/src/opus/silk/decode_core.c

Source
/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of Internet Society, IETF or IETF Trust, nor the
names of specific contributors, may be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
***********************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "main.h"
#include "stack_alloc.h"

/**********************************************************/
/* Core decoder. Performs inverse NSQ operation LTP + LPC */
/**********************************************************/
void silk_decode_core(
    silk_decoder_state          *psDec,                         /* I/O  Decoder state                               */
    silk_decoder_control        *psDecCtrl,                     /* I    Decoder control                             */
    opus_int16                  xq[],                           /* O    Decoded speech                              */
    const opus_int16            pulses[ MAX_FRAME_LENGTH ],     /* I    Pulse signal                                */
    int                         arch                            /* I    Run-time architecture                       */
)
{
    opus_int   i, k, lag = 0, start_idx, sLTP_buf_idx, NLSF_interpolation_flag, signalType;
    opus_int16 *A_Q12, *B_Q14, *pxq, A_Q12_tmp[ MAX_LPC_ORDER ];
    VARDECL( opus_int16, sLTP );
    VARDECL( opus_int32, sLTP_Q15 );
    opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q31, gain_adj_Q16, rand_seed, offset_Q10;
    opus_int32 *pred_lag_ptr, *pexc_Q14, *pres_Q14;
    VARDECL( opus_int32, res_Q14 );
    VARDECL( opus_int32, sLPC_Q14 );
    SAVE_STACK;

    silk_assert( psDec->prev_gain_Q16 != 0 );

    ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 );
    ALLOC( sLTP_Q15, psDec->ltp_mem_length + psDec->frame_length, opus_int32 );
    ALLOC( res_Q14, psDec->subfr_length, opus_int32 );
    /* Work around a clang bug (verified with clang 6.0 through clang 20.1.0) that causes the last
       memset to be flagged as an invalid read by valgrind (not caught by asan). */
#if defined(__clang__) && defined(VAR_ARRAYS)
    ALLOC( sLPC_Q14, MAX_SUB_FRAME_LENGTH + MAX_LPC_ORDER, opus_int32 );
#else
    ALLOC( sLPC_Q14, psDec->subfr_length + MAX_LPC_ORDER, opus_int32 );
#endif

    offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ];

    if( psDec->indices.NLSFInterpCoef_Q2 < 1 << 2 ) {
        NLSF_interpolation_flag = 1;
    } else {
        NLSF_interpolation_flag = 0;
    }

    /* Decode excitation */
    rand_seed = psDec->indices.Seed;
    for( i = 0; i < psDec->frame_length; i++ ) {
        rand_seed = silk_RAND( rand_seed );
        psDec->exc_Q14[ i ] = silk_LSHIFT( (opus_int32)pulses[ i ], 14 );
        if( psDec->exc_Q14[ i ] > 0 ) {
            psDec->exc_Q14[ i ] -= QUANT_LEVEL_ADJUST_Q10 << 4;
        } else
        if( psDec->exc_Q14[ i ] < 0 ) {
            psDec->exc_Q14[ i ] += QUANT_LEVEL_ADJUST_Q10 << 4;
        }
        psDec->exc_Q14[ i ] += offset_Q10 << 4;
        if( rand_seed < 0 ) {
           psDec->exc_Q14[ i ] = -psDec->exc_Q14[ i ];
        }

        rand_seed = silk_ADD32_ovflw( rand_seed, pulses[ i ] );
    }

    /* Copy LPC state */
    silk_memcpy( sLPC_Q14, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) );

    pexc_Q14 = psDec->exc_Q14;
    pxq      = xq;
    sLTP_buf_idx = psDec->ltp_mem_length;
    /* Loop over subframes */
    for( k = 0; k < psDec->nb_subfr; k++ ) {
        pres_Q14 = res_Q14;
        A_Q12 = psDecCtrl->PredCoef_Q12[ k >> 1 ];

        /* Preload LPC coefficients to array on stack. Gives small performance gain */
        silk_memcpy( A_Q12_tmp, A_Q12, psDec->LPC_order * sizeof( opus_int16 ) );
        B_Q14        = &psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER ];
        signalType   = psDec->indices.signalType;

        Gain_Q10     = silk_RSHIFT( psDecCtrl->Gains_Q16[ k ], 6 );
        inv_gain_Q31 = silk_INVERSE32_varQ( psDecCtrl->Gains_Q16[ k ], 47 );

