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| Copyright (c) 2006-2011, Skype Limited. All rights reserved. |
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| modification, are permitted provided that the following conditions |
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| this list of conditions and the following disclaimer. |
| - Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| - Neither the name of Internet Society, IETF or IETF Trust, nor the |
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| products derived from this software without specific prior written |
| permission. |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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| ***********************************************************************/ |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #include "SigProc_FLP.h" |
| |
| /* step up function, converts reflection coefficients to prediction coefficients */ |
| void silk_k2a_FLP( |
| silk_float *A, /* O prediction coefficients [order] */ |
| const silk_float *rc, /* I reflection coefficients [order] */ |
| opus_int32 order /* I prediction order */ |
| ) |
| { |
| opus_int k, n; |
| silk_float Atmp[ SILK_MAX_ORDER_LPC ]; |
| |
| for( k = 0; k < order; k++ ) { |
| for( n = 0; n < k; n++ ) { |
| Atmp[ n ] = A[ n ]; |
| } |
| for( n = 0; n < k; n++ ) { |
| A[ n ] += Atmp[ k - n - 1 ] * rc[ k ]; |
| } |
| A[ k ] = -rc[ k ]; |
| } |
| } |