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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /media/libopus/silk/sigm_Q15.c
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'media/libopus/silk/sigm_Q15.c')
-rw-r--r--media/libopus/silk/sigm_Q15.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/media/libopus/silk/sigm_Q15.c b/media/libopus/silk/sigm_Q15.c
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+++ b/media/libopus/silk/sigm_Q15.c
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+/***********************************************************************
+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
+
+/* Approximate sigmoid function */
+
+#include "SigProc_FIX.h"
+
+/* fprintf(1, '%d, ', round(1024 * ([1 ./ (1 + exp(-(1:5))), 1] - 1 ./ (1 + exp(-(0:5)))))); */
+static const opus_int32 sigm_LUT_slope_Q10[ 6 ] = {
+ 237, 153, 73, 30, 12, 7
+};
+/* fprintf(1, '%d, ', round(32767 * 1 ./ (1 + exp(-(0:5))))); */
+static const opus_int32 sigm_LUT_pos_Q15[ 6 ] = {
+ 16384, 23955, 28861, 31213, 32178, 32548
+};
+/* fprintf(1, '%d, ', round(32767 * 1 ./ (1 + exp((0:5))))); */
+static const opus_int32 sigm_LUT_neg_Q15[ 6 ] = {
+ 16384, 8812, 3906, 1554, 589, 219
+};
+
+opus_int silk_sigm_Q15(
+ opus_int in_Q5 /* I */
+)
+{
+ opus_int ind;
+
+ if( in_Q5 < 0 ) {
+ /* Negative input */
+ in_Q5 = -in_Q5;
+ if( in_Q5 >= 6 * 32 ) {
+ return 0; /* Clip */
+ } else {
+ /* Linear interpolation of look up table */
+ ind = silk_RSHIFT( in_Q5, 5 );
+ return( sigm_LUT_neg_Q15[ ind ] - silk_SMULBB( sigm_LUT_slope_Q10[ ind ], in_Q5 & 0x1F ) );
+ }
+ } else {
+ /* Positive input */
+ if( in_Q5 >= 6 * 32 ) {
+ return 32767; /* clip */
+ } else {
+ /* Linear interpolation of look up table */
+ ind = silk_RSHIFT( in_Q5, 5 );
+ return( sigm_LUT_pos_Q15[ ind ] + silk_SMULBB( sigm_LUT_slope_Q10[ ind ], in_Q5 & 0x1F ) );
+ }
+ }
+}
+