xref: /aosp_15_r20/external/libopus/silk/fixed/find_pred_coefs_FIX.c (revision a58d3d2adb790c104798cd88c8a3aff4fa8b82cc)
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27 
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31 
32 #include "main_FIX.h"
33 #include "stack_alloc.h"
34 
silk_find_pred_coefs_FIX(silk_encoder_state_FIX * psEnc,silk_encoder_control_FIX * psEncCtrl,const opus_int16 res_pitch[],const opus_int16 x[],opus_int condCoding)35 void silk_find_pred_coefs_FIX(
36     silk_encoder_state_FIX          *psEnc,                                 /* I/O  encoder state                                                               */
37     silk_encoder_control_FIX        *psEncCtrl,                             /* I/O  encoder control                                                             */
38     const opus_int16                res_pitch[],                            /* I    Residual from pitch analysis                                                */
39     const opus_int16                x[],                                    /* I    Speech signal                                                               */
40     opus_int                        condCoding                              /* I    The type of conditional coding to use                                       */
41 )
42 {
43     opus_int         i;
44     opus_int32       invGains_Q16[ MAX_NB_SUBFR ], local_gains[ MAX_NB_SUBFR ];
45     /* Set to NLSF_Q15 to zero so we don't copy junk to the state. */
46     opus_int16       NLSF_Q15[ MAX_LPC_ORDER ]={0};
47     const opus_int16 *x_ptr;
48     opus_int16       *x_pre_ptr;
49     VARDECL( opus_int16, LPC_in_pre );
50     opus_int32       min_gain_Q16, minInvGain_Q30;
51     SAVE_STACK;
52 
53     /* weighting for weighted least squares */
54     min_gain_Q16 = silk_int32_MAX >> 6;
55     for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
56         min_gain_Q16 = silk_min( min_gain_Q16, psEncCtrl->Gains_Q16[ i ] );
57     }
58     for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
59         /* Divide to Q16 */
60         silk_assert( psEncCtrl->Gains_Q16[ i ] > 0 );
61         /* Invert and normalize gains, and ensure that maximum invGains_Q16 is within range of a 16 bit int */
62         invGains_Q16[ i ] = silk_DIV32_varQ( min_gain_Q16, psEncCtrl->Gains_Q16[ i ], 16 - 2 );
63 
64         /* Limit inverse */
65         invGains_Q16[ i ] = silk_max( invGains_Q16[ i ], 100 );
66 
67         /* Square the inverted gains */
68         silk_assert( invGains_Q16[ i ] == silk_SAT16( invGains_Q16[ i ] ) );
69 
70         /* Invert the inverted and normalized gains */
71         local_gains[ i ] = silk_DIV32( ( (opus_int32)1 << 16 ), invGains_Q16[ i ] );
72     }
73 
74     ALLOC( LPC_in_pre,
75            psEnc->sCmn.nb_subfr * psEnc->sCmn.predictLPCOrder
76                + psEnc->sCmn.frame_length, opus_int16 );
77     if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
78         VARDECL( opus_int32, xXLTP_Q17 );
79         VARDECL( opus_int32, XXLTP_Q17 );
80 
81         /**********/
82         /* VOICED */
83         /**********/
84         celt_assert( psEnc->sCmn.ltp_mem_length - psEnc->sCmn.predictLPCOrder >= psEncCtrl->pitchL[ 0 ] + LTP_ORDER / 2 );
85 
86         ALLOC( xXLTP_Q17, psEnc->sCmn.nb_subfr * LTP_ORDER, opus_int32 );
