[jpsdr]

That's why i've said "i think". I should have said "what's seems".
The a0fc63d patch is the following :

Code:

+  /* Only allow slice threading, since frame threading is more
+   * sensitive to changes in frame sizes, and it causes crashes
+   * during HW accell */
+  m_pCodecContext->thread_type = FF_THREAD_SLICE;

Well, maybe it could "simply" be changed by :

Code:

if ("dxva is enabled") {m_pCodecContext->thread_type = FF_THREAD_SLICE;} else {m_pCodecContext->thread_type = "value wich allow frame threading";}

As i said, it seems easy, but you're the devs, not me. I don't know, how difficult it can be to get the "dxva enabled" information in this part of the code.

Of course, if this part of the code is called only once at the startup of XBMC, it's not good because change in settings will not be taken in, but if this part of the code is called each time a file is played (at the init of DVDPlayer), well, at first glance i don't realy see any trouble.
I'm using the "-mt" version maruchan build since it's been posted, and have encounter any problem in all the files i've played for now (i've dxva disabled of course).