FunctionalityDownloading and streaming VOD systems provide the user with all of the features of portable media players and DVD players. Some VOD systems store and stream programmes from hard disk drives and use a RAM, memory buffer to allow the user to trick mode, fast forward and rewind videos. It is possible to put video server (computing), servers on local area networks; these can provide rapid responses to users. Cable companies have rolled out their own versions of VOD services through apps, allowing television access wherever there is a device that is Internet capable. Cable media companies have combined VOD with live streaming services. The recent launches of apps from cable companies are attempts to compete with Subscription Video on Demand (SVOD) services because they lack live news and sports content. Streaming video servers can serve a wide community via a wide area network, WAN but responsiveness may be reduced. Download VOD services are practical in homes equipped with cable modems or DSL connections. Servers for traditional cable and telco VOD services are usually placed at the cable head-end, serving a particular market and cable hubs in larger markets. In the telco world, they are placed in either the central office or a newly created location called a Video Head-End Office (VHO).
HistoryVOD services first appeared in the early 1990s. Until then, it was not thought possible that a television program, television programme could be squeezed into the limited telecommunication bandwidth of a copper telephone cable to provide a VOD service of acceptable quality as the required bandwidth of a digital television signal is around 200Mbps, which is 2,000 times greater than the bandwidth of a speech signal over a copper telephone wire. VOD services were only made possible as a result of two major technological developments: discrete cosine transform (DCT) video compression and asymmetric digital subscriber line (ADSL) data transmission. DCT is a lossy compression technique that was first proposed by N. Ahmed, Nasir Ahmed in 1972, and was later adapted into a Motion compensation, motion-compensated DCT algorithm for video coding standards such as the H.26x formats from 1988 onwards and the MPEG formats from 1991 onwards. Motion-compensated DCT video compression significantly reduced the amount of bandwidth required for a television signal, while at the same time ADSL increased the bandwidth of data that could be sent over a copper telephone wire. ADSL increased the bandwidth of a telephone line from around 100Data-rate units#Kilobit per second, kbps to 2Mbps, while DCT compression reduced the required bandwidth of a television signal from around 200Mbps down to 2Mbps. The combination of DCT and ADSL technologies made it possible to practically implement VOD services at around 2Mbps bandwidth in the 1990s. A VOD service was proposed as early as 1986 in Japan, where there were plans to develop an "Integrated Network System" service. It was not possible, however, to practically implement such a VOD service until the adoption of DCT and ADSL technologies in the early 1990s. The first VOD systems used tapes as the real-time source of video streams. GTE started as a trial in 1990 with AT&T providing all components. By 1992, VOD servers were supplying previously encoded digital video from disks and DRAM. In the US, the 1982 anti-trust break-up of AT&T resulted in several smaller telephone companies nicknamed Baby Bells. Following this, the Cable Communications Policy Act of 1984 prohibited telephone companies from providing video services within their operating regions. In 1993 the National Communication and Information Infrastructure (NII) was proposed and passed by the US House and Senate, opening the way for the seven Baby Bells—Ameritech, Bell Atlantic, BellSouth, NYNEX, Pacific Telesis, Southwestern Bell, and US West—to implement VOD systems. These companies and others began holding trials to set up systems for supplying video on demand over telephone and cable lines. In November 1992, Bell Atlantic announced a VOD trial. IBM was developing a video server code-named Tiger Shark. Concurrently, Digital Equipment Corporation (DEC) was developing a scalable video server configured from small-to-large for a range of video streams. Bell Atlantic selected IBM and in April 1993 the system became the first VOD over ADSL to be deployed outside the lab, serving 50 video streams. In June 1993, US West filed for a patent to register a proprietary system consisting of the Digital Equipment Corporation Interactive Information Server, Scientific Atlanta providing the network, and 3DO Interactive Multiplayer, 3DO as the set-top box with video streams and other information to be deployed to 2,500 homes. In 1994–95, US West filed for a patent concerning the provision of VOD in several cities: 330,000 subscribers in Denver, 290,000 in Minneapolis, and 140,000 in Portland. In early 1994, British Telecommunications (BT) introduced a trial VOD