diff options
Diffstat (limited to 'libopus/silk/float/warped_autocorrelation_FLP.c')
| -rw-r--r-- | libopus/silk/float/warped_autocorrelation_FLP.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/libopus/silk/float/warped_autocorrelation_FLP.c b/libopus/silk/float/warped_autocorrelation_FLP.c new file mode 100644 index 0000000..09186e7 --- /dev/null +++ b/libopus/silk/float/warped_autocorrelation_FLP.c @@ -0,0 +1,73 @@ +/*********************************************************************** +Copyright (c) 2006-2011, Skype Limited. All rights reserved. +Redistribution and use in source and binary forms, with or without +modification, 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 Internet Society, IETF or IETF Trust, nor the +names of specific contributors, may be used to endorse or promote +products derived from this software without specific prior written +permission. +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 "main_FLP.h" + +/* Autocorrelations for a warped frequency axis */ +void silk_warped_autocorrelation_FLP( + silk_float *corr, /* O Result [order + 1] */ + const silk_float *input, /* I Input data to correlate */ + const silk_float warping, /* I Warping coefficient */ + const opus_int length, /* I Length of input */ + const opus_int order /* I Correlation order (even) */ +) +{ + opus_int n, i; + double tmp1, tmp2; + double state[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0 }; + double C[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0 }; + + /* Order must be even */ + celt_assert( ( order & 1 ) == 0 ); + + /* Loop over samples */ + for( n = 0; n < length; n++ ) { + tmp1 = input[ n ]; + /* Loop over allpass sections */ + for( i = 0; i < order; i += 2 ) { + /* Output of allpass section */ + tmp2 = state[ i ] + warping * ( state[ i + 1 ] - tmp1 ); + state[ i ] = tmp1; + C[ i ] += state[ 0 ] * tmp1; + /* Output of allpass section */ + tmp1 = state[ i + 1 ] + warping * ( state[ i + 2 ] - tmp2 ); + state[ i + 1 ] = tmp2; + C[ i + 1 ] += state[ 0 ] * tmp2; + } + state[ order ] = tmp1; + C[ order ] += state[ 0 ] * tmp1; + } + + /* Copy correlations in silk_float output format */ + for( i = 0; i < order + 1; i++ ) { + corr[ i ] = ( silk_float )C[ i ]; + } +} |