[Kwintv] Re: OpenGL view mode and a new threading solution

[Dirk Ziegelmeier]

On Saturday 05 June 2004 17:02, Koos Vriezen wrote:
> I have nvidia, so I could try. I just compiled it, but I can't find the
> OpenGL output driver. Where is it, what should I do?
Look in the configure options of the V4L plugin. Be aware of crashes when 
switching the view mode :-(

> > Another solution for the threading problems in kdetv may be a
> > "XInitThreads()" call in main.cpp. It works fine, only OpenGL freezes at
> > widget creation. Also, I found many places in the net where problems with
> > this call are described; even Qt does not call it by default. Does anyone
> > have experience with it?
>
> I use it in kxineplayer (kdeextragear-2/kmplayer/src/xineplayer.cpp).
> According to XInitThreads man page, it only works if all threads use the
> X(Un)LockDisplay and not some other mutex for accessing the display. (which
> also means that the grabber thread and Qt still excluding each other
> accessing the display) What are exactly the "threading problems" btw.
The ones you fixed. I don't like the usage of the Qt lib mutex, because all 
QDialog::exec() calls block video display due to recursive acquisition of the 
Qt lib mutex (there are still a few remaining). And the shutdown of the V4L 
plugin is quite a hack. When I use XInitThreads(), it looks like I do not 
need XLockDisplay(), the app seems to work just fine (as long as I don't 
create Qt events from the other thread). Only OpenGL has problems.

Dirk