michael@0: /***********************************************************************
michael@0: Copyright (c) 2006-2011, Skype Limited. All rights reserved.
michael@0: Redistribution and use in source and binary forms, with or without
michael@0: modification, are permitted provided that the following conditions
michael@0: are met:
michael@0: - Redistributions of source code must retain the above copyright notice,
michael@0: this list of conditions and the following disclaimer.
michael@0: - Redistributions in binary form must reproduce the above copyright
michael@0: notice, this list of conditions and the following disclaimer in the
michael@0: documentation and/or other materials provided with the distribution.
michael@0: - Neither the name of Internet Society, IETF or IETF Trust, nor the
michael@0: names of specific contributors, may be used to endorse or promote
michael@0: products derived from this software without specific prior written
michael@0: permission.
michael@0: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
michael@0: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
michael@0: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
michael@0: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
michael@0: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
michael@0: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
michael@0: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
michael@0: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
michael@0: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
michael@0: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
michael@0: POSSIBILITY OF SUCH DAMAGE.
michael@0: ***********************************************************************/
michael@0: 
michael@0: #ifdef HAVE_CONFIG_H
michael@0: #include "config.h"
michael@0: #endif
michael@0: 
michael@0: #include "main.h"
michael@0: 
michael@0: /* Predictive dequantizer for NLSF residuals */
michael@0: static OPUS_INLINE void silk_NLSF_residual_dequant(               /* O    Returns RD value in Q30                     */
michael@0:           opus_int16         x_Q10[],                        /* O    Output [ order ]                            */
michael@0:     const opus_int8          indices[],                      /* I    Quantization indices [ order ]              */
michael@0:     const opus_uint8         pred_coef_Q8[],                 /* I    Backward predictor coefs [ order ]          */
michael@0:     const opus_int           quant_step_size_Q16,            /* I    Quantization step size                      */
michael@0:     const opus_int16         order                           /* I    Number of input values                      */
michael@0: )
michael@0: {
michael@0:     opus_int     i, out_Q10, pred_Q10;
michael@0: 
michael@0:     out_Q10 = 0;
michael@0:     for( i = order-1; i >= 0; i-- ) {
michael@0:         pred_Q10 = silk_RSHIFT( silk_SMULBB( out_Q10, (opus_int16)pred_coef_Q8[ i ] ), 8 );
michael@0:         out_Q10  = silk_LSHIFT( indices[ i ], 10 );
michael@0:         if( out_Q10 > 0 ) {
michael@0:             out_Q10 = silk_SUB16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
michael@0:         } else if( out_Q10 < 0 ) {
michael@0:             out_Q10 = silk_ADD16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
michael@0:         }
michael@0:         out_Q10  = silk_SMLAWB( pred_Q10, (opus_int32)out_Q10, quant_step_size_Q16 );
michael@0:         x_Q10[ i ] = out_Q10;
michael@0:     }
michael@0: }
michael@0: 
michael@0: 
michael@0: /***********************/
michael@0: /* NLSF vector decoder */
michael@0: /***********************/
michael@0: void silk_NLSF_decode(
michael@0:           opus_int16            *pNLSF_Q15,                     /* O    Quantized NLSF vector [ LPC_ORDER ]         */
michael@0:           opus_int8             *NLSFIndices,                   /* I    Codebook path vector [ LPC_ORDER + 1 ]      */
michael@0:     const silk_NLSF_CB_struct   *psNLSF_CB                      /* I    Codebook object                             */
michael@0: )
michael@0: {
michael@0:     opus_int         i;
michael@0:     opus_uint8       pred_Q8[  MAX_LPC_ORDER ];
michael@0:     opus_int16       ec_ix[    MAX_LPC_ORDER ];
michael@0:     opus_int16       res_Q10[  MAX_LPC_ORDER ];
michael@0:     opus_int16       W_tmp_QW[ MAX_LPC_ORDER ];
michael@0:     opus_int32       W_tmp_Q9, NLSF_Q15_tmp;
michael@0:     const opus_uint8 *pCB_element;
michael@0: 
michael@0:     /* Decode first stage */
michael@0:     pCB_element = &psNLSF_CB->CB1_NLSF_Q8[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
michael@0:     for( i = 0; i < psNLSF_CB->order; i++ ) {
michael@0:         pNLSF_Q15[ i ] = silk_LSHIFT( (opus_int16)pCB_element[ i ], 7 );
michael@0:     }
michael@0: 
michael@0:     /* Unpack entropy table indices and predictor for current CB1 index */
michael@0:     silk_NLSF_unpack( ec_ix, pred_Q8, psNLSF_CB, NLSFIndices[ 0 ] );
michael@0: 
michael@0:     /* Predictive residual dequantizer */
michael@0:     silk_NLSF_residual_dequant( res_Q10, &NLSFIndices[ 1 ], pred_Q8, psNLSF_CB->quantStepSize_Q16, psNLSF_CB->order );
michael@0: 
michael@0:     /* Weights from codebook vector */
michael@0:     silk_NLSF_VQ_weights_laroia( W_tmp_QW, pNLSF_Q15, psNLSF_CB->order );
michael@0: 
michael@0:     /* Apply inverse square-rooted weights and add to output */
michael@0:     for( i = 0; i < psNLSF_CB->order; i++ ) {
michael@0:         W_tmp_Q9 = silk_SQRT_APPROX( silk_LSHIFT( (opus_int32)W_tmp_QW[ i ], 18 - NLSF_W_Q ) );
michael@0:         NLSF_Q15_tmp = silk_ADD32( pNLSF_Q15[ i ], silk_DIV32_16( silk_LSHIFT( (opus_int32)res_Q10[ i ], 14 ), W_tmp_Q9 ) );
michael@0:         pNLSF_Q15[ i ] = (opus_int16)silk_LIMIT( NLSF_Q15_tmp, 0, 32767 );
michael@0:     }
michael@0: 
michael@0:     /* NLSF stabilization */
michael@0:     silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->deltaMin_Q15, psNLSF_CB->order );
michael@0: }