ref: bad313c6ba835a3d9bdf729dd54353590a2c0ffd
dir: /silk/silk_code_signs.c/
/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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modification, (subject to the limitations in the disclaimer below)
are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
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documentation and/or other materials provided with the distribution.
- Neither the name of Skype Limited, nor the names of specific
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this software without specific prior written permission.
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
BY THIS LICENSE. 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
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
***********************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "silk_main.h"
//#define SKP_enc_map(a) ((a) > 0 ? 1 : 0)
//#define SKP_dec_map(a) ((a) > 0 ? 1 : -1)
/* shifting avoids if-statement */
#define SKP_enc_map(a) ( SKP_RSHIFT( (a), 15 ) + 1 )
#define SKP_dec_map(a) ( SKP_LSHIFT( (a), 1 ) - 1 )
/* Encodes signs of excitation */
void silk_encode_signs(
ec_enc *psRangeEnc, /* I/O Compressor data structure */
const opus_int8 pulses[], /* I pulse signal */
opus_int length, /* I length of input */
const opus_int signalType, /* I Signal type */
const opus_int quantOffsetType, /* I Quantization offset type */
const opus_int sum_pulses[ MAX_NB_SHELL_BLOCKS ] /* I Sum of absolute pulses per block */
)
{
opus_int i, j, p;
opus_uint8 icdf[ 2 ];
const opus_int8 *q_ptr;
const opus_uint8 *icdf_ptr;
icdf[ 1 ] = 0;
q_ptr = pulses;
i = SKP_SMULBB( 6, SKP_ADD_LSHIFT( quantOffsetType, signalType, 1 ) );
icdf_ptr = &silk_sign_iCDF[ i ];
length = SKP_RSHIFT( length + SHELL_CODEC_FRAME_LENGTH/2, LOG2_SHELL_CODEC_FRAME_LENGTH );
for( i = 0; i < length; i++ ) {
p = sum_pulses[ i ];
if( p > 0 ) {
icdf[ 0 ] = icdf_ptr[ SKP_min( p - 1, 5 ) ];
for( j = 0; j < SHELL_CODEC_FRAME_LENGTH; j++ ) {
if( q_ptr[ j ] != 0 ) {
ec_enc_icdf( psRangeEnc, SKP_enc_map( q_ptr[ j ]), icdf, 8 );
}
}
}
q_ptr += SHELL_CODEC_FRAME_LENGTH;
}
}
/* Decodes signs of excitation */
void silk_decode_signs(
ec_dec *psRangeDec, /* I/O Compressor data structure */
opus_int pulses[], /* I/O pulse signal */
opus_int length, /* I length of input */
const opus_int signalType, /* I Signal type */
const opus_int quantOffsetType, /* I Quantization offset type */
const opus_int sum_pulses[ MAX_NB_SHELL_BLOCKS ] /* I Sum of absolute pulses per block */
)
{
opus_int i, j, p;
opus_uint8 icdf[ 2 ];
opus_int *q_ptr;
const opus_uint8 *icdf_ptr;
icdf[ 1 ] = 0;
q_ptr = pulses;
i = SKP_SMULBB( 6, SKP_ADD_LSHIFT( quantOffsetType, signalType, 1 ) );
icdf_ptr = &silk_sign_iCDF[ i ];
length = SKP_RSHIFT( length + SHELL_CODEC_FRAME_LENGTH/2, LOG2_SHELL_CODEC_FRAME_LENGTH );
for( i = 0; i < length; i++ ) {
p = sum_pulses[ i ];
if( p > 0 ) {
icdf[ 0 ] = icdf_ptr[ SKP_min( p - 1, 5 ) ];
for( j = 0; j < SHELL_CODEC_FRAME_LENGTH; j++ ) {
if( q_ptr[ j ] > 0 ) {
/* attach sign */
#if 0
/* conditional implementation */
if( ec_dec_icdf( psRangeDec, icdf, 8 ) == 0 ) {
q_ptr[ j ] = -q_ptr[ j ];
}
#else
/* implementation with shift, subtraction, multiplication */
q_ptr[ j ] *= SKP_dec_map( ec_dec_icdf( psRangeDec, icdf, 8 ) );
#endif
}
}
}
q_ptr += SHELL_CODEC_FRAME_LENGTH;
}
}