<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd"><html><head><meta name="qrichtext" content="1" /><style type="text/css">p, li { white-space: pre-wrap; }</style></head><body style=" font-family:'DejaVu Sans'; font-size:9pt; font-weight:400; font-style:normal;"> Hi, I have two videos: 1 - An animated "title" text video (letters moving around with a complex schema) with a black background. 2 - Another video taken with a camera Using libpigment, I tried to put the video 1 over video 2 but the black background of titles is not transparent and covers the second video. If I try to change alpha value on the whole video the black will be mixed with the second video making it darker. Is it possible to make transparent a only part of the video with a specific color (the black on the first video in my case)? -- megabug</body></html>