From 3c88249d48870b826fd89d287ee6d46b284c4f45 Mon Sep 17 00:00:00 2001
From: Edward Hervey <bilboed@bilboed.com>
Date: Tue, 30 Jun 2009 12:40:02 +0200
Subject: videomixer: I420 blending : Fix main algorithm.

When blending a source layer with an alpha of 'a' on top of another
destination layer we take the sum of:
* 'a' percent of the source layer
* (100 - 'a') percent of the destination layer (the remainder)
---
 gst/videomixer/blend_i420.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'gst/videomixer')

diff --git a/gst/videomixer/blend_i420.c b/gst/videomixer/blend_i420.c
index 8d7399bc..e24d0ad4 100644
--- a/gst/videomixer/blend_i420.c
+++ b/gst/videomixer/blend_i420.c
@@ -192,7 +192,7 @@ gst_i420_do_blend (guint8 * src, guint8 * dest,
   int i, j;
   for (i = 0; i < src_height; i++) {
     for (j = 0; j < src_width; j++) {
-      *dest = src_alpha * (*dest) + (1. - src_alpha) * (*src);
+      *dest = src_alpha * (*src) + (1. - src_alpha) * (*dest);
       dest++;
       src++;
     }
-- 
cgit