ref: a6631746659a7d54bc342b1d7e56bbce1b6305a1
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.
*/
#include <math.h>
#include "modes.h"
#include "cwrs.h"
#include "arch.h"
#include "os_support.h"
#include "entcode.h"
#define BITRES 4
#define BITOVERFLOW 1000
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;
}
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;
}
int bits2pulses(int bits, int N)
{
int i, b, prev;
/* FIXME: This is terribly inefficient. Do a bisection instead
but be careful about overflows */
prev = 0;
i=1;
b = log2_frac64(ncwrs64(N, i),0);
while (b<bits)
{
prev=b;
i++;
b = log2_frac64(ncwrs64(N, i),0);
}
if (bits-prev < b-bits)
i--;
return i;
}
struct alloc_data {
int len;
int **bits;
int **rev_bits;
};
void alloc_init(struct alloc_data *alloc, const CELTMode *m)
{
int i, prevN, BC;
const int *eBands = m->eBands;
alloc->bits = celt_alloc(m->nbEBands*sizeof(int*));
alloc->rev_bits = celt_alloc(m->nbEBands*sizeof(int*));
alloc->len = m->nbEBands;
BC = m->nbMdctBlocks*m->nbChannels;
prevN = -1;
for (i=0;i<alloc->len;i++)
{
int N = BC*(eBands[i+1]-eBands[i]);
if (N == prevN)
{
alloc->bits[i] = alloc->bits[i-1];
alloc->rev_bits[i] = alloc->rev_bits[i-1];
} else {
int j;
/* FIXME: We could save memory here */
alloc->bits[i] = celt_alloc(64*sizeof(int));
alloc->rev_bits[i] = celt_alloc(64*sizeof(int));
for (j=0;j<64;j++)
{
alloc->bits[i][j] = log2_frac64(ncwrs64(N, j),BITRES);
/* We could just update rev_bits here */
if (alloc->bits[i][j] > (60>>BITRES))
break;
}
for (;j<64;j++)
alloc->bits[i][j] = BITOVERFLOW;
for (j=0;j<32;j++)
alloc->rev_bits[i][j] = bits2pulses(j, N);
prevN = N;
}
}
}
void alloc_clear(struct alloc_data *alloc)
{
int i;
int *prevPtr = NULL;
for (i=0;i<alloc->len;i++)
{
if (alloc->bits[i] != prevPtr)
{
prevPtr = alloc->bits[i];
celt_free(alloc->bits[i]);
celt_free(alloc->rev_bits[i]);
}
}
celt_free(alloc->bits);
celt_free(alloc->rev_bits);
}
int compute_allocation(const CELTMode *m, int *pulses)
{
int i, N, BC, bits;
const int *eBands = m->eBands;
BC = m->nbMdctBlocks*m->nbChannels;
bits = 0;
for (i=0;i<m->nbEBands;i++)
{
int q;
N = BC*(eBands[i+1]-eBands[i]);
q = pulses[i];
if (q<=0)
{
bits += log2_frac64(eBands[i] - (eBands[i+1]-eBands[i]), 8) + (1<<8);
q = -q;
}
if (q != 0)
bits += log2_frac64(ncwrs64(N, pulses[i]), 8);
}
return (bits+255)>>8;
}
int vec_bits2pulses(int *bands, int *bits, int *pulses, int len, int B)
{
int i;
int sum=0;
for (i=0;i<len;i++)
{
int N = (bands[i+1]-bands[i])*B;
pulses[i] = bits2pulses(bits[i], N);
sum += log2_frac64(ncwrs(N, pulses[i]),8);
}
return (sum+255)>>8;
}
int interp_bits2pulses(int *bands, int *bits1, int *bits2, int total, int *pulses, int len, int B)
{
int i;
/* FIXME: This too is terribly inefficient. We should do a bisection instead */
for (i=0;i<16;i++)
{
int j;
int bits[len];
for (j=0;j<len;j++)
bits[j] = ((16-i)*bits1[j] + i*bits2[j]) >> 4;
if (vec_bits2pulses(bands, bits, pulses, len, B) > total)
break;
}
if (i==0)
return -1;
else {
int j;
int bits[len];
/* Get the previous one (that didn't bust). Should rewrite that anyway */
i--;
for (j=0;j<len;j++)
bits[j] = ((16-i)*bits1[j] + i*bits2[j]) >> 4;
return vec_bits2pulses(bands, bits, pulses, len, B);
}
}
#if 0
int main()
{
int i;
/*for(i=1;i<2000000000;i+=1738)
{
printf ("%d %d\n", i, frac_log2(i, 10));
}*/
for (i=4;i<=32;i*=2)
{
int j;
for (j=0;j<30;j++)
{
printf ("%d %d %d\n", i, j, bits2pulses(j,i));
}
}
return 0;
}
#endif
#if 0
int main()
{
int i;
int bits[18] = {10, 9, 9, 8, 8, 8, 8, 8, 8, 8, 9, 10, 8, 9, 10, 11, 6, 7};
int bits1[18] = {8, 7, 7, 6, 6, 6, 5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5};
int bits2[18] = {15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15};
int bank[20] = {0, 4, 8, 12, 16, 20, 24, 28, 32, 38, 44, 52, 62, 74, 90,112,142,182, 232,256};
int pulses[18];
struct alloc_data alloc;
alloc_init(&alloc, celt_mode0);
int b = vec_bits2pulses(bank, bits, pulses, 18, 1);
printf ("total: %d bits\n", b);
for (i=0;i<18;i++)
printf ("%d ", pulses[i]);
printf ("\n");
b = interp_bits2pulses(bank, bits1, bits2, 160, pulses, 18, 1);
printf ("total: %d bits\n", b);
for (i=0;i<18;i++)
printf ("%d ", pulses[i]);
printf ("\n");
alloc_clear(&alloc);
return 0;
}
#endif