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media/libopus/silk/decode_indices.c@ac0c01689b40 (annotated)

media/libopus/silk/decode_indices.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.

michael@0 1 /***********************************************************************
michael@0 2 Copyright (c) 2006-2011, Skype Limited. All rights reserved.
michael@0 3 Redistribution and use in source and binary forms, with or without
michael@0 4 modification, are permitted provided that the following conditions
michael@0 5 are met:
michael@0 6 - Redistributions of source code must retain the above copyright notice,
michael@0 7 this list of conditions and the following disclaimer.
michael@0 8 - Redistributions in binary form must reproduce the above copyright
michael@0 9 notice, this list of conditions and the following disclaimer in the
michael@0 10 documentation and/or other materials provided with the distribution.
michael@0 11 - Neither the name of Internet Society, IETF or IETF Trust, nor the
michael@0 12 names of specific contributors, may be used to endorse or promote
michael@0 13 products derived from this software without specific prior written
michael@0 14 permission.
michael@0 15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
michael@0 16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
michael@0 17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
michael@0 18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
michael@0 19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
michael@0 20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
michael@0 21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
michael@0 22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
michael@0 23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
michael@0 24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
michael@0 25 POSSIBILITY OF SUCH DAMAGE.
michael@0 26 ***********************************************************************/
michael@0 27
michael@0 28 #ifdef HAVE_CONFIG_H
michael@0 29 #include "config.h"
michael@0 30 #endif
michael@0 31
michael@0 32 #include "main.h"
michael@0 33
michael@0 34 /* Decode side-information parameters from payload */
michael@0 35 void silk_decode_indices(
michael@0 36 silk_decoder_state *psDec, /* I/O State */
michael@0 37 ec_dec *psRangeDec, /* I/O Compressor data structure */
michael@0 38 opus_int FrameIndex, /* I Frame number */
michael@0 39 opus_int decode_LBRR, /* I Flag indicating LBRR data is being decoded */
michael@0 40 opus_int condCoding /* I The type of conditional coding to use */
michael@0 41 )
michael@0 42 {
michael@0 43 opus_int i, k, Ix;
michael@0 44 opus_int decode_absolute_lagIndex, delta_lagIndex;
michael@0 45 opus_int16 ec_ix[ MAX_LPC_ORDER ];
michael@0 46 opus_uint8 pred_Q8[ MAX_LPC_ORDER ];
michael@0 47
michael@0 48 /*******************************************/
michael@0 49 /* Decode signal type and quantizer offset */
michael@0 50 /*******************************************/
michael@0 51 if( decode_LBRR || psDec->VAD_flags[ FrameIndex ] ) {
michael@0 52 Ix = ec_dec_icdf( psRangeDec, silk_type_offset_VAD_iCDF, 8 ) + 2;
michael@0 53 } else {
michael@0 54 Ix = ec_dec_icdf( psRangeDec, silk_type_offset_no_VAD_iCDF, 8 );
michael@0 55 }
michael@0 56 psDec->indices.signalType = (opus_int8)silk_RSHIFT( Ix, 1 );
michael@0 57 psDec->indices.quantOffsetType = (opus_int8)( Ix & 1 );
michael@0 58
michael@0 59 /****************/
michael@0 60 /* Decode gains */
michael@0 61 /****************/
michael@0 62 /* First subframe */
michael@0 63 if( condCoding == CODE_CONDITIONALLY ) {
michael@0 64 /* Conditional coding */
michael@0 65 psDec->indices.GainsIndices[ 0 ] = (opus_int8)ec_dec_icdf( psRangeDec, silk_delta_gain_iCDF, 8 );
michael@0 66 } else {
michael@0 67 /* Independent coding, in two stages: MSB bits followed by 3 LSBs */
michael@0 68 psDec->indices.GainsIndices[ 0 ] = (opus_int8)silk_LSHIFT( ec_dec_icdf( psRangeDec, silk_gain_iCDF[ psDec->indices.signalType ], 8 ), 3 );
michael@0 69 psDec->indices.GainsIndices[ 0 ] += (opus_int8)ec_dec_icdf( psRangeDec, silk_uniform8_iCDF, 8 );
michael@0 70 }
michael@0 71
