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A digital video recorder (DVR), sometimes referred to by the merchandising term personal video recorder (PVR), is a consumer electronics
Consumer electronics
Consumer electronics are electronic equipment intended for everyday use, most often in entertainment, communications and office productivity. Radio broadcasting in the early 20th century brought the first major consumer product, the broadcast receiver...

 device or application software
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...

 that records video in a digital format to a disk drive, USB flash drive
USB flash drive
A flash drive is a data storage device that consists of flash memory with an integrated Universal Serial Bus interface. flash drives are typically removable and rewritable, and physically much smaller than a floppy disk. Most weigh less than 30 g...

, SD memory card
Memory card
A memory card or flash card is an electronic flash memory data storage device used for storing digital information. They are commonly used in many electronic devices, including digital cameras, mobile phones, laptop computers, MP3 players, and video game consoles...

 or other local or networked mass storage
Mass storage
In computing, mass storage refers to the storage of large amounts of data in a persisting and machine-readable fashion. Devices and/or systems that have been described as mass storage include tape libraries, RAID systems, hard disk drives, magnetic tape drives, optical disc drives, magneto-optical...

 device. The term includes set-top box
Set-top box
A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...

es (STB) with direct to disk recording
Direct to Disk Recording
Direct-to-disk recording refers to methods by which analog signals and digital signals such as digital audio and digital video are digitally recorded to optical disc recording technologies such as DVDs, and CD optical discs...

  facility, portable media players (PMP) with recording, recorders (PMR) as camcorder
Camcorder
A camcorder is an electronic device that combines a video camera and a video recorder into one unit. Equipment manufacturers do not seem to have strict guidelines for the term usage...

s that record onto Secure Digital
Secure Digital
Secure Digital is a non-volatile memory card format developed by the SD Card Association for use in portable devices. The SD technology is used by more than 400 brands across dozens of product categories and more than 8,000 models, and is considered the de-facto industry standard.Secure Digital...

 memory cards and software for personal computers which enables video capture
Video capture
Video capture is the process of converting an analog video signal—such as that produced by a video camera or DVD player—to digital video. The resulting digital data are computer files referred to as a digital video stream, or more often, simply video stream...

 and playback to and from a hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...

. A television set
Television set
A television set is a device that combines a tuner, display, and speakers for the purpose of viewing television. Television sets became a popular consumer product after the Second World War, using vacuum tubes and cathode ray tube displays...

 with built-in digital video-recording facilities was introduced by LG
LG Group
LG Corp. is the second-largest South Korean conglomerate company following Samsung, and it is headquartered in the LG Twin Towers in Yeouido-dong, Yeongdeungpo-gu, Seoul. LG produces electronics, chemicals, and telecommunications products and operates subsidiaries like LG Electronics, LG Display,...

 in 2007, followed by other manufacturers.

DVR adoption has rapidly accelerated in recent years: in January 2006, ACNielsen
ACNielsen
ACNielsen is a global marketing research firm, with worldwide headquarters in New York City. Regional headquarters for North America are located in Schaumburg, Illinois. As of May 2010, it is part of The Nielsen Company.-History:...

 recorded 1.2% of U.S. households having a DVR but by February 2011, this number had grown to 42.2% of viewers in the United States.

Hard-disk based digital video recorders



Consumer digital video recorders ReplayTV
ReplayTV
ReplayTV is a brand of digital video recorder , a term synonymous with personal video recorder . It is a consumer video device which allows users to capture television programming to internal hard disk storage for later viewing...

 and TiVo
TiVo
TiVo is a digital video recorder developed and marketed by TiVo, Inc. and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs, whose features include "Season Pass" schedules which record every new episode of a series, and "WishList"...

 were launched at the 1999 Consumer Electronics Show
Consumer Electronics Show
The International Consumer Electronics Show is a major technology-related trade show held each January in the Las Vegas Convention Center, Las Vegas, Nevada, United States. Not open to the public, the Consumer Electronics Association-sponsored show typically hosts previews of products and new...

 in Las Vegas
Las Vegas, Nevada
Las Vegas is the most populous city in the U.S. state of Nevada and is also the county seat of Clark County, Nevada. Las Vegas is an internationally renowned major resort city for gambling, shopping, and fine dining. The city bills itself as The Entertainment Capital of the World, and is famous...

, USA. Microsoft also demonstrated a unit with DVR capability, but this did not become available until the end of 1999 for full DVR features in Dish Network's DISHplayer receivers. TiVo shipped their first units on March 31, 1999. ReplayTV won the "Best of Show" award in the video category with Netscape
Netscape
Netscape Communications is a US computer services company, best known for Netscape Navigator, its web browser. When it was an independent company, its headquarters were in Mountain View, California...

 co-founder Marc Andreessen
Marc Andreessen
Marc Andreessen is an American entrepreneur, investor, software engineer, and multi-millionaire best known as co-author of Mosaic, the first widely-used web browser, and co-founder of Netscape Communications Corporation. He founded and later sold the software company Opsware to Hewlett-Packard...

 as an early investor and board member, but TiVo was more successful commercially. While early legal action by media companies forced ReplayTV to remove many features such as automatic commercial skip and the sharing of recordings over the Internet, newer devices have steadily regained these functions while adding complementary abilities, such as recording onto DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

s and programming and remote control facilities using PDAs, networked PCs, and Web browsers.

Hard-disk based digital video recorders make the "time shifting
Time shifting
Time shifting is the recording of programming to a storage medium to be viewed or listened to at a time more convenient to the consumer. Typically, this refers to TV programming but can also refer to radio shows via podcasts....

" feature (traditionally done by a VCR) much more convenient, and also allow for "trick modes" such as pausing live TV, instant replay of interesting scenes, chasing playback
Chase Play
Chase Play is a timeshifting facility of DVD-RAM DVD recorders and many Personal video recorders.It allows a user to simultaneously watch, stop or pause live television while continuing to record a program to its conclusion....

 where a recording can be viewed before it has been completed, and skipping of advertising
Advertising
Advertising is a form of communication used to persuade an audience to take some action with respect to products, ideas, or services. Most commonly, the desired result is to drive consumer behavior with respect to a commercial offering, although political and ideological advertising is also common...

. Most DVRs use the MPEG format for compressing the digitized video signals.

Video recording capabilities have become an essential part of the modern set-top box
Set-top box
A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...

, as TV viewers have wanted to take control of their viewing experiences. As consumers have been able to converge increasing amounts of video content on their set-tops, delivered by traditional ‘broadcast
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...

’ [ Cable, Satellite and terrestrial] as well as IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...

 networks, the ability to capture programming and view it whenever they want has become a must-have function for many consumers.

Digital video recorders tied to a video service

At the 1999 CES, Dish Network demonstrated the hardware that would later have DVR capability with the assistance of Microsoft software. which also included WebTV Networks internet TV. By the end of 1999 the Dishplayer had full DVR capabilities and within a year, over 200,000 units were sold.

