
57                /* Fractional part gives interpolation coefficients */
58                interpol_ind = silk_SMULWB( index_Q16 & 0xFFFF, FIR_Fracs );
59
60                /* Inner product */
61                interpol_ptr = &FIR_Coefs[ RESAMPLER_DOWN_ORDER_FIR0 / 2 * interpol_ind ];
62                res_Q6 = silk_SMULWB(         buf_ptr[ 0 ], interpol_ptr[ 0 ] );
63                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 1 ], interpol_ptr[ 1 ] );
64                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], interpol_ptr[ 2 ] );
65                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], interpol_ptr[ 3 ] );
66                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 4 ], interpol_ptr[ 4 ] );
67                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 5 ], interpol_ptr[ 5 ] );
68                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 6 ], interpol_ptr[ 6 ] );
69                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 7 ], interpol_ptr[ 7 ] );
70                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 8 ], interpol_ptr[ 8 ] );
71                interpol_ptr = &FIR_Coefs[ RESAMPLER_DOWN_ORDER_FIR0 / 2 * ( FIR_Fracs - 1 - interpol_ind ) ];
72                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 17 ], interpol_ptr[ 0 ] );
73                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 16 ], interpol_ptr[ 1 ] );
74                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 15 ], interpol_ptr[ 2 ] );
75                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 14 ], interpol_ptr[ 3 ] );
76                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 13 ], interpol_ptr[ 4 ] );
77                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 12 ], interpol_ptr[ 5 ] );
78                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 11 ], interpol_ptr[ 6 ] );
79                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 10 ], interpol_ptr[ 7 ] );
80                res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[  9 ], interpol_ptr[ 8 ] );
81
82                /* Scale down, saturate and store in output array */
83                *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );
84            }
85            break;
86        case RESAMPLER_DOWN_ORDER_FIR1:
87            for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
88                /* Integer part gives pointer to buffered input */
89                buf_ptr = buf + silk_RSHIFT( index_Q16, 16 );
90
91                /* Inner product */
92                res_Q6 = silk_SMULWB(         silk_ADD32( buf_ptr[  0 ], buf_ptr[ 23 ] ), FIR_Coefs[  0 ] );
93                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  1 ], buf_ptr[ 22 ] ), FIR_Coefs[  1 ] );
94                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  2 ], buf_ptr[ 21 ] ), FIR_Coefs[  2 ] );
95                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  3 ], buf_ptr[ 20 ] ), FIR_Coefs[  3 ] );
96                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  4 ], buf_ptr[ 19 ] ), FIR_Coefs[  4 ] );
97                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  5 ], buf_ptr[ 18 ] ), FIR_Coefs[  5 ] );
98                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  6 ], buf_ptr[ 17 ] ), FIR_Coefs[  6 ] );
99                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  7 ], buf_ptr[ 16 ] ), FIR_Coefs[  7 ] );
100                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  8 ], buf_ptr[ 15 ] ), FIR_Coefs[  8 ] );
101                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  9 ], buf_ptr[ 14 ] ), FIR_Coefs[  9 ] );
102                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 10 ], buf_ptr[ 13 ] ), FIR_Coefs[ 10 ] );
103                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 11 ], buf_ptr[ 12 ] ), FIR_Coefs[ 11 ] );
104
105                /* Scale down, saturate and store in output array */
106                *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );
107            }
108            break;
109        case RESAMPLER_DOWN_ORDER_FIR2:
110            for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
111                /* Integer part gives pointer to buffered input */
112                buf_ptr = buf + silk_RSHIFT( index_Q16, 16 );
113
114                /* Inner product */
