/src/opus/silk/resampler_down2_3.c
Line | Count | Source (jump to first uncovered line) |
1 | | /*********************************************************************** |
2 | | Copyright (c) 2006-2011, Skype Limited. All rights reserved. |
3 | | Redistribution and use in source and binary forms, with or without |
4 | | modification, are permitted provided that the following conditions |
5 | | are met: |
6 | | - Redistributions of source code must retain the above copyright notice, |
7 | | this list of conditions and the following disclaimer. |
8 | | - Redistributions in binary form must reproduce the above copyright |
9 | | notice, this list of conditions and the following disclaimer in the |
10 | | documentation and/or other materials provided with the distribution. |
11 | | - Neither the name of Internet Society, IETF or IETF Trust, nor the |
12 | | names of specific contributors, may be used to endorse or promote |
13 | | products derived from this software without specific prior written |
14 | | permission. |
15 | | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
16 | | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
17 | | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
18 | | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
19 | | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
20 | | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
21 | | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
22 | | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
23 | | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
24 | | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
25 | | POSSIBILITY 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 | | |
36 | 0 | #define ORDER_FIR 4 |
37 | | |
38 | | /* Downsample by a factor 2/3, low quality */ |
39 | | void silk_resampler_down2_3( |
40 | | opus_int32 *S, /* I/O State vector [ 6 ] */ |
41 | | opus_int16 *out, /* O Output signal [ floor(2*inLen/3) ] */ |
42 | | const opus_int16 *in, /* I Input signal [ inLen ] */ |
43 | | opus_int32 inLen /* I Number of input samples */ |
44 | | ) |
45 | 0 | { |
46 | 0 | opus_int32 nSamplesIn, counter, res_Q6; |
47 | 0 | VARDECL( opus_int32, buf ); |
48 | 0 | opus_int32 *buf_ptr; |
49 | 0 | SAVE_STACK; |
50 | |
|
51 | 0 | ALLOC( buf, RESAMPLER_MAX_BATCH_SIZE_IN + ORDER_FIR, opus_int32 ); |
52 | | |
53 | | /* Copy buffered samples to start of buffer */ |
54 | 0 | silk_memcpy( buf, S, ORDER_FIR * sizeof( opus_int32 ) ); |
55 | | |
56 | | /* Iterate over blocks of frameSizeIn input samples */ |
57 | 0 | while( 1 ) { |
58 | 0 | nSamplesIn = silk_min( inLen, RESAMPLER_MAX_BATCH_SIZE_IN ); |
59 | | |
60 | | /* Second-order AR filter (output in Q8) */ |
61 | 0 | silk_resampler_private_AR2( &S[ ORDER_FIR ], &buf[ ORDER_FIR ], in, |
62 | 0 | silk_Resampler_2_3_COEFS_LQ, nSamplesIn ); |
63 | | |
64 | | /* Interpolate filtered signal */ |
65 | 0 | buf_ptr = buf; |
66 | 0 | counter = nSamplesIn; |
67 | 0 | while( counter > 2 ) { |
68 | | /* Inner product */ |
69 | 0 | res_Q6 = silk_SMULWB( buf_ptr[ 0 ], silk_Resampler_2_3_COEFS_LQ[ 2 ] ); |
70 | 0 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 1 ], silk_Resampler_2_3_COEFS_LQ[ 3 ] ); |
71 | 0 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], silk_Resampler_2_3_COEFS_LQ[ 5 ] ); |
72 | 0 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], silk_Resampler_2_3_COEFS_LQ[ 4 ] ); |
73 | | |
74 | | /* Scale down, saturate and store in output array */ |
75 | 0 | *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) ); |
76 | |
|
77 | 0 | res_Q6 = silk_SMULWB( buf_ptr[ 1 ], silk_Resampler_2_3_COEFS_LQ[ 4 ] ); |
78 | 0 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], silk_Resampler_2_3_COEFS_LQ[ 5 ] ); |
79 | 0 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], silk_Resampler_2_3_COEFS_LQ[ 3 ] ); |
80 | 0 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 4 ], silk_Resampler_2_3_COEFS_LQ[ 2 ] ); |
81 | | |
82 | | /* Scale down, saturate and store in output array */ |
83 | 0 | *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) ); |
84 | |
|
85 | 0 | buf_ptr += 3; |
86 | 0 | counter -= 3; |
87 | 0 | } |
88 | |
|
89 | 0 | in += nSamplesIn; |
90 | 0 | inLen -= nSamplesIn; |
91 | |
|
92 | 0 | if( inLen > 0 ) { |
93 | | /* More iterations to do; copy last part of filtered signal to beginning of buffer */ |
94 | 0 | silk_memcpy( buf, &buf[ nSamplesIn ], ORDER_FIR * sizeof( opus_int32 ) ); |
95 | 0 | } else { |
96 | 0 | break; |
97 | 0 | } |
98 | 0 | } |
99 | | |
100 | | /* Copy last part of filtered signal to the state for the next call */ |
101 | 0 | silk_memcpy( S, &buf[ nSamplesIn ], ORDER_FIR * sizeof( opus_int32 ) ); |
102 | 0 | RESTORE_STACK; |
103 | 0 | } |