        /* Calculate gain adjustment factor */
        if( psDecCtrl->Gains_Q16[ k ] != psDec->prev_gain_Q16 ) {
            gain_adj_Q16 =  silk_DIV32_varQ( psDec->prev_gain_Q16, psDecCtrl->Gains_Q16[ k ], 16 );

            /* Scale short term state */
            for( i = 0; i < MAX_LPC_ORDER; i++ ) {
                sLPC_Q14[ i ] = silk_SMULWW( gain_adj_Q16, sLPC_Q14[ i ] );
            }
        } else {
            gain_adj_Q16 = (opus_int32)1 << 16;
        }

        /* Save inv_gain */
        silk_assert( inv_gain_Q31 != 0 );
        psDec->prev_gain_Q16 = psDecCtrl->Gains_Q16[ k ];

        /* Avoid abrupt transition from voiced PLC to unvoiced normal decoding */
        if( psDec->lossCnt && psDec->prevSignalType == TYPE_VOICED &&
            psDec->indices.signalType != TYPE_VOICED && k < MAX_NB_SUBFR/2 ) {

            silk_memset( B_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) );
            B_Q14[ LTP_ORDER/2 ] = SILK_FIX_CONST( 0.25, 14 );

            signalType = TYPE_VOICED;
            psDecCtrl->pitchL[ k ] = psDec->lagPrev;
        }

        if( signalType == TYPE_VOICED ) {
            /* Voiced */
            lag = psDecCtrl->pitchL[ k ];

            /* Re-whitening */
            if( k == 0 || ( k == 2 && NLSF_interpolation_flag ) ) {
                /* Rewhiten with new A coefs */
                start_idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
                celt_assert( start_idx > 0 );

                if( k == 2 ) {
                    silk_memcpy( &psDec->outBuf[ psDec->ltp_mem_length ], xq, 2 * psDec->subfr_length * sizeof( opus_int16 ) );
                }

                silk_LPC_analysis_filter( &sLTP[ start_idx ], &psDec->outBuf[ start_idx + k * psDec->subfr_length ],
                    A_Q12, psDec->ltp_mem_length - start_idx, psDec->LPC_order, arch );

                /* After rewhitening the LTP state is unscaled */
                if( k == 0 ) {
                    /* Do LTP downscaling to reduce inter-packet dependency */
                    inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, psDecCtrl->LTP_scale_Q14 ), 2 );
                }
                for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
                    sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWB( inv_gain_Q31, sLTP[ psDec->ltp_mem_length - i - 1 ] );
                }
            } else {
                /* Update LTP state when Gain changes */
                if( gain_adj_Q16 != (opus_int32)1 << 16 ) {
                    for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
                        sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWW( gain_adj_Q16, sLTP_Q15[ sLTP_buf_idx - i - 1 ] );
                    }
                }
            }
        }

        /* Long-term prediction */
        if( signalType == TYPE_VOICED ) {
            /* Set up pointer */
            pred_lag_ptr = &sLTP_Q15[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
            for( i = 0; i < psDec->subfr_length; i++ ) {
                /* Unrolled loop */
                /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
                LTP_pred_Q13 = 2;
                LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[  0 ], B_Q14[ 0 ] );
                LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
                LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
                LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
                LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
                pred_lag_ptr++;

                /* Generate LPC excitation */
                pres_Q14[ i ] = silk_ADD_LSHIFT32( pexc_Q14[ i ], LTP_pred_Q13, 1 );

                /* Update states */
                sLTP_Q15[ sLTP_buf_idx ] = silk_LSHIFT( pres_Q14[ i ], 1 );
                sLTP_buf_idx++;
            }
        } else {
            pres_Q14 = pexc_Q14;
        }

        for( i = 0; i < psDec->subfr_length; i++ ) {
            /* Short-term prediction */
            celt_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 );
            /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
            LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  1 ], A_Q12_tmp[ 0 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  2 ], A_Q12_tmp[ 1 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  3 ], A_Q12_tmp[ 2 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  4 ], A_Q12_tmp[ 3 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  5 ], A_Q12_tmp[ 4 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  6 ], A_Q12_tmp[ 5 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  7 ], A_Q12_tmp[ 6 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  8 ], A_Q12_tmp[ 7 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i -  9 ], A_Q12_tmp[ 8 ] );
            LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] );
            if( psDec->LPC_order == 16 ) {
                LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 11 ], A_Q12_tmp[ 10 ] );
                LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 12 ], A_Q12_tmp[ 11 ] );
                LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 13 ], A_Q12_tmp[ 12 ] );
                LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 14 ], A_Q12_tmp[ 13 ] );
                LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 15 ], A_Q12_tmp[ 14 ] );
                LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 16 ], A_Q12_tmp[ 15 ] );
            }

