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_int16 pulses[MAX_FRAME_LENGTH],int arch)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 {
46 opus_int i, k, lag = 0, start_idx, sLTP_buf_idx, NLSF_interpolation_flag, signalType;
47 opus_int16 *A_Q12, *B_Q14, *pxq, A_Q12_tmp[ MAX_LPC_ORDER ];
48 VARDECL( opus_int16, sLTP );
49 VARDECL( opus_int32, sLTP_Q15 );
50 opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q31, gain_adj_Q16, rand_seed, offset_Q10;
51 opus_int32 *pred_lag_ptr, *pexc_Q14, *pres_Q14;
52 VARDECL( opus_int32, res_Q14 );
53 VARDECL( opus_int32, sLPC_Q14 );
54 SAVE_STACK;
55
56 silk_assert( psDec->prev_gain_Q16 != 0 );
57
58 ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 );
59 ALLOC( sLTP_Q15, psDec->ltp_mem_length + psDec->frame_length, opus_int32 );
60 ALLOC( res_Q14, psDec->subfr_length, opus_int32 );
61 ALLOC( sLPC_Q14, psDec->subfr_length + MAX_LPC_ORDER, opus_int32 );
62
63 offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ];
64
65 if( psDec->indices.NLSFInterpCoef_Q2 < 1 << 2 ) {
66 NLSF_interpolation_flag = 1;
67 } else {
68 NLSF_interpolation_flag = 0;
69 }
70
71 /* Decode excitation */
72 rand_seed = psDec->indices.Seed;
73 for( i = 0; i < psDec->frame_length; i++ ) {
74 rand_seed = silk_RAND( rand_seed );
75 psDec->exc_Q14[ i ] = silk_LSHIFT( (opus_int32)pulses[ i ], 14 );
76 if( psDec->exc_Q14[ i ] > 0 ) {
77 psDec->exc_Q14[ i ] -= QUANT_LEVEL_ADJUST_Q10 << 4;
78 } else
79 if( psDec->exc_Q14[ i ] < 0 ) {
80 psDec->exc_Q14[ i ] += QUANT_LEVEL_ADJUST_Q10 << 4;
81 }
82 psDec->exc_Q14[ i ] += offset_Q10 << 4;
83 if( rand_seed < 0 ) {
84 psDec->exc_Q14[ i ] = -psDec->exc_Q14[ i ];
85 }
86
87 rand_seed = silk_ADD32_ovflw( rand_seed, pulses[ i ] );
88 }
89
90 /* Copy LPC state */
91 silk_memcpy( sLPC_Q14, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) );
92
93 pexc_Q14 = psDec->exc_Q14;
94 pxq = xq;
95 sLTP_buf_idx = psDec->ltp_mem_length;
96 /* Loop over subframes */
97 for( k = 0; k < psDec->nb_subfr; k++ ) {
98 pres_Q14 = res_Q14;
99 A_Q12 = psDecCtrl->PredCoef_Q12[ k >> 1 ];
100
101 /* Preload LPC coeficients to array on stack. Gives small performance gain */
102 silk_memcpy( A_Q12_tmp, A_Q12, psDec->LPC_order * sizeof( opus_int16 ) );
103 B_Q14 = &psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER ];
104 signalType = psDec->indices.signalType;
105
106 Gain_Q10 = silk_RSHIFT( psDecCtrl->Gains_Q16[ k ], 6 );
107 inv_gain_Q31 = silk_INVERSE32_varQ( psDecCtrl->Gains_Q16[ k ], 47 );
108
109 /* Calculate gain adjustment factor */
110 if( psDecCtrl->Gains_Q16[ k ] != psDec->prev_gain_Q16 ) {
111 gain_adj_Q16 = silk_DIV32_varQ( psDec->prev_gain_Q16, psDecCtrl->Gains_Q16[ k ], 16 );
112
113 /* Scale short term state */
114 for( i = 0; i < MAX_LPC_ORDER; i++ ) {
115 sLPC_Q14[ i ] = silk_SMULWW( gain_adj_Q16, sLPC_Q14[ i ] );
116 }
117 } else {
118 gain_adj_Q16 = (opus_int32)1 << 16;
119 }
120
121 /* Save inv_gain */
122 silk_assert( inv_gain_Q31 != 0 );
123 psDec->prev_gain_Q16 = psDecCtrl->Gains_Q16[ k ];
124
125 /* Avoid abrupt transition from voiced PLC to unvoiced normal decoding */
126 if( psDec->lossCnt && psDec->prevSignalType == TYPE_VOICED &&
127 psDec->indices.signalType != TYPE_VOICED && k < MAX_NB_SUBFR/2 ) {
128
129 silk_memset( B_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) );
130 B_Q14[ LTP_ORDER/2 ] = SILK_FIX_CONST( 0.25, 14 );
131
132 signalType = TYPE_VOICED;
133 psDecCtrl->pitchL[ k ] = psDec->lagPrev;
134 }
135
136 if( signalType == TYPE_VOICED ) {
137 /* Voiced */
138 lag = psDecCtrl->pitchL[ k ];
139
140 /* Re-whitening */
141 if( k == 0 || ( k == 2 && NLSF_interpolation_flag ) ) {
142 /* Rewhiten with new A coefs */
143 start_idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2;
144 silk_assert( start_idx > 0 );
145
146 if( k == 2 ) {
147 silk_memcpy( &psDec->outBuf[ psDec->ltp_mem_length ], xq, 2 * psDec->subfr_length * sizeof( opus_int16 ) );
148 }
149
