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Diffstat (limited to 'src/opus-1.0.2/silk/NLSF_stabilize.c')
| -rw-r--r-- | src/opus-1.0.2/silk/NLSF_stabilize.c | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/src/opus-1.0.2/silk/NLSF_stabilize.c b/src/opus-1.0.2/silk/NLSF_stabilize.c deleted file mode 100644 index 7498b54a..00000000 --- a/src/opus-1.0.2/silk/NLSF_stabilize.c +++ /dev/null @@ -1,142 +0,0 @@ -/*********************************************************************** -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 - -/* NLSF stabilizer: */ -/* */ -/* - Moves NLSFs further apart if they are too close */ -/* - Moves NLSFs away from borders if they are too close */ -/* - High effort to achieve a modification with minimum */ -/* Euclidean distance to input vector */ -/* - Output are sorted NLSF coefficients */ -/* */ - -#include "SigProc_FIX.h" - -/* Constant Definitions */ -#define MAX_LOOPS 20 - -/* NLSF stabilizer, for a single input data vector */ -void silk_NLSF_stabilize( - opus_int16 *NLSF_Q15, /* I/O Unstable/stabilized normalized LSF vector in Q15 [L] */ - const opus_int16 *NDeltaMin_Q15, /* I Min distance vector, NDeltaMin_Q15[L] must be >= 1 [L+1] */ - const opus_int L /* I Number of NLSF parameters in the input vector */ -) -{ - opus_int i, I=0, k, loops; - opus_int16 center_freq_Q15; - opus_int32 diff_Q15, min_diff_Q15, min_center_Q15, max_center_Q15; - - /* This is necessary to ensure an output within range of a opus_int16 */ - silk_assert( NDeltaMin_Q15[L] >= 1 ); - - for( loops = 0; loops < MAX_LOOPS; loops++ ) { - /**************************/ - /* Find smallest distance */ - /**************************/ - /* First element */ - min_diff_Q15 = NLSF_Q15[0] - NDeltaMin_Q15[0]; - I = 0; - /* Middle elements */ - for( i = 1; i <= L-1; i++ ) { - diff_Q15 = NLSF_Q15[i] - ( NLSF_Q15[i-1] + NDeltaMin_Q15[i] ); - if( diff_Q15 < min_diff_Q15 ) { - min_diff_Q15 = diff_Q15; - I = i; - } - } - /* Last element */ - diff_Q15 = ( 1 << 15 ) - ( NLSF_Q15[L-1] + NDeltaMin_Q15[L] ); - if( diff_Q15 < min_diff_Q15 ) { - min_diff_Q15 = diff_Q15; - I = L; - } - - /***************************************************/ - /* Now check if the smallest distance non-negative */ - /***************************************************/ - if( min_diff_Q15 >= 0 ) { - return; - } - - if( I == 0 ) { - /* Move away from lower limit */ - NLSF_Q15[0] = NDeltaMin_Q15[0]; - - } else if( I == L) { - /* Move away from higher limit */ - NLSF_Q15[L-1] = ( 1 << 15 ) - NDeltaMin_Q15[L]; - - } else { - /* Find the lower extreme for the location of the current center frequency */ - min_center_Q15 = 0; - for( k = 0; k < I; k++ ) { - min_center_Q15 += NDeltaMin_Q15[k]; - } - min_center_Q15 += silk_RSHIFT( NDeltaMin_Q15[I], 1 ); - - /* Find the upper extreme for the location of the current center frequency */ - max_center_Q15 = 1 << 15; - for( k = L; k > I; k-- ) { - max_center_Q15 -= NDeltaMin_Q15[k]; - } - max_center_Q15 -= silk_RSHIFT( NDeltaMin_Q15[I], 1 ); - - /* Move apart, sorted by value, keeping the same center frequency */ - center_freq_Q15 = (opus_int16)silk_LIMIT_32( silk_RSHIFT_ROUND( (opus_int32)NLSF_Q15[I-1] + (opus_int32)NLSF_Q15[I], 1 ), - min_center_Q15, max_center_Q15 ); - NLSF_Q15[I-1] = center_freq_Q15 - silk_RSHIFT( NDeltaMin_Q15[I], 1 ); - NLSF_Q15[I] = NLSF_Q15[I-1] + NDeltaMin_Q15[I]; - } - } - - /* Safe and simple fall back method, which is less ideal than the above */ - if( loops == MAX_LOOPS ) - { - /* Insertion sort (fast for already almost sorted arrays): */ - /* Best case: O(n) for an already sorted array */ - /* Worst case: O(n^2) for an inversely sorted array */ - silk_insertion_sort_increasing_all_values_int16( &NLSF_Q15[0], L ); - - /* First NLSF should be no less than NDeltaMin[0] */ - NLSF_Q15[0] = silk_max_int( NLSF_Q15[0], NDeltaMin_Q15[0] ); - - /* Keep delta_min distance between the NLSFs */ - for( i = 1; i < L; i++ ) - NLSF_Q15[i] = silk_max_int( NLSF_Q15[i], NLSF_Q15[i-1] + NDeltaMin_Q15[i] ); - - /* Last NLSF should be no higher than 1 - NDeltaMin[L] */ - NLSF_Q15[L-1] = silk_min_int( NLSF_Q15[L-1], (1<<15) - NDeltaMin_Q15[L] ); - - /* Keep NDeltaMin distance between the NLSFs */ - for( i = L-2; i >= 0; i-- ) - NLSF_Q15[i] = silk_min_int( NLSF_Q15[i], NLSF_Q15[i+1] - NDeltaMin_Q15[i+1] ); - } -} |