service in the United Kingdom. It used the DCT-based MPEG-1 and MPEG-2 video compression standards, along with ADSL technology. Many VOD trials were held with various combinations of server, network, and set-top box. Of these the primary players in the US were the telephone companies using DEC, Microsoft, Oracle, IBM, Hewlett-Packard, USA Video, nCube, SGI, and other servers. The DEC server system was the most-used in these trials. The DEC VOD server architecture used interactive gateways to set up video streams and other information for delivery from any of a large number of VAX servers, enabling it in 1993 to support more than 100,000 streams with full videocassette recorder (VCR)-like functionality. In 1994, it upgraded to a DEC Alpha–based computer for its VOD servers, allowing it to support more than a million users. By 1994 the Oracle scalable VOD system used massively parallel processors to support from 500 to 30,000 users. The SGI system supported 4,000 users. The servers connected to networks of increasing size to eventually support video stream delivery to entire cities. In the UK, from September 1994, a VOD service formed a major part of the Cambridge Digital Interactive Television Trial This provided video and data to 250 homes and several schools connected to the Cambridge Cable network, later part of NTL, now Virgin Media. The MPEG-1 encoded video was streamed over an ATM network from an International Computers Limited, ICL media server to Acorn Online Media Set Top Box, set-top boxes designed by Acorn Computers, Acorn Online Media. The trial commenced at a speed of 2 Mbit/s to the home, subsequently increased to 25 Mbit/s."Cambridge Corners the Future in Networking"
Role of peer-to-peer file sharingPeer-to-peer (P2P) file sharing, file-sharing software allows the distribution of content without the linear costs associated with centralised streaming media. This innovation proved it is technically possible to offer the consumer potentially every film ever made, and the popularity and ease of use of such services may have motivated the rise of centralised video-on-demand services. Some services such as Spotify use peer-to-peer distribution to better scale their platforms. Netflix was reported to be considering switching to a P2P model to cope with net neutrality problems from Downstream (networking), downstream providers.
TransactionalTransactional video on demand (TVOD) is a distribution method by which customers pay for each piece of video-on-demand content. For example, a customer would pay a fee for each movie or TV show that they watch. TVOD has two sub-categories: electronic sell-through (EST), by which customers can permanently access a piece of content once purchased via the Internet; and download to rent (DTR), by which customers can access the content for a limited time upon renting. Examples of TVOD services include the Apple iTunes Store and the Google Play Store, as well as VOD rental services offered through multichannel television (i.e., cable or satellite) providers.
PremiumPremium video on demand (PVOD) is a version of TVOD which allows customers to access video-on-demand content sooner than they would have been able to otherwise – often feature films made available alongside, or in place of, a traditional release in movie theaters – but at a much higher price point. A version of the model was tested in 2011 by American satellite TV provider DirecTV under the brand name "Home Premiere", which allowed viewers to rent select films from major studios for US$30 per rental as soon as 60 days after they debuted in cinemas, compared to 120 days for the regular TVOD window; this version only lasted a few months. PVOD made a return during the COVID-19 pandemic and the resulting Impact of the COVID-19 pandemic on cinema, global closures of cinemas. Certain films that had already been released including ''The Invisible Man (2020 film), The Invisible Man'' were quickly also released on VOD platforms for a higher rental price than usual, while other films including ''Trolls World Tour'' were released Simultaneous release, simultaneously on PVOD and in drive-in theaters, or in some cases directly to PVOD only. In most cases, these PVOD releases are offered through most of the same platforms as traditional TVOD, but at a higher price point, typically about US$20 for a 48-hour rental; this offering has again been branded as "Home Premiere" by some studios and platforms. The Walt Disney Company, Disney used the September 2020 release of Mulan (2020 film), the live-action remake of ''Mulan'' to launch a related model called Disney+#Premier Access, Premier Access; this requires customers to pay a premium fee (approximately US$26-30 depending on country) on top of a subscription to the Disney+ streaming service, but they then retain access as long as they maintain their subscription (for ''Mulan'', this was effectively a 90-day rental, as the film became available to all Disney+ subscribers at no extra charge in December).
