ref: 39cbc45828cdbb2a74e4bea44a399e3a5b0a4530
dir: /silk/fixed/residual_energy_FIX.c/
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#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "main_FIX.h"
#include "stack_alloc.h"
/* Calculates residual energies of input subframes where all subframes have LPC_order */
/* of preceding samples */
void silk_residual_energy_FIX(
opus_int32 nrgs[ MAX_NB_SUBFR ], /* O Residual energy per subframe */
opus_int nrgsQ[ MAX_NB_SUBFR ], /* O Q value per subframe */
const opus_int16 x[], /* I Input signal */
opus_int16 a_Q12[ 2 ][ MAX_LPC_ORDER ], /* I AR coefs for each frame half */
const opus_int32 gains[ MAX_NB_SUBFR ], /* I Quantization gains */
const opus_int subfr_length, /* I Subframe length */
const opus_int nb_subfr, /* I Number of subframes */
const opus_int LPC_order /* I LPC order */
)
{
opus_int offset, i, j, rshift, lz1, lz2;
opus_int16 *LPC_res_ptr;
VARDECL( opus_int16, LPC_res );
const opus_int16 *x_ptr;
opus_int32 tmp32;
SAVE_STACK;
x_ptr = x;
offset = LPC_order + subfr_length;
/* Filter input to create the LPC residual for each frame half, and measure subframe energies */
ALLOC( LPC_res, ( MAX_NB_SUBFR >> 1 ) * offset, opus_int16 );
silk_assert( ( nb_subfr >> 1 ) * ( MAX_NB_SUBFR >> 1 ) == nb_subfr );
for( i = 0; i < nb_subfr >> 1; i++ ) {
/* Calculate half frame LPC residual signal including preceding samples */
silk_LPC_analysis_filter( LPC_res, x_ptr, a_Q12[ i ], ( MAX_NB_SUBFR >> 1 ) * offset, LPC_order );
/* Point to first subframe of the just calculated LPC residual signal */
LPC_res_ptr = LPC_res + LPC_order;
for( j = 0; j < ( MAX_NB_SUBFR >> 1 ); j++ ) {
/* Measure subframe energy */
silk_sum_sqr_shift( &nrgs[ i * ( MAX_NB_SUBFR >> 1 ) + j ], &rshift, LPC_res_ptr, subfr_length );
/* Set Q values for the measured energy */
nrgsQ[ i * ( MAX_NB_SUBFR >> 1 ) + j ] = -rshift;
/* Move to next subframe */
LPC_res_ptr += offset;
}
/* Move to next frame half */
x_ptr += ( MAX_NB_SUBFR >> 1 ) * offset;
}
/* Apply the squared subframe gains */
for( i = 0; i < nb_subfr; i++ ) {
/* Fully upscale gains and energies */
lz1 = silk_CLZ32( nrgs[ i ] ) - 1;
lz2 = silk_CLZ32( gains[ i ] ) - 1;
tmp32 = silk_LSHIFT32( gains[ i ], lz2 );
/* Find squared gains */
tmp32 = silk_SMMUL( tmp32, tmp32 ); /* Q( 2 * lz2 - 32 )*/
/* Scale energies */
nrgs[ i ] = silk_SMMUL( tmp32, silk_LSHIFT32( nrgs[ i ], lz1 ) ); /* Q( nrgsQ[ i ] + lz1 + 2 * lz2 - 32 - 32 )*/
nrgsQ[ i ] += lz1 + 2 * lz2 - 32 - 32;
}
RESTORE_STACK;
}