In the UK, digital video recorders are often referred to as "plus boxes" (such as BSKYB's Sky+
Sky+
Sky+, or Sky Plus, is a personal video recorder service for Sky in the UK. Launched in September 2001, it allows the user to record, pause and instantly rewind live TV. The system performs these functions using an internal hard drive inside the Sky+ set top box...

 and Virgin Media's V+ which integrates an HD
High-definition television
High-definition television is video that has resolution substantially higher than that of traditional television systems . HDTV has one or two million pixels per frame, roughly five times that of SD...

 capability, and the subscription free Freesat+
Freesat+
Freesat+ is a consumer brand created to raise consumer awareness and promote sales of Freesat-capable digital TV recorders, otherwise known as personal video recorders...

 and Freeview+
Freeview+
Freeview+ and Freeview+ HD is a consumer brand created in the UK by DTV Services Ltd to "raise consumer awareness and promote sales" of Freeview capable digital TV recorders otherwise known as personal video recorders...

). British Sky Broadcasting markets a popular combined EPG
Electronic program guide
Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming...

 and DVR as Sky+
Sky+
Sky+, or Sky Plus, is a personal video recorder service for Sky in the UK. Launched in September 2001, it allows the user to record, pause and instantly rewind live TV. The system performs these functions using an internal hard drive inside the Sky+ set top box...

. TiVo
TiVo
TiVo is a digital video recorder developed and marketed by TiVo, Inc. and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs, whose features include "Season Pass" schedules which record every new episode of a series, and "WishList"...

 launched a UK model in 2000, and while no longer on sale, the subscription service is still maintained. South African based Africa Satellite TV beamer Multichoice recently launched their DVR which is available on their Dstv platform. In addition to ReplayTV and TiVo, there are a number of other suppliers of digital terrestrial (DTT
Digital terrestrial television
Digital terrestrial television is the technological evolution of broadcast television and advance from analog television, which broadcasts land-based signals...

) DVRs, including Thomson, Topfield
Topfield
Established in Korea in 1998, TOPFIELD Co., Ltd. is a consumer electronics manufacturer making broadcasting receivers, other video and audio related apparatus. Their main business is making products such as set top boxes and personal video recorders to be used with satellite television or...

, Fusion, Pace Micro Technology, Humax
Humax
Humax is an electronics company. Founded in South Korea in 1989, it manufactures set-top boxes, digital video recorders and other consumer electronics. It is publicly traded on KOSDAQ....

, AC Ryan Playon and Advanced Digital Broadcast
Advanced Digital Broadcast
Advanced Digital Broadcast designs, manufactures and deploys solutions to distribute pay-TV and multimedia services to the connected home, for all types of networks. The company has its global headquarters in Geneva, Switzerland and regional headquarters in Denver, USA and Taipei, Taiwan...

 (ADB).

Many satellite, cable and IPTV
IPTV
Internet Protocol television is a system through which television services are delivered using the Internet protocol suite over a packet-switched network such as the Internet, instead of being delivered through traditional terrestrial, satellite signal, and cable television formats.IPTV services...

 companies are incorporating digital video recording functions into their set-top box
Set-top box
A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...

, such as with DirecTiVo, DISHPlayer/DishDVR, Scientific Atlanta Explorer 8xxx
Explorer 8300
The Explorer 8300 is a digital video recorder manufactured by Scientific Atlanta and used by many digital cable companies. It works like a regular cable box with DVR capabilities and features an 80, 160 or 320 GB PATA internal hard drive. Some versions can also be used with an external SATA hard...

 from Time Warner, Total Home DVR from AT&T U-verse
U-Verse
AT&T U-verse is a registered service mark under which AT&T offers Internet access, television, and telephone services in various parts of the United States. It began in 2008 to serve mostly residences and small businesses in urban and suburban areas.-Services:...

, Motorola 6412
Motorola 6412
The Motorola DCT6412 is a dual tuner HDTV DVR deployed by the following companies:**Adelphia Communications**Armstrong Cable***Bresnan Communications*Brighthouse Networks*Buckeye Cablesystem*Cablevision*Cable One*Charter Communications**Cogeco...

 from Comcast and others, Moxi
Moxi
Moxi is a line of high definition Digital Video Recorders produced by ARRIS Group, Inc. Moxi was originally released only to cable operators but in December 2008 was released as a retail product to the general public. The current retail product, the Moxi HD DVR, provides a high definition user...

 Media Center by Digeo (available through Charter, Adelphia, Sunflower, Bend Broadband, and soon Comcast and other cable companies), or Sky+. Astro introduced their DVR system, called Astro MAX
Astro MAX
Astro MAX was a personal video recorder service for Astro launched in July 2006. It marked the first PVR system ever to be introduced in Malaysia, though LG's PVR-integrated Time Machine TV introduced later that year...

, which was the first PVR in Malaysia. Sadly, it was phased out two years after its introduction.

In the case of digital television, there is no encoding necessary in the DVR since the signal is already a digitally encoded MPEG stream. The digital video recorder simply stores the digital stream directly to disk. Having the broadcaster involved with, and sometimes subsidizing, the design of the DVR can lead to features such as the ability to use interactive TV on recorded shows, pre-loading of programs, or directly recording encrypted digital streams. It can, however, also force the manufacturer to implement non-skippable advertisements and automatically expiring recordings.

In the United States, the FCC has ruled that starting on July 1, 2007, consumers will be able to purchase a set-top box from a third-party company, rather than being forced to purchase or rent the set-top box from their cable company.
This ruling only applies to "navigation devices," otherwise known as a cable television set-top box, and not to the security functions that control the user’s access to the content of the cable operator. The overall net effect on digital video recorders and related technology is unlikely to be substantial as standalone DVRs are currently readily available on the open market.

Introduction of dual tuners


In 2003 many Satellite and Cable providers introduced dual-tuner digital video recorders. In the UK, BSkyB introduced their first PVR Sky+
Sky+
Sky+, or Sky Plus, is a personal video recorder service for Sky in the UK. Launched in September 2001, it allows the user to record, pause and instantly rewind live TV. The system performs these functions using an internal hard drive inside the Sky+ set top box...

 with dual tuner support in 2001. These machines have two independent tuners within the same receiver. The main use for this feature is the capability to record a live program while watching another live program simultaneously or to record two programs at the same time, possibly while watching a previously recorded one. Kogan Technologies
Kogan Technologies
Kogan Technologies is an Australian manufacturer and retailer of consumer electronics devices. The company, founded in 2006 by Ruslan Kogan, sells products direct from Asia to customers in Australia and the United Kingdom....

 introduced a dual-tuner PVR in the Australian market allowing free-to-air television to be recorded on a removable hard drive. Some dual-tuner DVRs also have the ability to output to two separate television sets at the same time. The PVR manufactured by UEC (Durban
Durban
Durban is the largest city in the South African province of KwaZulu-Natal and the third largest city in South Africa. It forms part of the eThekwini metropolitan municipality. Durban is famous for being the busiest port in South Africa. It is also seen as one of the major centres of tourism...

, South Africa) and used by Multichoice
MultiChoice
MultiChoice is a South African company which operates the DStv satellite television service, the main satellite TV service in Sub-Saharan Africa. It was formed out of the subscriber-management branch of the M-Net terrestrial pay TV company, and broadcasts the full range of M-Net channels on the...

 and Scientific Atlanta 8300DVB PVR have the ability to view two programs while recording a third using a triple tuner.

Where several digital subchannel
Digital subchannel
In broadcasting, digital subchannels are a means to transmit more than one independent program at the same time from the same digital radio or digital television station on the same radio frequency channel. This is done by using data compression techniques to reduce the size of each individual...

s are transmitted on a single RF channel, some PVRs can record two channels and view a third, so long as all three subchannels are on two channels (or one).

