eden-emu/opus
15
0
Fork 0
mirror of https://github.com/xiph/opus.git synced 2025-06-06 07:21:03 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 4

Changed the allocator to be smarter about the way it allocates

Browse source 
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
Download patch file Download diff file Expand all files Collapse all files

29
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;
}
allocEnergy[i*(mode->nbEBands+1)+mode->nbEBands] = sum;
allocVectors[i*mode->nbEBands+j] = (allocVectors[i*mode->nbEBands+j]+128)/256;
}
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;