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| author | Michael Niedermayer <michaelni@gmx.at> | 2015-06-23 18:47:18 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2015-06-23 18:59:00 +0200 |
| commit | 0416b5e0330c5eb226f92cf6c150eb6b7daa8b92 (patch) | |
| tree | c0a6c2387d2b9ced70a18a225fcaddf91a5e0419 /libavcodec/jpeg2000dwt.c | |
| parent | e22edbfd413242dda720dc5191fc00a51c24d74c (diff) | |
| download | ffmpeg-0416b5e0330c5eb226f92cf6c150eb6b7daa8b92.tar.gz | |
avcodec/jpeg2000dwt: Replace /2 by >>1
Divisions can be slow if the compiler fails to replace them by shifts
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/jpeg2000dwt.c')
| -rw-r--r-- | libavcodec/jpeg2000dwt.c | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/libavcodec/jpeg2000dwt.c b/libavcodec/jpeg2000dwt.c index e090eba10e..28ac6c429e 100644 --- a/libavcodec/jpeg2000dwt.c +++ b/libavcodec/jpeg2000dwt.c @@ -88,9 +88,9 @@ static void sd_1d53(int *p, int i0, int i1) extend53(p, i0, i1); - for (i = (i0+1)/2 - 1; i < (i1+1)/2; i++) + for (i = ((i0+1)>>1) - 1; i < (i1+1)>>1; i++) p[2*i+1] -= (p[2*i] + p[2*i+2]) >> 1; - for (i = (i0+1)/2; i < (i1+1)/2; i++) + for (i = ((i0+1)>>1); i < (i1+1)>>1; i++) p[2*i] += (p[2*i-1] + p[2*i+1] + 2) >> 2; } @@ -159,13 +159,13 @@ static void sd_1d97_float(float *p, int i0, int i1) extend97_float(p, i0, i1); i0++; i1++; - for (i = i0/2 - 2; i < i1/2 + 1; i++) + for (i = (i0>>1) - 2; i < (i1>>1) + 1; i++) p[2*i+1] -= 1.586134 * (p[2*i] + p[2*i+2]); - for (i = i0/2 - 1; i < i1/2 + 1; i++) + for (i = (i0>>1) - 1; i < (i1>>1) + 1; i++) p[2*i] -= 0.052980 * (p[2*i-1] + p[2*i+1]); - for (i = i0/2 - 1; i < i1/2; i++) + for (i = (i0>>1) - 1; i < (i1>>1); i++) p[2*i+1] += 0.882911 * (p[2*i] + p[2*i+2]); - for (i = i0/2; i < i1/2; i++) + for (i = (i0>>1); i < (i1>>1); i++) p[2*i] += 0.443506 * (p[2*i-1] + p[2*i+1]); } @@ -235,13 +235,13 @@ static void sd_1d97_int(int *p, int i0, int i1) extend97_int(p, i0, i1); i0++; i1++; - for (i = i0/2 - 2; i < i1/2 + 1; i++) + for (i = (i0>>1) - 2; i < (i1>>1) + 1; i++) p[2 * i + 1] -= (I_LFTG_ALPHA * (p[2 * i] + p[2 * i + 2]) + (1 << 15)) >> 16; - for (i = i0/2 - 1; i < i1/2 + 1; i++) + for (i = (i0>>1) - 1; i < (i1>>1) + 1; i++) p[2 * i] -= (I_LFTG_BETA * (p[2 * i - 1] + p[2 * i + 1]) + (1 << 15)) >> 16; - for (i = i0/2 - 1; i < i1/2; i++) + for (i = (i0>>1) - 1; i < (i1>>1); i++) p[2 * i + 1] += (I_LFTG_GAMMA * (p[2 * i] + p[2 * i + 2]) + (1 << 15)) >> 16; - for (i = i0/2; i < i1/2; i++) + for (i = (i0>>1); i < (i1>>1); i++) p[2 * i] += (I_LFTG_DELTA * (p[2 * i - 1] + p[2 * i + 1]) + (1 << 15)) >> 16; } @@ -317,9 +317,9 @@ static void sr_1d53(int *p, int i0, int i1) extend53(p, i0, i1); - for (i = i0 / 2; i < i1 / 2 + 1; i++) + for (i = (i0 >> 1); i < (i1 >> 1) + 1; i++) p[2 * i] -= (p[2 * i - 1] + p[2 * i + 1] + 2) >> 2; - for (i = i0 / 2; i < i1 / 2; i++) + for (i = (i0 >> 1); i < (i1 >> 1); i++) p[2 * i + 1] += (p[2 * i] + p[2 * i + 2]) >> 1; } @@ -386,16 +386,16 @@ static void sr_1d97_float(float *p, int i0, int i1) extend97_float(p, i0, i1); - for (i = i0 / 2 - 1; i < i1 / 2 + 2; i++) + for (i = (i0 >> 1) - 1; i < (i1 >> 1) + 2; i++) p[2 * i] -= F_LFTG_DELTA * (p[2 * i - 1] + p[2 * i + 1]); /* step 4 */ - for (i = i0 / 2 - 1; i < i1 / 2 + 1; i++) + for (i = (i0 >> 1) - 1; i < (i1 >> 1) + 1; i++) p[2 * i + 1] -= F_LFTG_GAMMA * (p[2 * i] + p[2 * i + 2]); /*step 5*/ - for (i = i0 / 2; i < i1 / 2 + 1; i++) + for (i = (i0 >> 1); i < (i1 >> 1) + 1; i++) p[2 * i] += F_LFTG_BETA * (p[2 * i - 1] + p[2 * i + 1]); /* step 6 */ - for (i = i0 / 2; i < i1 / 2; i++) + for (i = (i0 >> 1); i < (i1 >> 1); i++) p[2 * i + 1] += F_LFTG_ALPHA * (p[2 * i] + p[2 * i + 2]); } @@ -463,16 +463,16 @@ static void sr_1d97_int(int32_t *p, int i0, int i1) extend97_int(p, i0, i1); - for (i = i0 / 2 - 1; i < i1 / 2 + 2; i++) + for (i = (i0 >> 1) - 1; i < (i1 >> 1) + 2; i++) p[2 * i] -= (I_LFTG_DELTA * (p[2 * i - 1] + p[2 * i + 1]) + (1 << 15)) >> 16; /* step 4 */ - for (i = i0 / 2 - 1; i < i1 / 2 + 1; i++) + for (i = (i0 >> 1) - 1; i < (i1 >> 1) + 1; i++) p[2 * i + 1] -= (I_LFTG_GAMMA * (p[2 * i] + p[2 * i + 2]) + (1 << 15)) >> 16; /*step 5*/ - for (i = i0 / 2; i < i1 / 2 + 1; i++) + for (i = (i0 >> 1); i < (i1 >> 1) + 1; i++) p[2 * i] += (I_LFTG_BETA * (p[2 * i - 1] + p[2 * i + 1]) + (1 << 15)) >> 16; /* step 6 */ - for (i = i0 / 2; i < i1 / 2; i++) + for (i = (i0 >> 1); i < (i1 >> 1); i++) p[2 * i + 1] += (I_LFTG_ALPHA * (p[2 * i] + p[2 * i + 2]) + (1 << 15)) >> 16; } |