libfreenect2 0.4
Open source driver for the Kinect for Windows v2 (K4W2) sensor
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Kinect v1 versus Kinect v2

Table of Contents

This library drives the Kinect for Windows v2 only. If you have an Xbox 360 Kinect or a Kinect for Windows v1, nothing here will work for you — use libfreenect instead.

The two sensors share a brand and almost nothing else. They use different depth-sensing physics, different USB generations, different wire protocols, different resolutions, and different units. This page exists because the confusion is common and because a great deal of Kinect material online — much of it from 2011 — describes v1 without saying so.

Which one do you have?

The quickest check is physical: the v2 requires a separate AC power adapter and has a bulky powered USB 3.0 adapter brick. A v1 for Xbox 360 has a tilt motor in its base and audibly whirrs when it moves; the v2 base is fixed.

By USB ID:

Sensor Vendor:Product
Kinect v2 (K4W2, Xbox One) 045e:02c4, 045e:02d8, 045e:02d9
Kinect v1 (Xbox 360) — motor 045e:02b0
Kinect v1 (Xbox 360) — audio 045e:02ad
lsusb | grep 045e # Linux
system_profiler SPUSBDataType # macOS: look for "Xbox NUI Sensor"

The v2 IDs are the ones this project's udev rules match (platform/linux/udev/90-kinect2.rules). If none of the v2 IDs appear but a v1 ID does, you are in the wrong repository.

The v1 also enumerates as three separate USB devices behind an internal hub (camera, motor, audio); the v2 presents one device with two interface associations. See Kinect v2 USB protocol for the v2 topology.

How they differ

Kinect v1 Kinect v2
Depth principle Structured light — an 830 nm laser projects a fixed speckle pattern; depth comes from pattern distortion Time of flight — amplitude-modulated IR; depth comes from phase
Depth output 11-bit disparity, needs conversion to metric float millimeters, directly usable
Depth resolution 640×480 (rightmost 8 columns always invalid) 512×424
Invalid pixel 2047 0 (also non-positive, NaN, infinity)
IR output 640×488 512×424 float, range [0, 65535]
Color output 640×480 Bayer at 30 Hz, or 1280×1024 at 15 Hz 1920×1080, JPEG on the wire, BGRX/RGBX decoded
Color and IR together Impossible — one isochronous stream, one mode Both stream simultaneously
Field of view 58° H × 45° V ≈70° H × 60° V
Usable range 0.8–3.5 m 0.5–4.5 m
USB 2.0 3.0 SuperSpeed, required
Power From USB, plus adapter for Xbox models Dedicated AC adapter, mandatory
Tilt motor Yes, ±31° No
Accelerometer Yes (KXSD9) Not exposed
Status LED Yes, 7 fixed colors/patterns Yes, 2 LEDs, intensity 0–1000, constant or blink
Microphones 4, with firmware upload and hardware noise cancellation 4, not supported by this library — see Frequently asked questions

The v2 field of view is approximate: it is not reported by the device, but follows from the factory IR intrinsics, where a typical fx near 365 over a 512×424 image gives roughly 70° × 60°.

Why v1 answers mislead

Search results for "Kinect depth" skew heavily toward v1. These are the specific things that do not carry over:

  • Disparity conversion formulas. Expressions like 100/(-0.00307 * d + 3.33) or 0.1236 * tan(d/2842.5 + 1.1863) convert v1's raw 11-bit disparity to distance. The v2 reports millimeters directly; running depth values through these produces nonsense.
  • The 2047 sentinel. On v2, invalid pixels are 0. Testing for 2047 silently keeps bad data and discards good data.
  • Tilt and LED control transfers. The v1 control transfers for tilt (0x40 0x31), LED (0x40 0x06), and the 10-byte accelerometer report do not exist on v2. The v2 has no motor at all; its LED interface is a completely different command. See Kinect v2 USB protocol.
  • freenect_* API names. freenect_sync_get_depth(), freenect_set_tilt_degs(), FREENECT_LOG_SPEW and friends belong to libfreenect. This library's API is C++ and namespaced libfreenect2::.
  • Interference between two sensors. Two v1 sensors degrade each other by overlaying speckle patterns; advice about polarization tricks addresses that mechanism. Two v2 sensors interact differently, because the failure mode is modulated-light interference rather than pattern confusion.
  • USB 2.0 packet arithmetic. Figures like "242 packets of 1760 bytes per depth frame" describe v1's isochronous framing. The v2's framing is in Kinect v2 USB protocol.
  • Sensor part numbers. The MT9M001 / MT9V112 imagers, the PrimeSense PS1080, and the Marvell audio SoC are v1 hardware. The v2 shares none of them.

Provenance of this page

The v1 figures come from the OpenKinect project wiki, which documented libfreenect between 2010 and roughly 2012. That wiki lived at openkinect.org; the domain has since lapsed and now serves unrelated advertising — do not visit it expecting documentation. Archived copies remain reachable through the Internet Archive.

The v2 figures come from this repository's source and from the libfreenect2 wiki.

Next steps