media/libopus/silk/decode_pulses.c@ac0c01689b40
media/libopus/silk/decode_pulses.c
Thu, 15 Jan 2015 15:59:08 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 15 Jan 2015 15:59:08 +0100
- branch
- TOR_BUG_9701
- changeset 10
- ac0c01689b40
- permissions
- -rw-r--r--
Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 /***********************************************************************
2 Copyright (c) 2006-2011, Skype Limited. All rights reserved.
3 Redistribution and use in source and binary forms, with or without
4 modification, are permitted provided that the following conditions
5 are met:
6 - Redistributions of source code must retain the above copyright notice,
7 this list of conditions and the following disclaimer.
8 - Redistributions in binary form must reproduce the above copyright
9 notice, this list of conditions and the following disclaimer in the
10 documentation and/or other materials provided with the distribution.
11 - Neither the name of Internet Society, IETF or IETF Trust, nor the
12 names of specific contributors, may be used to endorse or promote
13 products derived from this software without specific prior written
14 permission.
15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 POSSIBILITY OF SUCH DAMAGE.
26 ***********************************************************************/
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
32 #include "main.h"
34 /*********************************************/
35 /* Decode quantization indices of excitation */
36 /*********************************************/
37 void 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;
50 /*********************/
51 /* Decode rate level */
52 /*********************/
53 RateLevelIndex = ec_dec_icdf( psRangeDec, silk_rate_levels_iCDF[ signalType >> 1 ], 8 );
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 }
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 );
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 }
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 }
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 }
111 /****************************************/
112 /* Decode and add signs to pulse signal */
113 /****************************************/
114 silk_decode_signs( psRangeDec, pulses, frame_length, signalType, quantOffsetType, sum_pulses );
115 }