            /* Add prediction to LPC excitation */
            sLPC_Q14[ MAX_LPC_ORDER + i ] = silk_ADD_SAT32( pres_Q14[ i ], silk_LSHIFT_SAT32( LPC_pred_Q10, 4 ) );

            /* Scale with gain */
            pxq[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14[ MAX_LPC_ORDER + i ], Gain_Q10 ), 8 ) );
        }

        /* Update LPC filter state */
        silk_memcpy( sLPC_Q14, &sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
        pexc_Q14 += psDec->subfr_length;
        pxq      += psDec->subfr_length;
    }

    /* Save LPC state */
    silk_memcpy( psDec->sLPC_Q14_buf, sLPC_Q14, MAX_LPC_ORDER * sizeof( opus_int32 ) );
    RESTORE_STACK;
}

Coverage Report

Created: 2026-03-19 07:24

Line	Count	Source
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.h"
33		#include "stack_alloc.h"
34
35		/**********************************************************/
36		/* Core decoder. Performs inverse NSQ operation LTP + LPC */
37		/**********************************************************/
38		void silk_decode_core(
39		silk_decoder_state psDec, / I/O Decoder state */
40		silk_decoder_control psDecCtrl, / I Decoder control */
41		opus_int16 xq[], /* O Decoded speech */
42		const opus_int16 pulses[ MAX_FRAME_LENGTH ], /* I Pulse signal */
43		int arch /* I Run-time architecture */
44		)
45	472k	{
46	472k	opus_int i, k, lag = 0, start_idx, sLTP_buf_idx, NLSF_interpolation_flag, signalType;
47	472k	opus_int16 A_Q12, B_Q14, *pxq, A_Q12_tmp[ MAX_LPC_ORDER ];
48	472k	VARDECL( opus_int16, sLTP );
49	472k	VARDECL( opus_int32, sLTP_Q15 );
50	472k	opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q31, gain_adj_Q16, rand_seed, offset_Q10;
51	472k	opus_int32 pred_lag_ptr, pexc_Q14, *pres_Q14;
52	472k	VARDECL( opus_int32, res_Q14 );
53	472k	VARDECL( opus_int32, sLPC_Q14 );
54	472k	SAVE_STACK;
55
56	472k	silk_assert( psDec->prev_gain_Q16 != 0 );
57
58	472k	ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 );
59	472k	ALLOC( sLTP_Q15, psDec->ltp_mem_length + psDec->frame_length, opus_int32 );
60	472k	ALLOC( res_Q14, psDec->subfr_length, opus_int32 );
61		/* Work around a clang bug (verified with clang 6.0 through clang 20.1.0) that causes the last
62		memset to be flagged as an invalid read by valgrind (not caught by asan). */
63	472k	#if defined(__clang__) && defined(VAR_ARRAYS)
64	472k	ALLOC( sLPC_Q14, MAX_SUB_FRAME_LENGTH + MAX_LPC_ORDER, opus_int32 );
65		#else
66		ALLOC( sLPC_Q14, psDec->subfr_length + MAX_LPC_ORDER, opus_int32 );
67		#endif
68
69	472k	offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ];
70
71	472k	if( psDec->indices.NLSFInterpCoef_Q2 < 1 << 2 ) {
72	87.8k	NLSF_interpolation_flag = 1;
73	384k	} else {
74	384k	NLSF_interpolation_flag = 0;
75	384k	}
76
77		/* Decode excitation */
78	472k	rand_seed = psDec->indices.Seed;
79	100M	for( i = 0; i < psDec->frame_length; i++ ) {
80	100M	rand_seed = silk_RAND( rand_seed );
81	100M	psDec->exc_Q14[ i ] = silk_LSHIFT( (opus_int32)pulses[ i ], 14 );
82	100M	if( psDec->exc_Q14[ i ] > 0 ) {
83	5.95M	psDec->exc_Q14[ i ] -= QUANT_LEVEL_ADJUST_Q10 << 4;
84	5.95M	} else
85	94.2M	if( psDec->exc_Q14[ i ] < 0 ) {
86	15.1M	psDec->exc_Q14[ i ] += QUANT_LEVEL_ADJUST_Q10 << 4;
87	15.1M	}
88	100M	psDec->exc_Q14[ i ] += offset_Q10 << 4;
89	100M	if( rand_seed < 0 ) {
90	49.8M	psDec->exc_Q14[ i ] = -psDec->exc_Q14[ i ];
91	49.8M	}
92