Catch-up TVA growing number of television stations offer "catch-up TV" as a way for viewers to watch programmes though their VOD services after the original television broadcast is over. Some studies show that catch-up television is starting to represent a large part of the views and watch-hours and that users tend to watch catch-up TV programmes for longer when compared to live television watching.
Subscription modelsSubscription VOD (SVOD) services use a subscription business model in which subscribers are charged a regular fee to access unlimited programmes. Examples of these services include Netflix, Amazon Prime Video, Disney+, Voot, HBO Max and Hulu.
Near video on demandNear video on demand (NVOD) is a pay-per-view consumer video technique used by multi-channel broadcasters using high-bandwidth distribution mechanisms such as satellite and cable television. Multiple copies of a programme are broadcast at short time intervals (typically staggered on a schedule of every 10–20 minutes) on linear channels providing convenience for viewers, who can watch the programme without needing to tune in at the only scheduled point in time. A viewer may only have to wait a few minutes before the next time a movie will be programmed. This form is bandwidth-intensive, reduces the number of channels a provider can offer, and is generally provided by large operators with a great deal of redundant capacity. This concept has been reduced in popularity as video on demand is implemented, along with providers often wanting to provide the maximum throughput for their broadband services possible. Only the satellite services DirecTV and Dish Network continue to provide NVOD services, as they do not offer broadband and much of their rural customer base only has access to slower dial-up internet access, dial-up and non-5G wireless and Satellite Internet access, satellite internet options which cannot stream films or have onerous data caps (and where possible, AT&T is now prioritizing their streaming service AT&T TV, which utilizes a fully immediate VOD experience, over DirecTV). Before the rise of VOD, the cable pay-per-view provider In Demand provided up to 40 channels in 2002, with several films receiving four channels on a staggered schedule to provide the NVOD experience for viewers. As of 2018, most cable pay-per-view channels now number mainly 3–5, and are used mainly for live ring sports events (boxing and professional wrestling), comedy specials, and concerts, though the latter two sources are declining due to streaming services offering much more lucrative performance contracts to performers, and several ring sports organisations (mainly UFC and WWE) now prefer direct marketing of their product via streaming services such as ESPN+, the WWE Network, and the apps of Fox Sports (United States), Fox Sports over pay-TV providers which require a portion of the profits they otherwise retain directly. In Australia, pay-TV broadcaster Foxtel offers NVOD for new-release movies over their satellite service. Edge Spectrum, an American holder of low-power broadcasting licenses, has an eventual business plan to use its network and a system of digital video recorders to simulate the video-on-demand experience. Most of Edge Spectrum's channels, where they are on air, carry televangelism.
Push video on demandPush video on demand is so-named because the provider "pushes" the content out to the viewer's set-top box without the viewer having requested the content. This technique is used by several broadcasters on systems that lack the connectivity and bandwidth to provide true "streaming" video on demand. Push VOD is also used by broadcasters that want to optimize their video streaming infrastructures by pre-loading the most popular contents to the consumers' set-top device. If the consumer requests one of these films, it is already loaded on her or his DVR. A push VOD system uses a personal video recorder (PVR) to store a selection of content, often transmitted in spare capacity overnight or all day long at low bandwidth. Users can watch the downloaded content at the time they desire, immediately and without any buffering issues. Push VOD depends on the viewer recording content so choices can be limited.
Advertising video on demandAdvertising video on demand (AVOD) uses an advertising-based revenue model. This allows companies that advertise on broadcast and cable channels to reach people who watch shows using VOD. This model also allows people to watch content without paying subscription fees. Hulu was a major AVOD company before ending its free service in August 2016, transferring it to Yahoo! View using the existing Hulu infrastructure. Sony Crackle has introduced a series of advertisements for the same company that ties into the content that is being watched. Ad-Supported Video on Demand (ASVOD) refers to video services that provide free content supported by advertisements. Popular services include Pluto TV, the Roku Channel, Crackle (streaming service), Crackle, Tubi, Vudu, and YouTube. Walmart is adding ASVOD original programming to Vudu, and YouTube Originals will be ASVOD by 2020.
See also* BitTorrent * Comparison of video hosting services * Direct-to-video * Electronic sell-through * Music on demand * Over-the-top media service * Streaming media *Trick mode
Further reading* * What is Broadcaster VOD