internal static int ec_laplace_decode(EntropyCoder dec, uint fs, int decay)
{
int val = 0;
uint fl;
uint fm;
fm = dec.decode_bin(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 = (uint)(((fs - 2 * LAPLACE_MINP) * (int)decay) >> 15);
fs += LAPLACE_MINP;
val++;
}
/* Everything beyond that has probability LAPLACE_MINP. */
if (fs <= LAPLACE_MINP)
{
int di;
di = (int)(fm - fl) >> (LAPLACE_LOG_MINP + 1);
val += di;
fl += (uint)(2 * di * LAPLACE_MINP);
}
if (fm < fl + fs)
{
val = -val;
}
else
{
fl += fs;
}
}
Inlines.OpusAssert(fl < 32768);
Inlines.OpusAssert(fs > 0);
Inlines.OpusAssert(fl <= fm);
Inlines.OpusAssert(fm < Inlines.IMIN(fl + fs, 32768));
dec.dec_update(fl, Inlines.IMIN(fl + fs, 32768), 32768);
return(val);
}
