File:GstPipAlpha.png

Picture in picture effect generated in gstreamer where the child picture is transparent. Pipeline:

gst-launch -e videotestsrc pattern="snow" ! video/x-raw-yuv, framerate=10/1, width=200, height=150 ! videobox border-alpha=0 alpha=0.6 top=-20 left=-25 ! \   videomixer name=mix ! ffmpegcolorspace ! xvimagesink videotestsrc ! video/x-raw-yuv, framerate=10/1, width=640, height=360 ! mix.