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http://www.gizmodo.com/gadgets/hom e-entertainment/dvrs/ Gizmodo: New DVR Technology Releases

Personal video recorder From Wikipedia, the free encyclopedia. The personal video recorder (PVR), also called digital video recorder (DVR) or digital personal video recorder, is a consumer electronics device that records television shows to a hard disk in digital format. Since first introduced by TiVo at the Consumer Electronics Show in 1999, PVRs have steadily developed complementary abilities, such as recording onto DVDs. 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, and skipping advertising. Most PVR recorders use the MPEG format for encoding analog video signals. The most popular PVRs on the market in the United States are the TiVo and DNNA's ReplayTV, although most home electronics manufacturers now offer models. In the UK Sky Plus dominates the digital satellite market, though TiVO and Thomson have a small presence; Thomson, Fusion, Pace and Humax also supply digital terrestrial (DTT) PVRs. Many satellite and cable companies are incorporating PVR functions into their set-top box, such as with DirecTiVo, 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 Plus. In this case there is no encoding necessary in the PVR, as the satellite signal is already a digitally encoded MPEG stream. The PVR simply stores the digital stream directly to disk. Having the broadcaster involved with (subsidizing) the design of the PVR, and directly recording encrypted digital streams can lead to fancy features - like the ability to use interactive TV on recorded shows, pre-loading of programs; but can also lead to too much control by the broadcaster - like denying the ability to skip adverts and automatically expiring recordings after a time determined by the broadcaster. Other entrants into the market include products such as Microsoft's Media Center In 2003, the Yakima, Washington Police Department began using PVRs in their patrol cars to record the activities of officers and suspects. Since then, many other police departments have followed suit, due to the increased reliability and decreased cost compared to analog video systems. There are ways to make one's own PVR using software and hardware available for Microsoft Windows, Linux and Macintosh operating systems. There are even people working on turning the Xbox into a PVR with a modchip. Contents [hide] 1 How a digital/personal video recorder works 1.1 Analog television 1.2 Analog Broadcast Copy Protection 1.3 Digital television 1.4 Satellite or Digital Cable 2 PVR software 2.1 Linux 2.2 Macintosh 2.3 Windows 3 See also 4 External links [edit] How a digital/personal video recorder works [edit] Analog television Analog television in NTSC, PAL or SECAM formats, analog cable, or regular VHS tapes use a signal that is fed directly to the electron beam within the television set. There are a number of details on how this is done, but in essence each line in each frame corresponds to a specific fraction of time within the signal. 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 PVR-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 silico. This greatly reduces the load on the CPU allowing an overall cheaper implementation . [edit] Analog Broadcast Copy Protection Many mass-produced consumer DVRs implement a copy- protection system called CGMS-A (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 DVR. [edit] Digital television Digital television are audio/visual signals that are broadcast over the air in a digital rather than analog format. Recording digital TV is generally a straightforward capture of the binary MPEG-2 data being received. No expensive hardware is required to quantize and compress the signal (as the television broadcaster has already done this in the studio). The MythTV PVR supports both European DVB signals and American ATSC signals while the HDTV Tivo supports the ATSC signals. In the US, the FCC attemped to place a road-block before digital PVRs with its "Broadcast flag" regulation. Personal Video Recorders which had not won prior approval from the FCC for implementing "effective" digital restrictions management would have been banned from interstate commerce as of July 2005. The regulation was struck down on 6 May 2005. [edit] Satellite or Digital Cable Recording satellite or digital cable signals on a personal video recorder is more complex than recording analog signals or broadcast digital signals. This is so because the MPEG-2 stream is usually encrypted to prevent people from viewing the content without paying for it (usually via subscription to a valid satellite decryption box and a decoder card). The satellite or cable decoder box does two things. First it decrypts the signal. Second, it decodes the MPEG-2 stream into an analog signal for play on the television. In order to record cable/satellite digital signals you would need to get the signal after it is decrypted but before it is decoded (between steps one and two). An alternative is that some satellite/cable decoder boxes have a firewire port that can be connected to a computer. The MPEG stream could be relayed to the computer via this firewire port although there is as yet few, if any, current cards or devices that allow for a firewire connection to the computer from this box. [edit] PVR software There is PVR software available for Linux and Windows for people who make their own homemade recorders. [edit] Linux The three main PVR applications for Linux are VDR, MythTV and Freevo all of which are GPL open source software. [edit] Macintosh Elgato makes a PVR device called EyeTV. [edit] Windows Microsoft Windows has several free PVR applications including GB-PVR and MediaPortal. There also are several proprietary applications including SageTV, SnapStream Beyond TV, ChrisTV, Showshifter, Meedio, InterVideo WinDVR and Recordit Plus. There is also a separate version of Microsoft Windows called Windows XP Media Center Edition which has PVR capabilities. However, it is only available as pre-loaded software on a new PC. Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111- 1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.

