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comparison: media/libopus/silk/fixed/schur64_FIX.c
media/libopus/silk/fixed/schur64_FIX.c
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:405c7c908ccd |
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| 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 | |
| 34 /* Slower than schur(), but more accurate. */ | |
| 35 /* Uses SMULL(), available on armv4 */ | |
| 36 opus_int32 silk_schur64( /* O returns residual energy */ | |
| 37 opus_int32 rc_Q16[], /* O Reflection coefficients [order] Q16 */ | |
| 38 const opus_int32 c[], /* I Correlations [order+1] */ | |
| 39 opus_int32 order /* I Prediction order */ | |
| 40 ) | |
| 41 { | |
| 42 opus_int k, n; | |
| 43 opus_int32 C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ]; | |
| 44 opus_int32 Ctmp1_Q30, Ctmp2_Q30, rc_tmp_Q31; | |
| 45 | |
| 46 silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 ); | |
| 47 | |
| 48 /* Check for invalid input */ | |
| 49 if( c[ 0 ] <= 0 ) { | |
| 50 silk_memset( rc_Q16, 0, order * sizeof( opus_int32 ) ); | |
| 51 return 0; | |
| 52 } | |
| 53 | |
| 54 for( k = 0; k < order + 1; k++ ) { | |
| 55 C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ]; | |
| 56 } | |
| 57 | |
| 58 for( k = 0; k < order; k++ ) { | |
| 59 /* Check that we won't be getting an unstable rc, otherwise stop here. */ | |
| 60 if (silk_abs_int32(C[ k + 1 ][ 0 ]) >= C[ 0 ][ 1 ]) { | |
| 61 if ( C[ k + 1 ][ 0 ] > 0 ) { | |
| 62 rc_Q16[ k ] = -SILK_FIX_CONST( .99f, 16 ); | |
| 63 } else { | |
| 64 rc_Q16[ k ] = SILK_FIX_CONST( .99f, 16 ); | |
| 65 } | |
| 66 k++; | |
| 67 break; | |
| 68 } | |
| 69 | |
| 70 /* Get reflection coefficient: divide two Q30 values and get result in Q31 */ | |
| 71 rc_tmp_Q31 = silk_DIV32_varQ( -C[ k + 1 ][ 0 ], C[ 0 ][ 1 ], 31 ); | |
| 72 | |
| 73 /* Save the output */ | |
| 74 rc_Q16[ k ] = silk_RSHIFT_ROUND( rc_tmp_Q31, 15 ); | |
| 75 | |
| 76 /* Update correlations */ | |
| 77 for( n = 0; n < order - k; n++ ) { | |
| 78 Ctmp1_Q30 = C[ n + k + 1 ][ 0 ]; | |
| 79 Ctmp2_Q30 = C[ n ][ 1 ]; | |
| 80 | |
| 81 /* Multiply and add the highest int32 */ | |
| 82 C[ n + k + 1 ][ 0 ] = Ctmp1_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp2_Q30, 1 ), rc_tmp_Q31 ); | |
| 83 C[ n ][ 1 ] = Ctmp2_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp1_Q30, 1 ), rc_tmp_Q31 ); | |
| 84 } | |
| 85 } | |
| 86 | |
| 87 for(; k < order; k++ ) { | |
| 88 rc_Q16[ k ] = 0; | |
| 89 } | |
| 90 | |
| 91 return silk_max_32( 1, C[ 0 ][ 1 ] ); | |
| 92 } |
