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Ordering Hadamard frequencies when increasing the time-resolution.

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This means we're "time-ordered" in all cases except when increasing
the time resolution on frames that already use short blocks.
There's no reordering when increasing the frequency resolution
on short blocks.
This commit is contained in:
Jean-Marc Valin 2010-12-21 01:04:11 -05:00
parent 034efa523a
commit dc6d69e64b
1 changed files with 50 additions and 14 deletions
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56
libcelt/bands.c
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@ -387,7 +387,18 @@ void measure_norm_mse(const CELTMode *m, float *X, float *X0, float *bandE, floa
#endif
static void interleave_vector(celt_norm *X, int N0, int stride)
/* Indexing table for converting from natural Hadamard to ordery Hadamard
This is essentially a bit-reversed Gray, on top of which we've added
an inversion of the order because we want the DC at the end rather than
the beginning. The lines are for N=2, 4, 8, 16 */
static const int ordery_table[] = {
1, 0,
3, 0, 2, 1,
7, 0, 4, 3, 6, 1, 5, 2,
15, 0, 8, 7, 12, 3, 11, 4, 14, 1, 9, 6, 13, 2, 10, 5,
};
static void deinterleave_hadamard(celt_norm *X, int N0, int stride, int hadamard)
{
int i,j;
VARDECL(celt_norm, tmp);
@ -395,15 +406,25 @@ static void interleave_vector(celt_norm *X, int N0, int stride)
SAVE_STACK;
N = N0*stride;
ALLOC(tmp, N, celt_norm);
if (hadamard)
{
const int *ordery = ordery_table+stride-2;
for (i=0;i<stride;i++)
{
for (j=0;j<N0;j++)
tmp[ordery[i]*N0+j] = X[j*stride+i];
}
} else {
for (i=0;i<stride;i++)
for (j=0;j<N0;j++)
tmp[j*stride+i] = X[i*N0+j];
tmp[i*N0+j] = X[j*stride+i];
}
for (j=0;j<N;j++)
X[j] = tmp[j];
RESTORE_STACK;
}
static void deinterleave_vector(celt_norm *X, int N0, int stride)
static void interleave_hadamard(celt_norm *X, int N0, int stride, int hadamard)
{
int i,j;
VARDECL(celt_norm, tmp);
@ -411,9 +432,17 @@ static void deinterleave_vector(celt_norm *X, int N0, int stride)
SAVE_STACK;
N = N0*stride;
ALLOC(tmp, N, celt_norm);
if (hadamard)
{
const int *ordery = ordery_table+stride-2;
for (i=0;i<stride;i++)
for (j=0;j<N0;j++)
tmp[i*N0+j] = X[j*stride+i];
tmp[j*stride+i] = X[ordery[i]*N0+j];
} else {
for (i=0;i<stride;i++)
for (j=0;j<N0;j++)
tmp[j*stride+i] = X[i*N0+j];
}
for (j=0;j<N;j++)
X[j] = tmp[j];
RESTORE_STACK;
@ -487,6 +516,9 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
int recombine=0;
int inv = 0;
celt_word16 mid=0, side=0;
int longBlocks;
longBlocks = B0==1;
N_B /= B;
N_B0 = N_B;
@ -565,9 +597,9 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
if (B0>1)
{
if (encode)
deinterleave_vector(X, N_B, B0);
deinterleave_hadamard(X, N_B, B0, longBlocks);
if (lowband)
deinterleave_vector(lowband, N_B, B0);
deinterleave_hadamard(lowband, N_B, B0, longBlocks);
}
}
@ -765,9 +797,13 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
int next_level=0;
/* Give more bits to low-energy MDCTs than they would otherwise deserve */
if (B>1 && !stereo && itheta > 8192)
delta -= delta>>(1+level);
if (B>1 && !stereo)
{
if (itheta > 8192)
delta -= delta>>(4+level-LM);
else
delta -= delta>>(5+level-LM);
}
mbits = (b-qalloc-delta)/2;
if (mbits > b-qalloc)
mbits = b-qalloc;
@ -866,7 +902,7 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
/* Undo the sample reorganization going from time order to frequency order */
if (B0>1)
interleave_vector(X, N_B, B0);
interleave_hadamard(X, N_B, B0, longBlocks);
/* Undo time-freq changes that we did earlier */
N_B = N_B0;