Am 22.09.2011 23:29, schrieb Pitt, Jason N:
I currently do not know if usbcore itself do not allow so many ISO frames, or only one controller can't handle it. Are there any system in this error? I mean do cams day on one controller or only one per controller? Regards, Alexey
It seems as if it is the usbcore itself, the 3 pcie cards I have
> are supposed to have 4 controllers per card and so I should have 1 camera
per controller....in the past I've found it is only possible to run two usb2 cameras per controller. The threshold really seems to be around 8 cameras.... is there a way I could decrease the bit depth to gray_scale to increase the throughput?
Short answer, no. Longer answer, if you have color image sensor, then it is probably bayer sensor. each pixel has only one color. There are different algorithms to reconstruct or predict what collor each pixel may have (demosaicing). So it looks like this: Image sensor -> Preprocessor (demosaicing)/ Bayer converted to YUV -> other processors (jpeg compression,...) -> usb -> pc
Currently i do not know any color camera which do Bayer to gray scale. But if you will find some camera what has 2 MP monochrome sensore, it will be really good :). You will get best quality will less data.
I only need gray_scale. Would decreasing the frame size help?
You can reduce frame rate, or frame size or use compressed stream, for example jpeg. But i have some doubt concerning this problem. If you use less cams from the start, do they work ok? I ask because, some webcams (like my logitech notebook pro) will freeze if you start and stop it before it start to send image. This web cam need about 10 seconds to start. So if you start your cam with interval of 2 seconds, then may be you triggered this bug.
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