sergeyu@chromium.org | 885f2ff | 2012-10-17 22:31:52 +0000 | [diff] [blame] | 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. |
tlegrand@chromium.org | e3ea049 | 2013-10-23 09:13:50 +0000 | [diff] [blame] | 11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the |
sergeyu@chromium.org | 885f2ff | 2012-10-17 22:31:52 +0000 | [diff] [blame] | 12 | names of specific contributors, may be used to endorse or promote |
| 13 | products derived from this software without specific prior written |
| 14 | permission. |
tlegrand@chromium.org | e3ea049 | 2013-10-23 09:13:50 +0000 | [diff] [blame] | 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
sergeyu@chromium.org | 885f2ff | 2012-10-17 22:31:52 +0000 | [diff] [blame] | 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 | ***********************************************************************/ |
| 27 | |
| 28 | #ifdef HAVE_CONFIG_H |
| 29 | #include "config.h" |
| 30 | #endif |
| 31 | |
| 32 | #include "main_FLP.h" |
| 33 | |
| 34 | /* Autocorrelations for a warped frequency axis */ |
| 35 | void silk_warped_autocorrelation_FLP( |
| 36 | silk_float *corr, /* O Result [order + 1] */ |
| 37 | const silk_float *input, /* I Input data to correlate */ |
| 38 | const silk_float warping, /* I Warping coefficient */ |
| 39 | const opus_int length, /* I Length of input */ |
| 40 | const opus_int order /* I Correlation order (even) */ |
| 41 | ) |
| 42 | { |
| 43 | opus_int n, i; |
| 44 | double tmp1, tmp2; |
| 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 }; |
| 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 }; |
| 47 | |
| 48 | /* Order must be even */ |
| 49 | silk_assert( ( order & 1 ) == 0 ); |
| 50 | |
| 51 | /* Loop over samples */ |
| 52 | for( n = 0; n < length; n++ ) { |
| 53 | tmp1 = input[ n ]; |
| 54 | /* Loop over allpass sections */ |
| 55 | for( i = 0; i < order; i += 2 ) { |
| 56 | /* Output of allpass section */ |
| 57 | tmp2 = state[ i ] + warping * ( state[ i + 1 ] - tmp1 ); |
| 58 | state[ i ] = tmp1; |
| 59 | C[ i ] += state[ 0 ] * tmp1; |
| 60 | /* Output of allpass section */ |
| 61 | tmp1 = state[ i + 1 ] + warping * ( state[ i + 2 ] - tmp2 ); |
| 62 | state[ i + 1 ] = tmp2; |
| 63 | C[ i + 1 ] += state[ 0 ] * tmp2; |
| 64 | } |
| 65 | state[ order ] = tmp1; |
| 66 | C[ order ] += state[ 0 ] * tmp1; |
| 67 | } |
| 68 | |
| 69 | /* Copy correlations in silk_float output format */ |
| 70 | for( i = 0; i < order + 1; i++ ) { |
| 71 | corr[ i ] = ( silk_float )C[ i ]; |
| 72 | } |
| 73 | } |