With this commit preliminary audio support in VirtualBox is enabled.
The backend supports playback as well as recording sounds from within
a guest VM. Depending on how the guest configures the device model
the audio output may sound disorted. If the guest uses buffers that
are too small, i.e., 10 ms or less, frequent buffer underruns will
occure.
To get this low-latency one has also to increase vbox' update hz
to 200 (i.e., 5ms).
Fixes#1647.
The information about connected devices is obtained from a ROM file named
'usb_devices', which is supposed to contain a device list as in the device
report generated by the USB driver (see issue #1506).
A policy for 'report_rom' would look like:
<policy label="vbox -> usb_devices" report="usb_drv -> devices"/>
If the 'usb_devices' ROM file is not available, a warning message gets
printed and VirtualBox continues without USB pass-through support.
The devices to be passed-through need to have a matching device filter in
the '.vbox' file. Example:
<USB>
<DeviceFilters>
<DeviceFilter name="USB Scanner" active="true" vendorId="04a9"
productId="2220" remote="0"/>
</DeviceFilters>
</USB>
The feature was tested with HID devices (mouse, keyboard) and a flatbed
scanner. Mass storage devices didn't work correctly (they also didn't work
with VirtualBox on Linux without the closed-source extension pack).
It should be made sure that the USB driver does not try to control the
devices to be passed-through itself, for example, when passing-through
a HID device, the '<hid/>' config option should not be set.
Fixes#1507
This commit enables the VirtualBox graphics adapter, provides guest mouse
pointer integration with Nitpicker using the 'vbox_pointer' application
and enhances the VirtualBox run scripts with the configuration of
Nitpicker, input merger and network driver.
Fixes#1474
