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The xcomposite window capture crashes were due to a few factors: ------------------------------- 1.) The source's X error handler was possibly being overwritten by another part of the program despite us locking the display, presumably something in Qt which isn't locking the display when pushing/popping its own error handler (though this is not yet certain). The source's calls to X functions happen in the graphics thread, which is separate from the UI thread, and it was noticed that somehow the error handler would be overwritten almost seemingly at random, indicating that something else in the program outside of OBS code was not locking the display while pushing/popping the error handler. To replicate this, make it so that the source cannot find the target window and so it continually searches for it each video_tick call, then resize the main OBS window continually (which causes Qt to push/pop its own error handlers). A crash will almost always occur due to BadWindow despite our error handling. 2.) Calling X functions with a window ID that no longer exists, particularly XGetWindowAttributes, in conjunction the unknown error handler set in case #1 would cause the program to outright crash because that error handler is programmed to crash on BadWindow for whatever reason. The source would call X functions without even checking if 'win' was 0. 3.) The source stored window IDs (in JSON, even if they've long since become invalid/pointless, such as system restarts). This is a bad practice and will result in more cases of BadWindow. Fixing the problem (reducing the possibility of getting BadWindow): ------------------------------- Step 1.) Deprecate and ignore window IDs in stored settings. Instead of using window IDs to find the window, we now must always search the windows and find the target window via the window name exclusively. This helps ensure that we actually consistently have a working window ID. Step 2.) Do not call any X functions if the window ID is 0. Step 3.) Reset the window ID to 0 any time the window has updated, and make the source find the window again to ensure it still exists before attempting to use any X functions on the window ID again.
Linux XShm capture plugin This plugin uses the MIT-SHM extension for the X-server to capture the desktop. Todo: - handle resolution changes of screens - handle adding/removing screens while recording - support different depths Contributing: If you are interested in helping out with the plugin, please drop by in the #obs-dev channel on quakenet. References: - http://www.x.org/releases/current/doc/xextproto/shm.html