Allow multiple QSV encoders, usefull for live + recorded parallel
sessions. The first QSV encoder will create a DirectX device and return
a handle / pointer. Any additional QSV encoder will use that same
pointer to the DirectX device. We keep track of the number of open
QSV encoders so that we wait to close the DirectX resources after all
encoders are closed.
Closesobsproject/obs-studio#1341
Use a d3d9 device and allocator to encode in QSV.
This fixes a random crash that could only happen on Windows 7. The QSV
Deviced returned a DEVICE_FAILURE after a random amount of time with the
old method.
This fix is totally based on Shinck's QSVHelper.exe patch for OBS
Classic (see
https://obsproject.com/forum/threads/0-633b-qsvhelper-exe-was-killed-encode-failed.19230/page-3#post-161984
for more information)
This is more like a proof of concept, but that fix is currently stable
and tested more than 50 hours, with a single session of +14 hours.
That commit doesn't respect all OBS Guidelines. It is currently
recommended to wait for a more "cleaner" implementation.
