lilium-voyager/code/opus-1.1/silk/CNG.c
2014-02-08 03:21:02 +00:00

172 lines
8.4 KiB
C

/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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are met:
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names of specific contributors, may be used to endorse or promote
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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***********************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "main.h"
#include "stack_alloc.h"
/* Generates excitation for CNG LPC synthesis */
static OPUS_INLINE void silk_CNG_exc(
opus_int32 residual_Q10[], /* O CNG residual signal Q10 */
opus_int32 exc_buf_Q14[], /* I Random samples buffer Q10 */
opus_int32 Gain_Q16, /* I Gain to apply */
opus_int length, /* I Length */
opus_int32 *rand_seed /* I/O Seed to random index generator */
)
{
opus_int32 seed;
opus_int i, idx, exc_mask;
exc_mask = CNG_BUF_MASK_MAX;
while( exc_mask > length ) {
exc_mask = silk_RSHIFT( exc_mask, 1 );
}
seed = *rand_seed;
for( i = 0; i < length; i++ ) {
seed = silk_RAND( seed );
idx = (opus_int)( silk_RSHIFT( seed, 24 ) & exc_mask );
silk_assert( idx >= 0 );
silk_assert( idx <= CNG_BUF_MASK_MAX );
residual_Q10[ i ] = (opus_int16)silk_SAT16( silk_SMULWW( exc_buf_Q14[ idx ], Gain_Q16 >> 4 ) );
}
*rand_seed = seed;
}
void silk_CNG_Reset(
silk_decoder_state *psDec /* I/O Decoder state */
)
{
opus_int i, NLSF_step_Q15, NLSF_acc_Q15;
NLSF_step_Q15 = silk_DIV32_16( silk_int16_MAX, psDec->LPC_order + 1 );
NLSF_acc_Q15 = 0;
for( i = 0; i < psDec->LPC_order; i++ ) {
NLSF_acc_Q15 += NLSF_step_Q15;
psDec->sCNG.CNG_smth_NLSF_Q15[ i ] = NLSF_acc_Q15;
}
psDec->sCNG.CNG_smth_Gain_Q16 = 0;
psDec->sCNG.rand_seed = 3176576;
}
/* Updates CNG estimate, and applies the CNG when packet was lost */
void silk_CNG(
silk_decoder_state *psDec, /* I/O Decoder state */
silk_decoder_control *psDecCtrl, /* I/O Decoder control */
opus_int16 frame[], /* I/O Signal */
opus_int length /* I Length of residual */
)
{
opus_int i, subfr;
opus_int32 sum_Q6, max_Gain_Q16;
opus_int16 A_Q12[ MAX_LPC_ORDER ];
silk_CNG_struct *psCNG = &psDec->sCNG;
SAVE_STACK;
if( psDec->fs_kHz != psCNG->fs_kHz ) {
/* Reset state */
silk_CNG_Reset( psDec );
psCNG->fs_kHz = psDec->fs_kHz;
}
if( psDec->lossCnt == 0 && psDec->prevSignalType == TYPE_NO_VOICE_ACTIVITY ) {
/* Update CNG parameters */
/* Smoothing of LSF's */
for( i = 0; i < psDec->LPC_order; i++ ) {
psCNG->CNG_smth_NLSF_Q15[ i ] += silk_SMULWB( (opus_int32)psDec->prevNLSF_Q15[ i ] - (opus_int32)psCNG->CNG_smth_NLSF_Q15[ i ], CNG_NLSF_SMTH_Q16 );
}
/* Find the subframe with the highest gain */
max_Gain_Q16 = 0;
subfr = 0;
for( i = 0; i < psDec->nb_subfr; i++ ) {
if( psDecCtrl->Gains_Q16[ i ] > max_Gain_Q16 ) {
max_Gain_Q16 = psDecCtrl->Gains_Q16[ i ];
subfr = i;
}
}
/* Update CNG excitation buffer with excitation from this subframe */
silk_memmove( &psCNG->CNG_exc_buf_Q14[ psDec->subfr_length ], psCNG->CNG_exc_buf_Q14, ( psDec->nb_subfr - 1 ) * psDec->subfr_length * sizeof( opus_int32 ) );
silk_memcpy( psCNG->CNG_exc_buf_Q14, &psDec->exc_Q14[ subfr * psDec->subfr_length ], psDec->subfr_length * sizeof( opus_int32 ) );
/* Smooth gains */
for( i = 0; i < psDec->nb_subfr; i++ ) {
psCNG->CNG_smth_Gain_Q16 += silk_SMULWB( psDecCtrl->Gains_Q16[ i ] - psCNG->CNG_smth_Gain_Q16, CNG_GAIN_SMTH_Q16 );
}
}
/* Add CNG when packet is lost or during DTX */
if( psDec->lossCnt ) {
VARDECL( opus_int32, CNG_sig_Q10 );
ALLOC( CNG_sig_Q10, length + MAX_LPC_ORDER, opus_int32 );
/* Generate CNG excitation */
silk_CNG_exc( CNG_sig_Q10 + MAX_LPC_ORDER, psCNG->CNG_exc_buf_Q14, psCNG->CNG_smth_Gain_Q16, length, &psCNG->rand_seed );
/* Convert CNG NLSF to filter representation */
silk_NLSF2A( A_Q12, psCNG->CNG_smth_NLSF_Q15, psDec->LPC_order );
/* Generate CNG signal, by synthesis filtering */
silk_memcpy( CNG_sig_Q10, psCNG->CNG_synth_state, MAX_LPC_ORDER * sizeof( opus_int32 ) );
for( i = 0; i < length; i++ ) {
silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 );
/* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */
sum_Q6 = silk_RSHIFT( psDec->LPC_order, 1 );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 1 ], A_Q12[ 0 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 2 ], A_Q12[ 1 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 3 ], A_Q12[ 2 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 4 ], A_Q12[ 3 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 5 ], A_Q12[ 4 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 6 ], A_Q12[ 5 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 7 ], A_Q12[ 6 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 8 ], A_Q12[ 7 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 9 ], A_Q12[ 8 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 10 ], A_Q12[ 9 ] );
if( psDec->LPC_order == 16 ) {
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 11 ], A_Q12[ 10 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 12 ], A_Q12[ 11 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 13 ], A_Q12[ 12 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 14 ], A_Q12[ 13 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 15 ], A_Q12[ 14 ] );
sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 16 ], A_Q12[ 15 ] );
}
/* Update states */
CNG_sig_Q10[ MAX_LPC_ORDER + i ] = silk_ADD_LSHIFT( CNG_sig_Q10[ MAX_LPC_ORDER + i ], sum_Q6, 4 );
frame[ i ] = silk_ADD_SAT16( frame[ i ], silk_RSHIFT_ROUND( sum_Q6, 6 ) );
}
silk_memcpy( psCNG->CNG_synth_state, &CNG_sig_Q10[ length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
} else {
silk_memset( psCNG->CNG_synth_state, 0, psDec->LPC_order * sizeof( opus_int32 ) );
}
RESTORE_STACK;
}