Frame rate drops considerably when lens obscured about libfreenect

[bwhite]

I believe this is because the device reinitializes when this happens.

[mattrobertwhelan]

Is that what this error message means?

[Stream 70] Inconsistent flag fa with 0 packets in buf (242 total), resyncing...

[zarvox]

If you look closely, the IR projector turns off during the brief hang. It's possible that this is a safety feature - the laser projector is probably eye-safe at a decent distance, but without dispersal, it could potentially be dangerous, especially with eyes and glasses focusing the beams.

It'd be nice if someone can verify this behavior on an Xbox360, if nothing else, to show that it's not our problem.

[marcan]

Exactly, the device shuts down the depth stream when the image has less than one fourth or so valid pixels. There may be a way to switch this off, but if there is, we don't know about it.

[zarvox]

Looks like it's done by setting register 0x0105 to 0.

The relevant pull request is issue #143.

[zarvox]

Disable the IR/depth restart-on-dark "feature"

The Kinect cycles the IR projector when it can't find the IR pattern in
the image. This causes the depth stream to hang during the restart,
which is annoying. This patch disables that feature.

Closed by 1543f93.

Signed-off-by: Drew Fisher <[email protected]> (zarvox)