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Changed the allocator to be smarter about the way it allocates

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fine energy bits. Also, doing better rounding of the bits.
This commit is contained in:
Jean-Marc Valin 2009-02-09 00:45:48 -05:00
parent 9acd9293c3
commit 9a6c496630
3 changed files with 35 additions and 47 deletions
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2
libcelt/cwrs.h
View file

@ -36,6 +36,8 @@
#include "entenc.h"
#include "entdec.h"
int log2_frac(ec_uint32 val, int frac);
/* Returns log of an integer with fractional accuracy */
int log2_frac64(ec_uint64 val, int frac);
/* Whether the CWRS codebook will fit into 32 bits */

27
libcelt/modes.c
View file

@ -228,7 +228,7 @@ static void compute_allocation_table(CELTMode *mode, int res)
celt_int32_t alloc;
edge = mode->eBands[eband+1]*res;
alloc = band_allocation[i*BARK_BANDS+j];
alloc = alloc*C*mode->mdctSize/256;
alloc = alloc*C*mode->mdctSize;
if (edge < bark_freq[j+1])
{
int num, den;
@ -243,30 +243,15 @@ static void compute_allocation_table(CELTMode *mode, int res)
}
}
}
/* Compute fine energy resolution and update the pulse allocation table to subtract that */
for (i=0;i<mode->nbAllocVectors;i++)
{
int sum = 0;
for (j=0;j<mode->nbEBands;j++)
{
int ebits;
int min_bits=0;
if (allocVectors[i*mode->nbEBands+j] > 0)
min_bits = 1;
ebits = IMAX(min_bits , allocVectors[i*mode->nbEBands+j] / (C*(mode->eBands[j+1]-mode->eBands[j])));
if (ebits>7)
ebits=7;
/* The bits used for fine allocation can't be used for pulses */
/* However, we give two "free" bits to all modes to compensate for the fact that some energy
resolution is needed regardless of the frame size. */
if (ebits>1)
allocVectors[i*mode->nbEBands+j] -= C*(ebits-2);
if (allocVectors[i*mode->nbEBands+j] < 0)
allocVectors[i*mode->nbEBands+j] = 0;
sum += ebits;
allocEnergy[i*(mode->nbEBands+1)+j] = ebits;
allocVectors[i*mode->nbEBands+j] = (allocVectors[i*mode->nbEBands+j]+128)/256;
}
allocEnergy[i*(mode->nbEBands+1)+mode->nbEBands] = sum;
for (i=0;i<mode->nbAllocVectors;i++)
{
for (j=0;j<mode->nbEBands;j++)
allocVectors[i*mode->nbEBands+j] += C;
}
mode->energy_alloc = allocEnergy;
mode->allocVectors = allocVectors;

51
libcelt/rate.c
View file

@ -73,9 +73,9 @@ celt_int16_t **compute_alloc_cache(CELTMode *m, int C)
static int interp_bits2pulses(const CELTMode *m, int *bits1, int *bits2, int *ebits1, int *ebits2, int total, int *bits, int *ebits, int len)
static void interp_bits2pulses(const CELTMode *m, int *bits1, int *bits2, int total, int *bits, int *ebits, int len)
{
int esum, psum;
int psum;
int lo, hi;
int j;
const int C = CHANNELS(m);
@ -86,26 +86,16 @@ static int interp_bits2pulses(const CELTMode *m, int *bits1, int *bits2, int *eb
{
int mid = (lo+hi)>>1;
psum = 0;
esum = 0;
for (j=0;j<len;j++)
{
esum += (((1<<BITRES)-mid)*ebits1[j] + mid*ebits2[j] + (1<<(BITRES-1)))>>BITRES;
psum += ((1<<BITRES)-mid)*bits1[j] + mid*bits2[j];
}
if (psum > (total-C*esum)<<BITRES)
if (psum > (total<<BITRES))
hi = mid;
else
lo = mid;
}
esum = 0;
psum = 0;
/*printf ("interp bisection gave %d\n", lo);*/
for (j=0;j<len;j++)
{
ebits[j] = (((1<<BITRES)-lo)*ebits1[j] + lo*ebits2[j] + (1<<(BITRES-1)))>>BITRES;
esum += ebits[j];
}
for (j=0;j<len;j++)
{
bits[j] = ((1<<BITRES)-lo)*bits1[j] + lo*bits2[j];
psum += bits[j];
@ -113,7 +103,7 @@ static int interp_bits2pulses(const CELTMode *m, int *bits1, int *bits2, int *eb
/* Allocate the remaining bits */
{
int left, perband;
left = ((total-C*esum)<<BITRES)-psum;
left = (total<<BITRES)-psum;
perband = left/len;
for (j=0;j<len;j++)
bits[j] += perband;
@ -121,26 +111,39 @@ static int interp_bits2pulses(const CELTMode *m, int *bits1, int *bits2, int *eb
for (j=0;j<left;j++)
bits[j]++;
}
for (j=0;j<len;j++)
{
int offset;
int min_bits=0;
if (bits[j] >= C>>BITRES)
min_bits = 1;
/* Offset for the number of fine bits compared to their "fair share" of total/N */
offset = 45 - log2_frac(m->eBands[j+1]-m->eBands[j], 4);
ebits[j] = IMAX(min_bits , ((bits[j]+C*(m->eBands[j+1]-m->eBands[j])/2) / (C*(m->eBands[j+1]-m->eBands[j])) - offset)>>BITRES );
/* 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;
/* 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;
return (total-C*esum)<<BITRES;
}
void compute_allocation(const CELTMode *m, int *offsets, const int *stereo_mode, int total, int *pulses, int *ebits)
{
int lo, hi, len, j;
int remaining_bits;
VARDECL(int, bits1);
VARDECL(int, bits2);
VARDECL(int, ebits1);
VARDECL(int, ebits2);
const int C = CHANNELS(m);
SAVE_STACK;
len = m->nbEBands;
ALLOC(bits1, len, int);
ALLOC(bits2, len, int);
ALLOC(ebits1, len, int);
ALLOC(ebits2, len, int);
lo = 0;
hi = m->nbAllocVectors - 1;
@ -157,7 +160,7 @@ void compute_allocation(const CELTMode *m, int *offsets, const int *stereo_mode,
/*printf ("%d ", bits[j]);*/
}
/*printf ("\n");*/
if (psum > (total-C*m->energy_alloc[mid*(len+1)+len])<<BITRES)
if (psum > (total<<BITRES))
hi = mid;
else
lo = mid;
@ -166,8 +169,6 @@ void compute_allocation(const CELTMode *m, int *offsets, const int *stereo_mode,
/*printf ("interp between %d and %d\n", lo, hi);*/
for (j=0;j<len;j++)
{
ebits1[j] = m->energy_alloc[lo*(len+1)+j];
ebits2[j] = m->energy_alloc[hi*(len+1)+j];
bits1[j] = m->allocVectors[lo*len+j] + offsets[j];
bits2[j] = m->allocVectors[hi*len+j] + offsets[j];
if (bits1[j] < 0)
@ -175,7 +176,7 @@ void compute_allocation(const CELTMode *m, int *offsets, const int *stereo_mode,
if (bits2[j] < 0)
bits2[j] = 0;
}
remaining_bits = interp_bits2pulses(m, bits1, bits2, ebits1, ebits2, total, pulses, ebits, len);
interp_bits2pulses(m, bits1, bits2, total, pulses, ebits, len);
RESTORE_STACK;
}