cannam@154: /***********************************************************************
cannam@154: Copyright (c) 2006-2011, Skype Limited. All rights reserved.
cannam@154: Redistribution and use in source and binary forms, with or without
cannam@154: modification, are permitted provided that the following conditions
cannam@154: are met:
cannam@154: - Redistributions of source code must retain the above copyright notice,
cannam@154: this list of conditions and the following disclaimer.
cannam@154: - Redistributions in binary form must reproduce the above copyright
cannam@154: notice, this list of conditions and the following disclaimer in the
cannam@154: documentation and/or other materials provided with the distribution.
cannam@154: - Neither the name of Internet Society, IETF or IETF Trust, nor the
cannam@154: names of specific contributors, may be used to endorse or promote
cannam@154: products derived from this software without specific prior written
cannam@154: permission.
cannam@154: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
cannam@154: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
cannam@154: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
cannam@154: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
cannam@154: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
cannam@154: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
cannam@154: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
cannam@154: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
cannam@154: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
cannam@154: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
cannam@154: POSSIBILITY OF SUCH DAMAGE.
cannam@154: ***********************************************************************/
cannam@154: 
cannam@154: #ifdef HAVE_CONFIG_H
cannam@154: #include "config.h"
cannam@154: #endif
cannam@154: 
cannam@154: #include "main.h"
cannam@154: 
cannam@154: /* Predictive dequantizer for NLSF residuals */
cannam@154: static OPUS_INLINE void silk_NLSF_residual_dequant(          /* O    Returns RD value in Q30                     */
cannam@154:           opus_int16         x_Q10[],                        /* O    Output [ order ]                            */
cannam@154:     const opus_int8          indices[],                      /* I    Quantization indices [ order ]              */
cannam@154:     const opus_uint8         pred_coef_Q8[],                 /* I    Backward predictor coefs [ order ]          */
cannam@154:     const opus_int           quant_step_size_Q16,            /* I    Quantization step size                      */
cannam@154:     const opus_int16         order                           /* I    Number of input values                      */
cannam@154: )
cannam@154: {
cannam@154:     opus_int     i, out_Q10, pred_Q10;
cannam@154: 
cannam@154:     out_Q10 = 0;
cannam@154:     for( i = order-1; i >= 0; i-- ) {
cannam@154:         pred_Q10 = silk_RSHIFT( silk_SMULBB( out_Q10, (opus_int16)pred_coef_Q8[ i ] ), 8 );
cannam@154:         out_Q10  = silk_LSHIFT( indices[ i ], 10 );
cannam@154:         if( out_Q10 > 0 ) {
cannam@154:             out_Q10 = silk_SUB16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
cannam@154:         } else if( out_Q10 < 0 ) {
cannam@154:             out_Q10 = silk_ADD16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
cannam@154:         }
cannam@154:         out_Q10  = silk_SMLAWB( pred_Q10, (opus_int32)out_Q10, quant_step_size_Q16 );
cannam@154:         x_Q10[ i ] = out_Q10;
cannam@154:     }
cannam@154: }
cannam@154: 
cannam@154: 
cannam@154: /***********************/
cannam@154: /* NLSF vector decoder */
cannam@154: /***********************/
cannam@154: void silk_NLSF_decode(
cannam@154:           opus_int16            *pNLSF_Q15,                     /* O    Quantized NLSF vector [ LPC_ORDER ]         */
cannam@154:           opus_int8             *NLSFIndices,                   /* I    Codebook path vector [ LPC_ORDER + 1 ]      */
cannam@154:     const silk_NLSF_CB_struct   *psNLSF_CB                      /* I    Codebook object                             */
cannam@154: )
cannam@154: {
cannam@154:     opus_int         i;
cannam@154:     opus_uint8       pred_Q8[  MAX_LPC_ORDER ];
cannam@154:     opus_int16       ec_ix[    MAX_LPC_ORDER ];
cannam@154:     opus_int16       res_Q10[  MAX_LPC_ORDER ];
cannam@154:     opus_int32       NLSF_Q15_tmp;
cannam@154:     const opus_uint8 *pCB_element;
cannam@154:     const opus_int16 *pCB_Wght_Q9;
cannam@154: 
cannam@154:     /* Unpack entropy table indices and predictor for current CB1 index */
cannam@154:     silk_NLSF_unpack( ec_ix, pred_Q8, psNLSF_CB, NLSFIndices[ 0 ] );
cannam@154: 
cannam@154:     /* Predictive residual dequantizer */
cannam@154:     silk_NLSF_residual_dequant( res_Q10, &NLSFIndices[ 1 ], pred_Q8, psNLSF_CB->quantStepSize_Q16, psNLSF_CB->order );
cannam@154: 
cannam@154:     /* Apply inverse square-rooted weights to first stage and add to output */
cannam@154:     pCB_element = &psNLSF_CB->CB1_NLSF_Q8[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
cannam@154:     pCB_Wght_Q9 = &psNLSF_CB->CB1_Wght_Q9[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
cannam@154:     for( i = 0; i < psNLSF_CB->order; i++ ) {
cannam@154:         NLSF_Q15_tmp = silk_ADD_LSHIFT32( silk_DIV32_16( silk_LSHIFT( (opus_int32)res_Q10[ i ], 14 ), pCB_Wght_Q9[ i ] ), (opus_int16)pCB_element[ i ], 7 );
cannam@154:         pNLSF_Q15[ i ] = (opus_int16)silk_LIMIT( NLSF_Q15_tmp, 0, 32767 );
cannam@154:     }
cannam@154: 
cannam@154:     /* NLSF stabilization */
cannam@154:     silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->deltaMin_Q15, psNLSF_CB->order );
cannam@154: }