Windows: Add isochronous support for libusbK and WinUSB

[piedar]

@JoshBlake proposed this patch to libusbx, but it was never merged. A cherry-pick still applies cleanly to libusb HEAD.

git clone https://github.com/libusb/libusb.git
cd libusb
git remote add jblake https://github.com/JoshBlake/libusbx.git
git fetch jblake
git cherry-pick c5b0af4 1c74211

I tested the patch and it appears to work with libusbK v3.0.7.0. Any chance this can be merged into libusb? It would make libfreenect a lot easier to build on Windows by replacing our emulation layer that is woefully out of date.

[jjqq2013]

from Windows 8.1, WinUSB also support isochronous mode. Hope this be implemented in future.

[mcuee]

It will be good to add WinUSB isoc support (directly to libusb WIndows backend or through libusbK). Travis mentioned he intended to add WinUSB isoc support to libusbK recently but I am not so sure when he will start that work.

[mcuee]

Another option is to look at usbdk backend which has not yet been integrated.

https://github.com/dmitryfleytman/libusb/tree/usbdk-backend-v3

[mkassner]

https://github.com/ktossell/libuvc would finally work on windows if isochronous transfers where to be implemented with winusb8.1: libuvc/libuvc#12

Any chance for this to happen in the near future?

[xlz]

@mcuee
What is the plan now?
Is the usbdk backend favored over the libusbk patch? WinUSB? What about Windows 7 users?

[mcuee]

Not sure when this support will be added to Windows backend which is now lagging behind Linux and Mac OS X (isoc support and hotplug support). It depends on the time and priority of the main Windows developer now. BTW, usbdk works under Windows 7.

[diabolo38]

with new Microsoft policy on driver signing i'm scared no new libusbk release will ever happen.
So usbdk and winusb seam the only possible candidate to enhance support on windows.

I will not be able to participate actively on development but i can participate and provide some punctual help with testing on win 7 (uvc cam, gadget 0 target) and bus level debug if needed.

[xlz]

I just tested usbdk. It failed to enumerate Kinect v2 sensor (no other tests could follow). It also has some incomplete support for important features daynix/UsbDk#10, which is specially required by libfreenect2.

The isochronous patch for libusbK backend just works, and has been extensively tested. What is the reason not to merge it?