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 "define.h"
michael@0: #include "SigProc_FIX.h"
michael@0: 
michael@0: /*
michael@0: R. Laroia, N. Phamdo and N. Farvardin, "Robust and Efficient Quantization of Speech LSP
michael@0: Parameters Using Structured Vector Quantization", Proc. IEEE Int. Conf. Acoust., Speech,
michael@0: Signal Processing, pp. 641-644, 1991.
michael@0: */
michael@0: 
michael@0: /* Laroia low complexity NLSF weights */
michael@0: void silk_NLSF_VQ_weights_laroia(
michael@0:     opus_int16                  *pNLSFW_Q_OUT,      /* O     Pointer to input vector weights [D]                        */
michael@0:     const opus_int16            *pNLSF_Q15,         /* I     Pointer to input vector         [D]                        */
michael@0:     const opus_int              D                   /* I     Input vector dimension (even)                              */
michael@0: )
michael@0: {
michael@0:     opus_int   k;
michael@0:     opus_int32 tmp1_int, tmp2_int;
michael@0: 
michael@0:     silk_assert( D > 0 );
michael@0:     silk_assert( ( D & 1 ) == 0 );
michael@0: 
michael@0:     /* First value */
michael@0:     tmp1_int = silk_max_int( pNLSF_Q15[ 0 ], 1 );
michael@0:     tmp1_int = silk_DIV32_16( (opus_int32)1 << ( 15 + NLSF_W_Q ), tmp1_int );
michael@0:     tmp2_int = silk_max_int( pNLSF_Q15[ 1 ] - pNLSF_Q15[ 0 ], 1 );
michael@0:     tmp2_int = silk_DIV32_16( (opus_int32)1 << ( 15 + NLSF_W_Q ), tmp2_int );
michael@0:     pNLSFW_Q_OUT[ 0 ] = (opus_int16)silk_min_int( tmp1_int + tmp2_int, silk_int16_MAX );
michael@0:     silk_assert( pNLSFW_Q_OUT[ 0 ] > 0 );
michael@0: 
michael@0:     /* Main loop */
michael@0:     for( k = 1; k < D - 1; k += 2 ) {
michael@0:         tmp1_int = silk_max_int( pNLSF_Q15[ k + 1 ] - pNLSF_Q15[ k ], 1 );
michael@0:         tmp1_int = silk_DIV32_16( (opus_int32)1 << ( 15 + NLSF_W_Q ), tmp1_int );
michael@0:         pNLSFW_Q_OUT[ k ] = (opus_int16)silk_min_int( tmp1_int + tmp2_int, silk_int16_MAX );
michael@0:         silk_assert( pNLSFW_Q_OUT[ k ] > 0 );
michael@0: 
michael@0:         tmp2_int = silk_max_int( pNLSF_Q15[ k + 2 ] - pNLSF_Q15[ k + 1 ], 1 );
michael@0:         tmp2_int = silk_DIV32_16( (opus_int32)1 << ( 15 + NLSF_W_Q ), tmp2_int );
michael@0:         pNLSFW_Q_OUT[ k + 1 ] = (opus_int16)silk_min_int( tmp1_int + tmp2_int, silk_int16_MAX );
michael@0:         silk_assert( pNLSFW_Q_OUT[ k + 1 ] > 0 );
michael@0:     }
michael@0: 
michael@0:     /* Last value */
michael@0:     tmp1_int = silk_max_int( ( 1 << 15 ) - pNLSF_Q15[ D - 1 ], 1 );
michael@0:     tmp1_int = silk_DIV32_16( (opus_int32)1 << ( 15 + NLSF_W_Q ), tmp1_int );
michael@0:     pNLSFW_Q_OUT[ D - 1 ] = (opus_int16)silk_min_int( tmp1_int + tmp2_int, silk_int16_MAX );
michael@0:     silk_assert( pNLSFW_Q_OUT[ D - 1 ] > 0 );
michael@0: }