How to set transparency

[kususe]

How do you code the part of pipeline to fix the transparency
(sink_1::alpha=0.7)?

"gst-launch-0.10 filesrc location=/home/boss/Scrivania/test_dc/geo.png !
pngdec ! imagefreeze ! ffmpegcolorspace ! videomixer name=mix
sink_1::alpha=0.7 ! ffmpegcolorspace ! xvimagesink filesrc
location=video.webm ! matroskademux ! vp8dec ! mix. 

I tried using alpha element, but it doesn't work. 
I tried to use videoboxelement but the transparency setted up with alpha
doesn't work. 
I tried saving a transparent image, but it doesn't work. 

Have you got any suggestion?
Thanks in advance, 
K.




--
View this message in context: http://gstreamer-devel.966125.n4.nabble.com/How-to-set-transparency-tp4529144p4529144.html
Sent from the GStreamer-devel mailing list archive at Nabble.com.