Digital video recorder
The DVR design was a chapter of Edward Y. Chang's PhD dissertation, supervised by Professors Hector Garcia-Molina and Jennifer Widom.
[7] ReplayTV won the "Best of Show" award in the video category[8] with Netscape co-founder Marc Andreessen as an early investor and board member,[9] but TiVo was more successful commercially.
[10] Legal action by media companies forced ReplayTV to remove many features such as automatic commercial skip and the sharing of recordings over the Internet,[11] but newer devices have steadily regained these functions while adding complementary abilities, such as recording onto DVDs and programming and remote control facilities using PDAs, networked PCs, and Web browsers.
[12] Video recording capabilities have become an essential part of the modern set-top box, as TV viewers have wanted to take control of their viewing experiences.
At the 1999 CES, Dish Network demonstrated the hardware that would later have DVR capability with the assistance of Microsoft software, which also included access to the WebTV service.
[14][15] In the UK, digital video recorders are often referred to as "plus boxes" (such as BSKYB's Sky+ and Virgin Media's V+ which integrates an HD capability, and the subscription free Freesat+ and Freeview+).
South African based Africa Satellite TV beamer Multichoice recently launched their DVR which is available on their DStv platform.
Many satellite, cable and IPTV companies are incorporating digital video recording functions into their set-top box, such as with DirecTiVo, DISHPlayer/DishDVR, Scientific Atlanta Explorer 8xxx from Time Warner, Total Home DVR from AT&T U-verse, Motorola DCT6412 from Comcast and others, Moxi Media Center by Digeo (available through Charter, Adelphia, Sunflower, Bend Broadband, and soon Comcast and other cable companies), or Sky+.
[18] 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.
Kogan.com introduced a dual-tuner PVR in the Australian market allowing free-to-air television to be recorded on a removable hard drive.
These systems simplify wiring and operation because they employ a single power cable, have no interconnected ports (e.g., HDMI), and share a common remote control.
[24] Some pay-TV operators provide receivers that allow subscribers to attach their own network-attached storage (NAS) hard drives or solid-state or flash memory to record video and other media files (e.g., audio and photos).
Software and hardware are available which can turn personal computers running Microsoft Windows, Linux, and Mac OS X into DVRs, and is a popular option for home-theater PC (HTPC) enthusiasts.
Other examples include MythTV, Video Disk Recorder (VDR), LinuxMCE, TiVo, VBox Home TV Gateway, and Kodi (formerly XBMC).
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.
There are several free digital video recording applications available for Microsoft Windows including GB-PVR, MediaPortal, and Orb (web-based remote interface).
The control keypad is usually connected with a detachable cable, to allow it to be located on the system's exterior while the DVR circuitry resides inside the equipment.
Many consumer DVRs implement a copy-protection system called Copy Generation Management System—Analog (CGMS-A), which specifies one of four possible copy permissions by means of two bits encoded in the vertical blanking interval: 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.
These DVRs have access to the encrypted video stream, and generally enforce the provider's restrictions on copying of material even after recording.
They generally use Secure Digital cards, can include wireless connections (Bluetooth and Wi-Fi), and can play SWF files.
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.
An embedded type DVR is specifically designed as a digital video recorder with its operating system and application software contained in firmware or read-only memory.
Hardware features of security DVRs vary between manufacturers and may include but are not necessarily limited to: Software features vary between manufacturers and may include but are not necessarily limited to: Some (very few), but certainly not all, digital video recorders which are designed to send information to a service provider over a telephone line or Internet (or any other way) can gather and send real-time data on users' viewing habits.
In 1985, an employee of Honeywell's Physical Sciences Center, David Rafner, first described a drive-based DVR designed for home TV recording, time shifting, and commercial skipping.
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.
[citation needed] In 1999, the first DVR which had a built-in commercial skipping feature was introduced by ReplayTV at the Consumer Electronics Show in Las Vegas.
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.
[40] On July 14, 2005, Forgent Networks filed suit[41] against various companies alleging infringement on U.S. patent 6,285,746, entitled "Computer controlled video system allowing playback during recording".
[42] 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.