Closed-circuit television From Wikipedia, the free encyclopedia. The two-year-old Jamie Bulger being led away by his killers, recorded on shopping centre CCTV.Closed-circuit television (CCTV), as a collection of surveillance cameras doing video surveillance, is the use of television cameras for surveillance. It differs from broadcast television in that all components are directly linked via cables or other direct means. CCTV is used in banks, casinos, shopping centres, streets, airports etc. (the eye in the sky). The use of CCTVs in public places has increased, causing debate over security vs. privacy. Closed Circuit TV (CCTV) - where the picture is viewed or recorded, but not broadcast - was initially developed as a means of security for banks. Today it has developed to the point where it is simple and inexpensive enough to be used in home security systems, and for everyday surveillance. Contents [hide] 1 Use of CCTV 1.1 Crime prevention and detection 1.2 Traffic 2 Privacy 3 Fears of technological developments 4 See also 5 External links [edit] Use of CCTV The use of CCTV surveillance cameras monitoring public spaces has become common in the 21st century. [edit] Crime prevention and detection Closed-circuit cameras are often used to discourage crimeIn the United Kingdom, initial experiments in the 1970s and 1980s (including outdoor CCTV being installed in Bournemouth in 1985), led to in several larger trial programs in the early 1990s. These were deemed successful in the government report "CCTV: Looking Out For You", issued by the Home Office in 1994, and paved a way with massive increase in the number of CCTV systems installed. Nowadays systems cover most town and city centres, and many stations, car-parks and estates. The exact number of CCTV cameras in the UK is not known. A 2002 working paper by Michael McCahill and Clive Norris of UrbanEye [1], based on a small sample in Putney High Street, "guesstimated" the number of surveillance cameras in private premises in London as around 400,000 and the total number of cameras in the UK as around 4,000,000. Claims that they reduce or deter crime have not been clearly borne out by independent studies, though the government claim that when properly used they do result in deterrence, rather than displacement. One clear effect that has been is a reduction of car crime when used in car parks. Despite the little proof that CCTV deters crimes, the British public remain so far generally supportive of CCTV, and local authorities continue to press ahead with more cameras. Cameras have also been installed in taxis in various parts of the country, to deter violence against drivers [2] [3], and also in mobile police surveillance vans [4]. In some cases CCTV cameras have become a target of attacks themselves. [5] Criticism has also come from angle that local authorities and police are over- relying on CCTVs with their limited crime reduction budgets, and that this money would be better spent on ensuring a visible police presence in trouble spots. The use of CCTV in the United States is less prevalent, though increasing, and generally meets stronger opposition. In 1998 3,000 CCTV systems were found in New York City. [6] The use in France is also not as prevalent as in the UK. Local authorities are installing new systems but this tends to meet controversy. The most measurable effect of CCTV is not on crime prevention, but on detection and prosecution. Several notable murder cases have been solved with the use of CCTV evidence, notably the Jamie Bulger case, and catching David Copeland, the Soho nail bomber. The use of CCTV to track the movements of missing children is now routine. After the bombings of London on 7 July 2005, CCTV footage was used to identify the bombers. The men believed to have been the suicide bombers responsible for the 7 July attacks on London, captured on CCTV.Although not generally considered alongside CCTV, the widespread of adoption of camera phones has led to witnesses of a crime being able to take photographs of it in progress, and then quickly send the images to the police, and has led to similar privacy concerns. [edit] Traffic Many cities and motorway networks have extensive traffic-monitoring systems involving the use of closed-circuit television to detect congestion and notice accidents. In London, the Congestion Charge is enforced by cameras positioned at the boundaries of and inside the Congestion Charge Zone, which automatically read the registration plates of cars - if they do not pay the charge that day, they will be billed. Similar systems are also being developed as a means of locating cars reported stolen. Speed cameras are installed in various places, ostsensibly to deter speeding, although critics have claimed often to generate revenue for the installing agent, who collects the fines. [edit] Privacy Opponents of CCTV point out the loss of privacy of the people under surveillance, and the negative impact of surveillance on civil liberties. Furthermore, they argue that CCTV displaces crime, rather than reducing it. Critics often dub CCTV as "Big Brother surveillance", a reference to George Orwell's novel Nineteen Eighty-Four, which featured a two-way telescreen in every home through which The Party would monitor the populace. The recent growth of CCTV in housing areas also raises serious issues about the extent to which CCTV is being