ref: bf8577992e69de9182d29fe37739dbd6b5ac7354
dir: /src_common/SKP_Silk_NLSF_MSVQ_decode.c/
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#include "SKP_Silk_main.h"
/* NLSF vector decoder */
void SKP_Silk_NLSF_MSVQ_decode(
SKP_int *pNLSF_Q15, /* O Pointer to decoded output vector [LPC_ORDER x 1] */
const SKP_Silk_NLSF_CB_struct *psNLSF_CB, /* I Pointer to NLSF codebook struct */
const SKP_int8 *NLSFIndices, /* I Pointer to NLSF indices [nStages x 1] */
const SKP_int LPC_order /* I LPC order used */
)
{
const SKP_int8 *pCB_element;
SKP_int i, s;
SKP_int pNLSF_Q8[ MAX_LPC_ORDER ];
/* Check that index is within valid range */
SKP_assert( 0 <= NLSFIndices[ 0 ] && NLSFIndices[ 0 ] < psNLSF_CB->CBStages[ 0 ].nVectors );
/* Point to the first vector element */
pCB_element = &psNLSF_CB->CBStages[ 0 ].CB_NLSF_Q8[ SKP_SMULBB( (SKP_int16)NLSFIndices[ 0 ], LPC_order ) ];
/* Initialize with the codebook vector from stage 0 */
for( i = 0; i < LPC_order; i++ ) {
pNLSF_Q8[ i ] = SKP_LSHIFT( ( SKP_int )pCB_element[ i ], NLSF_Q_DOMAIN_STAGE_2_TO_LAST - NLSF_Q_DOMAIN_STAGE_0 );
}
if( LPC_order == 16 ) {
for( s = 1; s < psNLSF_CB->nStages; s++ ) {
/* Check that each index is within valid range */
SKP_assert( 0 <= NLSFIndices[ s ] && NLSFIndices[ s ] < psNLSF_CB->CBStages[ s ].nVectors );
/* Point to the first vector element */
pCB_element = &psNLSF_CB->CBStages[ s ].CB_NLSF_Q8[ 16 * (SKP_int16)NLSFIndices[ s ] ];
/* Add the codebook vector from the current stage */
pNLSF_Q8[ 0 ] += ( SKP_int )pCB_element[ 0 ];
pNLSF_Q8[ 1 ] += ( SKP_int )pCB_element[ 1 ];
pNLSF_Q8[ 2 ] += ( SKP_int )pCB_element[ 2 ];
pNLSF_Q8[ 3 ] += ( SKP_int )pCB_element[ 3 ];
pNLSF_Q8[ 4 ] += ( SKP_int )pCB_element[ 4 ];
pNLSF_Q8[ 5 ] += ( SKP_int )pCB_element[ 5 ];
pNLSF_Q8[ 6 ] += ( SKP_int )pCB_element[ 6 ];
pNLSF_Q8[ 7 ] += ( SKP_int )pCB_element[ 7 ];
pNLSF_Q8[ 8 ] += ( SKP_int )pCB_element[ 8 ];
pNLSF_Q8[ 9 ] += ( SKP_int )pCB_element[ 9 ];
pNLSF_Q8[ 10 ] += ( SKP_int )pCB_element[ 10 ];
pNLSF_Q8[ 11 ] += ( SKP_int )pCB_element[ 11 ];
pNLSF_Q8[ 12 ] += ( SKP_int )pCB_element[ 12 ];
pNLSF_Q8[ 13 ] += ( SKP_int )pCB_element[ 13 ];
pNLSF_Q8[ 14 ] += ( SKP_int )pCB_element[ 14 ];
pNLSF_Q8[ 15 ] += ( SKP_int )pCB_element[ 15 ];
}
} else {
SKP_assert( LPC_order == 10 );
for( s = 1; s < psNLSF_CB->nStages; s++ ) {
/* Point to the first vector element */
pCB_element = &psNLSF_CB->CBStages[ s ].CB_NLSF_Q8[ SKP_SMULBB( (SKP_int16)NLSFIndices[ s ], LPC_order ) ];
/* Add the codebook vector from the current stage */
pNLSF_Q8[ 0 ] += ( SKP_int )pCB_element[ 0 ];
pNLSF_Q8[ 1 ] += ( SKP_int )pCB_element[ 1 ];
pNLSF_Q8[ 2 ] += ( SKP_int )pCB_element[ 2 ];
pNLSF_Q8[ 3 ] += ( SKP_int )pCB_element[ 3 ];
pNLSF_Q8[ 4 ] += ( SKP_int )pCB_element[ 4 ];
pNLSF_Q8[ 5 ] += ( SKP_int )pCB_element[ 5 ];
pNLSF_Q8[ 6 ] += ( SKP_int )pCB_element[ 6 ];
pNLSF_Q8[ 7 ] += ( SKP_int )pCB_element[ 7 ];
pNLSF_Q8[ 8 ] += ( SKP_int )pCB_element[ 8 ];
pNLSF_Q8[ 9 ] += ( SKP_int )pCB_element[ 9 ];
}
}
/* Add 1/2 in Q15 */
for( i = 0; i < LPC_order; i++ ) {
pNLSF_Q15[ i ] = SKP_LSHIFT16( pNLSF_Q8[ i ], 15 - NLSF_Q_DOMAIN_STAGE_2_TO_LAST ) + SKP_FIX_CONST( 0.5f, 15 );
}
/* NLSF stabilization */
SKP_Silk_NLSF_stabilize( pNLSF_Q15, psNLSF_CB->NDeltaMin_Q15, LPC_order );
}