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
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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
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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
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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 /* Generates excitation for CNG LPC synthesis */
silk_CNG_exc(opus_int32 exc_Q14[],opus_int32 exc_buf_Q14[],opus_int length,opus_int32 * rand_seed)36 static OPUS_INLINE void silk_CNG_exc(
37 opus_int32 exc_Q14[], /* O CNG excitation signal Q10 */
38 opus_int32 exc_buf_Q14[], /* I Random samples buffer Q10 */
39 opus_int length, /* I Length */
40 opus_int32 *rand_seed /* I/O Seed to random index generator */
41 )
42 {
43 opus_int32 seed;
44 opus_int i, idx, exc_mask;
45
46 exc_mask = CNG_BUF_MASK_MAX;
47 while( exc_mask > length ) {
48 exc_mask = silk_RSHIFT( exc_mask, 1 );
49 }
50
51 seed = *rand_seed;
52 for( i = 0; i < length; i++ ) {
53 seed = silk_RAND( seed );
54 idx = (opus_int)( silk_RSHIFT( seed, 24 ) & exc_mask );
55 silk_assert( idx >= 0 );
56 silk_assert( idx <= CNG_BUF_MASK_MAX );
57 exc_Q14[ i ] = exc_buf_Q14[ idx ];
58 }
59 *rand_seed = seed;
60 }
61
silk_CNG_Reset(silk_decoder_state * psDec)62 void silk_CNG_Reset(
63 silk_decoder_state *psDec /* I/O Decoder state */
64 )
65 {
66 opus_int i, NLSF_step_Q15, NLSF_acc_Q15;
67
68 NLSF_step_Q15 = silk_DIV32_16( silk_int16_MAX, psDec->LPC_order + 1 );
69 NLSF_acc_Q15 = 0;
70 for( i = 0; i < psDec->LPC_order; i++ ) {
71 NLSF_acc_Q15 += NLSF_step_Q15;
72 psDec->sCNG.CNG_smth_NLSF_Q15[ i ] = NLSF_acc_Q15;
73 }
74 psDec->sCNG.CNG_smth_Gain_Q16 = 0;
75 psDec->sCNG.rand_seed = 3176576;
76 }
77
78 /* Updates CNG estimate, and applies the CNG when packet was lost */
silk_CNG(silk_decoder_state * psDec,silk_decoder_control * psDecCtrl,opus_int16 frame[],opus_int length)79 void silk_CNG(
80 silk_decoder_state *psDec, /* I/O Decoder state */
81 silk_decoder_control *psDecCtrl, /* I/O Decoder control */
82 opus_int16 frame[], /* I/O Signal */
83 opus_int length /* I Length of residual */
84 )
85 {
86 opus_int i, subfr;
87 opus_int32 LPC_pred_Q10, max_Gain_Q16, gain_Q16, gain_Q10;
88 opus_int16 A_Q12[ MAX_LPC_ORDER ];
89 silk_CNG_struct *psCNG = &psDec->sCNG;
90 SAVE_STACK;
91
92 if( psDec->fs_kHz != psCNG->fs_kHz ) {
93 /* Reset state */
94 silk_CNG_Reset( psDec );
95
96 psCNG->fs_kHz = psDec->fs_kHz;
97 }
98 if( psDec->lossCnt == 0 && psDec->prevSignalType == TYPE_NO_VOICE_ACTIVITY ) {
99 /* Update CNG parameters */
100
101 /* Smoothing of LSF's */
102 for( i = 0; i < psDec->LPC_order; i++ ) {
103 psCNG->CNG_smth_NLSF_Q15[ i ] += silk_SMULWB( (opus_int32)psDec->prevNLSF_Q15[ i ] - (opus_int32)psCNG->CNG_smth_NLSF_Q15[ i ], CNG_NLSF_SMTH_Q16 );
104 }
105 /* Find the subframe with the highest gain */
106 max_Gain_Q16 = 0;
107 subfr = 0;
108 for( i = 0; i < psDec->nb_subfr; i++ ) {
109 if( psDecCtrl->Gains_Q16[ i ] > max_Gain_Q16 ) {
110 max_Gain_Q16 = psDecCtrl->Gains_Q16[ i ];
111 subfr = i;
112 }
113 }
114 /* Update CNG excitation buffer with excitation from this subframe */
115 silk_memmove( &psCNG->CNG_exc_buf_Q14[ psDec->subfr_length ], psCNG->CNG_exc_buf_Q14, ( psDec->nb_subfr - 1 ) * psDec->subfr_length * sizeof( opus_int32 ) );
116 silk_memcpy( psCNG->CNG_exc_buf_Q14, &psDec->exc_Q14[ subfr * psDec->subfr_length ], psDec->subfr_length * sizeof( opus_int32 ) );
117
118 /* Smooth gains */
119 for( i = 0; i < psDec->nb_subfr; i++ ) {
