Hello; ext Bin Chen wrote: > On Jan 10, 2008 4:26 PM, Tapani Pälli <[EMAIL PROTECTED]> wrote: > >> Hello; >> >> ext Bin Chen wrote: >> >>> Hello, >>> >>> I am running GTK+ in a singal machine, the machine is slow so I want >>> make GTK+ use XSHM extension to accelerate the drawing speed. >>> >>> By taking a look at both GTK+ source code and the MIT-SHM paper, my >>> conclusion is : >>> >>> 1) The XSHM can only support XImage and Pixmap. >>> >>> >> It is supporting the creation of XImage structure in shared memory and >> 'transferring' it to X-server to be used as a pixmap. >> >> >>> 2) The GTK+ engine update the image using XCopyArea, so its impossible >>> to accelerate the entire process. >>> >>> I am thinking a case, we do all the rendering process in GTK+ >>> side(such as use pango to render text, use other library to render >>> image), the transfer the rendered image to XServer using XSHM, then >>> draw this Image to the window. >>> >>> >>> >> SHM extension is made to 'accelerate' data transfer between X client and >> server when they reside on same machine. When data is on server end, it >> can be used and manipulated via Xlib commands such as XCopyArea and the >> operation is done on server side. Operation performance depends on the >> X-server driver implementation. >> >> >>> Will this work? >>> >>> >> Your usecase is valid, but are you facing some performance issues with >> current implementation? Have you profiled where the time is actually >> spent? You might want to create these buffers (images) beforehand and >> then transfer them to server. See also XRender API for rendering and >> manipulating buffers on server-side. >> >> > I am not doing very detailed profiling against this, but by comparing > the frame rate in my player against using pure framebuffer > implementation. The performance difference is large. If not using > shared memory to transfer the decoded image data, obviously the > performance can't be good in slow machine. >
You did not mention a 'player' before. Video playback is very much of a special case. Are you drawing/compositing other elements on top of video? If so, you are entering very experimental areas here. You might want to check out Xv extension which is available for video. I don't know much about video so I'll stop here, good luck :-) > The GTK+ can draw pixbuf and image to the drawable, is there any > existing method for me to choose to force the low level gdk to use SHM > extension? > > Thanks. > Bin > > // Tapani Pälli -- Software Engineer Open Source Software Operations _______________________________________________ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
