Chris@69: /***********************************************************************
Chris@69: Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Chris@69: Redistribution and use in source and binary forms, with or without
Chris@69: modification, are permitted provided that the following conditions
Chris@69: are met:
Chris@69: - Redistributions of source code must retain the above copyright notice,
Chris@69: this list of conditions and the following disclaimer.
Chris@69: - Redistributions in binary form must reproduce the above copyright
Chris@69: notice, this list of conditions and the following disclaimer in the
Chris@69: documentation and/or other materials provided with the distribution.
Chris@69: - Neither the name of Internet Society, IETF or IETF Trust, nor the
Chris@69: names of specific contributors, may be used to endorse or promote
Chris@69: products derived from this software without specific prior written
Chris@69: permission.
Chris@69: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
Chris@69: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
Chris@69: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
Chris@69: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
Chris@69: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
Chris@69: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
Chris@69: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
Chris@69: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
Chris@69: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
Chris@69: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
Chris@69: POSSIBILITY OF SUCH DAMAGE.
Chris@69: ***********************************************************************/
Chris@69: 
Chris@69: #ifdef HAVE_CONFIG_H
Chris@69: #include "config.h"
Chris@69: #endif
Chris@69: 
Chris@69: #include "main.h"
Chris@69: 
Chris@69: /* Predictive dequantizer for NLSF residuals */
Chris@69: static OPUS_INLINE void silk_NLSF_residual_dequant(          /* O    Returns RD value in Q30                     */
Chris@69:           opus_int16         x_Q10[],                        /* O    Output [ order ]                            */
Chris@69:     const opus_int8          indices[],                      /* I    Quantization indices [ order ]              */
Chris@69:     const opus_uint8         pred_coef_Q8[],                 /* I    Backward predictor coefs [ order ]          */
Chris@69:     const opus_int           quant_step_size_Q16,            /* I    Quantization step size                      */
Chris@69:     const opus_int16         order                           /* I    Number of input values                      */
Chris@69: )
Chris@69: {
Chris@69:     opus_int     i, out_Q10, pred_Q10;
Chris@69: 
Chris@69:     out_Q10 = 0;
Chris@69:     for( i = order-1; i >= 0; i-- ) {
Chris@69:         pred_Q10 = silk_RSHIFT( silk_SMULBB( out_Q10, (opus_int16)pred_coef_Q8[ i ] ), 8 );
Chris@69:         out_Q10  = silk_LSHIFT( indices[ i ], 10 );
Chris@69:         if( out_Q10 > 0 ) {
Chris@69:             out_Q10 = silk_SUB16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
Chris@69:         } else if( out_Q10 < 0 ) {
Chris@69:             out_Q10 = silk_ADD16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
Chris@69:         }
Chris@69:         out_Q10  = silk_SMLAWB( pred_Q10, (opus_int32)out_Q10, quant_step_size_Q16 );
Chris@69:         x_Q10[ i ] = out_Q10;
Chris@69:     }
Chris@69: }
Chris@69: 
Chris@69: 
Chris@69: /***********************/
Chris@69: /* NLSF vector decoder */
Chris@69: /***********************/
Chris@69: void silk_NLSF_decode(
Chris@69:           opus_int16            *pNLSF_Q15,                     /* O    Quantized NLSF vector [ LPC_ORDER ]         */
Chris@69:           opus_int8             *NLSFIndices,                   /* I    Codebook path vector [ LPC_ORDER + 1 ]      */
Chris@69:     const silk_NLSF_CB_struct   *psNLSF_CB                      /* I    Codebook object                             */
Chris@69: )
Chris@69: {
Chris@69:     opus_int         i;
Chris@69:     opus_uint8       pred_Q8[  MAX_LPC_ORDER ];
Chris@69:     opus_int16       ec_ix[    MAX_LPC_ORDER ];
Chris@69:     opus_int16       res_Q10[  MAX_LPC_ORDER ];
Chris@69:     opus_int32       NLSF_Q15_tmp;
Chris@69:     const opus_uint8 *pCB_element;
Chris@69:     const opus_int16 *pCB_Wght_Q9;
Chris@69: 
Chris@69:     /* Unpack entropy table indices and predictor for current CB1 index */
Chris@69:     silk_NLSF_unpack( ec_ix, pred_Q8, psNLSF_CB, NLSFIndices[ 0 ] );
Chris@69: 
Chris@69:     /* Predictive residual dequantizer */
Chris@69:     silk_NLSF_residual_dequant( res_Q10, &NLSFIndices[ 1 ], pred_Q8, psNLSF_CB->quantStepSize_Q16, psNLSF_CB->order );
Chris@69: 
Chris@69:     /* Apply inverse square-rooted weights to first stage and add to output */
Chris@69:     pCB_element = &psNLSF_CB->CB1_NLSF_Q8[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
Chris@69:     pCB_Wght_Q9 = &psNLSF_CB->CB1_Wght_Q9[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
Chris@69:     for( i = 0; i < psNLSF_CB->order; i++ ) {
Chris@69:         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 );
Chris@69:         pNLSF_Q15[ i ] = (opus_int16)silk_LIMIT( NLSF_Q15_tmp, 0, 32767 );
Chris@69:     }
Chris@69: 
Chris@69:     /* NLSF stabilization */
Chris@69:     silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->deltaMin_Q15, psNLSF_CB->order );
Chris@69: }