Add copy of opus library in deps/third_party.
TBR=dannyb@google.com
Review URL: https://codereview.chromium.org/11196031
git-svn-id: svn://svn.chromium.org/chrome/trunk/deps/third_party/opus@162558 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/silk/NLSF_stabilize.c b/silk/NLSF_stabilize.c
new file mode 100644
index 0000000..fc642af
--- /dev/null
+++ b/silk/NLSF_stabilize.c
@@ -0,0 +1,142 @@
+/***********************************************************************
+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 futher 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] );
+ }
+}