In the United States, DVRs were used by 32 percent of all TV households in 2009, and 38 percent by 2010, with viewership among 18- to 40-year-olds 40 percent higher in homes that have them.

Integrated TV-set digital video recorders


Digital video recorders are often integrated in the LCD and LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....

 TV-sets. These systems let the user simplify the wiring and installation, because they do not use ports (SCART
SCART
SCART is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment together...

 or HDMI
HDMI
HDMI is a compact audio/video interface for transmitting uncompressed digital data. It is a digital alternative to consumer analog standards, such as radio frequency coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, or VGA...

), and they only need to use only one device and power and the same remote control
Remote control
A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...

 instead of two.

There are examples of security systems integrated into such DVRs, and thus they are capable of recording more input streams in parallel. Some of them include wireless ports such as (Bluetooth
Bluetooth
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...

 and WiFi
WIFI
WIFI is a radio station broadcasting a brokered format. Licensed to Florence, New Jersey, USA, the station is currently operated by Florence Broadcasting Partners, LLC.This station was previously owned by Real Life Broadcasting...

), so they can play and record files to or from cellular phones and other devices. Such devices can also be used as disguised observation systems, displaying pictures or videos as typical store display.

VESA Compatible digital video recorders


VESA
VESA
VESA is an international standards body for computer graphics founded in 1989 by NEC Home Electronics and eight other video display adapter manufacturers.VESA's initial goal was to produce a standard for 800×600 SVGA resolution video displays...

 compatible DVR are designed small and light enough to mount to the back of an LCD monitor that has clear access to VESA mounting holes (100x100mm). This allows users to use their own personal monitor to save on cost and space.

PC-based digital video recorders


Software and hardware is available which can turn personal computers running Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

, Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, and Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

 into DVRs, and is a popular option for home-theater PC (HTPC) enthusiasts.

NAS DVR


An increasing number of Pay-TV operators are offering their subscribers the ability to create their own digital recording platform capable of storing video, audio, photos, etc. These customizable hardware and software platforms enable subscribers to attach their own NAS (Network Attached Storage
Network-attached storage
Network-attached storage is file-level computer data storage connected to a computer network providing data access to heterogeneous clients. NAS not only operates as a file server, but is specialized for this task either by its hardware, software, or configuration of those elements...

) hard drives or solid state/flash memory to set-tops which do not have their own internal storage. This minimizes an operator’s investment, while offering subscribers the flexibility to create a digital recording solution that meets their specific requirements.

One such product is DVR-Lite(™), a vertically integrated hardware and software platform from Advanced Digital Broadcast
Advanced Digital Broadcast
Advanced Digital Broadcast designs, manufactures and deploys solutions to distribute pay-TV and multimedia services to the connected home, for all types of networks. The company has its global headquarters in Geneva, Switzerland and regional headquarters in Denver, USA and Taipei, Taiwan...

, available on its Set-Back Box
Set-Back Box
The term set-back box is used in the digital TV industry to describe a piece of consumer hardware that enables them to access both linear broadcast and internet-based video content, plus a range of interactive services like Electronic Programme Guides , Pay Per View and Video on Demand as well...

, which allows external storage to added by subscribers.

Linux


There are many free DVR applications available for Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, each released as free
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

 and open source software under the GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

:
  • MythTV
    MythTV
    MythTV is a free and open source home entertainment application with a simplified "10-foot user interface" design for the living-room TV, and turns a computer with the necessary hardware into a network streaming digital video recorder, a digital multimedia home entertainment system, or home theater...

  • VDR
    Video Disk Recorder
    VDR is an open source application for Linux designed to allow any computer to function as a digital video recorder, in order to record and replay TV programming using the computer's hard drive. The computer needs to be equipped with a digital TV tuner card. VDR can also operate as an mp3 player...

  • LinuxMCE
    LinuxMCE
    LinuxMCE is a free and open source software platform with a 10-foot user interface designed to allow a computer to act as a home theater PC for the living-room TV, personal video recorder, and home automation system. It allows control of everything in the home, from lighting and climate to...

  • Freevo


A commercial and proprietary
Proprietary software
Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...

 application called SageTV
SageTV
SageTV Media Center was a proprietary, commercial DVR and HTPC software for Mac OS X, Windows and Linux. It requires that the host computer have a hardware based TV tuner card. The SageTV software has an integrated Electronic Programming Guide that is updated via the Internet...

 is available for most popular Linux distributions.

Mac OS


Elgato
Elgato
ElgatoSystems is a hardware and software manufacturer that makes television viewing and recording products specifically for the Macintosh family of personal computers, including EyeTV software...

 makes a series of digital video recording devices called EyeTV. The software supplied with each device is also called EyeTV, and is available separately for use on compatible third-party tuners from manufacturers such as Pinnacle, TerraTec, and Hauppauge.

SageTV
SageTV
SageTV Media Center was a proprietary, commercial DVR and HTPC software for Mac OS X, Windows and Linux. It requires that the host computer have a hardware based TV tuner card. The SageTV software has an integrated Electronic Programming Guide that is updated via the Internet...

 provided DVR software for the Mac but no longer sells it. Previously sold devices support the Hauppauge HVR-950, myTV.PVR and HDHomeRun hardware with its DVR software. SageTV
SageTV
SageTV Media Center was a proprietary, commercial DVR and HTPC software for Mac OS X, Windows and Linux. It requires that the host computer have a hardware based TV tuner card. The SageTV software has an integrated Electronic Programming Guide that is updated via the Internet...

 software also included the ability to watch YouTube and other online video with a remote control.

MythTV
MythTV
MythTV is a free and open source home entertainment application with a simplified "10-foot user interface" design for the living-room TV, and turns a computer with the necessary hardware into a network streaming digital video recorder, a digital multimedia home entertainment system, or home theater...

 (see above) also runs under Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

, but most recording devices are currently only supported under Linux. Precompiled binaries are available for the MythTV front-end, allowing a Mac to watch video from (and control) a MythTV server running under Linux.

Apple provides applications in the FireWire software developer kit which allow any Mac with a FireWire port to record the MPEG2 transport stream from a FireWire equipped cable box (for example: Motorola 62xx, including HD streams). Applications can also change channels on the cable box via the firewire interface. Only broadcast channels can be recorded as the rest of the channels are encrypted. FireRecord (formerly iRecord) is a free scheduled-recording program derived from this SDK.

Windows


There are several free digital video recording applications available for Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

 Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 including GB-PVR
GB-PVR
GB-PVR is a PVR application, running on Microsoft Windows, whose main function is scheduling TV recordings and playing back live TV. This PVR also acts as a home media center with a digital video recorder, a radio station online tuner, a music and movie player, a library of images and other...

, MediaPortal
MediaPortal
MediaPortal is an open-source media center software project, often considered an alternative to Windows Media Center. It provides a 10-foot user interface for performing typical PVR/TiVo functionality, including playing, pausing, and recording live TV; playing DVDs, videos, and music; viewing...

, and Orb
Orb (software)
Orb is freeware streaming software that enables users to remotely access all their personal digital media files including pictures, music, videos, webcams and television...

 (web-based remote interface).

There are also several commercial
Proprietary software
Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...

 applications available including CyberLink
CyberLink
CyberLink is a digital entertainment and multimedia products software corporation. CyberLink's 2008 revenue was $140 million with market capitalization of $420 million. Cyberlink's headquarters are based in Taipei, Taiwan with worldwide offices in Fremont, USA; Tokyo, Japan; and the Netherlands...

