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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /media/libopus/celt/laplace.c
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'media/libopus/celt/laplace.c')
-rw-r--r--media/libopus/celt/laplace.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/media/libopus/celt/laplace.c b/media/libopus/celt/laplace.c
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+++ b/media/libopus/celt/laplace.c
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+/* Copyright (c) 2007 CSIRO
+ Copyright (c) 2007-2009 Xiph.Org Foundation
+ Written by Jean-Marc Valin */
+/*
+ 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.
+
+ 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 "laplace.h"
+#include "mathops.h"
+
+/* The minimum probability of an energy delta (out of 32768). */
+#define LAPLACE_LOG_MINP (0)
+#define LAPLACE_MINP (1<<LAPLACE_LOG_MINP)
+/* The minimum number of guaranteed representable energy deltas (in one
+ direction). */
+#define LAPLACE_NMIN (16)
+
+/* When called, decay is positive and at most 11456. */
+static unsigned ec_laplace_get_freq1(unsigned fs0, int decay)
+{
+ unsigned ft;
+ ft = 32768 - LAPLACE_MINP*(2*LAPLACE_NMIN) - fs0;
+ return ft*(opus_int32)(16384-decay)>>15;
+}
+
+void ec_laplace_encode(ec_enc *enc, int *value, unsigned fs, int decay)
+{
+ unsigned fl;
+ int val = *value;
+ fl = 0;
+ if (val)
+ {
+ int s;
+ int i;
+ s = -(val<0);
+ val = (val+s)^s;
+ fl = fs;
+ fs = ec_laplace_get_freq1(fs, decay);
+ /* Search the decaying part of the PDF.*/
+ for (i=1; fs > 0 && i < val; i++)
+ {
+ fs *= 2;
+ fl += fs+2*LAPLACE_MINP;
+ fs = (fs*(opus_int32)decay)>>15;
+ }
+ /* Everything beyond that has probability LAPLACE_MINP. */
+ if (!fs)
+ {
+ int di;
+ int ndi_max;
+ ndi_max = (32768-fl+LAPLACE_MINP-1)>>LAPLACE_LOG_MINP;
+ ndi_max = (ndi_max-s)>>1;
+ di = IMIN(val - i, ndi_max - 1);
+ fl += (2*di+1+s)*LAPLACE_MINP;
+ fs = IMIN(LAPLACE_MINP, 32768-fl);
+ *value = (i+di+s)^s;
+ }
+ else
+ {
+ fs += LAPLACE_MINP;
+ fl += fs&~s;
+ }
+ celt_assert(fl+fs<=32768);
+ celt_assert(fs>0);
+ }
+ ec_encode_bin(enc, fl, fl+fs, 15);
+}
+
+int ec_laplace_decode(ec_dec *dec, unsigned fs, int decay)
+{
+ int val=0;
+ unsigned fl;
+ unsigned fm;
+ fm = ec_decode_bin(dec, 15);
+ fl = 0;
+ if (fm >= fs)
+ {
+ val++;
+ fl = fs;
+ fs = ec_laplace_get_freq1(fs, decay)+LAPLACE_MINP;
+ /* Search the decaying part of the PDF.*/
+ while(fs > LAPLACE_MINP && fm >= fl+2*fs)
+ {
+ fs *= 2;
+ fl += fs;
+ fs = ((fs-2*LAPLACE_MINP)*(opus_int32)decay)>>15;
+ fs += LAPLACE_MINP;
+ val++;
+ }
+ /* Everything beyond that has probability LAPLACE_MINP. */
+ if (fs <= LAPLACE_MINP)
+ {
+ int di;
+ di = (fm-fl)>>(LAPLACE_LOG_MINP+1);
+ val += di;
+ fl += 2*di*LAPLACE_MINP;
+ }
+ if (fm < fl+fs)
+ val = -val;
+ else
+ fl += fs;
+ }
+ celt_assert(fl<32768);
+ celt_assert(fs>0);
+ celt_assert(fl<=fm);
+ celt_assert(fm<IMIN(fl+fs,32768));
+ ec_dec_update(dec, fl, IMIN(fl+fs,32768), 32768);
+ return val;
+}