On 07/21/2009 07:32 PM, Devin Heitmueller wrote:
I agree that *in theory* you should be able to do two devices. A back
of the envelope calculation of 640x480 at 30fps in YUVY capture should
be about 148Mbps. That said, I don't think the scenario you are
describing has really been tested/debugged previously. If I had to
guess, my suspicion would be a bug in the driver code that calculates
which USB alternate mode to operate in, which results in the driver
reserving more bandwidth than necessary.
I would have dig into the code and do some testing in order to have a
better idea where the problem is. Do you have a specific em28xx
product in mind that you intend to use?
Well in theory there's no difference between theory and practice,
but in practice there is (c:
More than happy to coordinate some testing of a variety of em28xx
devices we have handy around the office if it would help isolate any
bugs. We could throw some QA resource at the problem if nothing else.
One of the devices we're supposed to be able to acquire in bulk is
no-name brand that simply says "VC-211A" on the label. "lsusb" output
looks like this:
ID eb1a:2861 eMPIA Technology, Inc.
The other says "GrabBeeX+ deluxe" and has this identifier:
ID eb1a:2821 eMPIA Technology, Inc.
We have a 2-3 others on hand as well.
Once again, thanks for the responsiveness and please let me know
what we can do to contribute.
Cheers
Steve
--
Steve Castellotti
sc@xxxxxxxxxxxxx
Technical Director
Eyemagnet Limited
http://www.eyemagnet.com
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