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
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11- Neither the name of Internet Society, IETF or IETF Trust, nor the
12names of specific contributors, may be used to endorse or promote
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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
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18ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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24ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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26***********************************************************************/
27
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32#include "main.h"
33
34/*********************************************/
35/* Decode quantization indices of excitation */
36/*********************************************/
37void silk_decode_pulses(
38    ec_dec                      *psRangeDec,                    /* I/O  Compressor data structure                   */
39    opus_int                    pulses[],                       /* O    Excitation signal                           */
40    const opus_int              signalType,                     /* I    Sigtype                                     */
41    const opus_int              quantOffsetType,                /* I    quantOffsetType                             */
42    const opus_int              frame_length                    /* I    Frame length                                */
43)
44{
45    opus_int   i, j, k, iter, abs_q, nLS, RateLevelIndex;
46    opus_int   sum_pulses[ MAX_NB_SHELL_BLOCKS ], nLshifts[ MAX_NB_SHELL_BLOCKS ];
47    opus_int   *pulses_ptr;
48    const opus_uint8 *cdf_ptr;
49
50    /*********************/
51    /* Decode rate level */
52    /*********************/
53    RateLevelIndex = ec_dec_icdf( psRangeDec, silk_rate_levels_iCDF[ signalType >> 1 ], 8 );
54
55    /* Calculate number of shell blocks */
56    silk_assert( 1 << LOG2_SHELL_CODEC_FRAME_LENGTH == SHELL_CODEC_FRAME_LENGTH );
57    iter = silk_RSHIFT( frame_length, LOG2_SHELL_CODEC_FRAME_LENGTH );
58    if( iter * SHELL_CODEC_FRAME_LENGTH < frame_length ) {
59        silk_assert( frame_length == 12 * 10 ); /* Make sure only happens for 10 ms @ 12 kHz */
60        iter++;
61    }
62
63    /***************************************************/
64    /* Sum-Weighted-Pulses Decoding                    */
65    /***************************************************/
66    cdf_ptr = silk_pulses_per_block_iCDF[ RateLevelIndex ];
67    for( i = 0; i < iter; i++ ) {
68        nLshifts[ i ] = 0;
69        sum_pulses[ i ] = ec_dec_icdf( psRangeDec, cdf_ptr, 8 );
70
71        /* LSB indication */
72        while( sum_pulses[ i ] == MAX_PULSES + 1 ) {
73            nLshifts[ i ]++;
74            /* When we've already got 10 LSBs, we shift the table to not allow (MAX_PULSES + 1) */
75            sum_pulses[ i ] = ec_dec_icdf( psRangeDec,
76                    silk_pulses_per_block_iCDF[ N_RATE_LEVELS - 1] + ( nLshifts[ i ] == 10 ), 8 );
77        }
78    }
79
80    /***************************************************/
81    /* Shell decoding                                  */
82    /***************************************************/
83    for( i = 0; i < iter; i++ ) {
84        if( sum_pulses[ i ] > 0 ) {
85            silk_shell_decoder( &pulses[ silk_SMULBB( i, SHELL_CODEC_FRAME_LENGTH ) ], psRangeDec, sum_pulses[ i ] );
86        } else {
87            silk_memset( &pulses[ silk_SMULBB( i, SHELL_CODEC_FRAME_LENGTH ) ], 0, SHELL_CODEC_FRAME_LENGTH * sizeof( opus_int ) );
88        }
89    }
90
91    /***************************************************/
92    /* LSB Decoding                                    */
93    /***************************************************/
94    for( i = 0; i < iter; i++ ) {
95        if( nLshifts[ i ] > 0 ) {
96            nLS = nLshifts[ i ];
97            pulses_ptr = &pulses[ silk_SMULBB( i, SHELL_CODEC_FRAME_LENGTH ) ];
98            for( k = 0; k < SHELL_CODEC_FRAME_LENGTH; k++ ) {
99                abs_q = pulses_ptr[ k ];
100                for( j = 0; j < nLS; j++ ) {
101                    abs_q = silk_LSHIFT( abs_q, 1 );
102                    abs_q += ec_dec_icdf( psRangeDec, silk_lsb_iCDF, 8 );
103                }
104                pulses_ptr[ k ] = abs_q;
105            }
106            /* Mark the number of pulses non-zero for sign decoding. */
107            sum_pulses[ i ] |= nLS << 5;
108        }
109    }
110
111    /****************************************/
112    /* Decode and add signs to pulse signal */
113    /****************************************/
114    silk_decode_signs( psRangeDec, pulses, frame_length, signalType, quantOffsetType, sum_pulses );
115}
116