diff options
Diffstat (limited to 'lib/rbcodec/codecs/libopus/silk/resampler_down2_3.c')
-rw-r--r-- | lib/rbcodec/codecs/libopus/silk/resampler_down2_3.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libopus/silk/resampler_down2_3.c b/lib/rbcodec/codecs/libopus/silk/resampler_down2_3.c new file mode 100644 index 0000000000..4342614dcc --- /dev/null +++ b/lib/rbcodec/codecs/libopus/silk/resampler_down2_3.c | |||
@@ -0,0 +1,103 @@ | |||
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 | #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 | { | ||
46 | opus_int32 nSamplesIn, counter, res_Q6; | ||
47 | VARDECL( opus_int32, buf ); | ||
48 | opus_int32 *buf_ptr; | ||
49 | SAVE_STACK; | ||
50 | |||
51 | ALLOC( buf, RESAMPLER_MAX_BATCH_SIZE_IN + ORDER_FIR, opus_int32 ); | ||
52 | |||
53 | /* Copy buffered samples to start of buffer */ | ||
54 | silk_memcpy( buf, S, ORDER_FIR * sizeof( opus_int32 ) ); | ||
55 | |||
56 | /* Iterate over blocks of frameSizeIn input samples */ | ||
57 | while( 1 ) { | ||
58 | nSamplesIn = silk_min( inLen, RESAMPLER_MAX_BATCH_SIZE_IN ); | ||
59 | |||
60 | /* Second-order AR filter (output in Q8) */ | ||
61 | silk_resampler_private_AR2( &S[ ORDER_FIR ], &buf[ ORDER_FIR ], in, | ||
62 | silk_Resampler_2_3_COEFS_LQ, nSamplesIn ); | ||
63 | |||
64 | /* Interpolate filtered signal */ | ||
65 | buf_ptr = buf; | ||
66 | counter = nSamplesIn; | ||
67 | while( counter > 2 ) { | ||
68 | /* Inner product */ | ||
69 | res_Q6 = silk_SMULWB( buf_ptr[ 0 ], silk_Resampler_2_3_COEFS_LQ[ 2 ] ); | ||
70 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 1 ], silk_Resampler_2_3_COEFS_LQ[ 3 ] ); | ||
71 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], silk_Resampler_2_3_COEFS_LQ[ 5 ] ); | ||
72 | 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 | *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) ); | ||
76 | |||
77 | res_Q6 = silk_SMULWB( buf_ptr[ 1 ], silk_Resampler_2_3_COEFS_LQ[ 4 ] ); | ||
78 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], silk_Resampler_2_3_COEFS_LQ[ 5 ] ); | ||
79 | res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], silk_Resampler_2_3_COEFS_LQ[ 3 ] ); | ||
80 | 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 | *out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) ); | ||
84 | |||
85 | buf_ptr += 3; | ||
86 | counter -= 3; | ||
87 | } | ||
88 | |||
89 | in += nSamplesIn; | ||
90 | inLen -= nSamplesIn; | ||
91 | |||
92 | if( inLen > 0 ) { | ||
93 | /* More iterations to do; copy last part of filtered signal to beginning of buffer */ | ||
94 | silk_memcpy( buf, &buf[ nSamplesIn ], ORDER_FIR * sizeof( opus_int32 ) ); | ||
95 | } else { | ||
96 | break; | ||
97 | } | ||
98 | } | ||
99 | |||
100 | /* Copy last part of filtered signal to the state for the next call */ | ||
101 | silk_memcpy( S, &buf[ nSamplesIn ], ORDER_FIR * sizeof( opus_int32 ) ); | ||
102 | RESTORE_STACK; | ||
103 | } | ||