93	100M	rand_seed = silk_ADD32_ovflw( rand_seed, pulses[ i ] );
94	100M	}
95
96		/* Copy LPC state */
97	472k	silk_memcpy( sLPC_Q14, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) );
98
99	472k	pexc_Q14 = psDec->exc_Q14;
100	472k	pxq = xq;
101	472k	sLTP_buf_idx = psDec->ltp_mem_length;
102		/* Loop over subframes */
103	2.09M	for( k = 0; k < psDec->nb_subfr; k++ ) {
104	1.62M	pres_Q14 = res_Q14;
105	1.62M	A_Q12 = psDecCtrl->PredCoef_Q12[ k >> 1 ];
106
107		/* Preload LPC coefficients to array on stack. Gives small performance gain */
108	1.62M	silk_memcpy( A_Q12_tmp, A_Q12, psDec->LPC_order * sizeof( opus_int16 ) );
109	1.62M	B_Q14 = &psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER ];
110	1.62M	signalType = psDec->indices.signalType;
111
112	1.62M	Gain_Q10 = silk_RSHIFT( psDecCtrl->Gains_Q16[ k ], 6 );
113	1.62M	inv_gain_Q31 = silk_INVERSE32_varQ( psDecCtrl->Gains_Q16[ k ], 47 );
114
115		/* Calculate gain adjustment factor */
116	1.62M	if( psDecCtrl->Gains_Q16[ k ] != psDec->prev_gain_Q16 ) {
117	858k	gain_adj_Q16 = silk_DIV32_varQ( psDec->prev_gain_Q16, psDecCtrl->Gains_Q16[ k ], 16 );
118
119		/* Scale short term state */
120	14.5M	for( i = 0; i < MAX_LPC_ORDER; i++ ) {
121	13.7M	sLPC_Q14[ i ] = silk_SMULWW( gain_adj_Q16, sLPC_Q14[ i ] );
122	13.7M	}
123	858k	} else {
124	762k	gain_adj_Q16 = (opus_int32)1 << 16;
125	762k	}
126
127		/* Save inv_gain */
128	1.62M	silk_assert( inv_gain_Q31 != 0 );
129	1.62M	psDec->prev_gain_Q16 = psDecCtrl->Gains_Q16[ k ];
130
131		/* Avoid abrupt transition from voiced PLC to unvoiced normal decoding */
132	1.62M	if( psDec->lossCnt && psDec->prevSignalType == TYPE_VOICED &&
133	21.5k	psDec->indices.signalType != TYPE_VOICED && k < MAX_NB_SUBFR/2 ) {
134
135	7.31k	silk_memset( B_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) );
136	7.31k	B_Q14[ LTP_ORDER/2 ] = SILK_FIX_CONST( 0.25, 14 );
137
138	7.31k	signalType = TYPE_VOICED;
139	7.31k	psDecCtrl->pitchL[ k ] = psDec->lagPrev;
140	7.31k	}
141
142	1.62M	if( signalType == TYPE_VOICED ) {
143		/* Voiced */
144	492k	lag = psDecCtrl->pitchL[ k ];
145
146		/* Re-whitening */
147	492k	if( k == 0 \|\| ( k == 2 && NLSF_interpolation_flag ) ) {
148		/* Rewhiten with new A coefs */
149	158k	start_idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
150	158k	celt_assert( start_idx > 0 );
151
152	158k	if( k == 2 ) {
153	22.6k	silk_memcpy( &psDec->outBuf[ psDec->ltp_mem_length ], xq, 2 * psDec->subfr_length * sizeof( opus_int16 ) );
154	22.6k	}
155
156	158k	silk_LPC_analysis_filter( &sLTP[ start_idx ], &psDec->outBuf[ start_idx + k * psDec->subfr_length ],
157	158k	A_Q12, psDec->ltp_mem_length - start_idx, psDec->LPC_order, arch );
158
159		/* After rewhitening the LTP state is unscaled */
160	158k	if( k == 0 ) {
161		/* Do LTP downscaling to reduce inter-packet dependency */
162	136k	inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, psDecCtrl->LTP_scale_Q14 ), 2 );
163	136k	}
164	14.6M	for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
165	14.5M	sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWB( inv_gain_Q31, sLTP[ psDec->ltp_mem_length - i - 1 ] );
166	14.5M	}
167	333k	} else {
168		/* Update LTP state when Gain changes */
169	333k	if( gain_adj_Q16 != (opus_int32)1 << 16 ) {
170	13.6M	for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
171	13.4M	sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWW( gain_adj_Q16, sLTP_Q15[ sLTP_buf_idx - i - 1 ] );
