I doubt this'll be greatly relevant, but there's a program called xpra that runs a headless X server and redirects it. They've got a few performance tricks mentioned if I remember rightly, so maybe it'd be worth a quick look under the hood, if only for some fresh ideas. <div class="gmail_quote">On Jan 11, 2013 10:55 PM, "Stirling Westrup" <<a href="mailto:swestrup@gmail.com">swestrup@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> I'm currently prototyping a new video source to add to my application. I've been asked to implement an X session as a source. However, I'm getting strangely inconsistent results from tests of ximagesrc. When I first gave this a try last last November, just to see if it was feasible, I used gst-launch-1.0 to make a test pipeline that read from one X session and wrote to another. It was *really* sluggish in performance, enough so that I reported to my boss that it looked unlikely to work. A few weeks later I had a free afternoon on my hand, and tried again, and THIS time I had no problems and was even able to capture a playing YouTube video and display it on another screen without any noticeable lag or delays. Alas, I did not keep a record of what the pipeline I fed to gst-launch actually looked like, because I can't reproduce this result. Right now I'm trying to get a working test pipeline so I know what to implement, and I can't get decent performance. No idea what I am doing different this time. My command line is: gst-launch-1.0 ximagesrc display-name=":1" ! videoconvert ! "video/x-raw,framerate=(fraction)25/1,pixel-aspect-ratio=(fraction)1/2,format=(string)I420" ! xvimagesink display=":2" No idea why this is so slow, when the same machine can decode a 4K video and display it on four monitors simultaneously without problem. Anyway, does anyone have any suggestions as to what I could try to get this working faster? -- Stirling Westrup Programmer, Entrepreneur. <a href="https://www.linkedin.com/e/fpf/77228" target="_blank">https://www.linkedin.com/e/fpf/77228</a> <a href="http://www.linkedin.com/in/swestrup" target="_blank">http://www.linkedin.com/in/swestrup</a> <a href="http://technaut.livejournal.com" target="_blank">http://technaut.livejournal.com</a> <a href="http://sourceforge.net/users/stirlingwestrup" target="_blank">http://sourceforge.net/users/stirlingwestrup</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </blockquote></div>