120 psCNG->CNG_smth_Gain_Q16 += silk_SMULWB( psDecCtrl->Gains_Q16[ i ] - psCNG->CNG_smth_Gain_Q16, CNG_GAIN_SMTH_Q16 );
121 }
122 }
123
124 /* Add CNG when packet is lost or during DTX */
125 if( psDec->lossCnt ) {
126 VARDECL( opus_int32, CNG_sig_Q14 );
127 ALLOC( CNG_sig_Q14, length + MAX_LPC_ORDER, opus_int32 );
128
129 /* Generate CNG excitation */
130 gain_Q16 = silk_SMULWW( psDec->sPLC.randScale_Q14, psDec->sPLC.prevGain_Q16[1] );
131 if( gain_Q16 >= (1 << 21) || psCNG->CNG_smth_Gain_Q16 > (1 << 23) ) {
132 gain_Q16 = silk_SMULTT( gain_Q16, gain_Q16 );
133 gain_Q16 = silk_SUB_LSHIFT32(silk_SMULTT( psCNG->CNG_smth_Gain_Q16, psCNG->CNG_smth_Gain_Q16 ), gain_Q16, 5 );
134 gain_Q16 = silk_LSHIFT32( silk_SQRT_APPROX( gain_Q16 ), 16 );
135 } else {
136 gain_Q16 = silk_SMULWW( gain_Q16, gain_Q16 );
137 gain_Q16 = silk_SUB_LSHIFT32(silk_SMULWW( psCNG->CNG_smth_Gain_Q16, psCNG->CNG_smth_Gain_Q16 ), gain_Q16, 5 );
138 gain_Q16 = silk_LSHIFT32( silk_SQRT_APPROX( gain_Q16 ), 8 );
139 }
140 gain_Q10 = silk_RSHIFT( gain_Q16, 6 );
141
142 silk_CNG_exc( CNG_sig_Q14 + MAX_LPC_ORDER, psCNG->CNG_exc_buf_Q14, length, &psCNG->rand_seed );
143
144 /* Convert CNG NLSF to filter representation */
145 silk_NLSF2A( A_Q12, psCNG->CNG_smth_NLSF_Q15, psDec->LPC_order, psDec->arch );
146
147 /* Generate CNG signal, by synthesis filtering */
148 silk_memcpy( CNG_sig_Q14, psCNG->CNG_synth_state, MAX_LPC_ORDER * sizeof( opus_int32 ) );
149 for( i = 0; i < length; i++ ) {
150 silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 );
151 /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
152 LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 );
153 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12[ 0 ] );
154 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12[ 1 ] );
155 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12[ 2 ] );
156 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12[ 3 ] );
157 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12[ 4 ] );
158 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12[ 5 ] );
159 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12[ 6 ] );
160 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12[ 7 ] );
161 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12[ 8 ] );
162 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12[ 9 ] );
163 if( psDec->LPC_order == 16 ) {
164 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 11 ], A_Q12[ 10 ] );
165 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 12 ], A_Q12[ 11 ] );
166 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 13 ], A_Q12[ 12 ] );
167 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 14 ], A_Q12[ 13 ] );
168 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 15 ], A_Q12[ 14 ] );
169 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, CNG_sig_Q14[ MAX_LPC_ORDER + i - 16 ], A_Q12[ 15 ] );
170 }
171
172 /* Update states */
173 CNG_sig_Q14[ MAX_LPC_ORDER + i ] = silk_ADD_SAT32( CNG_sig_Q14[ MAX_LPC_ORDER + i ], silk_LSHIFT_SAT32( LPC_pred_Q10, 4 ) );
174
175 /* Scale with Gain and add to input signal */
176 frame[ i ] = (opus_int16)silk_ADD_SAT16( frame[ i ], silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( CNG_sig_Q14[ MAX_LPC_ORDER + i ], gain_Q10 ), 8 ) ) );
177
178 }
179 silk_memcpy( psCNG->CNG_synth_state, &CNG_sig_Q14[ length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
180 } else {
181 silk_memset( psCNG->CNG_synth_state, 0, psDec->LPC_order * sizeof( opus_int32 ) );
182 }
183 RESTORE_STACK;
184 }
185