, SageTV
SageTV
SageTV Media Center was a proprietary, commercial DVR and HTPC software for Mac OS X, Windows and Linux. It requires that the host computer have a hardware based TV tuner card. The SageTV software has an integrated Electronic Programming Guide that is updated via the Internet...

, Beyond TV, Showshifter
ShowShifter
ShowShifter is widely regarded as the original Media Center/10 foot UI/HTPC software application but is no longer commercially available. It is notable in that it was the first publicly downloadable software to attempt to do this and as such defined this market for years to come...

, InterVideo WinDVR
InterVideo WinDVR
InterVideo WinDVR was a commercial digital video recorder software package for Windows operating systems. It lets you watch and record TV shows on the PC by allowing it to work as a TV set and a DVR at the same time. It requires that the host PC have a hardware based TV turner card...

, the R5000-HD and Meedio
Meedio
Meedio is a company that made a media center software with the same name, and was acquired by Yahoo! in 2006. The new software is named ....

 (now a dead product - Yahoo! bought most of the company's technology and discontinued the Meedio line, and rebranded the software Yahoo! Go - TV, which is now a free product but only works in the U.S.). Most TV tuner card
TV tuner card
A TV tuner card is a kind of television tuner that allows television signals to be received by a computer. Most TV tuners also function as video capture cards, allowing them to record television programs onto a hard disk much like the Tivo digital video recorder does.-Variants: The interfaces for...

s come bundled with software which allows the PC to record television to hard disk. For example, Leadtek
Leadtek
Leadtek Research, Inc. is a Taiwanese company, founded in 1986, which focuses on research and development that is specialized in the design and manufacture of graphics cards.- Products :...

's WinFast DTV1000 digital TV card comes bundled with the WinFast PVR2 software, which can also record analog video from the card's composite video
Composite video
Composite video is the format of an analog television signal before it is combined with a sound signal and modulated onto an RF carrier. In contrast to component video it contains all required video information, including colors in a single line-level signal...

 input socket.

Windows Media Center
Windows Media Center
Windows Media Center is a digital video recorder and media player developed by Microsoft. It is an application that allows users to view and record live television, as well as organize and play music and videos...

 is a DVR software by Microsoft bundled with the Media Center edition of Windows XP
Windows XP Media Center Edition
Windows XP Media Center Edition is a version of the Windows XP operating system designed to serve as a home-entertainment hub. The last version, Windows XP Media Center Edition 2005, was released in October 2004.-Versions:...

, the Home Premium / Ultimate editions of Windows Vista
Windows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...

, as well as most editions of Windows 7.

Source video


Television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...

 and video
Video
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...

 are terms that are sometimes used interchangeably, but differ in their technical meaning. Video is the visual portion of television, whereas television is the combination of video and audio modulated
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

 onto a carrier frequency
Carrier wave
In telecommunications, a carrier wave or carrier is a waveform that is modulated with an input signal for the purpose of conveying information. This carrier wave is usually a much higher frequency than the input signal...

 (i.e., a television channel) for delivery. Most DVRs can record both.

Analog sources overview


The first digital video recorders were designed to record Analog television
Analog television
Analog television is the analog transmission that involves the broadcasting of encoded analog audio and analog video signal: one in which the message conveyed by the broadcast signal is a function of deliberate variations in the amplitude and/or frequency of the signal...

 in NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...

, PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...

 or SECAM
SECAM
SECAM, also written SÉCAM , is an analog color television system first used in France....

 formats.

To record an analog signal a few steps are required. TV tuner card
TV tuner card
A TV tuner card is a kind of television tuner that allows television signals to be received by a computer. Most TV tuners also function as video capture cards, allowing them to record television programs onto a hard disk much like the Tivo digital video recorder does.-Variants: The interfaces for...

 tunes
Tuner (radio)
A radio tuner is a subsystem that receives radio broadcasts and converts them into audio-frequency signals which can be fed into an amplifier driving a loudspeaker. FM tuner, AM tuner, Digital Audio Broadcasting DAB tuner, etc. are types of radio tuner dealing with transmissions using different...

 into a particular frequency and then functions as a frame grabber
Frame grabber
A frame grabber is an electronic device that captures individual, digital still frames from an analog video signal or a digital video stream. It is usually employed as a component of a computer vision system, in which video frames are captured in digital form and then displayed, stored or...

, breaking the lines into individual pixels and quantizing
Quantization (signal processing)
Quantization, in mathematics and digital signal processing, is the process of mapping a large set of input values to a smaller set – such as rounding values to some unit of precision. A device or algorithmic function that performs quantization is called a quantizer. The error introduced by...

 them into a format that a computer can comprehend. Then the series of frames along with the audio (also sampled and quantized) are compressed into a manageable format, like MPEG-2
MPEG-2
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...

, usually in software.

Analog broadcast copy protection


Many mass-produced consumer DVRs implement a copy-protection system called CGMS-A
CGMS-A
Copy Generation Management System - Analog is a copy protection mechanism for analog television signals. It consists of a waveform inserted into the non-picture Vertical Blanking Interval of an analogue video signal...

 or Copy Generation Management System—Analog. This encodes a pair of bits in the VBI of the analog video signal that specify one of the following settings:
  • Copying is freely allowed
  • Copying is prohibited
  • Only one copy of this material may be made
  • This is a copy of material for which only one copy was allowed to be made, so no further copies are allowed.


CGMS-A information may be present in analog broadcast TV signals, and is preserved when the signal is recorded and played back by analog VCRs, which of course don't understand the meanings of the bits. But the restrictions still come into effect when you try to copy the tape onto a PVR.

DVRs such as Tivo also detect and act upon analogue protection systems such as Macrovision
Macrovision
Rovi Corporation is a globally operating, US-based company that provides guidance technology, entertainment data, copy protection, industry standard networking and media management technology for digital entertainment devices and services...

 and DCS Copy Protection
DCS Copy Protection
DCS Copy Protection Ltd is a UK company that licenses proprietary content protection technology. It is a direct competitor to Rovi in the field of analogue copy protection....

 which were originally designed to block copying on analog VCRs.

Digital sources overview


Recording digital signals is generally a straightforward capture of the binary MPEG data being received. No expensive hardware is required to quantize
Quantization (signal processing)
Quantization, in mathematics and digital signal processing, is the process of mapping a large set of input values to a smaller set – such as rounding values to some unit of precision. A device or algorithmic function that performs quantization is called a quantizer. The error introduced by...

 and compress the signal (as the television broadcaster
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...

 has already done this in the studio).

DVD-based PVRs available on the market as of 2006 are not capable of capturing the full range of the visual signal available with high definition television (HDTV). This is largely because HDTV standards were finalized at a later time than the standards for DVDs. However, DVD-based PVRs can still be used (albeit at reduced visual quality) with HDTV since currently available HDTV sets also have standard A/V connections.

ATSC broadcast


ATSC
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....

 television broadcasting is primarily used in North America. The ATSC
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....

 data stream can be directly recorded by a digital video recorder, though many DVRs record only a subset of this information (that can later be transferred to DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

. An ATSC DVR will also act as a Set-top box
Set-top box
A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...

, allowing older televisions or monitors to receive digital television.
Copy protection

The U.S. FCC
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...

 attempted to limit the abilities of DVRs with its "broadcast flag
Broadcast flag
A broadcast flag is a set of status bits sent in the data stream of a digital television program that indicates whether or not the data stream can be recorded, or if there are any restrictions on recorded content...

" regulation. Digital video recorders that had not won prior approval from the FCC for implementing "effective" digital rights management
Digital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...

 would have been banned from interstate commerce from July 2005, but the regulation was struck down on May 6, 2005.

DVB


DVB Digital television
Digital television
Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...

 contains audio/visual signals that are broadcast over the air in a digital
Digital
A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...

 rather than analog format. The DVB data stream can be directly recorded by the DVR. Autonomous devices (this is, that can be used without a computer/tablet) that can store in an external hard disk are called a telememory.

Digital cable and satellite television


Recording satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 or digital cable
Digital cable
Digital cable is a generic term for any type of cable television distribution using digital video compression or distribution. The technology was originally developed by Motorola.-Background:...

 signals on a digital video recorder can be more complex than recording analog signals or broadcast digital signals. There are several different transmission schemes, and the video streams may be encrypted to restrict access to subscribers only.

A satellite or cable set-top box
Set-top box
A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...

 both decrypts the signal if encrypted, and decodes the MPEG stream into an analog signal for viewing on the television. In order to record cable or satellite digital signals the signal must be captured after it has been decrypted but before it is decoded; this is how DVRs built into set-top boxes work.

Cable and satellite providers often offer their own digital video recorders along with a service plan. These DVRs have access to the encrypted video stream, and generally enforce the provider's restrictions on copying of material even after recording.

DVD


Many DVD-based DVRs have the capability to copy content from a source DVD (ripping
Ripping
Ripping is the process of copying audio or video content to a hard disk, typically from removable media. The word is used to refer to all forms of media. Despite the name, neither the media nor the data is damaged after extraction....

).

In the U.S. this is prohibited under the Digital Millennium Copyright Act
Digital Millennium Copyright Act
The Digital Millennium Copyright Act is a United States copyright law that implements two 1996 treaties of the World Intellectual Property Organization . It criminalizes production and dissemination of technology, devices, or services intended to circumvent measures that control access to...

 if the disc is encrypted. Most such DVRs will hence not allow recording of video streams from encrypted movie discs.

Digital camcorders


A digital camcorder
Camcorder
A camcorder is an electronic device that combines a video camera and a video recorder into one unit. Equipment manufacturers do not seem to have strict guidelines for the term usage...

 combines a camera and a digital video recorder.

Some DVD-based DVRs incorporate connectors that can be used to capture digital video from a camcorder. Some editing of the resulting DVD is usually possible, such as adding chapter points.

Some digital video recorders can now record to solid state flash memory cards (called flash camcorders). They generally use Secure Digital
Secure Digital
Secure Digital is a non-volatile memory card format developed by the SD Card Association for use in portable devices. The SD technology is used by more than 400 brands across dozens of product categories and more than 8,000 models, and is considered the de-facto industry standard.Secure Digital...

 cards, can include wireless connections (Bluetooth
Bluetooth
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...

 and Wi-Fi
Wi-Fi
Wi-Fi or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, or digital audio player, can connect to the Internet via a wireless network access point. An access point has a range of about 20...

), and can play SWF
SWF
SWF is an Adobe Flash file format used for multimedia, vector graphics and ActionScript. Originating with FutureWave Software, then transferred to Macromedia, and then coming under the control of Adobe, SWF files can contain animations or applets of varying degrees of interactivity and function.,...

 files. There are some digital video recorders that combine video and graphics in real time to the flash card, called DTE
DTE (Direct To Edit)
DTE is a digital video direct-to-disk recording method used to streamline the post-production video editing workflow of raw video files into a Non-linear editing system .-See also:* Computer file...

 or "direct to edit". These are used to speed-up the editing workflow in video and television production, since linear videotapes do not then need to be transferred to the edit workstation (see Non-linear editing system
Non-linear editing system
In video, a non-linear editing system is a video editing or audio editing digital audio workstation system which can perform random access non-destructive editing on the source material...

).

File formats, resolutions and file systems


DVRs can usually record and play H.264
H.264/MPEG-4 AVC
H.264/MPEG-4 Part 10 or AVC is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video...

, MPEG-4 Part 2
MPEG-4 Part 2
MPEG-4 Part 2, MPEG-4 Visual is a video compression technology developed by MPEG. It belongs to the MPEG-4 ISO/IEC standards. It is a discrete cosine transform compression standard, similar to previous standards such as MPEG-1 and MPEG-2...

, MPEG-2
MPEG-2
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...

 .mpg, MPEG-2
MPEG-2
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...

 .TS, VOB
VOB
A VOB file is a container format in DVD-Video media. VOB can contain video, audio, subtitle, menu and navigation contents multiplexed together into a stream form. VOB is based on the MPEG program stream format, but with additional limitations and specifications in the private streams...

 and ISO image
ISO image
An ISO image is an archive file of an optical disc, composed of the data contents of every written sector of an optical disc, including the optical disc file system...

s video, with MP3
MP3
MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...

 and AC3 audio tracks. They can also display images (JPEG
JPEG
In computing, JPEG . The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality....

 and PNG) and play music files (MP3
MP3
MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...

 and Ogg
Ogg
Ogg is a free, open container format maintained by the Xiph.Org Foundation. The creators of the Ogg format state that it is unrestricted by software patents and is designed to provide for efficient streaming and manipulation of high quality digital multimedia.The Ogg container format can multiplex...

).

Some devices can be updated
Firmware
In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...

 to play and record in new formats.

Recordings from standard-definition television
Standard-definition television
Sorete-definition television is a television system that uses a resolution that is not considered to be either enhanced-definition television or high-definition television . The term is usually used in reference to digital television, in particular when broadcasting at the same resolution as...

 usually have 480p/i/576p/i while HDTV is usually in 720p/1080i.

DVRs usually record in proprietary filesystems for copy protection
Copy protection
Copy protection, also known as content protection, copy obstruction, copy prevention and copy restriction, refer to techniques used for preventing the reproduction of software, films, music, and other media, usually for copyright reasons.- Terminology :Media corporations have always used the term...

, although some can use FAT
File Allocation Table
File Allocation Table is a computer file system architecture now widely used on many computer systems and most memory cards, such as those used with digital cameras. FAT file systems are commonly found on floppy disks, flash memory cards, digital cameras, and many other portable devices because of...

 filesystems.

Security


Digital video recorders configured for physical security
Physical security
Physical security describes measures that are designed to deny access to unauthorized personnel from physically accessing a building, facility, resource, or stored information; and guidance on how to design structures to resist potentially hostile acts...

 applications record video signals from closed circuit television
Closed-circuit television
Closed-circuit television is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors....

 cameras for detection and documentation purposes. Many are designed to record audio as well. DVRs have evolved into devices that are feature rich and provide services that exceed the simple recording of video images that was previously done through VCRs. A DVR CCTV system provides a multitude of advanced functions over VCR technology including video searches by event, time, date and camera. There is also much more control over quality and frame rate allowing disk space usage to be optimized and the DVR can also be set to overwrite the oldest security footage should the disk become full. In some DVR security systems remote access to security footage using a PC can also be achieved by connecting the DVR to a LAN network or the internet. videoNEXT also makes a NVR surveillance application for the Mac OS X.
Some of the latest professional digital video recorders include video analytics firmware, to enable functionality such as 'virtual tripwire' or even the detection of abandoned objects on the scene.

