mirror of
https://github.com/DrKLO/Telegram.git
synced 2024-12-23 06:50:36 +01:00
4ede311055
Audio notes (opus codec) A lot of different improvements and bug fixes Thanks to: https://github.com/DrKLO/Telegram/issues/293 https://github.com/DrKLO/Telegram/issues/256 FOSS configuration not ready yet I will move main dev branch to github in next couple commits
134 lines
3.9 KiB
C
134 lines
3.9 KiB
C
/* 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;
|
|
}
|