media/libopus/silk/float/find_LPC_FLP.c@b8a032363ba2 (annotated)
media/libopus/silk/float/find_LPC_FLP.c
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| michael@0 | 1 | /*********************************************************************** |
| michael@0 | 2 | Copyright (c) 2006-2011, Skype Limited. All rights reserved. |
| michael@0 | 3 | Redistribution and use in source and binary forms, with or without |
| michael@0 | 4 | modification, are permitted provided that the following conditions |
| michael@0 | 5 | are met: |
| michael@0 | 6 | - Redistributions of source code must retain the above copyright notice, |
| michael@0 | 7 | this list of conditions and the following disclaimer. |
| michael@0 | 8 | - Redistributions in binary form must reproduce the above copyright |
| michael@0 | 9 | notice, this list of conditions and the following disclaimer in the |
| michael@0 | 10 | documentation and/or other materials provided with the distribution. |
| michael@0 | 11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the |
| michael@0 | 12 | names of specific contributors, may be used to endorse or promote |
| michael@0 | 13 | products derived from this software without specific prior written |
| michael@0 | 14 | permission. |
| michael@0 | 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| michael@0 | 16 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| michael@0 | 17 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| michael@0 | 18 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| michael@0 | 19 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| michael@0 | 20 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| michael@0 | 21 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| michael@0 | 22 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| michael@0 | 23 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| michael@0 | 24 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| michael@0 | 25 | POSSIBILITY OF SUCH DAMAGE. |
| michael@0 | 26 | ***********************************************************************/ |
| michael@0 | 27 | |
| michael@0 | 28 | #ifdef HAVE_CONFIG_H |
| michael@0 | 29 | #include "config.h" |
| michael@0 | 30 | #endif |
| michael@0 | 31 | |
| michael@0 | 32 | #include "define.h" |
| michael@0 | 33 | #include "main_FLP.h" |
| michael@0 | 34 | #include "tuning_parameters.h" |
| michael@0 | 35 | |
| michael@0 | 36 | /* LPC analysis */ |
| michael@0 | 37 | void silk_find_LPC_FLP( |
| michael@0 | 38 | silk_encoder_state *psEncC, /* I/O Encoder state */ |
| michael@0 | 39 | opus_int16 NLSF_Q15[], /* O NLSFs */ |
| michael@0 | 40 | const silk_float x[], /* I Input signal */ |
| michael@0 | 41 | const silk_float minInvGain /* I Inverse of max prediction gain */ |
| michael@0 | 42 | ) |
| michael@0 | 43 | { |
| michael@0 | 44 | opus_int k, subfr_length; |
| michael@0 | 45 | silk_float a[ MAX_LPC_ORDER ]; |
| michael@0 | 46 | |
| michael@0 | 47 | /* Used only for NLSF interpolation */ |
| michael@0 | 48 | silk_float res_nrg, res_nrg_2nd, res_nrg_interp; |
| michael@0 | 49 | opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ]; |
| michael@0 | 50 | silk_float a_tmp[ MAX_LPC_ORDER ]; |
| michael@0 | 51 | silk_float LPC_res[ MAX_FRAME_LENGTH + MAX_NB_SUBFR * MAX_LPC_ORDER ]; |
| michael@0 | 52 | |
| michael@0 | 53 | subfr_length = psEncC->subfr_length + psEncC->predictLPCOrder; |
| michael@0 | 54 | |
| michael@0 | 55 | /* Default: No interpolation */ |
| michael@0 | 56 | psEncC->indices.NLSFInterpCoef_Q2 = 4; |
| michael@0 | 57 | |
| michael@0 | 58 | /* Burg AR analysis for the full frame */ |
| michael@0 | 59 | res_nrg = silk_burg_modified_FLP( a, x, minInvGain, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder ); |
| michael@0 | 60 | |
| michael@0 | 61 | if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) { |
| michael@0 | 62 | /* Optimal solution for last 10 ms; subtract residual energy here, as that's easier than */ |
| michael@0 | 63 | /* adding it to the residual energy of the first 10 ms in each iteration of the search below */ |
| michael@0 | 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 ); |
| michael@0 | 65 | |
| michael@0 | 66 | /* Convert to NLSFs */ |
| michael@0 | 67 | silk_A2NLSF_FLP( NLSF_Q15, a_tmp, psEncC->predictLPCOrder ); |
| michael@0 | 68 | |
| michael@0 | 69 | /* Search over interpolation indices to find the one with lowest residual energy */ |
| michael@0 | 70 | res_nrg_2nd = silk_float_MAX; |
| michael@0 | 71 | for( k = 3; k >= 0; k-- ) { |
| michael@0 | 72 | /* Interpolate NLSFs for first half */ |
| michael@0 | 73 | silk_interpolate( NLSF0_Q15, psEncC->prev_NLSFq_Q15, NLSF_Q15, k, psEncC->predictLPCOrder ); |
| michael@0 | 74 | |
| michael@0 | 75 | /* Convert to LPC for residual energy evaluation */ |
| michael@0 | 76 | silk_NLSF2A_FLP( a_tmp, NLSF0_Q15, psEncC->predictLPCOrder ); |
| michael@0 | 77 | |
| michael@0 | 78 | /* Calculate residual energy with LSF interpolation */ |
| michael@0 | 79 | silk_LPC_analysis_filter_FLP( LPC_res, a_tmp, x, 2 * subfr_length, psEncC->predictLPCOrder ); |
| michael@0 | 80 | res_nrg_interp = (silk_float)( |
| michael@0 | 81 | silk_energy_FLP( LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder ) + |
| michael@0 | 82 | silk_energy_FLP( LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder ) ); |
| michael@0 | 83 | |
| michael@0 | 84 | /* Determine whether current interpolated NLSFs are best so far */ |
| michael@0 | 85 | if( res_nrg_interp < res_nrg ) { |
| michael@0 | 86 | /* Interpolation has lower residual energy */ |
| michael@0 | 87 | res_nrg = res_nrg_interp; |
| michael@0 | 88 | psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k; |
| michael@0 | 89 | } else if( res_nrg_interp > res_nrg_2nd ) { |
| michael@0 | 90 | /* No reason to continue iterating - residual energies will continue to climb */ |
| michael@0 | 91 | break; |
| michael@0 | 92 | } |
| michael@0 | 93 | res_nrg_2nd = res_nrg_interp; |
| michael@0 | 94 | } |
| michael@0 | 95 | } |
| michael@0 | 96 | |
| michael@0 | 97 | if( psEncC->indices.NLSFInterpCoef_Q2 == 4 ) { |
| michael@0 | 98 | /* NLSF interpolation is currently inactive, calculate NLSFs from full frame AR coefficients */ |
| michael@0 | 99 | silk_A2NLSF_FLP( NLSF_Q15, a, psEncC->predictLPCOrder ); |
| michael@0 | 100 | } |
| michael@0 | 101 | |
| michael@0 | 102 | silk_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 || |
| michael@0 | 103 | ( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) ); |
| michael@0 | 104 | } |