87         ALLOC( XXLTP_Q17, psEnc->sCmn.nb_subfr * LTP_ORDER * LTP_ORDER, opus_int32 );
88 
89         /* LTP analysis */
90         silk_find_LTP_FIX( XXLTP_Q17, xXLTP_Q17, res_pitch,
91             psEncCtrl->pitchL, psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.arch );
92 
93         /* Quantize LTP gain parameters */
94         silk_quant_LTP_gains( psEncCtrl->LTPCoef_Q14, psEnc->sCmn.indices.LTPIndex, &psEnc->sCmn.indices.PERIndex,
95             &psEnc->sCmn.sum_log_gain_Q7, &psEncCtrl->LTPredCodGain_Q7, XXLTP_Q17, xXLTP_Q17, psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.arch );
96 
97         /* Control LTP scaling */
98         silk_LTP_scale_ctrl_FIX( psEnc, psEncCtrl, condCoding );
99 
100         /* Create LTP residual */
101         silk_LTP_analysis_filter_FIX( LPC_in_pre, x - psEnc->sCmn.predictLPCOrder, psEncCtrl->LTPCoef_Q14,
102             psEncCtrl->pitchL, invGains_Q16, psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.predictLPCOrder );
103 
104     } else {
105         /************/
106         /* UNVOICED */
107         /************/
108         /* Create signal with prepended subframes, scaled by inverse gains */
109         x_ptr     = x - psEnc->sCmn.predictLPCOrder;
110         x_pre_ptr = LPC_in_pre;
111         for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
112             silk_scale_copy_vector16( x_pre_ptr, x_ptr, invGains_Q16[ i ],
113                 psEnc->sCmn.subfr_length + psEnc->sCmn.predictLPCOrder );
114             x_pre_ptr += psEnc->sCmn.subfr_length + psEnc->sCmn.predictLPCOrder;
115             x_ptr     += psEnc->sCmn.subfr_length;
116         }
117 
118         silk_memset( psEncCtrl->LTPCoef_Q14, 0, psEnc->sCmn.nb_subfr * LTP_ORDER * sizeof( opus_int16 ) );
119         psEncCtrl->LTPredCodGain_Q7 = 0;
120         psEnc->sCmn.sum_log_gain_Q7 = 0;
121     }
122 
123     /* Limit on total predictive coding gain */
124     if( psEnc->sCmn.first_frame_after_reset ) {
125         minInvGain_Q30 = SILK_FIX_CONST( 1.0f / MAX_PREDICTION_POWER_GAIN_AFTER_RESET, 30 );
126     } else {
127         minInvGain_Q30 = silk_log2lin( silk_SMLAWB( 16 << 7, (opus_int32)psEncCtrl->LTPredCodGain_Q7, SILK_FIX_CONST( 1.0 / 3, 16 ) ) );      /* Q16 */
128         minInvGain_Q30 = silk_DIV32_varQ( minInvGain_Q30,
129             silk_SMULWW( SILK_FIX_CONST( MAX_PREDICTION_POWER_GAIN, 0 ),
130                 silk_SMLAWB( SILK_FIX_CONST( 0.25, 18 ), SILK_FIX_CONST( 0.75, 18 ), psEncCtrl->coding_quality_Q14 ) ), 14 );
131     }
132 
133     /* LPC_in_pre contains the LTP-filtered input for voiced, and the unfiltered input for unvoiced */
134     silk_find_LPC_FIX( &psEnc->sCmn, NLSF_Q15, LPC_in_pre, minInvGain_Q30 );
135 
136     /* Quantize LSFs */
137     silk_process_NLSFs( &psEnc->sCmn, psEncCtrl->PredCoef_Q12, NLSF_Q15, psEnc->sCmn.prev_NLSFq_Q15 );
138 
139     /* Calculate residual energy using quantized LPC coefficients */
140     silk_residual_energy_FIX( psEncCtrl->ResNrg, psEncCtrl->ResNrgQ, LPC_in_pre, psEncCtrl->PredCoef_Q12, local_gains,
141         psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.predictLPCOrder, psEnc->sCmn.arch );
142 
143     /* Copy to prediction struct for use in next frame for interpolation */
144     silk_memcpy( psEnc->sCmn.prev_NLSFq_Q15, NLSF_Q15, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) );
145     RESTORE_STACK;
146 }
147