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
34 /* Predictive dequantizer for NLSF residuals */
silk_NLSF_residual_dequant(opus_int16 x_Q10[],const opus_int8 indices[],const opus_uint8 pred_coef_Q8[],const opus_int quant_step_size_Q16,const opus_int16 order)35 static inline void silk_NLSF_residual_dequant( /* O Returns RD value in Q30 */
36 opus_int16 x_Q10[], /* O Output [ order ] */
37 const opus_int8 indices[], /* I Quantization indices [ order ] */
38 const opus_uint8 pred_coef_Q8[], /* I Backward predictor coefs [ order ] */
39 const opus_int quant_step_size_Q16, /* I Quantization step size */
40 const opus_int16 order /* I Number of input values */
41 )
42 {
43 opus_int i, out_Q10, pred_Q10;
44
45 out_Q10 = 0;
46 for( i = order-1; i >= 0; i-- ) {
47 pred_Q10 = silk_RSHIFT( silk_SMULBB( out_Q10, (opus_int16)pred_coef_Q8[ i ] ), 8 );
48 out_Q10 = silk_LSHIFT( indices[ i ], 10 );
49 if( out_Q10 > 0 ) {
50 out_Q10 = silk_SUB16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
51 } else if( out_Q10 < 0 ) {
52 out_Q10 = silk_ADD16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
53 }
54 out_Q10 = silk_SMLAWB( pred_Q10, (opus_int32)out_Q10, quant_step_size_Q16 );
55 x_Q10[ i ] = out_Q10;
56 }
57 }
58
59
60 /***********************/
61 /* NLSF vector decoder */
62 /***********************/
silk_NLSF_decode(opus_int16 * pNLSF_Q15,opus_int8 * NLSFIndices,const silk_NLSF_CB_struct * psNLSF_CB)63 void silk_NLSF_decode(
64 opus_int16 *pNLSF_Q15, /* O Quantized NLSF vector [ LPC_ORDER ] */
65 opus_int8 *NLSFIndices, /* I Codebook path vector [ LPC_ORDER + 1 ] */
66 const silk_NLSF_CB_struct *psNLSF_CB /* I Codebook object */
67 )
68 {
69 opus_int i;
70 opus_uint8 pred_Q8[ MAX_LPC_ORDER ];
71 opus_int16 ec_ix[ MAX_LPC_ORDER ];
72 opus_int16 res_Q10[ MAX_LPC_ORDER ];
73 opus_int16 W_tmp_QW[ MAX_LPC_ORDER ];
74 opus_int32 W_tmp_Q9, NLSF_Q15_tmp;
75 const opus_uint8 *pCB_element;
76
77 /* Decode first stage */
78 pCB_element = &psNLSF_CB->CB1_NLSF_Q8[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
79 for( i = 0; i < psNLSF_CB->order; i++ ) {
80 pNLSF_Q15[ i ] = silk_LSHIFT( (opus_int16)pCB_element[ i ], 7 );
81 }
82
83 /* Unpack entropy table indices and predictor for current CB1 index */
84 silk_NLSF_unpack( ec_ix, pred_Q8, psNLSF_CB, NLSFIndices[ 0 ] );
85
86 /* Predictive residual dequantizer */
87 silk_NLSF_residual_dequant( res_Q10, &NLSFIndices[ 1 ], pred_Q8, psNLSF_CB->quantStepSize_Q16, psNLSF_CB->order );
88
89 /* Weights from codebook vector */
90 silk_NLSF_VQ_weights_laroia( W_tmp_QW, pNLSF_Q15, psNLSF_CB->order );
91
92 /* Apply inverse square-rooted weights and add to output */
93 for( i = 0; i < psNLSF_CB->order; i++ ) {
94 W_tmp_Q9 = silk_SQRT_APPROX( silk_LSHIFT( (opus_int32)W_tmp_QW[ i ], 18 - NLSF_W_Q ) );
95 NLSF_Q15_tmp = silk_ADD32( pNLSF_Q15[ i ], silk_DIV32_16( silk_LSHIFT( (opus_int32)res_Q10[ i ], 14 ), W_tmp_Q9 ) );
96 pNLSF_Q15[ i ] = (opus_int16)silk_LIMIT( NLSF_Q15_tmp, 0, 32767 );
97 }
98
99 /* NLSF stabilization */
100 silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->deltaMin_Q15, psNLSF_CB->order );
101 }
102