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comparison: media/libopus/silk/fixed/find_LPC_FIX.c
media/libopus/silk/fixed/find_LPC_FIX.c
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- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:c90933eb5c03 |
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| 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 "main_FIX.h" | |
| 33 #include "stack_alloc.h" | |
| 34 #include "tuning_parameters.h" | |
| 35 | |
| 36 /* Finds LPC vector from correlations, and converts to NLSF */ | |
| 37 void silk_find_LPC_FIX( | |
| 38 silk_encoder_state *psEncC, /* I/O Encoder state */ | |
| 39 opus_int16 NLSF_Q15[], /* O NLSFs */ | |
| 40 const opus_int16 x[], /* I Input signal */ | |
| 41 const opus_int32 minInvGain_Q30 /* I Inverse of max prediction gain */ | |
| 42 ) | |
| 43 { | |
| 44 opus_int k, subfr_length; | |
| 45 opus_int32 a_Q16[ MAX_LPC_ORDER ]; | |
| 46 opus_int isInterpLower, shift; | |
| 47 opus_int32 res_nrg0, res_nrg1; | |
| 48 opus_int rshift0, rshift1; | |
| 49 | |
| 50 /* Used only for LSF interpolation */ | |
| 51 opus_int32 a_tmp_Q16[ MAX_LPC_ORDER ], res_nrg_interp, res_nrg, res_tmp_nrg; | |
| 52 opus_int res_nrg_interp_Q, res_nrg_Q, res_tmp_nrg_Q; | |
| 53 opus_int16 a_tmp_Q12[ MAX_LPC_ORDER ]; | |
| 54 opus_int16 NLSF0_Q15[ MAX_LPC_ORDER ]; | |
| 55 SAVE_STACK; | |
| 56 | |
| 57 subfr_length = psEncC->subfr_length + psEncC->predictLPCOrder; | |
| 58 | |
| 59 /* Default: no interpolation */ | |
| 60 psEncC->indices.NLSFInterpCoef_Q2 = 4; | |
| 61 | |
| 62 /* Burg AR analysis for the full frame */ | |
| 63 silk_burg_modified( &res_nrg, &res_nrg_Q, a_Q16, x, minInvGain_Q30, subfr_length, psEncC->nb_subfr, psEncC->predictLPCOrder, psEncC->arch ); | |
| 64 | |
| 65 if( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) { | |
| 66 VARDECL( opus_int16, LPC_res ); | |
| 67 | |
| 68 /* Optimal solution for last 10 ms */ | |
| 69 silk_burg_modified( &res_tmp_nrg, &res_tmp_nrg_Q, a_tmp_Q16, x + 2 * subfr_length, minInvGain_Q30, subfr_length, 2, psEncC->predictLPCOrder, psEncC->arch ); | |
| 70 | |
| 71 /* subtract residual energy here, as that's easier than adding it to the */ | |
| 72 /* residual energy of the first 10 ms in each iteration of the search below */ | |
| 73 shift = res_tmp_nrg_Q - res_nrg_Q; | |
| 74 if( shift >= 0 ) { | |
| 75 if( shift < 32 ) { | |
| 76 res_nrg = res_nrg - silk_RSHIFT( res_tmp_nrg, shift ); | |
| 77 } | |
| 78 } else { | |
| 79 silk_assert( shift > -32 ); | |
| 80 res_nrg = silk_RSHIFT( res_nrg, -shift ) - res_tmp_nrg; | |
| 81 res_nrg_Q = res_tmp_nrg_Q; | |
| 82 } | |
| 83 | |
| 84 /* Convert to NLSFs */ | |
| 85 silk_A2NLSF( NLSF_Q15, a_tmp_Q16, psEncC->predictLPCOrder ); | |
| 86 | |
| 87 ALLOC( LPC_res, 2 * subfr_length, opus_int16 ); | |
