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 /**********************************************************/
silk_decode_core(silk_decoder_state * psDec,silk_decoder_control * psDecCtrl,opus_int16 xq[],const opus_int pulses[MAX_FRAME_LENGTH])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_int pulses[ MAX_FRAME_LENGTH ] /* I Pulse signal */
43 )
44 {
45 opus_int i, k, lag = 0, start_idx, sLTP_buf_idx, NLSF_interpolation_flag, signalType;
46 opus_int16 *A_Q12, *B_Q14, *pxq, A_Q12_tmp[ MAX_LPC_ORDER ];
47 VARDECL( opus_int16, sLTP );
48 VARDECL( opus_int32, sLTP_Q15 );
49 opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q31, gain_adj_Q16, rand_seed, offset_Q10;
50 opus_int32 *pred_lag_ptr, *pexc_Q14, *pres_Q14;
51 VARDECL( opus_int32, res_Q14 );
52 VARDECL( opus_int32, sLPC_Q14 );
53 SAVE_STACK;
54
55 silk_assert( psDec->prev_gain_Q16 != 0 );
56
57 ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 );
58 ALLOC( sLTP_Q15, psDec->ltp_mem_length + psDec->frame_length, opus_int32 );
59 ALLOC( res_Q14, psDec->subfr_length, opus_int32 );
60 ALLOC( sLPC_Q14, psDec->subfr_length + MAX_LPC_ORDER, opus_int32 );
61
62 offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ];
63
64 if( psDec->indices.NLSFInterpCoef_Q2 < 1 << 2 ) {
65 NLSF_interpolation_flag = 1;
66 } else {
67 NLSF_interpolation_flag = 0;
68 }
69
70 /* Decode excitation */
71 rand_seed = psDec->indices.Seed;
72 for( i = 0; i < psDec->frame_length; i++ ) {
73 rand_seed = silk_RAND( rand_seed );
74 psDec->exc_Q14[ i ] = silk_LSHIFT( (opus_int32)pulses[ i ], 14 );
75 if( psDec->exc_Q14[ i ] > 0 ) {
76 psDec->exc_Q14[ i ] -= QUANT_LEVEL_ADJUST_Q10 << 4;
77 } else
78 if( psDec->exc_Q14[ i ] < 0 ) {
79 psDec->exc_Q14[ i ] += QUANT_LEVEL_ADJUST_Q10 << 4;
80 }
81 psDec->exc_Q14[ i ] += offset_Q10 << 4;
82 if( rand_seed < 0 ) {
83 psDec->exc_Q14[ i ] = -psDec->exc_Q14[ i ];
84 }
85
86 rand_seed = silk_ADD32_ovflw( rand_seed, pulses[ i ] );
87 }
88
89 /* Copy LPC state */
90 silk_memcpy( sLPC_Q14, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) );
91
92 pexc_Q14 = psDec->exc_Q14;
93 pxq = xq;
94 sLTP_buf_idx = psDec->ltp_mem_length;
95 /* Loop over subframes */
96 for( k = 0; k < psDec->nb_subfr; k++ ) {
97 pres_Q14 = res_Q14;
98 A_Q12 = psDecCtrl->PredCoef_Q12[ k >> 1 ];
99
100 /* Preload LPC coeficients to array on stack. Gives small performance gain */
101 silk_memcpy( A_Q12_tmp, A_Q12, psDec->LPC_order * sizeof( opus_int16 ) );
102 B_Q14 = &psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER ];
103 signalType = psDec->indices.signalType;
104
105 Gain_Q10 = silk_RSHIFT( psDecCtrl->Gains_Q16[ k ], 6 );
106 inv_gain_Q31 = silk_INVERSE32_varQ( psDecCtrl->Gains_Q16[ k ], 47 );
107
108 /* Calculate gain adjustment factor */
109 if( psDecCtrl->Gains_Q16[ k ] != psDec->prev_gain_Q16 ) {
110 gain_adj_Q16 = silk_DIV32_varQ( psDec->prev_gain_Q16, psDecCtrl->Gains_Q16[ k ], 16 );
111
112 /* Scale short term state */
113 for( i = 0; i < MAX_LPC_ORDER; i++ ) {
114 sLPC_Q14[ i ] = silk_SMULWW( gain_adj_Q16, sLPC_Q14[ i ] );
115 }
116 } else {
117 gain_adj_Q16 = (opus_int32)1 << 16;
118 }
119
120 /* Save inv_gain */
121 silk_assert( inv_gain_Q31 != 0 );
122 psDec->prev_gain_Q16 = psDecCtrl->Gains_Q16[ k ];
123
124 /* Avoid abrupt transition from voiced PLC to unvoiced normal decoding */
125 if( psDec->lossCnt && psDec->prevSignalType == TYPE_VOICED &&
126 psDec->indices.signalType != TYPE_VOICED && k < MAX_NB_SUBFR/2 ) {
127
128 silk_memset( B_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) );
129 B_Q14[ LTP_ORDER/2 ] = SILK_FIX_CONST( 0.25, 14 );
130
131 signalType = TYPE_VOICED;
132 psDecCtrl->pitchL[ k ] = psDec->lagPrev;
133 }
134
135 if( signalType == TYPE_VOICED ) {
136 /* Voiced */
137 lag = psDecCtrl->pitchL[ k ];
138
139 /* Re-whitening */
140 if( k == 0 || ( k == 2 && NLSF_interpolation_flag ) ) {
141 /* Rewhiten with new A coefs */
142 start_idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
143 silk_assert( start_idx > 0 );
144
145 if( k == 2 ) {
146 silk_memcpy( &psDec->outBuf[ psDec->ltp_mem_length ], xq, 2 * psDec->subfr_length * sizeof( opus_int16 ) );
