forked from len0rd/rockbox
		
	
		
			
				
	
	
		
			93 lines
		
	
	
	
		
			4.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			93 lines
		
	
	
	
		
			4.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /***********************************************************************
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| Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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| Redistribution and use in source and binary forms, with or without
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| modification, are permitted provided that the following conditions
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| are met:
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| - Redistributions of source code must retain the above copyright notice,
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| this list of conditions and the following disclaimer.
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| - Redistributions in binary form must reproduce the above copyright
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| notice, this list of conditions and the following disclaimer in the
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| documentation and/or other materials provided with the distribution.
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| - Neither the name of Internet Society, IETF or IETF Trust, nor the
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| names of specific contributors, may be used to endorse or promote
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| products derived from this software without specific prior written
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| permission.
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| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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| POSSIBILITY OF SUCH DAMAGE.
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| ***********************************************************************/
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| 
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| #ifdef HAVE_CONFIG_H
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| #include "config.h"
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| #endif
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| 
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| #include "main.h"
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| 
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| /* Predictive dequantizer for NLSF residuals */
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| static OPUS_INLINE void silk_NLSF_residual_dequant(          /* O    Returns RD value in Q30                     */
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|           opus_int16         x_Q10[],                        /* O    Output [ order ]                            */
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|     const opus_int8          indices[],                      /* I    Quantization indices [ order ]              */
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|     const opus_uint8         pred_coef_Q8[],                 /* I    Backward predictor coefs [ order ]          */
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|     const opus_int           quant_step_size_Q16,            /* I    Quantization step size                      */
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|     const opus_int16         order                           /* I    Number of input values                      */
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| )
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| {
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|     opus_int     i, out_Q10, pred_Q10;
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| 
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|     out_Q10 = 0;
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|     for( i = order-1; i >= 0; i-- ) {
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|         pred_Q10 = silk_RSHIFT( silk_SMULBB( out_Q10, (opus_int16)pred_coef_Q8[ i ] ), 8 );
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|         out_Q10  = silk_LSHIFT( indices[ i ], 10 );
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|         if( out_Q10 > 0 ) {
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|             out_Q10 = silk_SUB16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
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|         } else if( out_Q10 < 0 ) {
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|             out_Q10 = silk_ADD16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
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|         }
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|         out_Q10  = silk_SMLAWB( pred_Q10, (opus_int32)out_Q10, quant_step_size_Q16 );
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|         x_Q10[ i ] = out_Q10;
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|     }
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| }
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| 
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| 
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| /***********************/
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| /* NLSF vector decoder */
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| /***********************/
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| void silk_NLSF_decode(
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|           opus_int16            *pNLSF_Q15,                     /* O    Quantized NLSF vector [ LPC_ORDER ]         */
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|           opus_int8             *NLSFIndices,                   /* I    Codebook path vector [ LPC_ORDER + 1 ]      */
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|     const silk_NLSF_CB_struct   *psNLSF_CB                      /* I    Codebook object                             */
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| )
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| {
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|     opus_int         i;
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|     opus_uint8       pred_Q8[  MAX_LPC_ORDER ];
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|     opus_int16       ec_ix[    MAX_LPC_ORDER ];
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|     opus_int16       res_Q10[  MAX_LPC_ORDER ];
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|     opus_int32       NLSF_Q15_tmp;
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|     const opus_uint8 *pCB_element;
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|     const opus_int16 *pCB_Wght_Q9;
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| 
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|     /* Unpack entropy table indices and predictor for current CB1 index */
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|     silk_NLSF_unpack( ec_ix, pred_Q8, psNLSF_CB, NLSFIndices[ 0 ] );
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| 
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|     /* Predictive residual dequantizer */
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|     silk_NLSF_residual_dequant( res_Q10, &NLSFIndices[ 1 ], pred_Q8, psNLSF_CB->quantStepSize_Q16, psNLSF_CB->order );
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| 
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|     /* Apply inverse square-rooted weights to first stage and add to output */
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|     pCB_element = &psNLSF_CB->CB1_NLSF_Q8[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
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|     pCB_Wght_Q9 = &psNLSF_CB->CB1_Wght_Q9[ NLSFIndices[ 0 ] * psNLSF_CB->order ];
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|     for( i = 0; i < psNLSF_CB->order; i++ ) {
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|         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 );
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|         pNLSF_Q15[ i ] = (opus_int16)silk_LIMIT( NLSF_Q15_tmp, 0, 32767 );
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|     }
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| 
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|     /* NLSF stabilization */
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|     silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->deltaMin_Q15, psNLSF_CB->order );
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| }
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