diff options
author | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-09-16 12:16:53 +0400 |
---|---|---|
committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-09-16 12:16:53 +0400 |
commit | 1c2f5633d101c08b5ef8095a8682d3d52cbd952d (patch) | |
tree | 66f80e67f075db5fa5233759a89f475d8bedade2 /silk/float/LPC_inv_pred_gain_FLP.c | |
parent | fb3a437c9dabb4aafe4a3927158161590ed745ab (diff) |
Removed all the silk_ prefixes in source file names (not symbols)
Diffstat (limited to 'silk/float/LPC_inv_pred_gain_FLP.c')
-rw-r--r-- | silk/float/LPC_inv_pred_gain_FLP.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/silk/float/LPC_inv_pred_gain_FLP.c b/silk/float/LPC_inv_pred_gain_FLP.c new file mode 100644 index 00000000..a141d111 --- /dev/null +++ b/silk/float/LPC_inv_pred_gain_FLP.c @@ -0,0 +1,77 @@ +/*********************************************************************** +Copyright (c) 2006-2011, Skype Limited. All rights reserved. +Redistribution and use in source and binary forms, with or without +modification, (subject to the limitations in the disclaimer below) +are permitted provided that the following conditions are met: +- Redistributions of source code must retain the above copyright notice, +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 Skype Limited, nor the names of specific +contributors, may be used to endorse or promote products derived from +this software without specific prior written permission. +NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED +BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND +CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, +BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND +FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON +ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +***********************************************************************/ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "SigProc_FIX.h" +#include "SigProc_FLP.h" + +#define RC_THRESHOLD 0.9999f + +/* compute inverse of LPC prediction gain, and */ +/* test if LPC coefficients are stable (all poles within unit circle) */ +/* this code is based on silk_a2k_FLP() */ +opus_int silk_LPC_inverse_pred_gain_FLP( /* O: returns 1 if unstable, otherwise 0 */ + silk_float *invGain, /* O: inverse prediction gain, energy domain */ + const silk_float *A, /* I: prediction coefficients [order] */ + opus_int32 order /* I: prediction order */ +) +{ + opus_int k, n; + double rc, rc_mult1, rc_mult2; + silk_float Atmp[ 2 ][ SILK_MAX_ORDER_LPC ]; + silk_float *Aold, *Anew; + + Anew = Atmp[ order & 1 ]; + silk_memcpy( Anew, A, order * sizeof(silk_float) ); + + *invGain = 1.0f; + for( k = order - 1; k > 0; k-- ) { + rc = -Anew[ k ]; + if (rc > RC_THRESHOLD || rc < -RC_THRESHOLD) { + return 1; + } + rc_mult1 = 1.0f - rc * rc; + rc_mult2 = 1.0f / rc_mult1; + *invGain *= (silk_float)rc_mult1; + /* swap pointers */ + Aold = Anew; + Anew = Atmp[ k & 1 ]; + for( n = 0; n < k; n++ ) { + Anew[ n ] = (silk_float)( ( Aold[ n ] - Aold[ k - n - 1 ] * rc ) * rc_mult2 ); + } + } + rc = -Anew[ 0 ]; + if ( rc > RC_THRESHOLD || rc < -RC_THRESHOLD ) { + return 1; + } + rc_mult1 = 1.0f - rc * rc; + *invGain *= (silk_float)rc_mult1; + return 0; +} |