ref: c9d5bea13e3cb7381bfa897a45d8bab4e7b767a7
dir: /silk/decode_pulses.c/
/***********************************************************************
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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
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***********************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "main.h"
/*********************************************/
/* Decode quantization indices of excitation */
/*********************************************/
void silk_decode_pulses(
ec_dec *psRangeDec, /* I/O Compressor data structure */
opus_int16 pulses[], /* O Excitation signal */
const opus_int signalType, /* I Sigtype */
const opus_int quantOffsetType, /* I quantOffsetType */
const opus_int frame_length /* I Frame length */
)
{
opus_int i, j, k, iter, abs_q, nLS, RateLevelIndex;
opus_int sum_pulses[ MAX_NB_SHELL_BLOCKS ], nLshifts[ MAX_NB_SHELL_BLOCKS ];
opus_int16 *pulses_ptr;
const opus_uint8 *cdf_ptr;
/*********************/
/* Decode rate level */
/*********************/
RateLevelIndex = ec_dec_icdf( psRangeDec, silk_rate_levels_iCDF[ signalType >> 1 ], 8 );
/* Calculate number of shell blocks */
silk_assert( 1 << LOG2_SHELL_CODEC_FRAME_LENGTH == SHELL_CODEC_FRAME_LENGTH );
iter = silk_RSHIFT( frame_length, LOG2_SHELL_CODEC_FRAME_LENGTH );
if( iter * SHELL_CODEC_FRAME_LENGTH < frame_length ) {
celt_assert( frame_length == 12 * 10 ); /* Make sure only happens for 10 ms @ 12 kHz */
iter++;
}
/***************************************************/
/* Sum-Weighted-Pulses Decoding */
/***************************************************/
cdf_ptr = silk_pulses_per_block_iCDF[ RateLevelIndex ];
for( i = 0; i < iter; i++ ) {
nLshifts[ i ] = 0;
sum_pulses[ i ] = ec_dec_icdf( psRangeDec, cdf_ptr, 8 );
/* LSB indication */
while( sum_pulses[ i ] == SILK_MAX_PULSES + 1 ) {
nLshifts[ i ]++;
/* When we've already got 10 LSBs, we shift the table to not allow (SILK_MAX_PULSES + 1) */
sum_pulses[ i ] = ec_dec_icdf( psRangeDec,
silk_pulses_per_block_iCDF[ N_RATE_LEVELS - 1] + ( nLshifts[ i ] == 10 ), 8 );
}
}
/***************************************************/
/* Shell decoding */
/***************************************************/
for( i = 0; i < iter; i++ ) {
if( sum_pulses[ i ] > 0 ) {
silk_shell_decoder( &pulses[ silk_SMULBB( i, SHELL_CODEC_FRAME_LENGTH ) ], psRangeDec, sum_pulses[ i ] );
} else {
silk_memset( &pulses[ silk_SMULBB( i, SHELL_CODEC_FRAME_LENGTH ) ], 0, SHELL_CODEC_FRAME_LENGTH * sizeof( pulses[0] ) );
}
}
/***************************************************/
/* LSB Decoding */
/***************************************************/
for( i = 0; i < iter; i++ ) {
if( nLshifts[ i ] > 0 ) {
nLS = nLshifts[ i ];
pulses_ptr = &pulses[ silk_SMULBB( i, SHELL_CODEC_FRAME_LENGTH ) ];
for( k = 0; k < SHELL_CODEC_FRAME_LENGTH; k++ ) {
abs_q = pulses_ptr[ k ];
for( j = 0; j < nLS; j++ ) {
abs_q = silk_LSHIFT( abs_q, 1 );
abs_q += ec_dec_icdf( psRangeDec, silk_lsb_iCDF, 8 );
}
pulses_ptr[ k ] = abs_q;
}
/* Mark the number of pulses non-zero for sign decoding. */
sum_pulses[ i ] |= nLS << 5;
}
}
/****************************************/
/* Decode and add signs to pulse signal */
/****************************************/
silk_decode_signs( psRangeDec, pulses, frame_length, signalType, quantOffsetType, sum_pulses );
}