Re: Image-Data upload using SHM
Chris Wilson <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
On Thu, 20 Oct 2011 11:08:35 +0200, Clemens Eisserer <[email protected]> wrote: > Hi, > > I did some profiling of Firefox's html5 video element which uses > cairo, and the low performance I observed seems to be caused by not > using XShmPutImage for uploading video-data. > Instead, XPutImage is used - with xcb's 16kb buffer this results in > about ~25k cs/s, slowing my machine down to a crawl. > > Does cairo support using the XSHM extensions, or are there patches available? At the moment the most mature use of XSHM is exposed through cairo-xcb. The catch is that to avoid the copy, you need to decode the pixel data into the ShmSegment which needs application support and the use of cairo_surface_create_similar_image() or even cairo_surface_map_to_image(). Why is xcb not using a BigReq anyway? -Chris -- Chris Wilson, Intel Open Source Technology Centre -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo