michon@ATHENA.MIT.EDU (02/06/91)
>Does anybody have any information regarding the use of X windows (v11) and >multi-media conferencing? I'm particulary interested in the X interface, and >the ability to map bitmap images (such as digitized pictures, video etc) to a >Sun workstation screen. I've build the following: -Brian Michon XDither is a tool that digitizes video images into dithered bitonal X11 bitmap format files. A floyd-steinberg dither with edge enhancement produces a good quality rendering. XDither also provides a way for users to display video frames as bitonal images on standard monochrome X workstations. A live video source, fed into a video workstation, can be digitized and dithered into an XImage structure for transmission on internet. XMIT is an application that uses XDither to view motion video on monochrome X workstations. XMIT is highly optimized for digitizing video on the Parallax 1280 video sub-system. XLib's getPixel and putPixel routines are replaced with routines that cheat X by taking advantage of the fact the they know the format of the video buffer. XMIT can transmits images as dithered bitonal images or grey scale images. The image transmission is submitted as an X workproc and runs in the background of an X session. Using a DecStation 3100 as a remote display, a microVAXII and Parallax 1280 as a frame grabber, and, transmitting images over MIT's internet, XMIT delivers grey scale video images (whose linear dimensions are scaled by 1/4) at a rates up to 12-15 frames per second.