ref: 49134381d07579f4d1d15039c66f9e883bc6bd10
dir: /libcelt/rate.c/
/* (C) 2007 Jean-Marc Valin, CSIRO
*/
/*
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 the Xiph.org Foundation nor the names of its
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 FOUNDATION 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 <math.h>
#include "modes.h"
#include "cwrs.h"
#include "arch.h"
#include "os_support.h"
#include "entcode.h"
#include "rate.h"
#define BITRES 4
#define BITROUND 8
#define BITOVERFLOW 10000
#ifndef STATIC_MODES
static int log2_frac(ec_uint32 val, int frac)
{
int i;
/* EC_ILOG() actually returns log2()+1, go figure */
int L = EC_ILOG(val)-1;
/*printf ("in: %d %d ", val, L);*/
if (L>14)
val >>= L-14;
else if (L<14)
val <<= 14-L;
L <<= frac;
/*printf ("%d\n", val);*/
for (i=0;i<frac;i++)
{
val = (val*val) >> 15;
/*printf ("%d\n", val);*/
if (val > 16384)
L |= (1<<(frac-i-1));
else
val <<= 1;
}
return L;
}
static int log2_frac64(ec_uint64 val, int frac)
{
int i;
/* EC_ILOG64() actually returns log2()+1, go figure */
int L = EC_ILOG64(val)-1;
/*printf ("in: %d %d ", val, L);*/
if (L>14)
val >>= L-14;
else if (L<14)
val <<= 14-L;
L <<= frac;
/*printf ("%d\n", val);*/
for (i=0;i<frac;i++)
{
val = (val*val) >> 15;
/*printf ("%d\n", val);*/
if (val > 16384)
L |= (1<<(frac-i-1));
else
val <<= 1;
}
return L;
}
void compute_alloc_cache(CELTMode *m)
{
int i, prevN, BC;
celt_int16_t **bits;
const celt_int16_t *eBands = m->eBands;
bits = celt_alloc(m->nbEBands*sizeof(celt_int16_t*));
BC = m->nbMdctBlocks*m->nbChannels;
prevN = -1;
for (i=0;i<m->nbEBands;i++)
{
int N = BC*(eBands[i+1]-eBands[i]);
if (N == prevN && eBands[i] < m->pitchEnd)
{
bits[i] = bits[i-1];
} else {
int j;
/* FIXME: We could save memory here */
bits[i] = celt_alloc(MAX_PULSES*sizeof(celt_int16_t));
for (j=0;j<MAX_PULSES;j++)
{
int done = 0;
int pulses = j;
/* For bands where there's no pitch, id 1 corresponds to intra prediction
with no pulse. id 2 means intra prediction with one pulse, and so on.*/
if (eBands[i] >= m->pitchEnd)
pulses -= 1;
if (pulses < 0)
bits[i][j] = 0;
else {
bits[i][j] = log2_frac64(ncwrs64(N, pulses),BITRES);
/* FIXME: Could there be a better test for the max number of pulses that fit in 64 bits? */
if (bits[i][j] > (60<<BITRES))
done = 1;
/* Add the intra-frame prediction bits */
if (eBands[i] >= m->pitchEnd)
{
int max_pos = 2*eBands[i]-eBands[i+1];
if (max_pos > 32)
max_pos = 32;
bits[i][j] += (1<<BITRES) + log2_frac(max_pos,BITRES);
}
}
if (done)
break;
}
for (;j<MAX_PULSES;j++)
bits[i][j] = BITOVERFLOW;
prevN = N;
}
}
m->bits = (const celt_int16_t * const *)bits;
}
#endif /* !STATIC_MODES */
static int bits2pulses(const CELTMode *m, int band, int bits)
{
int i;
int lo, hi;
lo = 0;
hi = MAX_PULSES-1;
/* Instead of using the "bisection confition" we use a fixed number of
iterations because it should be faster */
/*while (hi-lo != 1)*/
for (i=0;i<LOG_MAX_PULSES;i++)
{
int mid = (lo+hi)>>1;
if (m->bits[band][mid] >= bits)
hi = mid;
else
lo = mid;
}
if (bits-m->bits[band][lo] <= m->bits[band][hi]-bits)
return lo;
else
return hi;
}
static int vec_bits2pulses(const CELTMode *m, int *bits, int *pulses, int len)
{
int i;
int sum=0;
for (i=0;i<len;i++)
{
pulses[i] = bits2pulses(m, i, bits[i]);
sum += m->bits[i][pulses[i]];
}
/*printf ("sum = %d\n", sum);*/
return sum;
}
static int interp_bits2pulses(const CELTMode *m, int *bits1, int *bits2, int total, int *pulses, int len)
{
int lo, hi, out;
int j;
int firstpass;
VARDECL(int, bits);
SAVE_STACK;
ALLOC(bits, len, int);
lo = 0;
hi = 1<<BITRES;
while (hi-lo != 1)
{
int mid = (lo+hi)>>1;
for (j=0;j<len;j++)
bits[j] = ((1<<BITRES)-mid)*bits1[j] + mid*bits2[j];
if (vec_bits2pulses(m, bits, pulses, len) > total<<BITRES)
hi = mid;
else
lo = mid;
}
/*printf ("interp bisection gave %d\n", lo);*/
for (j=0;j<len;j++)
bits[j] = ((1<<BITRES)-lo)*bits1[j] + lo*bits2[j];
out = vec_bits2pulses(m, bits, pulses, len);
/* Do some refinement to use up all bits. In the first pass, we can only add pulses to
bands that are under their allocated budget. In the second pass, anything goes */
firstpass = 1;
while(1)
{
int incremented = 0;
for (j=0;j<len;j++)
{
if ((!firstpass || m->bits[j][pulses[j]] < bits[j]) && pulses[j]<MAX_PULSES-1)
{
if (out+m->bits[j][pulses[j]+1]-m->bits[j][pulses[j]] <= total<<BITRES)
{
out = out+m->bits[j][pulses[j]+1]-m->bits[j][pulses[j]];
pulses[j] += 1;
incremented = 1;
}
}
}
if (!incremented)
{
if (firstpass)
firstpass = 0;
else
break;
}
}
RESTORE_STACK;
return (out+BITROUND) >> BITRES;
}
int compute_allocation(const CELTMode *m, int *offsets, int total, int *pulses)
{
int lo, hi, len, ret;
VARDECL(int, bits1);
VARDECL(int, bits2);
SAVE_STACK;
len = m->nbEBands;
ALLOC(bits1, len, int);
ALLOC(bits2, len, int);
lo = 0;
hi = m->nbAllocVectors - 1;
while (hi-lo != 1)
{
int j;
int mid = (lo+hi) >> 1;
for (j=0;j<len;j++)
{
bits1[j] = (m->allocVectors[mid*len+j] + offsets[j])<<BITRES;
if (bits1[j] < 0)
bits1[j] = 0;
/*printf ("%d ", bits[j]);*/
}
/*printf ("\n");*/
if (vec_bits2pulses(m, bits1, pulses, len) > total<<BITRES)
hi = mid;
else
lo = mid;
/*printf ("lo = %d, hi = %d\n", lo, hi);*/
}
{
int j;
for (j=0;j<len;j++)
{
bits1[j] = m->allocVectors[lo*len+j] + offsets[j];
bits2[j] = m->allocVectors[hi*len+j] + offsets[j];
if (bits1[j] < 0)
bits1[j] = 0;
if (bits2[j] < 0)
bits2[j] = 0;
}
ret = interp_bits2pulses(m, bits1, bits2, total, pulses, len);
RESTORE_STACK;
return ret;
}
}