ref: 7364e758ed15fa499021d2823e0efc6024c8dd66
dir: /libcelt/rate.c/
/* (C) 2007-2008 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 30000
#ifndef STATIC_MODES
celt_int16_t **compute_alloc_cache(CELTMode *m, int C)
{
int i, prevN;
celt_int16_t **bits;
const celt_int16_t *eBands = m->eBands;
bits = celt_alloc(m->nbEBands*sizeof(celt_int16_t*));
prevN = -1;
for (i=0;i<m->nbEBands;i++)
{
int N = C*(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 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] = get_required_bits(N, pulses, BITRES);
/* Add the intra-frame prediction sign bit */
if (eBands[i] >= m->pitchEnd)
bits[i][j] += (1<<BITRES);
}
}
for (;j<MAX_PULSES;j++)
bits[i][j] = BITOVERFLOW;
prevN = N;
}
}
return bits;
}
#endif /* !STATIC_MODES */
static inline int bits2pulses(const CELTMode *m, const celt_int16_t *cache, int bits)
{
int i;
int lo, hi;
lo = 0;
hi = MAX_PULSES-1;
/* Instead of using the "bisection condition" 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;
/* OPT: Make sure this is implemented with a conditional move */
if (cache[mid] >= bits)
hi = mid;
else
lo = mid;
}
if (bits-cache[lo] <= cache[hi]-bits)
return lo;
else
return hi;
}
static int vec_bits2pulses(const CELTMode *m, const celt_int16_t * const *cache, int *bits, int *pulses, int len)
{
int i;
int sum=0;
for (i=0;i<len;i++)
{
pulses[i] = bits2pulses(m, cache[i], bits[i]);
sum += cache[i][pulses[i]];
}
/*printf ("sum = %d\n", sum);*/
return sum;
}
static int interp_bits2pulses(const CELTMode *m, const celt_int16_t * const *cache, int *bits1, int *bits2, int total, int *pulses, int len)
{
int lo, hi, out;
int j;
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, cache, 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, cache, 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 */
for (j=0;j<len;j++)
{
if (cache[j][pulses[j]] < bits[j] && pulses[j]<MAX_PULSES-1)
{
if (out+cache[j][pulses[j]+1]-cache[j][pulses[j]] <= total<<BITRES)
{
out = out+cache[j][pulses[j]+1]-cache[j][pulses[j]];
pulses[j] += 1;
}
}
}
while(1)
{
int incremented = 0;
for (j=0;j<len;j++)
{
if (pulses[j]<MAX_PULSES-1)
{
if (out+cache[j][pulses[j]+1]-cache[j][pulses[j]] <= total<<BITRES)
{
out = out+cache[j][pulses[j]+1]-cache[j][pulses[j]];
pulses[j] += 1;
incremented = 1;
}
}
}
if (!incremented)
break;
}
RESTORE_STACK;
return (out+BITROUND) >> BITRES;
}
int compute_allocation(const CELTMode *m, int *offsets, const int *stereo_mode, int total, int *pulses)
{
int lo, hi, len, ret, i;
VARDECL(int, bits1);
VARDECL(int, bits2);
VARDECL(const celt_int16_t*, cache);
SAVE_STACK;
len = m->nbEBands;
ALLOC(bits1, len, int);
ALLOC(bits2, len, int);
ALLOC(cache, len, const celt_int16_t*);
if (m->nbChannels==2)
{
for (i=0;i<len;i++)
{
if (stereo_mode[i]==0)
cache[i] = m->bits_stereo[i];
else
cache[i] = m->bits[i];
}
} else {
for (i=0;i<len;i++)
cache[i] = m->bits[i];
}
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, cache, 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, cache, bits1, bits2, total, pulses, len);
RESTORE_STACK;
return ret;
}
}