[vlc-devel] [PATCH 2/2] Added windowless support to linux

Rémi Denis-Courmont remi at remlab.net
Tue Nov 20 12:06:03 CET 2012


On Mon, 19 Nov 2012 23:29:10 +0200, "Rémi Denis-Courmont"
<remi at remlab.net>
> Converting systematically to RV32 is CPU-intensive. And XCreateImage()
> will copy every frame a second time. And XPutImage() will copy it
> another two times over the socket.
> If I get this right, this patch causes every frame to be copied three
> times more than previously (four times instead of one). This does not
> seem like a good idea at all.

Just to be clear, normally, we have zero copies in VLC, and one copy in
the X server (from the shared memory segment to the frame buffer).

With this patch, we have one conversion in VLC to RV32 (which is copy, but
worse), one copy in XCreateImage(), one kernel copy in the socket send of
XPutImage() and one more kernel copy in the socket receive of the X server.
And then, I suspect the X server will copy once more like it normally
would. Performance will be TERRIBLE.

As far as I understand the concept of window-less plugins, VLC should
render directly in the drawable/pixmap, with the normal optimized X11
output plugins. The rendering logic should not be in the Mozilla plugin.

Rémi Denis-Courmont
Sent from my collocated server

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