media/libopus/silk/fixed/schur64_FIX.c@b8a032363ba2 (annotated)
media/libopus/silk/fixed/schur64_FIX.c
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| 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 "SigProc_FIX.h" |
| michael@0 | 33 | |
| michael@0 | 34 | /* Slower than schur(), but more accurate. */ |
| michael@0 | 35 | /* Uses SMULL(), available on armv4 */ |
| michael@0 | 36 | opus_int32 silk_schur64( /* O returns residual energy */ |
| michael@0 | 37 | opus_int32 rc_Q16[], /* O Reflection coefficients [order] Q16 */ |
| michael@0 | 38 | const opus_int32 c[], /* I Correlations [order+1] */ |
| michael@0 | 39 | opus_int32 order /* I Prediction order */ |
| michael@0 | 40 | ) |
| michael@0 | 41 | { |
| michael@0 | 42 | opus_int k, n; |
| michael@0 | 43 | opus_int32 C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ]; |
| michael@0 | 44 | opus_int32 Ctmp1_Q30, Ctmp2_Q30, rc_tmp_Q31; |
| michael@0 | 45 | |
| michael@0 | 46 | silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 ); |
| michael@0 | 47 | |
| michael@0 | 48 | /* Check for invalid input */ |
| michael@0 | 49 | if( c[ 0 ] <= 0 ) { |
| michael@0 | 50 | silk_memset( rc_Q16, 0, order * sizeof( opus_int32 ) ); |
| michael@0 | 51 | return 0; |
| michael@0 | 52 | } |
| michael@0 | 53 | |
| michael@0 | 54 | for( k = 0; k < order + 1; k++ ) { |
| michael@0 | 55 | C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ]; |
| michael@0 | 56 | } |
| michael@0 | 57 | |
| michael@0 | 58 | for( k = 0; k < order; k++ ) { |
| michael@0 | 59 | /* Check that we won't be getting an unstable rc, otherwise stop here. */ |
| michael@0 | 60 | if (silk_abs_int32(C[ k + 1 ][ 0 ]) >= C[ 0 ][ 1 ]) { |
| michael@0 | 61 | if ( C[ k + 1 ][ 0 ] > 0 ) { |
| michael@0 | 62 | rc_Q16[ k ] = -SILK_FIX_CONST( .99f, 16 ); |
| michael@0 | 63 | } else { |
| michael@0 | 64 | rc_Q16[ k ] = SILK_FIX_CONST( .99f, 16 ); |
| michael@0 | 65 | } |
| michael@0 | 66 | k++; |
| michael@0 | 67 | break; |
| michael@0 | 68 | } |
| michael@0 | 69 | |
| michael@0 | 70 | /* Get reflection coefficient: divide two Q30 values and get result in Q31 */ |
| michael@0 | 71 | rc_tmp_Q31 = silk_DIV32_varQ( -C[ k + 1 ][ 0 ], C[ 0 ][ 1 ], 31 ); |
| michael@0 | 72 | |
| michael@0 | 73 | /* Save the output */ |
| michael@0 | 74 | rc_Q16[ k ] = silk_RSHIFT_ROUND( rc_tmp_Q31, 15 ); |
| michael@0 | 75 | |
| michael@0 | 76 | /* Update correlations */ |
| michael@0 | 77 | for( n = 0; n < order - k; n++ ) { |
| michael@0 | 78 | Ctmp1_Q30 = C[ n + k + 1 ][ 0 ]; |
| michael@0 | 79 | Ctmp2_Q30 = C[ n ][ 1 ]; |
| michael@0 | 80 | |
| michael@0 | 81 | /* Multiply and add the highest int32 */ |
| michael@0 | 82 | C[ n + k + 1 ][ 0 ] = Ctmp1_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp2_Q30, 1 ), rc_tmp_Q31 ); |
| michael@0 | 83 | C[ n ][ 1 ] = Ctmp2_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp1_Q30, 1 ), rc_tmp_Q31 ); |
| michael@0 | 84 | } |
| michael@0 | 85 | } |
| michael@0 | 86 | |
| michael@0 | 87 | for(; k < order; k++ ) { |
| michael@0 | 88 | rc_Q16[ k ] = 0; |
| michael@0 | 89 | } |
| michael@0 | 90 | |
| michael@0 | 91 | return silk_max_32( 1, C[ 0 ][ 1 ] ); |
| michael@0 | 92 | } |