147 }
148
149 silk_LPC_analysis_filter( &sLTP[ start_idx ], &psDec->outBuf[ start_idx + k * psDec->subfr_length ],
150 A_Q12, psDec->ltp_mem_length - start_idx, psDec->LPC_order );
151
152 /* After rewhitening the LTP state is unscaled */
153 if( k == 0 ) {
154 /* Do LTP downscaling to reduce inter-packet dependency */
155 inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, psDecCtrl->LTP_scale_Q14 ), 2 );
156 }
157 for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
158 sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWB( inv_gain_Q31, sLTP[ psDec->ltp_mem_length - i - 1 ] );
159 }
160 } else {
161 /* Update LTP state when Gain changes */
162 if( gain_adj_Q16 != (opus_int32)1 << 16 ) {
163 for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
164 sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWW( gain_adj_Q16, sLTP_Q15[ sLTP_buf_idx - i - 1 ] );
165 }
166 }
167 }
168 }
169
170 /* Long-term prediction */
171 if( signalType == TYPE_VOICED ) {
172 /* Set up pointer */
173 pred_lag_ptr = &sLTP_Q15[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
174 for( i = 0; i < psDec->subfr_length; i++ ) {
175 /* Unrolled loop */
176 /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
177 LTP_pred_Q13 = 2;
178 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
179 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
180 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
181 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
182 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
183 pred_lag_ptr++;
184
185 /* Generate LPC excitation */
186 pres_Q14[ i ] = silk_ADD_LSHIFT32( pexc_Q14[ i ], LTP_pred_Q13, 1 );
187
188 /* Update states */
189 sLTP_Q15[ sLTP_buf_idx ] = silk_LSHIFT( pres_Q14[ i ], 1 );
190 sLTP_buf_idx++;
191 }
192 } else {
193 pres_Q14 = pexc_Q14;
194 }
195
196 for( i = 0; i < psDec->subfr_length; i++ ) {
197 /* Short-term prediction */
198 silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 );
199 /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
200 LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 );
201 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] );
202 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12_tmp[ 1 ] );
203 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12_tmp[ 2 ] );
204 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12_tmp[ 3 ] );
205 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12_tmp[ 4 ] );
206 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12_tmp[ 5 ] );
207 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12_tmp[ 6 ] );
208 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12_tmp[ 7 ] );
209 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12_tmp[ 8 ] );
210 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] );
211 if( psDec->LPC_order == 16 ) {
212 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 11 ], A_Q12_tmp[ 10 ] );
213 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 12 ], A_Q12_tmp[ 11 ] );
214 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 13 ], A_Q12_tmp[ 12 ] );
215 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 14 ], A_Q12_tmp[ 13 ] );
216 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 15 ], A_Q12_tmp[ 14 ] );
217 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 16 ], A_Q12_tmp[ 15 ] );
218 }
219
220 /* Add prediction to LPC excitation */
221 sLPC_Q14[ MAX_LPC_ORDER + i ] = silk_ADD_LSHIFT32( pres_Q14[ i ], LPC_pred_Q10, 4 );
222
223 /* Scale with gain */
224 pxq[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14[ MAX_LPC_ORDER + i ], Gain_Q10 ), 8 ) );
225 }
226
227 /* DEBUG_STORE_DATA( dec.pcm, pxq, psDec->subfr_length * sizeof( opus_int16 ) ) */
228
229 /* Update LPC filter state */
230 silk_memcpy( sLPC_Q14, &sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
231 pexc_Q14 += psDec->subfr_length;
232 pxq += psDec->subfr_length;
233 }
234
235 /* Save LPC state */
236 silk_memcpy( psDec->sLPC_Q14_buf, sLPC_Q14, MAX_LPC_ORDER * sizeof( opus_int32 ) );
237 RESTORE_STACK;
238 }
239