Gregory Maxwell | ae23114 | 2011-07-30 08:18:48 -0400 | [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 |
Jean-Marc Valin | ae00e60 | 2012-04-20 16:31:04 -0400 | [diff] [blame] | 4 | modification, are permitted provided that the following conditions |
| 5 | are met: |
Gregory Maxwell | ae23114 | 2011-07-30 08:18:48 -0400 | [diff] [blame] | 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. |
Ralph Giles | f2446c2 | 2013-09-16 14:40:04 -0700 | [diff] [blame] | 11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the |
Jean-Marc Valin | ae00e60 | 2012-04-20 16:31:04 -0400 | [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. |
Timothy B. Terriberry | 80ad383 | 2013-05-19 18:00:39 -0700 | [diff] [blame] | 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
Jean-Marc Valin | ae00e60 | 2012-04-20 16:31:04 -0400 | [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. |
Gregory Maxwell | ae23114 | 2011-07-30 08:18:48 -0400 | [diff] [blame] | 26 | ***********************************************************************/ |
| 27 | |
Jean-Marc Valin | 5a48412 | 2011-08-15 10:49:53 -0400 | [diff] [blame] | 28 | #ifdef HAVE_CONFIG_H |
| 29 | #include "config.h" |
| 30 | #endif |
| 31 | |
Jean-Marc Valin | 1c2f563 | 2011-09-16 01:16:53 -0700 | [diff] [blame] | 32 | #include "SigProc_FIX.h" |
Gregory Maxwell | ae23114 | 2011-07-30 08:18:48 -0400 | [diff] [blame] | 33 | |
| 34 | /* Chirp (bandwidth expand) LP AR filter */ |
| 35 | void silk_bwexpander_32( |
Koen Vos | acc7a6c | 2011-10-28 19:44:26 -0400 | [diff] [blame] | 36 | opus_int32 *ar, /* I/O AR filter to be expanded (without leading 1) */ |
| 37 | const opus_int d, /* I Length of ar */ |
| 38 | opus_int32 chirp_Q16 /* I Chirp factor in Q16 */ |
Gregory Maxwell | ae23114 | 2011-07-30 08:18:48 -0400 | [diff] [blame] | 39 | ) |
| 40 | { |
| 41 | opus_int i; |
| 42 | opus_int32 chirp_minus_one_Q16 = chirp_Q16 - 65536; |
| 43 | |
| 44 | for( i = 0; i < d - 1; i++ ) { |
Jean-Marc Valin | fb3a437 | 2011-09-16 00:58:26 -0700 | [diff] [blame] | 45 | ar[ i ] = silk_SMULWW( chirp_Q16, ar[ i ] ); |
| 46 | chirp_Q16 += silk_RSHIFT_ROUND( silk_MUL( chirp_Q16, chirp_minus_one_Q16 ), 16 ); |
Gregory Maxwell | ae23114 | 2011-07-30 08:18:48 -0400 | [diff] [blame] | 47 | } |
Jean-Marc Valin | fb3a437 | 2011-09-16 00:58:26 -0700 | [diff] [blame] | 48 | ar[ d - 1 ] = silk_SMULWW( chirp_Q16, ar[ d - 1 ] ); |
Gregory Maxwell | ae23114 | 2011-07-30 08:18:48 -0400 | [diff] [blame] | 49 | } |
| 50 | |