150 silk_LPC_analysis_filter( &sLTP[ start_idx ], &psDec->outBuf[ start_idx + k * psDec->subfr_length ],
151 A_Q12, psDec->ltp_mem_length - start_idx, psDec->LPC_order, arch );
152
153 /* After rewhitening the LTP state is unscaled */
154 if( k == 0 ) {
155 /* Do LTP downscaling to reduce inter-packet dependency */
156 inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, psDecCtrl->LTP_scale_Q14 ), 2 );
157 }
158 for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
159 sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWB( inv_gain_Q31, sLTP[ psDec->ltp_mem_length - i - 1 ] );
160 }
161 } else {
162 /* Update LTP state when Gain changes */
163 if( gain_adj_Q16 != (opus_int32)1 << 16 ) {
164 for( i = 0; i < lag + LTP_ORDER/2; i++ ) {
165 sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWW( gain_adj_Q16, sLTP_Q15[ sLTP_buf_idx - i - 1 ] );
166 }
167 }
168 }
169 }
170
171 /* Long-term prediction */
172 if( signalType == TYPE_VOICED ) {
173 /* Set up pointer */
174 pred_lag_ptr = &sLTP_Q15[ sLTP_buf_idx - lag + LTP_ORDER / 2 ];
175 for( i = 0; i < psDec->subfr_length; i++ ) {
176 /* Unrolled loop */
177 /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
178 LTP_pred_Q13 = 2;
179 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
180 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
181 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
182 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
183 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
184 pred_lag_ptr++;
185
186 /* Generate LPC excitation */
187 pres_Q14[ i ] = silk_ADD_LSHIFT32( pexc_Q14[ i ], LTP_pred_Q13, 1 );
188
189 /* Update states */
190 sLTP_Q15[ sLTP_buf_idx ] = silk_LSHIFT( pres_Q14[ i ], 1 );
191 sLTP_buf_idx++;
192 }
193 } else {
194 pres_Q14 = pexc_Q14;
195 }
196
197 for( i = 0; i < psDec->subfr_length; i++ ) {
198 /* Short-term prediction */
199 silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 );
200 /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
201 LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 );
202 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] );
203 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12_tmp[ 1 ] );
204 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12_tmp[ 2 ] );
205 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12_tmp[ 3 ] );
206 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12_tmp[ 4 ] );
207 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12_tmp[ 5 ] );
208 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12_tmp[ 6 ] );
209 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12_tmp[ 7 ] );
210 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12_tmp[ 8 ] );
211 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] );
212 if( psDec->LPC_order == 16 ) {
213 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 11 ], A_Q12_tmp[ 10 ] );
214 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 12 ], A_Q12_tmp[ 11 ] );
215 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 13 ], A_Q12_tmp[ 12 ] );
216 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 14 ], A_Q12_tmp[ 13 ] );
217 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 15 ], A_Q12_tmp[ 14 ] );
218 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 16 ], A_Q12_tmp[ 15 ] );
219 }
220
221 /* Add prediction to LPC excitation */
222 sLPC_Q14[ MAX_LPC_ORDER + i ] = silk_ADD_SAT32( pres_Q14[ i ], silk_LSHIFT_SAT32( LPC_pred_Q10, 4 ) );
223
224 /* Scale with gain */
225 pxq[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14[ MAX_LPC_ORDER + i ], Gain_Q10 ), 8 ) );
226 }
227
228 /* Update LPC filter state */
229 silk_memcpy( sLPC_Q14, &sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
230 pexc_Q14 += psDec->subfr_length;
231 pxq += psDec->subfr_length;
232 }
233
234 /* Save LPC state */
235 silk_memcpy( psDec->sLPC_Q14_buf, sLPC_Q14, MAX_LPC_ORDER * sizeof( opus_int32 ) );
236 RESTORE_STACK;
237 }
238