thomas.fuchs@xxxxxxx wrote: > Hi, > > i want to create an application using bttv/video4linux > for my MiroPCTV, but one problem bothers me: > each time i move/resize the window containing the overlay > window, i must apply clipping. This creates some trash on the > screen. By reading the source of some other applications > (xawtv, kwintv), i've understood that by mapping/unmapping > a window i can remove this trash. This just does trigger a refresh of the screen (i.e. send expose to all visible windows). > This solution makes the handling > of X11 events quite complicated, and i am really clueless about > the "algorithm" to use for handling all the events (ConfigureNotify, > Expose, Visibility ...). All you _really_ need is SubStructureNotifyMask for the root window to track window clipping changes. Using VisibilityNotify for the video window allows to do some optimizations. The refresh (i.e. map/unmap that window) also does trigger some events which must be ignored to avoid a endless loop... This all is pretty standard X11 stuff. Keep in mind that X11 (without Xvideo) doesn't know anything about the video. Because the X11 protocol is asyncron xawtv is allways late in reconfiguing the grabber card, and that's why the screen refresh is needed. "xawtv -v 2" prints plenty of debug info to stderr ... Gerd -- Damn lot people confuse usability and eye-candy.
