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jpeg2000: Optimize dequantization 

Float:   4700 -> 2700 cycles
Integer: 4400 -> 2800 cycles

(sandybridge  i7)

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
This commit is contained in:
Michael Niedermayer 2013-07-01 10:01:35 +02:00 committed by Luca Barbato
parent c1dcbc590d
commit e11099db20
1 changed files with 16 additions and 15 deletions
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27
libavcodec/jpeg2000dec.c
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@ -1006,12 +1006,13 @@ static void dequantization_float(int x, int y, Jpeg2000Cblk *cblk,
Jpeg2000Component *comp,
Jpeg2000T1Context *t1, Jpeg2000Band *band)
{
int i, j, idx;
float *datap = &comp->f_data[(comp->coord[0][1] - comp->coord[0][0]) * y + x];
for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j)
for (i = 0; i < (cblk->coord[0][1] - cblk->coord[0][0]); ++i) {
idx = (comp->coord[0][1] - comp->coord[0][0]) * j + i;
datap[idx] = (float)(t1->data[j][i]) * band->f_stepsize;
int i, j;
int w = cblk->coord[0][1] - cblk->coord[0][0];
for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j) {
float *datap = &comp->f_data[(comp->coord[0][1] - comp->coord[0][0]) * (y + j) + x];
int *src = t1->data[j];
for (i = 0; i < w; ++i)
datap[i] = src[i] * band->f_stepsize;
}
}
@ -1020,13 +1021,13 @@ static void dequantization_int(int x, int y, Jpeg2000Cblk *cblk,
Jpeg2000Component *comp,
Jpeg2000T1Context *t1, Jpeg2000Band *band)
{
int i, j, idx;
int32_t *datap = &comp->i_data[(comp->coord[0][1] - comp->coord[0][0]) * y + x];
for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j)
for (i = 0; i < (cblk->coord[0][1] - cblk->coord[0][0]); ++i) {
idx = (comp->coord[0][1] - comp->coord[0][0]) * j + i;
datap[idx] =
((int32_t)(t1->data[j][i]) * band->i_stepsize + (1 << 15)) >> 16;
int i, j;
int w = cblk->coord[0][1] - cblk->coord[0][0];
for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j) {
int32_t *datap = &comp->i_data[(comp->coord[0][1] - comp->coord[0][0]) * (y + j) + x];
int *src = t1->data[j];
for (i = 0; i < w; ++i)
datap[i] = (src[i] * band->i_stepsize + (1 << 15)) >> 16;
}
}