Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -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 |
| 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 | ***********************************************************************/ |
| 27 | |
| 28 | #ifdef HAVE_CONFIG_H |
| 29 | #include "config.h" |
| 30 | #endif |
| 31 | |
| 32 | #include "SigProc_FIX.h" |
| 33 | #include "resampler_private.h" |
| 34 | |
| 35 | /* Second order AR filter with single delay elements */ |
| 36 | void silk_resampler_private_AR2( |
| 37 | opus_int32 S[], /* I/O State vector [ 2 ] */ |
| 38 | opus_int32 out_Q8[], /* O Output signal */ |
| 39 | const opus_int16 in[], /* I Input signal */ |
| 40 | const opus_int16 A_Q14[], /* I AR coefficients, Q14 */ |
| 41 | opus_int32 len /* I Signal length */ |
| 42 | ) |
| 43 | { |
| 44 | opus_int32 k; |
| 45 | opus_int32 out32; |
| 46 | |
| 47 | for( k = 0; k < len; k++ ) { |
| 48 | out32 = silk_ADD_LSHIFT32( S[ 0 ], (opus_int32)in[ k ], 8 ); |
| 49 | out_Q8[ k ] = out32; |
| 50 | out32 = silk_LSHIFT( out32, 2 ); |
| 51 | S[ 0 ] = silk_SMLAWB( S[ 1 ], out32, A_Q14[ 0 ] ); |
| 52 | S[ 1 ] = silk_SMULWB( out32, A_Q14[ 1 ] ); |
| 53 | } |
| 54 | } |
| 55 | |