media/libopus/silk/float/warped_autocorrelation_FLP.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_FLP.h"
michael@0 33
michael@0 34 /* Autocorrelations for a warped frequency axis */
michael@0 35 void silk_warped_autocorrelation_FLP(
michael@0 36 silk_float *corr, /* O Result [order + 1] */
michael@0 37 const silk_float *input, /* I Input data to correlate */
michael@0 38 const silk_float warping, /* I Warping coefficient */
michael@0 39 const opus_int length, /* I Length of input */
michael@0 40 const opus_int order /* I Correlation order (even) */
michael@0 41 )
michael@0 42 {
michael@0 43 opus_int n, i;
michael@0 44 double tmp1, tmp2;
michael@0 45 double state[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
michael@0 46 double C[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
michael@0 47
michael@0 48 /* Order must be even */
michael@0 49 silk_assert( ( order & 1 ) == 0 );
michael@0 50
michael@0 51 /* Loop over samples */
michael@0 52 for( n = 0; n < length; n++ ) {
michael@0 53 tmp1 = input[ n ];
michael@0 54 /* Loop over allpass sections */
michael@0 55 for( i = 0; i < order; i += 2 ) {
michael@0 56 /* Output of allpass section */
michael@0 57 tmp2 = state[ i ] + warping * ( state[ i + 1 ] - tmp1 );
michael@0 58 state[ i ] = tmp1;
michael@0 59 C[ i ] += state[ 0 ] * tmp1;
michael@0 60 /* Output of allpass section */
michael@0 61 tmp1 = state[ i + 1 ] + warping * ( state[ i + 2 ] - tmp2 );
michael@0 62 state[ i + 1 ] = tmp2;
michael@0 63 C[ i + 1 ] += state[ 0 ] * tmp2;
michael@0 64 }
michael@0 65 state[ order ] = tmp1;
michael@0 66 C[ order ] += state[ 0 ] * tmp1;
michael@0 67 }
michael@0 68
michael@0 69 /* Copy correlations in silk_float output format */
michael@0 70 for( i = 0; i < order + 1; i++ ) {
michael@0 71 corr[ i ] = ( silk_float )C[ i ];
michael@0 72 }
michael@0 73 }

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