usbvc(7D) Devices usbvc(7D)
NAME
usbvc - USB video class driver
SYNOPSIS
#include <sys/usb/clients/video/usbvc/usbvc.h>
#include <sys/videodev2.h>
usbvc@unit-address
DESCRIPTION
The usbvc driver is a USBA (Solaris USB Architecture)-compliant client driver that supports the USB Device Class Definition for Video
Devices specification, Versions 1.0 and 1.1. The usbvc driver supports a subset of the video controls and formats described in the USB
specification.
The usbvc driver also implements the Video4Linux2 API (V4L2), Version 0.20 for applications. For more information on the V4L2 API, visit
http://www.thedirks.org/v4l2.
Note that the usbvc driver supports the video capture function only and that video output is not supported. For more information on sup-
ported USB video-class devices and functions, visit http://www.sun.com/io.
READING DATA
The usbvc driver reads video data from the isochronous endpoint of the device. Bulk data endpoints are not supported.
MJPEG and UNCOMPRESSED video formats are supported. Isochronous data are read from the isochronous input device frame-by-frame and are
maintained in a buffer array within the driver. Video frames are read from the driver using the read(2) or mmap(2) I/O method. For read(2),
each read returns a buffer of a video frame. For mmap(2), each VIDIOC_DQBUF ioctl returns the buffer structure v4l2_buffer. (A video frame
buffer pointer is included in the structure). See the V4L2 API for buffer structure and other related data structure information.
IOCTLS
A brief overview of supported ioctl requests appears below. For more detailed information, refer to the V4L2 API document. Note: ioctl
information presented in the V4L2 API document may differ slightly from the content of this manpage. In such cases, you should rely on the
information in this manpage.
VIDIOC_QUERYCAP
Query the device capabilities. Besides device capabilities, the usbvc driver returns structure v4l2_capability which includes informa-
tion on the driver, data bus and OS kernel. Please note that the "Version" structure member has no meaning in Solaris and is always set
to 1.
VIDIOC_ENUM_FMT
Enumerate the video formats supported by the device.
VIDIOC_S_FMT
Set a video format.
VIDIOC_G_FMT
Get a video format.
VIDIOC_REQBUFS
Request the usbvc driver to allocate video data buffers. If a buffer is set to zero, the driver stops reading video data from the
device and releases all allocated buffers. (For mmap(2) only).
VIDIOC_QUERYBUF
Query a given buffer's status. (For mmap(2) only).
VIDIOC_QBUF
Enqueue an empty buffer to the video data buffer array. (For mmap(2) only).
VIDIOC_DQBUF
Dequeue a done buffer from the video data buffer array. (For mmap(2) only).
VIDIOC_STREAMON
Start reading video data.
VIDIOC_STREAMOFF
Stop reading video data.
VIDIOC_ENUMINPUT
Enumerate all device inputs. Currently, the usbvc driver supports one input only.
VIDIOC_G_INPUT
Get the device's current input. At this time, the usbvc driver supports one input only.
VIDIOC_S_INPUT
Set the device's current input. At this time, the usbvc driver supports one input only.
VIDIOC_QUERYCTRL
Query the device and driver for supported video controls. Currently, the usbvc driver supports the brightness, contrast, saturation,
hue, and gamma video controls.
VIDIOC_G_CTRL
Get the device's current video control.
VIDIOC_S_CTRL
Set the device's current video control.
VIDIOC_G_PARM
Get streaming parameters, the number of frames per second and number of buffers used internally by driver in read/write mode.
VIDIOC_S_PARM
Set streaming parameters, the number of frames per second and number of buffers used internally by driver in read/write mode.
ERRORS
EBUSY An open was attempted after the device has already been opened.
EINVAL An unsupported ioctl is received or an ioctl is attempted with an out-of-range value.
EIO The driver received an unrecoverable device error or the device did not respond or the device stalled when attempting an access.
A read(2) or ioctl(2) did not complete due to a peripheral access.
ENXIO The driver received an open(2) request for a device for which the attach failed.
ENODEV The driver received an open(2) request for a disconnected device.
FILES
/kernel/drv/usbvc
32-bit ELF kernel module. (x86)
/kernel/drv/amd64/usbvc
64-bit ELF kernel module. (x86)
/kernel/drv/sparcv9/usbvc
64-bit ELF kernel module. (SPARC)
/dev/usb/*/*/*
ugen(7D) nodes.
/dev/videoN
Device node for isochronous input from USB video device and device control.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-------------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-------------------------------+
|Architecture | SPARC, x86, PCI-based systems |
+-----------------------------+-------------------------------+
|Availability |SUNWusbvc |
+-----------------------------+-------------------------------+
SEE ALSO
cfgadm_usb(1M), ioctl(2), open(2), mmap(2), read(2), libusb(3LIB), attributes(5),ugen(7D), usba(7D), attach(9E)
Writing Device Drivers
System Administration Guide: Basic Administration
Universal Serial Bus Specification 1.0, 1.1 and 2.0-- 1996, 1998, 2000
USB Device Class Definition for Video Devices 1.0 and 1.1-- 2003, 2005
Video4Linux2 API (V4L2), Version 0.20
I/O Technologies and Solutions --http://www.sun.com/io
http://docs.sun.com
http://www.usb.org
http://www.thedirks.org/v4l2
DIAGNOSTICS
In addition to being logged, the following messages may appear on the system console. All messages are formatted in the following man-
ner:
Warning: <device path> (usbvc<instance num>):Error Message...
Device was disconnected while open. Data may have been lost.
The device has been hot-removed or powered off while it was open and a possible data transfer was in progress. The job may be aborted.
Cannot access <device>. Please reconnect.
This device has been disconnected because a device other than the original one has been inserted. The driver informs you of this fact
by displaying the name of the original device.
Device is not identical to the previous one on this port. Please disconnect and reconnect.
The device was hot-removed while open. A new device was hot-inserted which is not identical to the original device. Please disconnect
the device and reconnect the original device to the same port.
NOTES
The USB video device will be power-managed when the device is idle.
If a USB video device is hot-removed while active, a console warning is displayed requesting you to put the device back in the same port
and telling you of potential data loss. Hot-removal of an active video device is strongly discouraged.
Always close all applications before hot-removing or hot-inserting a device. If an application is open when a device is hot-removed,
inserting the device in a different port will create new /dev/videoN links. Moving an active device to another port is not recom-
mended.
SunOS 5.11 18 July 2008 usbvc(7D)