From 96b71a6ec509023c892aaf9e7597ed0accbafb32 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Sun, 2 Jun 2013 22:18:29 +0200
Subject: [PATCH] avcodec/jpeg2000dwt: merge rescaling with interleave in 9/7
float IDWT
10% faster
Reviewed-by: Nicolas BERTRAND <nicoinattendu@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
libavcodec/jpeg2000dwt.c | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)
diff --git a/libavcodec/jpeg2000dwt.c b/libavcodec/jpeg2000dwt.c
index 7e82a56f192..13712d97030 100644
--- a/libavcodec/jpeg2000dwt.c
+++ b/libavcodec/jpeg2000dwt.c
@@ -359,13 +359,6 @@ static void sr_1d97_float(float *p, int i0, int i1)
extend97_float(p, i0, i1);
- /*step 1*/
- for (i = i0 / 2 - 1; i < i1 / 2 + 2; i++)
- p[2 * i] *= F_LFTG_K;
- /* step 2*/
- for (i = i0 / 2 - 2; i < i1 / 2 + 2; i++)
- p[2 * i + 1] *= F_LFTG_X;
- /* step 3*/
for (i = i0 / 2 - 1; i < i1 / 2 + 2; i++)
p[2 * i] -= F_LFTG_DELTA * (p[2 * i - 1] + p[2 * i + 1]);
/* step 4 */
@@ -401,9 +394,9 @@ static void dwt_decode97_float(DWTContext *s, float *t)
int i, j = 0;
// copy with interleaving
for (i = mh; i < lh; i += 2, j++)
- l[i] = data[w * lp + j];
+ l[i] = data[w * lp + j] * F_LFTG_K;
for (i = 1 - mh; i < lh; i += 2, j++)
- l[i] = data[w * lp + j];
+ l[i] = data[w * lp + j] * F_LFTG_X;
sr_1d97_float(line, mh, mh + lh);
@@ -417,9 +410,9 @@ static void dwt_decode97_float(DWTContext *s, float *t)
int i, j = 0;
// copy with interleaving
for (i = mv; i < lv; i += 2, j++)
- l[i] = data[w * j + lp];
+ l[i] = data[w * j + lp] * F_LFTG_K;
for (i = 1 - mv; i < lv; i += 2, j++)
- l[i] = data[w * j + lp];
+ l[i] = data[w * j + lp] * F_LFTG_X;
sr_1d97_float(line, mv, mv + lv);
--
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