diff options
Diffstat (limited to 'lib/rbcodec/codecs/libopus/silk/float/find_LPC_FLP.c')
-rw-r--r-- | lib/rbcodec/codecs/libopus/silk/float/find_LPC_FLP.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libopus/silk/float/find_LPC_FLP.c b/lib/rbcodec/codecs/libopus/silk/float/find_LPC_FLP.c new file mode 100644 index 0000000000..fa3ffe7f8b --- /dev/null +++ b/lib/rbcodec/codecs/libopus/silk/float/find_LPC_FLP.c | |||
@@ -0,0 +1,104 @@ | |||
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 "define.h" | ||
33 | #include "main_FLP.h" | ||
34 | #include "tuning_parameters.h" | ||
35 | |||
36 | /* LPC analysis */ | ||
37 | void silk_find_LPC_FLP( | ||
38 | silk_encoder_state *psEncC, /* I/O Encoder state */ | ||
39 | opus_int16 NLSF_Q15[], /* O NLSFs */ | ||
40 | const silk_float x[], /* I Input signal */ | ||
41 | const silk_float minInvGain /* I Inverse of max prediction gain */ | ||
42 | ) | ||
43 | { | ||
44 | opus_int k, subfr_length; | ||
45 | silk_float a[ MAX_LPC_ORDER ]; | ||
46 | |||
47 | /* Used only for NLSF interpolation */ | ||
48 | silk_float res_nrg, res_nrg_2nd, res_nrg_interp; | ||
49 | opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ]; | ||
50 | silk_float a_tmp[ MAX_LPC_ORDER ]; | ||
51 | silk_float LPC_res[ MAX_FRAME_LENGTH + MAX_NB_SUBFR * MAX_LPC_ORDER ]; | ||
52 | |||
53 | subfr_length = psEncC->subfr_length + psEncC->predictLPCOrder; | ||
54 | |||
55 | /* Default: No interpolation */ | ||
56 | psEncC->indices.NLSFInterpCoef_Q2 = 4; | ||
57 | |||
58 | /* Burg AR analysis for the full frame */ | ||
59 | res_nrg = silk_burg_modified_FLP( a, x, minInvGain, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder ); | ||
60 | |||
61 | if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) { | ||
62 | /* Optimal solution for last 10 ms; subtract residual energy here, as that's easier than */ | ||
63 | /* adding it to the residual energy of the first 10 ms in each iteration of the search below */ | ||
64 | res_nrg -= silk_burg_modified_FLP( a_tmp, x + ( MAX_NB_SUBFR / 2 ) * subfr_length, minInvGain, subfr_length, MAX_NB_SUBFR / 2, psEncC->predictLPCOrder ); | ||
65 | |||
66 | /* Convert to NLSFs */ | ||
67 | silk_A2NLSF_FLP( NLSF_Q15, a_tmp, psEncC->predictLPCOrder ); | ||
68 | |||
69 | /* Search over interpolation indices to find the one with lowest residual energy */ | ||
70 | res_nrg_2nd = silk_float_MAX; | ||
71 | for( k = 3; k >= 0; k-- ) { | ||
72 | /* Interpolate NLSFs for first half */ | ||
73 | silk_interpolate( NLSF0_Q15, psEncC->prev_NLSFq_Q15, NLSF_Q15, k, psEncC->predictLPCOrder ); | ||
74 | |||
75 | /* Convert to LPC for residual energy evaluation */ | ||
76 | silk_NLSF2A_FLP( a_tmp, NLSF0_Q15, psEncC->predictLPCOrder, psEncC->arch ); | ||
77 | |||
78 | /* Calculate residual energy with LSF interpolation */ | ||
79 | silk_LPC_analysis_filter_FLP( LPC_res, a_tmp, x, 2 * subfr_length, psEncC->predictLPCOrder ); | ||
80 | res_nrg_interp = (silk_float)( | ||
81 | silk_energy_FLP( LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder ) + | ||
82 | silk_energy_FLP( LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder ) ); | ||
83 | |||
84 | /* Determine whether current interpolated NLSFs are best so far */ | ||
85 | if( res_nrg_interp < res_nrg ) { | ||
86 | /* Interpolation has lower residual energy */ | ||
87 | res_nrg = res_nrg_interp; | ||
88 | psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k; | ||
89 | } else if( res_nrg_interp > res_nrg_2nd ) { | ||
90 | /* No reason to continue iterating - residual energies will continue to climb */ | ||
91 | break; | ||
92 | } | ||
93 | res_nrg_2nd = res_nrg_interp; | ||
94 | } | ||
95 | } | ||
96 | |||
97 | if( psEncC->indices.NLSFInterpCoef_Q2 == 4 ) { | ||
98 | /* NLSF interpolation is currently inactive, calculate NLSFs from full frame AR coefficients */ | ||
99 | silk_A2NLSF_FLP( NLSF_Q15, a, psEncC->predictLPCOrder ); | ||
100 | } | ||
101 | |||
102 | celt_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 || | ||
103 | ( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) ); | ||
104 | } | ||