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authorStefano Sabatini <stefasab@gmail.com>2011-10-31 11:32:11 +0100
committerStefano Sabatini <stefasab@gmail.com>2011-11-02 21:44:13 +0100
commit0b3e9d5dc61bb705d93db1e87d78d8d5131905c6 (patch)
tree2678dcc81060e2275393530d298bd7050adedb42 /libavfilter/vf_overlay.c
parent91dfb7385271b5fb18b0b4fddfbcf934c6cb6954 (diff)
vf_overlay: adopts FAST_DIV255 macro for calculating destination alpha
Ease readability, improve exactness.
Diffstat (limited to 'libavfilter/vf_overlay.c')
-rw-r--r--libavfilter/vf_overlay.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/libavfilter/vf_overlay.c b/libavfilter/vf_overlay.c
index 06967c2db5..6fa10aec8e 100644
--- a/libavfilter/vf_overlay.c
+++ b/libavfilter/vf_overlay.c
@@ -452,7 +452,8 @@ static void blend_slice(AVFilterContext *ctx,
alpha = (alpha_v + alpha_h) >> 1;
} else
alpha = a[0];
- *d = (*d * (0xff - alpha) + *s++ * alpha + 128) >> 8;
+ *d = FAST_DIV255(*d * (255 - alpha) + *s * alpha);
+ s++;
d++;
a += 1 << hsub;
}