Security DVRs may be categorized as being either PC based or embedded
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...

. A PC based DVR’s architecture is a classical personal computer with video capture cards designed to capture video images. An embedded type DVR is specifically designed as a digital video recorder with its operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

 and application software
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...

 contained in firmware
Firmware
In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...

 or read only memory.

Hardware features


Hardware
Computer hardware
Personal computer hardware are component devices which are typically installed into or peripheral to a computer case to create a personal computer upon which system software is installed including a firmware interface such as a BIOS and an operating system which supports application software that...

 features of security DVRs vary between manufacturers and may include but are not necessarily limited to
  • Designed for rack
    19-inch rack
    A 19-inch rack is a standardized frame or enclosure for mounting multiple equipment modules. Each module has a front panel that is wide, including edges or ears that protrude on each side which allow the module to be fastened to the rack frame with screws.-Overview and history:Equipment designed...

     mounting or desktop configurations.
  • Single or multiple video inputs with connector types consistent with the analogue or digital video provided such as coaxial cable
    Coaxial cable
    Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...

    , twisted pair
    Twisted pair
    Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...

     or optical fiber
    Optical fiber
    An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...

     cable. The most common number of inputs are 1, 2, 4, 8, 16 and 32. Systems may be configured with a very large number of inputs by networking or bussing
    Electrical bus
    Electric bus is a bus powered by electric energy. "Electric bus" can also refer to:* Bus , used for connecting components of a computer or communication between computers* Busbars, thick conductors acting as nodes in electrical substations...

     individual DVRs together.
  • Looping video outputs for each input which duplicates the corresponding input video signal and connector type. These output signals are used by other video equipment such as matrix switchers, multiplexer
    Multiplexer
    In electronics, a multiplexer is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2n inputs has n select lines, which are used to select which input line to send to the output...

    s, and video monitor
    Video monitor
    A video monitor also called a broadcast monitor, broadcast reference monitor or just reference monitor, is a display device similar to a television set, used to monitor the output of a video-generating device, such as playout from a video server, IRD, video camera, VCR, or DVD player. It may or...

    s.
  • Controlled outputs to external video display monitors.
  • Front panel switches and indicators that allow the various features of the machine to be controlled.
  • Network connections consistent with the network type and utilized to control features of the recorder and to send and/or receive video signals.
  • Connections to external control devices such as keyboards
    Computer keyboard
    In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...

    .
  • A connection to external pan-tilt-zoom drives that position cameras.
  • Internal CD, DVD, VCR devices typically for archiving video.
  • Connections to external storage media.
  • Alarm event inputs from external security detection devices, usually one per video input.
  • Alarm event outputs from internal detection features such as motion detection or loss of video.

Software features


Software features vary between manufacturers and may include but are not necessarily limited to
  • User selectable image capture
    Capture
    Capture may refer to:* Capture , to remove the opponent's piece from the board by taking it with one's own piece* Capture , situations in which a government agency created to act in the public interest instead acts in favor of other interests...

     rates either on an all input basis or input by input basis. The capture rate feature may be programmed to automatically adjust the capture rate on the occurrence of an external alarm or an internal event
  • Selectable image resolution
    Image resolution
    Image resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail....

     either on an all input basis or input by input basis. The image resolution feature may be programmed to automatically adjust the image resolution on the occurrence of an external alarm or an internal event.
  • Compression methods determine quality of playback. H.264 hardware compression offers fast transfer rates over the internet with high quality video.
  • Motion detection
    Motion detection
    Motion detection is a process of confirming a change in position of an object relative to its surroundings or the change in the surroundings relative to an object. This detection can be achieved by both mechanical and electronic methods...

    : Provided on an input by input basis, this feature detects motion in the total image or a user definable portion of the image and usually provides sensitivity settings. Detection causes an internal event that may be output to external equipment and/or be used to trigger changes in other internal features.
  • Lack of motion detection. Provided on an input by input basis, this feature detects the movement of an object into the field of view and remaining still for a user definable time. Detection causes an internal event that may be output to external equipment and/or used to trigger changes in other internal features.
  • Direction of motion detection. Provided on an input by input basis, this feature detects the direction of motion in the image that has been determined by the user as an unacceptable occurrence. Detection causes an internal event that may be output to external equipment and/or be used to trigger
    Event-driven programming
    In computer programming, event-driven programming or event-based programming is a programming paradigm in which the flow of the program is determined by events—i.e., sensor outputs or user actions or messages from other programs or threads.Event-driven programming can also be defined as an...

     changes in other internal features.
  • Routing of input video to video monitors based on user inputs or automatically on alarms or events.
  • Input, time and date stamping.
  • Alarm
    Alarm
    An alarm device or system of alarm devices gives an audible or visual alarm signal about a problem or condition.Alarm devices include:* burglar alarms, designed to warn of burglaries; this is often a silent alarm: the police or guards are warned without indication to the burglar, which increases...

     and event logging on appropriate video inputs.
  • Alarm and event search.
  • One or more sound recording channels.
  • Archival.
  • Commercial hopping. Rather than fast-forwarding through commercials, an undocumented feature
    Undocumented feature
    Undocumented features are frequently found in computer software releases. Sometimes the documentation is omitted through simple oversight, but undocumented features are often elements of the software not intended for use by end users, but left available for use by the vendor for software support...

     of the TiVo
    TiVo
    TiVo is a digital video recorder developed and marketed by TiVo, Inc. and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs, whose features include "Season Pass" schedules which record every new episode of a series, and "WishList"...

     box is that the user can reprogram the tab-to-end button by entering a sequence of buttons on the remote: SELECT-PLAY-SELECT-3-0-SELECT and listening for the confirming chimes that signal the feature has been activated (or deactivated). The tab-to-end button no longer jumps to the end of a recording when so activated: It skips 30 seconds, which is the length of U.S. commercials. In combination with the 8-second rewind button, most viewers can completely miss commercial breaks in programming.

Privacy concerns


Some digital video recorders which are designed to send information to a service provider over a telephone line
Telephone line
A telephone line or telephone circuit is a single-user circuit on a telephone communication system...

, Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

, (or any other way) can gather and send real-time data on users' viewing habits.

The future of TV advertisements


Digital video recorders are also changing the way television programs advertise products. Watching pre-recorded programs allows users to fast-forward through commercials, and some technology allows users to remove commercials entirely. Half of viewers in the United States, for example, use DVRs to skip commercials entirely. This feature has been controversial for the last decade, with major television networks and movie studios claiming it violates copyright and should be banned.

In 1985, an employee of Honeywell’s Physical Sciences Center, David Rafner, first described a drive-based DVR designed for home TV recording, time-slipping, and commercial skipping. U.S. Patent 4,972,396 focused on a multi-channel design to allow simultaneous independent recording and playback. Broadly anticipating future DVR developments, it describes possible applications such as streaming compression, editing, captioning, multi-channel security monitoring, military sensor platforms, and remotely piloted vehicles.