| 88 | |
| 89 /* Search over interpolation indices to find the one with lowest residual energy */ | |
| 90 for( k = 3; k >= 0; k-- ) { | |
| 91 /* Interpolate NLSFs for first half */ | |
| 92 silk_interpolate( NLSF0_Q15, psEncC->prev_NLSFq_Q15, NLSF_Q15, k, psEncC->predictLPCOrder ); | |
| 93 | |
| 94 /* Convert to LPC for residual energy evaluation */ | |
| 95 silk_NLSF2A( a_tmp_Q12, NLSF0_Q15, psEncC->predictLPCOrder ); | |
| 96 | |
| 97 /* Calculate residual energy with NLSF interpolation */ | |
| 98 silk_LPC_analysis_filter( LPC_res, x, a_tmp_Q12, 2 * subfr_length, psEncC->predictLPCOrder ); | |
| 99 | |
| 100 silk_sum_sqr_shift( &res_nrg0, &rshift0, LPC_res + psEncC->predictLPCOrder, subfr_length - psEncC->predictLPCOrder ); | |
| 101 silk_sum_sqr_shift( &res_nrg1, &rshift1, LPC_res + psEncC->predictLPCOrder + subfr_length, subfr_length - psEncC->predictLPCOrder ); | |
| 102 | |
| 103 /* Add subframe energies from first half frame */ | |
| 104 shift = rshift0 - rshift1; | |
| 105 if( shift >= 0 ) { | |
| 106 res_nrg1 = silk_RSHIFT( res_nrg1, shift ); | |
| 107 res_nrg_interp_Q = -rshift0; | |
| 108 } else { | |
| 109 res_nrg0 = silk_RSHIFT( res_nrg0, -shift ); | |
| 110 res_nrg_interp_Q = -rshift1; | |
| 111 } | |
| 112 res_nrg_interp = silk_ADD32( res_nrg0, res_nrg1 ); | |
| 113 | |
| 114 /* Compare with first half energy without NLSF interpolation, or best interpolated value so far */ | |
| 115 shift = res_nrg_interp_Q - res_nrg_Q; | |
| 116 if( shift >= 0 ) { | |
| 117 if( silk_RSHIFT( res_nrg_interp, shift ) < res_nrg ) { | |
| 118 isInterpLower = silk_TRUE; | |
| 119 } else { | |
| 120 isInterpLower = silk_FALSE; | |
| 121 } | |
| 122 } else { | |
| 123 if( -shift < 32 ) { | |
| 124 if( res_nrg_interp < silk_RSHIFT( res_nrg, -shift ) ) { | |
| 125 isInterpLower = silk_TRUE; | |
| 126 } else { | |
| 127 isInterpLower = silk_FALSE; | |
| 128 } | |
| 129 } else { | |
| 130 isInterpLower = silk_FALSE; | |
| 131 } | |
| 132 } | |
| 133 | |
| 134 /* Determine whether current interpolated NLSFs are best so far */ | |
| 135 if( isInterpLower == silk_TRUE ) { | |
| 136 /* Interpolation has lower residual energy */ | |
| 137 res_nrg = res_nrg_interp; | |
| 138 res_nrg_Q = res_nrg_interp_Q; | |
| 139 psEncC->indices.NLSFInterpCoef_Q2 = (opus_int8)k; | |
| 140 } | |
| 141 } | |
| 142 } | |
| 143 | |
| 144 if( psEncC->indices.NLSFInterpCoef_Q2 == 4 ) { | |
| 145 /* NLSF interpolation is currently inactive, calculate NLSFs from full frame AR coefficients */ | |
| 146 silk_A2NLSF( NLSF_Q15, a_Q16, psEncC->predictLPCOrder ); | |
| 147 } | |
| 148 | |
| 149 silk_assert( psEncC->indices.NLSFInterpCoef_Q2 == 4 || ( psEncC->useInterpolatedNLSFs && !psEncC->first_frame_after_reset && psEncC->nb_subfr == MAX_NB_SUBFR ) ); | |
| 150 RESTORE_STACK; | |
| 151 } |
