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why is it just one kinect per USB host?

asked 2013-04-30 03:00:59 -0500

dinamex gravatar image

updated 2016-10-24 09:01:11 -0500

ngrennan gravatar image

Due to definition a USB 2.0 host offers a max Bandwidth of 36 to 40MB/s.

A kinect: (source from openkinect) There are 242 packets for one frame for the depth camera together with the header packets. All data packets are of 1760 bytes size. That results in 12672000 bytes/sec for 30 frames per second. The RGB camera needs 162 packets for one frame -> 9216000 bytes/sec for 30fps.

Which sums up tor 21MB/s for rgb and ir stream.

Do I miss something or why is it not possible to use another device beside the Kinect (in 640x480 and not even in 320x240)?

hope someone can show me what I miss.

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There is probably also some overhead. But isn't it an advice to use one kinect per host? Perhaps it is possible but not recommended.

davinci gravatar image davinci  ( 2013-04-30 03:40:32 -0500 )edit

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answered 2013-04-30 04:10:04 -0500

Philip gravatar image

I don't know if I understood your question correctly. To my knowledge, it is possible to use a Kinect and (one or more) additional device such as mouse, keyboard etc. on the same USB host; at least I've never heard otherwise. If a Kinect is the only connected device, though, you can be sure that no other device can interfere in any way. Which is probably why many people use it this way.

However, it is not possible to use more than one Kinect at the same USB host due to the required bandwidth (even when lowering the resolution as the bandwidth is negotiated when the device is plugged in). For technical details, see also this answer.

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Asked: 2013-04-30 03:00:59 -0500

Seen: 2,090 times

Last updated: Apr 30 '13