The first DVR which had a built-in commercial skipping feature introduced in 1999 by ReplayTV
ReplayTV
ReplayTV is a brand of digital video recorder , a term synonymous with personal video recorder . It is a consumer video device which allows users to capture television programming to internal hard disk storage for later viewing...

 at the Consumer Electronics Show
Consumer Electronics Show
The International Consumer Electronics Show is a major technology-related trade show held each January in the Las Vegas Convention Center, Las Vegas, Nevada, United States. Not open to the public, the Consumer Electronics Association-sponsored show typically hosts previews of products and new...

 in Las Vegas. In 2002 five owners of the ReplayTV DVR sued the main television networks and movie studios, asking the federal judge to uphold consumers' rights to record TV shows and skip commercials claiming that features such as commercial skipping
Commercial skipping
Commercial skipping is an advanced feature in some digital video recorders that makes it possible to automatically skip commercials in recorded programs...

 help parents protect their kids from excessive consumerism. ReplayTV was purchased by SONICblue in 2001 and on March 2003 SONICblue filed for Chapter 11 bankruptcy after fighting a copyright infringement suit over the ReplayTV's ability to skip commercials. In 2007 DirecTV
DirecTV
DirecTV is an American direct broadcast satellite service provider and broadcaster based in El Segundo, California. Its satellite service, launched on June 17, 1994, transmits digital satellite television and audio to households in the United States, Latin America, and the Anglophone Caribbean. ...

 purchased the remaining assets of ReplayTV.
A third-party
Third-party software component
In computer programming, a third-party software component is a reusable software component developed to be either freely distributed or sold by an entity other than the original vendor of the development platform...

 add-on for Windows Media Center called "DVRMSToolbox" has the ability to skip commercials.
There is a command-line program called Comskip that detects commercials in an MPEG-2 file and saves their positions to a text file. This file can then be fed to a program like MEncoder
MEncoder
MEncoder is a free command line video decoding, encoding and filtering tool released under the GNU General Public License. It is a close sibling to MPlayer and can convert all the formats that MPlayer understands into a variety of compressed and uncompressed formats using different codecs.MEncoder...

 to actually remove the commercials.

Many speculate that television advertisements will be eliminated altogether, replaced by advertising in the TV shows themselves
Product placement
Product placement, or embedded marketing, is a form of advertisement, where branded goods or services are placed in a context usually devoid of ads, such as movies, music videos, the story line of television shows, or news programs. The product placement is often not disclosed at the time that the...

. For example, Extreme Makeover: Home Edition advertises Sears
Sears, Roebuck and Company
Sears, officially named Sears, Roebuck and Co., is an American chain of department stores which was founded by Richard Warren Sears and Alvah Curtis Roebuck in the late 19th century...

, Kenmore
Kenmore Appliances
Kenmore Appliances was a line of household appliances produced by a variety of manufacturers such as Whirlpool Corp, GE, Panasonic, LG, Bosch, Electrolux, and Mabe Mexico, and controlled by Sears Holdings Corporation; the brand is owned by KCD IP, LLC, a special purpose entity created by Sears...

, Kohler
Kohler
Kohler is a family name of German origin. The name was first found in Saxony. It means, "Charcoal burner" so the first "Kohlers" were most likely of that occupation.-People:*Alan Kohler, Australian journalist*Herbert Kohler, Jr., businessman...

, and Home Depot by specifically using products from these companies, and some sports events like the Sprint Cup of NASCAR
NASCAR
The National Association for Stock Car Auto Racing is a family-owned and -operated business venture that sanctions and governs multiple auto racing sports events. It was founded by Bill France Sr. in 1947–48. As of 2009, the CEO for the company is Brian France, grandson of the late Bill France Sr...

 are named after sponsors.

Another type of advertisement shown more and more, mostly for advertising TV shows on the same channel, is where the ad overlays the bottom of the TV screen, blocking out some of the picture. "Banners", or "Logo Bugs", as they are called, are referred to by media companies as Secondary Events (2E). This is done in much the same way as severe weather warnings are done. Sometimes these take up only 5-10% of the screen, but in the extreme, can take up as much as 25% of the viewing area. Some even make noise or move across the screen. One example of this is the 2E ads for Three Moons Over Milford
Three Moons Over Milford
Three Moons Over Milford is an American science fiction dramedy set in a picturesque small town in southern Vermont. Shortly before the series begins, an asteroid hits the Moon, shattering it into three fragments, threatening to eventually fall to Earth and end life...

in the months before its premiere. A video taking up approximately 25% of the bottom-left portion of the screen would show a comet impacting into the moon with an accompanying explosion, during another television program.

Because of this widely used new technology, advertisers are now looking at a new way to market their products on television. An excerpt from the magazine Advertising Age
Advertising Age
Advertising Age is a magazine, delivering news, analysis and data on marketing and media. The magazine was started as a broadsheet newspaper in Chicago in 1930...

reads: "As advertisers lose the ability to invade the home, and consumer's minds, they will be forced to wait for an invitation. This means that they have to learn what kinds of advertising content customers will actually be willing to seek out and receive."

With ad skipping and the time-sensitive nature of certain ads, advertisers are wary of buying commercial time on shows that are heavily digitally video-recorded. However, technology today makes it possible for networks to insert ads dynamically on videos being played in DVRs. Advertisers could inject time-relevant ads to recorded programs when the program is viewed. This way the ads could be not just topical but also personalized to viewers interests. DirectTV in March 2011 signed an arrangement with NDS Group
NDS Group
NDS Group Plc. is a developer of pay TV technology. NDS was established in 1988 as an Israeli start up company. It was acquired by News Corporation in 1992. The company is currently headquartered in Staines, United Kingdom...

 to enable the delivery of such addressable advertisement.
It is believed that viewers prefer to forward ads, than to switch the channel. By switching channels viewers will have the probability of skipping the beginning of their program. Users might switch to a channel that is also showing ads. Having the ability to pause, rewind, and forward live TV gives users a chance to change the channel less times. Forwarding ads can have a later affect on the viewer. Ads that get the viewers attention will influence the viewers to rewind and watch what was missed.

Patent and copyright litigation



On July 14, 2005, Forgent Networks
Forgent Networks
Asure Software is a software company which has licensing as its primary revenue source. Prior to September 13, 2007, the company was known as Forgent Networks. Critics claim Asure profits primarily as a patent troll...

 filed suit against various companies alleging infringement on , entitled "Computer controlled video system allowing playback during recording". The listed companies included EchoStar, Directv, Charter Communications, Cox Communications, Comcast, Time Warner, and Cable One.

Scientific-Atlanta
Scientific-Atlanta
Scientific Atlanta Inc is a Georgia-based manufacturer of cable television, telecommunications, and broadband equipment.Scientific Atlanta was founded in 1951 by a group of engineers from the Georgia Institute of Technology, and was purchased by Cisco Systems in 2005.-Products:Scientific Atlanta is...

 and Motorola
Motorola
Motorola, Inc. was an American multinational telecommunications company based in Schaumburg, Illinois, which was eventually divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011, after losing $4.3 billion from 2007 to 2009...

, the manufacturers of the equipment sold by the above mentioned companies, filed a counter-suit against Forgent Networks claiming that their products do not violate the patent, and that the patent is invalid. The two cases were combined into case 6:06-cv-208, filed in the United States District Court for the Eastern District of Texas, Tyler Division.

According to court documents, on June 20, 2006, Motorola requested that the United States Patent and Trademarks Office reexamine the patent, which was first filed in 1991, but has been amended several times.

