Video capture cards are a class of video capture devices designed to plug directly into expansion slots in personal computers and servers. Models from many manufacturers are available; all comply with one of the popular host bus standards including
PCI, newer
PCI Express (PCIe) or
AGP bus interfaces. These cards typically include one or more
software drivers to expose the cards' features, via various
operating systems, to software applications that further process the video for specific purposes. As a class, the cards are used to capture baseband analog
composite video,
S-Video, and, in models equipped with tuners,
RF modulated video. Some specialized cards support digital video via digital video delivery standards including
serial digital interface (SDI) and, more recently, the emerging
HDMI standard. These models often support both standard definition (SD) and
high definition (HD) variants. While most PCI and PCI-Express capture devices are dedicated to that purpose, AGP capture devices are usually included with the graphics adapted on the board as an all-in-one package. Unlike
video editing cards, these cards tend to not have dedicated hardware for processing video beyond the
analog-to-digital conversion. Most, but not all, video capture cards also support one or more channels of audio. New technologies allow PCI-Express and HD-SDI to be implemented on video capture cards at lower costs than before. An early example is the
Mass Microsystems Colorspace FX card from 1989.
Applications There are many applications for video capture cards, including converting a live analog source into some type of analog or digital media, (such as
VHS-to-
DVD conversion), archiving, video editing, scheduled recording (such as a
DVR), television tuning, or video surveillance. The cards may have significantly different designs to optimally support each of these functions. A common application of capture cards is making a recording of a
video game longplay (LP) for purposes such as
gameplay walkthrough videos. Another of the most popular applications for video capture cards is to capture video and audio for live Internet video streaming. The live stream can also be simultaneously archived and formatted for
video on demand (VOD). The capture cards used for this purpose are typically purchased, installed, and configured in host PC systems by hobbyists or systems integrators. Some care is required to select suitable host systems for video encoding, particularly
HD applications which are more affected by
CPU performance, number of
CPU cores, and certain
motherboard characteristics that heavily influence capture performance. == Fall in popularity ==