1/***********************************************************************
2Copyright (c) 2006-2011, Skype Limited. All rights reserved.
3Redistribution and use in source and binary forms, with or without
4modification, are permitted provided that the following conditions
5are met:
6- Redistributions of source code must retain the above copyright notice,
7this list of conditions and the following disclaimer.
8- Redistributions in binary form must reproduce the above copyright
9notice, this list of conditions and the following disclaimer in the
10documentation and/or other materials provided with the distribution.
11- Neither the name of Internet Society, IETF or IETF Trust, nor the
12names of specific contributors, may be used to endorse or promote
13products derived from this software without specific prior written
14permission.
15THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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24ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25POSSIBILITY OF SUCH DAMAGE.
26***********************************************************************/
27
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32#include "main.h"
33
34/*#define silk_enc_map(a)                ((a) > 0 ? 1 : 0)*/
35/*#define silk_dec_map(a)                ((a) > 0 ? 1 : -1)*/
36/* shifting avoids if-statement */
37#define silk_enc_map(a)                  ( silk_RSHIFT( (a), 15 ) + 1 )
38#define silk_dec_map(a)                  ( silk_LSHIFT( (a),  1 ) - 1 )
39
40/* Encodes signs of excitation */
41void silk_encode_signs(
42    ec_enc                      *psRangeEnc,                        /* I/O  Compressor data structure                   */
43    const opus_int8             pulses[],                           /* I    pulse signal                                */
44    opus_int                    length,                             /* I    length of input                             */
45    const opus_int              signalType,                         /* I    Signal type                                 */
46    const opus_int              quantOffsetType,                    /* I    Quantization offset type                    */
47    const opus_int              sum_pulses[ MAX_NB_SHELL_BLOCKS ]   /* I    Sum of absolute pulses per block            */
48)
49{
50    opus_int         i, j, p;
51    opus_uint8       icdf[ 2 ];
52    const opus_int8  *q_ptr;
53    const opus_uint8 *icdf_ptr;
54
55    icdf[ 1 ] = 0;
56    q_ptr = pulses;
57    i = silk_SMULBB( 7, silk_ADD_LSHIFT( quantOffsetType, signalType, 1 ) );
58    icdf_ptr = &silk_sign_iCDF[ i ];
59    length = silk_RSHIFT( length + SHELL_CODEC_FRAME_LENGTH/2, LOG2_SHELL_CODEC_FRAME_LENGTH );
60    for( i = 0; i < length; i++ ) {
61        p = sum_pulses[ i ];
62        if( p > 0 ) {
63            icdf[ 0 ] = icdf_ptr[ silk_min( p & 0x1F, 6 ) ];
64            for( j = 0; j < SHELL_CODEC_FRAME_LENGTH; j++ ) {
65                if( q_ptr[ j ] != 0 ) {
66                    ec_enc_icdf( psRangeEnc, silk_enc_map( q_ptr[ j ]), icdf, 8 );
67                }
68            }
69        }
70        q_ptr += SHELL_CODEC_FRAME_LENGTH;
71    }
72}
73
74/* Decodes signs of excitation */
75void silk_decode_signs(
76    ec_dec                      *psRangeDec,                        /* I/O  Compressor data structure                   */
77    opus_int                    pulses[],                           /* I/O  pulse signal                                */
78    opus_int                    length,                             /* I    length of input                             */
79    const opus_int              signalType,                         /* I    Signal type                                 */
80    const opus_int              quantOffsetType,                    /* I    Quantization offset type                    */
81    const opus_int              sum_pulses[ MAX_NB_SHELL_BLOCKS ]   /* I    Sum of absolute pulses per block            */
82)
83{
84    opus_int         i, j, p;
85    opus_uint8       icdf[ 2 ];
86    opus_int         *q_ptr;
87    const opus_uint8 *icdf_ptr;
88
89    icdf[ 1 ] = 0;
90    q_ptr = pulses;
91    i = silk_SMULBB( 7, silk_ADD_LSHIFT( quantOffsetType, signalType, 1 ) );
92    icdf_ptr = &silk_sign_iCDF[ i ];
93    length = silk_RSHIFT( length + SHELL_CODEC_FRAME_LENGTH/2, LOG2_SHELL_CODEC_FRAME_LENGTH );
94    for( i = 0; i < length; i++ ) {
95        p = sum_pulses[ i ];
96        if( p > 0 ) {
97            icdf[ 0 ] = icdf_ptr[ silk_min( p & 0x1F, 6 ) ];
98            for( j = 0; j < SHELL_CODEC_FRAME_LENGTH; j++ ) {
99                if( q_ptr[ j ] > 0 ) {
100                    /* attach sign */
101#if 0
102                    /* conditional implementation */
103                    if( ec_dec_icdf( psRangeDec, icdf, 8 ) == 0 ) {
104                        q_ptr[ j ] = -q_ptr[ j ];
105                    }
106#else
107                    /* implementation with shift, subtraction, multiplication */
108                    q_ptr[ j ] *= silk_dec_map( ec_dec_icdf( psRangeDec, icdf, 8 ) );
109#endif
110                }
111            }
112        }
113        q_ptr += SHELL_CODEC_FRAME_LENGTH;
114    }
115}
116