Oracle VM VirtualBox includes a feature called webcam passthrough, which enables a guest to use a host webcam. This complements the general USB passthrough support which was the typical way of using host webcams in legacy releases. The webcam passthrough support can handle non-USB video sources in theory, but this is completely untested.
The webcam passthrough module is shipped as part of the Oracle VM VirtualBox extension pack, which must be installed separately. See Installing Oracle VM VirtualBox and Extension Packs.
The host webcam can be attached to the VM using the Devices menu in the VM menu bar. The Webcams menu contains a list of available video input devices on the host. Clicking on a webcam name attaches or detaches the corresponding host device.
The VBoxManage command line tool can be used to enable webcam passthrough. Please see the host-specific sections below for additional details. The following commands are available:
Get a list of host webcams, or other video input devices:
$ VBoxManage list webcams
The output format is as follows:
alias "user friendly name" host path or identifier
The alias can be used as a shortcut in other commands. Alias '.0' means the default video input device on the host. Alias '.1', '.2'means first, second video input device, and so on. The device order is host-specific.
Attach a webcam to a running VM, as follows:
VBoxManage controlvm
VM name
webcam attach [host_path
|alias
[settings
]]This attaches a USB webcam device to the guest.
The
settings
parameter is a stringSetting1=Value1;Setting2=Value2
, which enables you to configure the emulated webcam device. The following settings are supported:MaxFramerate
: The highest rate at which video frames are sent to the guest. A higher frame rate requires more CPU power. Therefore sometimes it is useful to set a lower limit. Default is no limit and allow the guest to use all frame rates supported by the host webcam.MaxPayloadTransferSize
: How many bytes the emulated webcam can send to the guest at a time. Default value is 3060 bytes, which is used by some webcams. Higher values can slightly reduce CPU load, if the guest is able to use larger buffers. However, a highMaxPayloadTransferSize
might be not supported by some guests.
Detach a webcam from a running VM, as follows:
VBoxManage controlvm
VM-name
webcam detach [host_path
|alias
]List the webcams attached to a running VM, as follows:
VBoxManage controlvm
VM-name
webcam listThe output contains the path or alias which was used in the webcam attach command for each attached webcam.
When the webcam device is detached from the host, the emulated webcam device is automatically detached from the guest.
Mac OS X version 10.9 or later is required.
When the webcam device is detached from the host, the emulated
webcam device remains attached to the guest and must be manually
detached using the VBoxManage controlvm
VM-name
webcam detach
command.
When the webcam is detached from the host the emulated webcam
device is automatically detached from the guest only if the
webcam is streaming video. If the emulated webcam is inactive it
should be manually detached using the VBoxManage
controlvm VM-name
webcam
detach command.
Aliases .0
and .1
are
mapped to /dev/video0
, alias
.2
is mapped to
/dev/video1
and so forth.