On March 23, 2007 Cablevision Systems Corp lost a legal battle against several Hollywood studios and television networks to introduce a network-based digital video recorder service to its subscribers. However, on August 4, 2008, Cablevision won its appeal. John M. Walker Jr., a Second Circuit judge, declared that the technology "would not directly infringe" on the media companies' rights. An appeal to the Supreme Court was rejected.

In court, the media companies argued that network digital video recorders were tantamount to video-on-demand, and that they should receive license fees for the recording. Cablevision and the appeals court disagreed. The company noted that each user would record programs on his or her own individual server space, making it a DVR that has a "very long cord."

In 2004, TiVo sued EchoStar Corp
TiVo Inc. v. EchoStar Corp.
TiVo Inc. v. EchoStar Corp. is a case stretching from 2004 to 2011, which took place in the United States District Court for the Eastern District of Texas and the United States Court of Appeals for the Federal Circuit. TiVo Inc. sued EchoStar Corp. claiming patent infringement of a DVR technology...

, a manufacturer of DVR units, for patent infringement. The parties reached a settlement in 2011 wherein EchoStar paid TiVo a licensing fee for its technology.

See also


  • 10-foot user interface
    10-foot user interface
    In computing a 10-foot user interface is a software GUI designed for display on a large television with interaction using a regular television-style remote control."10 foot" refers to the fact that the GUI's...

  • Astro MAX
    Astro MAX
    Astro MAX was a personal video recorder service for Astro launched in July 2006. It marked the first PVR system ever to be introduced in Malaysia, though LG's PVR-integrated Time Machine TV introduced later that year...

  • Boxee
    BOXEE
    Boxee is a cross-platform freeware HTPC software application with a 10-foot user interface and social networking features designed for the living-room TV...

  • Comparison of PVR software packages
    Comparison of PVR software packages
    The following is a comparison guide for popular DVR software packages.-General information:Basic general information for popular DVR software packages....

  • Direct to disk recording
    Direct to Disk Recording
    Direct-to-disk recording refers to methods by which analog signals and digital signals such as digital audio and digital video are digitally recorded to optical disc recording technologies such as DVDs, and CD optical discs...

  • DTE (Direct To Edit)
    DTE (Direct To Edit)
    DTE is a digital video direct-to-disk recording method used to streamline the post-production video editing workflow of raw video files into a Non-linear editing system .-See also:* Computer file...

  • DTVPal DVR
  • FAT32
  • Freeview+
    Freeview+
    Freeview+ and Freeview+ HD is a consumer brand created in the UK by DTV Services Ltd to "raise consumer awareness and promote sales" of Freeview capable digital TV recorders otherwise known as personal video recorders...

  • Freesat+
    Freesat+
    Freesat+ is a consumer brand created to raise consumer awareness and promote sales of Freesat-capable digital TV recorders, otherwise known as personal video recorders...

  • Handheld television
    Handheld television
    A Handheld television is a portable device that usually uses a TFT LCD or Organic light-emitting diode color display. Many of these devices resemble handheld transistor radios.-Hardware:...

  • HD media player
    HD media player
    HD media player or HDD media player is a generic term used for a category of consumer product that combines a hard drive enclosure with hardware and software for playing audio, video and photos through a home entertainment system...

  • Hard disk recorder
    Hard disk recorder
    A hard disk recorder is a type of direct to disk recording system that uses a high-capacity hard disk to record digital audio or digital video. Hard disk recording systems represent an alternative to more traditional reel-to-reel tape or cassette multitrack systems, and provide editing...

  • HDMI
    HDMI
    HDMI is a compact audio/video interface for transmitting uncompressed digital data. It is a digital alternative to consumer analog standards, such as radio frequency coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, or VGA...

  • Integrated circuit
    Integrated circuit
    An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

  • List of portable software#Recorders
  • Media PC
  • Media server
    Media Server
    A media server refers either to a dedicated computer appliance or to a specialized application software, ranging from an enterprise class machine providing video on demand, to, more commonly, a small personal computer or NAS for the home, dedicated for storing various digital media .-Purpose:By...

     (Consumer)

  • Moxi
    Moxi
    Moxi is a line of high definition Digital Video Recorders produced by ARRIS Group, Inc. Moxi was originally released only to cable operators but in December 2008 was released as a retail product to the general public. The current retail product, the Moxi HD DVR, provides a high definition user...

  • MythTV
    MythTV
    MythTV is a free and open source home entertainment application with a simplified "10-foot user interface" design for the living-room TV, and turns a computer with the necessary hardware into a network streaming digital video recorder, a digital multimedia home entertainment system, or home theater...

  • Network Video Recorder
    Network Video Recorder
    A network video recorder is a software program that records video in a digital format to a disk drive, USB flash drive, SD memory card or other mass storage device. NVRs are similar to DVRs but with several distinct differences. NVRs take video input over a network, as opposed to directly...

  • ReplayTV
    ReplayTV
    ReplayTV is a brand of digital video recorder , a term synonymous with personal video recorder . It is a consumer video device which allows users to capture television programming to internal hard disk storage for later viewing...

  • SubRip
    SubRip
    SubRip is a software program for Windows which "rips" subtitles and their timings from video. It is free software, released under the GNU GPL...

  • Sky+
    Sky+
    Sky+, or Sky Plus, is a personal video recorder service for Sky in the UK. Launched in September 2001, it allows the user to record, pause and instantly rewind live TV. The system performs these functions using an internal hard drive inside the Sky+ set top box...

  • TiVo
    TiVo
    TiVo is a digital video recorder developed and marketed by TiVo, Inc. and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs, whose features include "Season Pass" schedules which record every new episode of a series, and "WishList"...

  • TV-Anytime
    TV-Anytime
    TV-Anytime is a set of specifications for the controlled delivery of multimedia content to a user's digital video recorder . It seeks to exploit the evolution in convenient, high capacity storage of digital information to provide consumers with a highly personalized TV experience...

  • Proprietary DVR
    Proprietary DVR
    DVRs, or Digital Video Recorders, are devices which record video to a hard drive. The term Proprietary DVR refers to exclusive methodologies used to maintain commercial control over the DVR format and prevent third-party copying of a particular file...

  • PVR-resistant advertising
    PVR-resistant advertising
    PVR -resistant advertising is a form of advertising which is designed specifically to remain viewable despite a user skipping through the commercials when using a device such as a TiVo or other digital video recorder....

  • Remote control
    Remote control
    A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...

  • Remote storage digital video recorder
    Remote storage digital video recorder
    Network DVR , or network personal video recorder , or remote storage digital video recorder is a network-based digital video recorder stored at the provider's central location rather than at the consumer's private home...

  • Time shifting
    Time shifting
    Time shifting is the recording of programming to a storage medium to be viewed or listened to at a time more convenient to the consumer. Typically, this refers to TV programming but can also refer to radio shows via podcasts....

  • USB hard disk
  • USB On-The-Go
    USB On-The-Go
    USB On-The-Go, often abbreviated USB OTG, is a specification that allows USB devices such as digital audio players or mobile phones to act as a host allowing a USB Flash Drive, mouse, or keyboard to be attached.- Architecture :...

  • V+
  • Video server
    Video server
    A video server is a computer based device dedicated to delivering video.Unlike personal computers, being multi-application devices, a video server is designed for one purpose; provisioning video, often for broadcasters. A professional grade video server records, stores, and playout of multiple...

     (Broadcast)
  • XBMC


External links