ref: ca8b9928c9ffe41d3cded442a86d8c8b65f97b78
dir: /libcelt/rate.c/
/* Copyright (c) 2007-2008 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.
- 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"
#ifndef STATIC_MODES
/*Determines if V(N,K) fits in a 32-bit unsigned integer.
N and K are themselves limited to 15 bits.*/
static int fits_in32(int _n, int _k)
{
static const celt_int16 maxN[15] = {
32767, 32767, 32767, 1476, 283, 109, 60, 40,
29, 24, 20, 18, 16, 14, 13};
static const celt_int16 maxK[15] = {
32767, 32767, 32767, 32767, 1172, 238, 95, 53,
36, 27, 22, 18, 16, 15, 13};
if (_n>=14)
{
if (_k>=14)
return 0;
else
return _n <= maxN[_k];
} else {
return _k <= maxK[_n];
}
}
void compute_pulse_cache(CELTMode *m, int LM)
{
int i;
int curr=0;
int nbEntries=0;
int entryN[100], entryK[100], entryI[100];
const celt_int16 *eBands = m->eBands;
PulseCache *cache = &m->cache;
celt_int16 *cindex;
unsigned char *bits;
cindex = celt_alloc(sizeof(cache->index[0])*m->nbEBands*(LM+2));
cache->index = cindex;
for (i=0;i<=LM+1;i++)
{
int j;
for (j=0;j<m->nbEBands;j++)
{
int k;
int N = (eBands[j+1]-eBands[j])<<i>>1;
cindex[i*m->nbEBands+j] = -1;
for (k=0;k<=i;k++)
{
int n;
for (n=0;n<m->nbEBands && (k!=i || n<j);n++)
{
if (N == (eBands[n+1]-eBands[n])<<k>>1)
{
cindex[i*m->nbEBands+j] = cindex[k*m->nbEBands+n];
break;
}
}
}
if (cache->index[i*m->nbEBands+j] == -1 && N!=0)
{
int K;
entryN[nbEntries] = N;
K = 0;
while (fits_in32(N,get_pulses(K+1)) && K<MAX_PSEUDO-1)
K++;
entryK[nbEntries] = K;
cindex[i*m->nbEBands+j] = curr;
entryI[nbEntries] = curr;
curr += K+1;
nbEntries++;
}
}
}
bits = celt_alloc(sizeof(unsigned char)*curr);
cache->bits = bits;
cache->size = curr;
for (i=0;i<nbEntries;i++)
{
int j;
unsigned char *ptr = bits+entryI[i];
celt_int16 tmp[MAX_PULSES];
get_required_bits(tmp, entryN[i], get_pulses(entryK[i]), BITRES);
for (j=1;j<=entryK[i];j++)
ptr[j] = tmp[get_pulses(j)]-1;
ptr[0] = entryK[i];
}
}
#endif /* !STATIC_MODES */
static inline void interp_bits2pulses(const CELTMode *m, int start, int end, int *bits1, int *bits2, int total, int *bits, int *ebits, int *fine_priority, int len, int _C, int M)
{
int psum;
int lo, hi;
int j;
int logM;
const int C = CHANNELS(_C);
SAVE_STACK;
logM = log2_frac(M, BITRES);
lo = 0;
hi = 1<<BITRES;
while (hi-lo != 1)
{
int mid = (lo+hi)>>1;
psum = 0;
for (j=start;j<end;j++)
psum += (((1<<BITRES)-mid)*bits1[j] + mid*bits2[j])>>BITRES;
if (psum > (total<<BITRES))
hi = mid;
else
lo = mid;
}
psum = 0;
/*printf ("interp bisection gave %d\n", lo);*/
for (j=start;j<end;j++)
{
bits[j] = (((1<<BITRES)-lo)*bits1[j] + lo*bits2[j])>>BITRES;
psum += bits[j];
}
/* Allocate the remaining bits */
{
int left, perband;
left = (total<<BITRES)-psum;
perband = left/(end-start);
for (j=start;j<end;j++)
bits[j] += perband;
left = left-end*perband;
for (j=start;j<start+left;j++)
bits[j]++;
}
for (j=start;j<end;j++)
{
int N0, N, den;
int offset;
int fine_offset;
N0 = m->eBands[j+1]-m->eBands[j];
N=M*N0;
/* Compensate for the extra DoF in stereo */
den=(C*N+ ((C==2 && N>2) ? 1 : 0));
if (N0==1)
fine_offset = 19;
else if (N0<=4)
fine_offset = 14;
else
fine_offset = 12;
/* Offset for the number of fine bits compared to their "fair share" of total/N */
offset = N*C*((m->logN[j] + logM - 2*fine_offset)>>1);
/* Compensate for the prediction gain in stereo */
if (C==2)
offset -= 1<<BITRES;
ebits[j] = (bits[j] + offset + (den<<(BITRES-1))) / (den<<BITRES);
/* If we rounded down, make it a candidate for final fine energy pass */
fine_priority[j] = ebits[j]*(den<<BITRES) >= bits[j]+offset;
/* For N=1, all bits go to fine energy except for a single sign bit */
if (N==1)
ebits[j] = (bits[j]/C >> BITRES)-1;
/* Make sure the first bit is spent on fine energy */
if (ebits[j] < 1)
ebits[j] = 1;
/* Make sure not to bust */
if (C*ebits[j] > (bits[j]>>BITRES))
ebits[j] = bits[j]/C >> BITRES;
if (ebits[j]>7)
ebits[j]=7;
if (ebits[j]<0)
ebits[j]=0;
/* The bits used for fine allocation can't be used for pulses */
bits[j] -= C*ebits[j]<<BITRES;
if (bits[j] < 0)
bits[j] = 0;
}
RESTORE_STACK;
}
void compute_allocation(const CELTMode *m, int start, int end, int *offsets, int total, int *pulses, int *ebits, int *fine_priority, int _C, int M)
{
int lo, hi, len, j;
const int C = CHANNELS(_C);
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 psum = 0;
int mid = (lo+hi) >> 1;
for (j=start;j<end;j++)
{
int N = m->eBands[j+1]-m->eBands[j];
bits1[j] = (C*M*N*m->allocVectors[mid*len+j] + offsets[j]);
if (bits1[j] < 0)
bits1[j] = 0;
psum += bits1[j];
/*printf ("%d ", bits[j]);*/
}
/*printf ("\n");*/
if (psum > (total<<BITRES))
hi = mid;
else
lo = mid;
/*printf ("lo = %d, hi = %d\n", lo, hi);*/
}
/*printf ("interp between %d and %d\n", lo, hi);*/
for (j=start;j<end;j++)
{
int N = m->eBands[j+1]-m->eBands[j];
bits1[j] = C*M*N*m->allocVectors[lo*len+j] + offsets[j];
bits2[j] = C*M*N*m->allocVectors[hi*len+j] + offsets[j];
if (bits1[j] < 0)
bits1[j] = 0;
if (bits2[j] < 0)
bits2[j] = 0;
}
interp_bits2pulses(m, start, end, bits1, bits2, total, pulses, ebits, fine_priority, len, C, M);
RESTORE_STACK;
}