Editing Video4Linux (section)

{{Short description|Device drivers for real-time video capture}}
{{Infobox software
| name                   = Video4Linux
| title                  = Video4Linux
| logo                   = <!-- Image name is enough -->
| logo caption           = 
| logo_size              = 
| logo_alt               = 
| screenshot             = <!-- Image name is enough -->
| caption                = 
| screenshot_size        = 
| screenshot_alt         = 
| collapsible            = 
| author                 = 
| developer              = 
| released               = <!-- {{Start date and age|YYYY|MM|DD|df=yes/no}} -->
| discontinued           = 
| latest release version = 
| latest release date    = <!-- {{Start date and age|YYYY|MM|DD|df=yes/no}} -->
| latest preview version = 
| latest preview date    = <!-- {{Start date and age|YYYY|MM|DD|df=yes/no}} -->
| frequently updated     = <!-- DO NOT include this parameter unless you know what it does -->
| programming language   = [[C (programming language)|C]]
| operating system       = [[Linux]]
| platform               = [[Linux kernel]]
| size                   = 
| language               = 
| language count         = <!-- DO NOT include this parameter unless you know what it does -->
| language footnote      = 
| genre                  = 
| repo                   = {{URL|https://git.linuxtv.org/v4l-utils.git}} 
| license                = [[GNU General Public License]]
| website                = {{URL|http://www.linuxtv.org/}}
}}
'''Video4Linux''' ('''V4L''' for short) is a collection of [[device driver]]s and an [[application programming interface|API]] for supporting realtime [[video capture]] on [[Linux]] systems.<ref>{{cite web |url=https://fosdem.org/2014/schedule/event/v4l_intro/ |title=An Introduction to the Video4Linux Framework: How to write a video capture driver |date=2014-02-02 |access-date=2014-02-16}}</ref> It supports [[USB]] [[webcam]]s, [[TV tuner card|TV tuners]], [[Camera Serial Interface|CSI]] cameras, and related devices, standardizing their output, so programmers can easily add video support to their applications.

Video4Linux is responsible for creating V4L2 device nodes aka a device file (/dev/videoX, /dev/vbiX and /dev/radioX) and tracking data from these nodes. The device node creation is handled by V4L device drivers using the video_device struct (v4l2-dev.h) and it can either be allocated dynamically or embedded in another larger struct.

Video4Linux was named after [[Video for Windows]] (which is sometimes abbreviated "V4W"), but is not technically related to it.<ref>{{cite web |url=https://www.kernel.org/doc/Documentation/video4linux/v4l2-framework.txt |title=Overview of the V4L2 driver framework |access-date=2013-12-04 |url-status=dead |archive-url=https://web.archive.org/web/20140221165356/https://www.kernel.org/doc/Documentation/video4linux/v4l2-framework.txt |archive-date=2014-02-21 }} Overview of the V4L2 driver framework.</ref><ref>{{cite web| url=https://events.linuxfoundation.org/images/stories/pdf/lceu2012_debski.pdfVideo4Linux2 | title=Path to a Standardized Video Codec API |archive-url=https://web.archive.org/web/20140106032317/https://events.linuxfoundation.org/images/stories/pdf/lceu2012_debski.pdf |archive-date=2014-01-06 }}</ref>

While Video4Linux is only available on Linux, there is a compatibility layer available for [[FreeBSD]] called Video4BSD. This provides a way for many programs that depend on V4L to also compile and run on the FreeBSD operating system.