used as a social control measure rather than simply a deterrent to crime. Quite apart from government-permitted use (or abuse), questions are also raised about illegal access to CCTV footage. In May 2005 four men were charged with use of CCTV for the purposes of voyeurism in Merseyside [7], and previously a CCTV operator in Glamorgan was convicted on obscenity charges after making obscene phone calls to people he had been spying on. Other specific examples include a video Caught in the Act, released in 1996 which featured various couples having sex, captured on CCTV, and broadcast of footage of a man, Geoff Peck, attempting to commit suicide. [8], [9]. The Data Protection Act 1998 in the United Kingdom led to legal restrictions being imposed on the use that CCTV footage can be put to, and also mandated their registration with the Data Protection Agency. The successor to the DPA, the Information Commissioner in 2004 clarified that this required registration of all CCTV systems with the Commissioner, and prompt deletion of archived footage. [10] In the United States there is no such data protection mechanisms, it has been questioned whether CCTV evidence is allowable under the Fourth Amendment which prohibits "unreasonable searches and seizures". The courts have generally not taken this view. In Canada the use of video surveillance has grown exponentially. Disturbingly to some, corporations may legally record video even in changerooms. The Talisman Centre in Calgary, AB a fitness centre, has numerous video cameras in the men's changeroom that record men changing and showering. [edit] Fears of technological developments The first CCTV cameras used in public spaces were crude, conspicuous, low definition black and white systems without the ability to zoom or pan. Modern CCTV cameras use small high definition colour cameras that can not only focus to resolve minute detail, but by linking the control of the cameras to a computer, objects can be tracked semi-automatically. For example, they can track movement across a scene where there should be no movement, or they can lock onto a single object in a busy environment and follow it. Being computerised, this tracking process can also work between cameras. The implementation of automatic number plate recognition produces a potential source of information on the location of persons or groups. There is no technological limitation preventing a network of such cameras from tracking the movement of individuals. Reports have also been made of plate recognition misreading numbers leading to the billing of entirely the wrong people. [11] Security camera at London (Heathrow) AirportCCTV critics see the most disturbing extension to this technology is the recognition of faces from high- definition CCTV images. With this technology, it would be possible to determine a person's identity without the need to stop and ask them in the street, or even alert them that their identity is being checked and logged. The systems can check many thousands of faces in a database in under a second. This combination of CCTV with facial recognition technology has been tried as a form of mass surveillance, but has been ineffective because of the low discriminating power of facial recognition technology and the very high number of false positives generated. This type of system has generally been proposed to compare faces at airports and seaports with those of suspected terrorists or other undesirable entrants. The latest developments in CCTV and imaging techniques, being developed in the UK and USA, is developing computerised monitoring so that the CCTV operator does not have to endlessly look at all the screens. This also means that an operator can run many more CCTV cameras. These systems do not observe people directly. Instead they track their behaviour by looking for particular types of movement, or particular types of clothing or baggage. The theory behind this notes that in public spaces people behave in set and predictable ways. People who are not part of the 'crowd', for example car thieves, do not behave in the same way. The computer can identify their movements, and alert the operator that they are acting out of the ordinary. Potentially, waiting in a busy street to meet someone could trigger this system. Eye-in-the-sky surveillance dome camera watching from a high steel poleThe same type of system can, if required, go one step further and track an identified individual as they move through the area covered by CCTV. This is currently being developed in the USA as part of the project co- funded by the US Defense Advanced Research Projects Agency. With software tools, the system will be able to develop three-dimensional models of an area and track/monitor the movement of objects within it. To many, the development of CCTV in public areas, linked to computer databases of people's pictures and identity, presents a serious breach of civil liberties. Critics fear the possibility that one would not be able to meet anonymously in a public place or drive and walk anonymously around a city. Demonstrations or assemblies in public places could be affected as the state would be able to collate lists of those leading them, taking part, or even just talking with protesters in the street. Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111- 1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.