michael@0 72 /* Remaining subframes */
michael@0 73 for( i = 1; i < psDec->nb_subfr; i++ ) {
michael@0 74 psDec->indices.GainsIndices[ i ] = (opus_int8)ec_dec_icdf( psRangeDec, silk_delta_gain_iCDF, 8 );
michael@0 75 }
michael@0 76
michael@0 77 /**********************/
michael@0 78 /* Decode LSF Indices */
michael@0 79 /**********************/
michael@0 80 psDec->indices.NLSFIndices[ 0 ] = (opus_int8)ec_dec_icdf( psRangeDec, &psDec->psNLSF_CB->CB1_iCDF[ ( psDec->indices.signalType >> 1 ) * psDec->psNLSF_CB->nVectors ], 8 );
michael@0 81 silk_NLSF_unpack( ec_ix, pred_Q8, psDec->psNLSF_CB, psDec->indices.NLSFIndices[ 0 ] );
michael@0 82 silk_assert( psDec->psNLSF_CB->order == psDec->LPC_order );
michael@0 83 for( i = 0; i < psDec->psNLSF_CB->order; i++ ) {
michael@0 84 Ix = ec_dec_icdf( psRangeDec, &psDec->psNLSF_CB->ec_iCDF[ ec_ix[ i ] ], 8 );
michael@0 85 if( Ix == 0 ) {
michael@0 86 Ix -= ec_dec_icdf( psRangeDec, silk_NLSF_EXT_iCDF, 8 );
michael@0 87 } else if( Ix == 2 * NLSF_QUANT_MAX_AMPLITUDE ) {
michael@0 88 Ix += ec_dec_icdf( psRangeDec, silk_NLSF_EXT_iCDF, 8 );
michael@0 89 }
michael@0 90 psDec->indices.NLSFIndices[ i+1 ] = (opus_int8)( Ix - NLSF_QUANT_MAX_AMPLITUDE );
michael@0 91 }
michael@0 92
michael@0 93 /* Decode LSF interpolation factor */
michael@0 94 if( psDec->nb_subfr == MAX_NB_SUBFR ) {
michael@0 95 psDec->indices.NLSFInterpCoef_Q2 = (opus_int8)ec_dec_icdf( psRangeDec, silk_NLSF_interpolation_factor_iCDF, 8 );
michael@0 96 } else {
michael@0 97 psDec->indices.NLSFInterpCoef_Q2 = 4;
michael@0 98 }
michael@0 99
michael@0 100 if( psDec->indices.signalType == TYPE_VOICED )
michael@0 101 {
michael@0 102 /*********************/
michael@0 103 /* Decode pitch lags */
michael@0 104 /*********************/
michael@0 105 /* Get lag index */
michael@0 106 decode_absolute_lagIndex = 1;
michael@0 107 if( condCoding == CODE_CONDITIONALLY && psDec->ec_prevSignalType == TYPE_VOICED ) {
michael@0 108 /* Decode Delta index */
michael@0 109 delta_lagIndex = (opus_int16)ec_dec_icdf( psRangeDec, silk_pitch_delta_iCDF, 8 );
michael@0 110 if( delta_lagIndex > 0 ) {
michael@0 111 delta_lagIndex = delta_lagIndex - 9;
michael@0 112 psDec->indices.lagIndex = (opus_int16)( psDec->ec_prevLagIndex + delta_lagIndex );
michael@0 113 decode_absolute_lagIndex = 0;
michael@0 114 }
michael@0 115 }
michael@0 116 if( decode_absolute_lagIndex ) {
michael@0 117 /* Absolute decoding */
michael@0 118 psDec->indices.lagIndex = (opus_int16)ec_dec_icdf( psRangeDec, silk_pitch_lag_iCDF, 8 ) * silk_RSHIFT( psDec->fs_kHz, 1 );
michael@0 119 psDec->indices.lagIndex += (opus_int16)ec_dec_icdf( psRangeDec, psDec->pitch_lag_low_bits_iCDF, 8 );
michael@0 120 }
michael@0 121 psDec->ec_prevLagIndex = psDec->indices.lagIndex;
michael@0 122
michael@0 123 /* Get countour index */
michael@0 124 psDec->indices.contourIndex = (opus_int8)ec_dec_icdf( psRangeDec, psDec->pitch_contour_iCDF, 8 );
michael@0 125
michael@0 126 /********************/
michael@0 127 /* Decode LTP gains */
michael@0 128 /********************/
michael@0 129 /* Decode PERIndex value */
michael@0 130 psDec->indices.PERIndex = (opus_int8)ec_dec_icdf( psRangeDec, silk_LTP_per_index_iCDF, 8 );
michael@0 131
michael@0 132 for( k = 0; k < psDec->nb_subfr; k++ ) {
michael@0 133 psDec->indices.LTPIndex[ k ] = (opus_int8)ec_dec_icdf( psRangeDec, silk_LTP_gain_iCDF_ptrs[ psDec->indices.PERIndex ], 8 );
michael@0 134 }
michael@0 135
michael@0 136 /**********************/
michael@0 137 /* Decode LTP scaling */
michael@0 138 /**********************/
michael@0 139 if( condCoding == CODE_INDEPENDENTLY ) {
michael@0 140 psDec->indices.LTP_scaleIndex = (opus_int8)ec_dec_icdf( psRangeDec, silk_LTPscale_iCDF, 8 );
michael@0 141 } else {
michael@0 142 psDec->indices.LTP_scaleIndex = 0;
michael@0 143 }
michael@0 144 }
michael@0 145 psDec->ec_prevSignalType = psDec->indices.signalType;
michael@0 146
michael@0 147 /***************/
michael@0 148 /* Decode seed */
michael@0 149 /***************/
michael@0 150 psDec->indices.Seed = (opus_int8)ec_dec_icdf( psRangeDec, silk_uniform4_iCDF, 8 );
michael@0 151 }

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