115                res_Q6 = silk_SMULWB(         silk_ADD32( buf_ptr[  0 ], buf_ptr[ 35 ] ), FIR_Coefs[  0 ] );
116                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  1 ], buf_ptr[ 34 ] ), FIR_Coefs[  1 ] );
117                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  2 ], buf_ptr[ 33 ] ), FIR_Coefs[  2 ] );
118                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  3 ], buf_ptr[ 32 ] ), FIR_Coefs[  3 ] );
119                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  4 ], buf_ptr[ 31 ] ), FIR_Coefs[  4 ] );
120                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  5 ], buf_ptr[ 30 ] ), FIR_Coefs[  5 ] );
121                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  6 ], buf_ptr[ 29 ] ), FIR_Coefs[  6 ] );
122                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  7 ], buf_ptr[ 28 ] ), FIR_Coefs[  7 ] );
123                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  8 ], buf_ptr[ 27 ] ), FIR_Coefs[  8 ] );
124                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[  9 ], buf_ptr[ 26 ] ), FIR_Coefs[  9 ] );
125                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 10 ], buf_ptr[ 25 ] ), FIR_Coefs[ 10 ] );
126                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 11 ], buf_ptr[ 24 ] ), FIR_Coefs[ 11 ] );
127                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 12 ], buf_ptr[ 23 ] ), FIR_Coefs[ 12 ] );
128                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 13 ], buf_ptr[ 22 ] ), FIR_Coefs[ 13 ] );
129                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 14 ], buf_ptr[ 21 ] ), FIR_Coefs[ 14 ] );
130                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 15 ], buf_ptr[ 20 ] ), FIR_Coefs[ 15 ] );
131                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 16 ], buf_ptr[ 19 ] ), FIR_Coefs[ 16 ] );
132                res_Q6 = silk_SMLAWB( res_Q6, silk_ADD32( buf_ptr[ 17 ], buf_ptr[ 18 ] ), FIR_Coefs[ 17 ] );
133
134                /* Scale down, saturate and store in output array */
135                *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );
136            }
137            break;
138        default:
139            silk_assert( 0 );
140    }
141    return out;
142}
143
144/* Resample with a 2nd order AR filter followed by FIR interpolation */
145void silk_resampler_private_down_FIR(
146    void                            *SS,            /* I/O  Resampler state             */
147    opus_int16                      out[],          /* O    Output signal               */
148    const opus_int16                in[],           /* I    Input signal                */
149    opus_int32                      inLen           /* I    Number of input samples     */
150)
151{
152    silk_resampler_state_struct *S = (silk_resampler_state_struct *)SS;
153    opus_int32 nSamplesIn;
154    opus_int32 max_index_Q16, index_increment_Q16;
155    VARDECL( opus_int32, buf );
156    const opus_int16 *FIR_Coefs;
157    SAVE_STACK;
158
159    ALLOC( buf, S->batchSize + S->FIR_Order, opus_int32 );
160
161    /* Copy buffered samples to start of buffer */
162    silk_memcpy( buf, S->sFIR.i32, S->FIR_Order * sizeof( opus_int32 ) );
163
164    FIR_Coefs = &S->Coefs[ 2 ];
165
166    /* Iterate over blocks of frameSizeIn input samples */
167    index_increment_Q16 = S->invRatio_Q16;
168    while( 1 ) {
169        nSamplesIn = silk_min( inLen, S->batchSize );
170
171        /* Second-order AR filter (output in Q8) */
172        silk_resampler_private_AR2( S->sIIR, &buf[ S->FIR_Order ], in, S->Coefs, nSamplesIn );
173
174        max_index_Q16 = silk_LSHIFT32( nSamplesIn, 16 );
175
176        /* Interpolate filtered signal */
177        out = silk_resampler_private_down_FIR_INTERPOL( out, buf, FIR_Coefs, S->FIR_Order,
178            S->FIR_Fracs, max_index_Q16, index_increment_Q16 );
179
180        in += nSamplesIn;
181        inLen -= nSamplesIn;
182
183        if( inLen > 1 ) {
184            /* More iterations to do; copy last part of filtered signal to beginning of buffer */
185            silk_memcpy( buf, &buf[ nSamplesIn ], S->FIR_Order * sizeof( opus_int32 ) );
186        } else {
187            break;
188        }
189    }
190
191    /* Copy last part of filtered signal to the state for the next call */
192    silk_memcpy( S->sFIR.i32, &buf[ nSamplesIn ], S->FIR_Order * sizeof( opus_int32 ) );
193    RESTORE_STACK;
194}
195