/src/opus/silk/NLSF_stabilize.c

Source (jump to first uncovered line)
/***********************************************************************
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], silk_ADD_SAT16( 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] );
    }
}

Line	Count	Source (jump to first uncovered line)
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		/* NLSF stabilizer: */
33		/* */
34		/* - Moves NLSFs further apart if they are too close */
35		/* - Moves NLSFs away from borders if they are too close */
36		/* - High effort to achieve a modification with minimum */
37		/* Euclidean distance to input vector */
38		/* - Output are sorted NLSF coefficients */
39		/* */
40
41		#include "SigProc_FIX.h"
42
43		/* Constant Definitions */
44	0	#define MAX_LOOPS 20
45
46		/* NLSF stabilizer, for a single input data vector */
47		void silk_NLSF_stabilize(
48		opus_int16 NLSF_Q15, / I/O Unstable/stabilized normalized LSF vector in Q15 [L] */
49		const opus_int16 NDeltaMin_Q15, / I Min distance vector, NDeltaMin_Q15[L] must be >= 1 [L+1] */
50		const opus_int L /* I Number of NLSF parameters in the input vector */
51		)
52	0	{
53	0	opus_int i, I=0, k, loops;
54	0	opus_int16 center_freq_Q15;
55	0	opus_int32 diff_Q15, min_diff_Q15, min_center_Q15, max_center_Q15;
56
57		/* This is necessary to ensure an output within range of a opus_int16 */
58	0	silk_assert( NDeltaMin_Q15[L] >= 1 );
59
60	0	for( loops = 0; loops < MAX_LOOPS; loops++ ) {
61		/**************************/
62		/* Find smallest distance */
63		/**************************/
64		/* First element */
65	0	min_diff_Q15 = NLSF_Q15[0] - NDeltaMin_Q15[0];
66	0	I = 0;
67		/* Middle elements */
68	0	for( i = 1; i <= L-1; i++ ) {
69	0	diff_Q15 = NLSF_Q15[i] - ( NLSF_Q15[i-1] + NDeltaMin_Q15[i] );
70	0	if( diff_Q15 < min_diff_Q15 ) {
71	0	min_diff_Q15 = diff_Q15;
72	0	I = i;
73	0	}
74	0	}
75		/* Last element */
76	0	diff_Q15 = ( 1 << 15 ) - ( NLSF_Q15[L-1] + NDeltaMin_Q15[L] );
77	0	if( diff_Q15 < min_diff_Q15 ) {
78	0	min_diff_Q15 = diff_Q15;
79	0	I = L;
80	0	}
81
82		/***************************************************/
83		/* Now check if the smallest distance non-negative */
84		/***************************************************/
85	0	if( min_diff_Q15 >= 0 ) {
86	0	return;
87	0	}
88
89	0	if( I == 0 ) {
90		/* Move away from lower limit */
91	0	NLSF_Q15[0] = NDeltaMin_Q15[0];
92
93	0	} else if( I == L) {
94		/* Move away from higher limit */
95	0	NLSF_Q15[L-1] = ( 1 << 15 ) - NDeltaMin_Q15[L];
96
97	0	} else {
98		/* Find the lower extreme for the location of the current center frequency */
99	0	min_center_Q15 = 0;
100	0	for( k = 0; k < I; k++ ) {
101	0	min_center_Q15 += NDeltaMin_Q15[k];
102	0	}
103	0	min_center_Q15 += silk_RSHIFT( NDeltaMin_Q15[I], 1 );
104
105		/* Find the upper extreme for the location of the current center frequency */
106	0	max_center_Q15 = 1 << 15;
107	0	for( k = L; k > I; k-- ) {
108	0	max_center_Q15 -= NDeltaMin_Q15[k];
109	0	}
110	0	max_center_Q15 -= silk_RSHIFT( NDeltaMin_Q15[I], 1 );
111
112		/* Move apart, sorted by value, keeping the same center frequency */
113	0	center_freq_Q15 = (opus_int16)silk_LIMIT_32( silk_RSHIFT_ROUND( (opus_int32)NLSF_Q15[I-1] + (opus_int32)NLSF_Q15[I], 1 ),
114	0	min_center_Q15, max_center_Q15 );
115	0	NLSF_Q15[I-1] = center_freq_Q15 - silk_RSHIFT( NDeltaMin_Q15[I], 1 );
116	0	NLSF_Q15[I] = NLSF_Q15[I-1] + NDeltaMin_Q15[I];
117	0	}
118	0	}
119
120		/* Safe and simple fall back method, which is less ideal than the above */
121	0	if( loops == MAX_LOOPS )
122	0	{
123		/* Insertion sort (fast for already almost sorted arrays): */
124		/* Best case: O(n) for an already sorted array */
125		/* Worst case: O(n^2) for an inversely sorted array */
126	0	silk_insertion_sort_increasing_all_values_int16( &NLSF_Q15[0], L );
127
128		/* First NLSF should be no less than NDeltaMin[0] */
129	0	NLSF_Q15[0] = silk_max_int( NLSF_Q15[0], NDeltaMin_Q15[0] );
130
131		/* Keep delta_min distance between the NLSFs */
132	0	for( i = 1; i < L; i++ )
133	0	NLSF_Q15[i] = silk_max_int( NLSF_Q15[i], silk_ADD_SAT16( NLSF_Q15[i-1], NDeltaMin_Q15[i] ) );
134
135		/* Last NLSF should be no higher than 1 - NDeltaMin[L] */
136	0	NLSF_Q15[L-1] = silk_min_int( NLSF_Q15[L-1], (1<<15) - NDeltaMin_Q15[L] );
137
138		/* Keep NDeltaMin distance between the NLSFs */
139	0	for( i = L-2; i >= 0; i-- )
140	0	NLSF_Q15[i] = silk_min_int( NLSF_Q15[i], NLSF_Q15[i+1] - NDeltaMin_Q15[i+1] );
141	0	}
142	0	}

Coverage Report

Created: 2024-09-06 07:53