172	13.4M	}
173	151k	}
174	333k	}
175	492k	}
176
177		/* Long-term prediction */
178	1.62M	if( signalType == TYPE_VOICED ) {
179		/* Set up pointer */
180	492k	pred_lag_ptr = &sLTP_Q15[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
181	31.4M	for( i = 0; i < psDec->subfr_length; i++ ) {
182		/* Unrolled loop */
183		/* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
184	30.9M	LTP_pred_Q13 = 2;
185	30.9M	LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
186	30.9M	LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
187	30.9M	LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
188	30.9M	LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
189	30.9M	LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
190	30.9M	pred_lag_ptr++;
191
192		/* Generate LPC excitation */
193	30.9M	pres_Q14[ i ] = silk_ADD_LSHIFT32( pexc_Q14[ i ], LTP_pred_Q13, 1 );
194
195		/* Update states */
196	30.9M	sLTP_Q15[ sLTP_buf_idx ] = silk_LSHIFT( pres_Q14[ i ], 1 );
197	30.9M	sLTP_buf_idx++;
198	30.9M	}
199	1.12M	} else {
200	1.12M	pres_Q14 = pexc_Q14;
201	1.12M	}
202
203	101M	for( i = 0; i < psDec->subfr_length; i++ ) {
204		/* Short-term prediction */
205	100M	celt_assert( psDec->LPC_order == 10 \|\| psDec->LPC_order == 16 );
206		/* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
207	100M	LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 );
208	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] );
209	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12_tmp[ 1 ] );
210	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12_tmp[ 2 ] );
211	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12_tmp[ 3 ] );
212	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12_tmp[ 4 ] );
213	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12_tmp[ 5 ] );
214	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12_tmp[ 6 ] );
215	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12_tmp[ 7 ] );
216	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12_tmp[ 8 ] );
217	100M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] );
218	100M	if( psDec->LPC_order == 16 ) {
219	54.1M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 11 ], A_Q12_tmp[ 10 ] );
220	54.1M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 12 ], A_Q12_tmp[ 11 ] );
221	54.1M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 13 ], A_Q12_tmp[ 12 ] );
222	54.1M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 14 ], A_Q12_tmp[ 13 ] );
223	54.1M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 15 ], A_Q12_tmp[ 14 ] );
224	54.1M	LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 16 ], A_Q12_tmp[ 15 ] );
225	54.1M	}
226
227		/* Add prediction to LPC excitation */
228	100M	sLPC_Q14[ MAX_LPC_ORDER + i ] = silk_ADD_SAT32( pres_Q14[ i ], silk_LSHIFT_SAT32( LPC_pred_Q10, 4 ) );
229
230		/* Scale with gain */
231	100M	pxq[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14[ MAX_LPC_ORDER + i ], Gain_Q10 ), 8 ) );
232	100M	}
233
234		/* Update LPC filter state */
235	1.62M	silk_memcpy( sLPC_Q14, &sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
236	1.62M	pexc_Q14 += psDec->subfr_length;
237	1.62M	pxq += psDec->subfr_length;
238	1.62M	}
239
240		/* Save LPC state */
241	472k	silk_memcpy( psDec->sLPC_Q14_buf, sLPC_Q14, MAX_LPC_ORDER * sizeof( opus_int32 ) );
242	472k	RESTORE_STACK;
243	472k	}