A digital video recorder (DVR) or personal video recorder (PVR) is a device that records video in a digital format to a disk drive or other memory medium within a device. The term includes stand-alone set-top boxes, portable media players (PMP) and software for personal computers which enables video capture and playback to and from disk. Some consumer electronic manufacturers have started to offer televisions with DVR hardware and software built in to the television itself; LG was first to launch one in 2007. It has also become the main way for CCTV companies to record their surveillance, as it provides far longer recording times than the previously used VCRs.
The two early consumer DVRs, ReplayTV and TiVo, were launched at the 1999 Consumer Electronics Show in Las Vegas. Microsoft also demonstrated a unit with DVR capability but commercial availability of this software would have to wait until the end of 1999 for full DVR features in Dish Network's DISHplayer receivers. TiVo shipped their first units on March 31 1999, and to this day the last Friday in March is celebrated as a company holiday known as 'Blue Moon'. Although ReplayTV won the "Best of Show" award in the video category, it was TiVo that went on to much greater commercial success. The devices have steadily developed complementary abilities, such as recording onto DVDs, commercial skip, sharing of recordings over the Internet, and programming and remote control facilities using PDAs, networked PCs, and Web browsers. The label PVR has almost fallen completely into disuse in the trade news media in favor of the more popular DVR descriptor. The name PVR never really caught on, although its use has not entirely vanished.
This makes the "time shifting" feature (traditionally done by a VCR) much more convenient, and also allows for "trick modes" such as pausing live TV, instant replay of interesting scenes, chasing playback where a recording can be viewed before it has been completed and skipping advertising. Most DVRs use the MPEG format for compressing the digitized video signals.
DVRs tied to a video service: At the 1999 CES show Dish Network demonstrated the hardware that would later have DVR capability with the assistance of Microsoft software. The 7100 satellite receiver (later rebranded as the DISHPlayer). Users would have to wait until June 1999 for simple time shifting capabilities in the 7100, rebranded as the DISHPlayer satellite receiver, 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, DVRs are often referred to as plus boxes (such as BSKYB's sky + and Virgin Media's V+ which integrates an HD Capability). British Sky Broadcasting markets a popular combined EPG and DVR as Sky+. South African based Africa Satellite TV beamer Multichoice recently launched their PVR which is available on their Dstv platform. In addition to ReplayTV and TiVo, there are a number of other suppliers of digital terrestrial (DTT) DVRs, including Thomson, Topfield, Fusion, Pace Micro Technology and Humax.
Many satellite and cable companies are incorporating DVR functions into their set-top box, such as with DirecTiVo, DISHPlayer/DishDVR, Scientific Atlanta Explorer 8xxx from Time Warner, Motorola 6xxx from Comcast, Moxi Media Center by Digeo (available through Charter, Adelphia, Sunflower, Bend Broadband, and soon Comcast and other cable companies), or Sky+. Also LG Group offers a television with DVR functions built in.
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 DVR 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 DVRs and related technology is unlikely to be substantial as standalone DVRs are currently readily available on the open market.
SageTV provides DVR software for the Mac with built in placeshifting for watching TV remotely and sells and supports the Hauppauge HVR-950, myTV.PVR and HDHomeRun hardware with its DVR software. SageTV software also includes the ability to watch YouTube and other online video with a remote control.
Other Mac DVR products include myTV.PVR from Hauppauge/EskapeLabs and ConvertX PVR from Plextor. MythTV (see above) also runs under Mac OS X, 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. iRecord is a free scheduled-recording program derived from this SDK.
There are also several proprietary applications available including AVS TV Box , CyberLink PowerCinema, SageTV, SnapStream Beyond TV, ChrisTV , Showshifter, Meedio (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. and Canada), InterVideo WinDVR, Recordit Plus and the R5000-HD.
To record an analog signal a few steps are required. A TV tuner card tunes into a particular frequency and then functions as a frame grabber, breaking the lines into individual pixels and quantizing 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, or WMF, usually in software. Some TV tuner cards like the DVR-250/350 or the TiVo chip deliver an MPEG-2 or other compressed stream directly to the computer, performing both the frame grabbing and compression in hardware. This greatly reduces the load on the CPU allowing an overall cheaper implementation.
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.
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.
The satellite or cable set-top box does two things. First, it decrypts the signal. Second, it decodes the MPEG stream into an analog, DVI, or HDMI signal for viewing on the television. In order to record cable/satellite digital signals you must get the signal after it is decrypted, but before it is decoded (between steps one and two); this is how DVRs built into set-top boxes work.
An alternative is that some satellite or (more commonly) cable set-top boxes have a FireWire port that can be connected to a computer. The recorded MPEG stream can be relayed to the computer via this FireWire port; though it can be done live, this is more commonly used for transferring shows from a set-top box with built-in DVR. (For instructions on doing this on a popular set-top box with DVR, please see the Wikibook entry How to use a Motorola DVR; some of the ideas there may apply to other set-top boxes as well.)
Security DVRs may be categorized as being either PC based or embedded. 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 and application software contained in firmware or read only memory.
Digital video recorders cannot record from a high definition digital audio/video source such as HDMI or DVI, due to restrictions imposed by High Definition Content protection (hdcp)
Due to this widely-used, groundbreaking technology, advertisers are now looking at a new way to market their products on television. An excerpt from the magazine, Advertising Age, 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.
Scientific-Atlanta and Motorola, 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. But 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.
In court, the media companies argued that network DVRs 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."
US Patent Issued to Enreach Technology on Jan. 25 for "Method and System of Providing a Non-Skippable Sub-Advertisement Stream" (California Inventors)
Feb 01, 2011; ALEXANDRIA, Va., Feb. 1 -- United States Patent no. 7,877,766, issued on Jan. 25, was assigned to Enreach Technology Inc. (San...