Video on demand
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Video on demand (VOD) is a video media distribution system that allows users to access video entertainment without a traditional video entertainment device and without the constraints of a typical static broadcasting schedule. In the 20th century, broadcasting in the form of over-the-air programming was the commonest form of media distribution. As Internet and IPTV technologies continued to develop in the 1990s, consumers began to gravitate towards non-traditional modes of content consumption, which culminated in the arrival of VOD on televisions and personal computers.
Unlike broadcast television, VOD systems initially required each user to have an Internet connection with considerable bandwidth to access each system's content. In 2000, the Fraunhofer Institute IIS developed the JPEG2000 codec, which enabled the distribution of movies via Digital Cinema Packages. This technology has since expanded its services from feature-film production to include broadcast television and has resulted in lower bandwidth requirements for VOD applications. Disney, Paramount, Sony, Universal and Warner Bros. subsequently launched the Digital Cinema Initiative, in 2002.
Television VOD systems can stream content, either through a traditional set-top box or through remote devices such as computers, tablets, and smartphones. VOD users can permanently download content to a device such as a computer, digital video recorder or a portable media player for continued viewing. The majority of cable and telephone company-based television providers offer VOD streaming, whereby a user selects a video program that begins to play immediately or downloading to a digital video recorder (DVR) rented or purchased from the provider, or to a PC or to a portable device for delayed viewing.
Internet television has emerged as an increasingly popular medium of VOD provision. Desktop client applications such as the Apple iTunes online content store and Smart TV apps such as Amazon Prime Video allow temporary rentals and purchases of video entertainment content. Other internet-based VOD systems provide users with access to bundles of video entertainment content rather than individual movies and shows. The most common of these systems, Netflix, Hulu and Disney+, use a subscription model that requires users to pay a monthly fee for access to bundle of movies, television shows, and original series. In contrast, YouTube, another internet-based VOD system, uses an advertising-funded model in which users can access most of YouTube's video content free of charge but must pay a subscription fee for premium content. Some airlines offer VOD services as in-flight entertainment to passengers through video screens embedded in seats or externally provided portable media players.
Downloading 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 programs from hard disk drives and use a memory buffer to allow the user to fast forward and rewind videos. It is possible to put video 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[when?] 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.[clarification needed] Streaming video servers can serve a wide community via a 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).
VOD services first appeared in the early 1990s. Until then, it was not thought possible that a television program 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 200 Mbps, 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 Nasir Ahmed in 1972, and was later adapted into a 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 100 kbps to 2 Mbps, while DCT compression reduced the required bandwidth of a television signal from around 200 Mbps down to 2 Mpps. The combination of DCT and ADSL technologies made it possible to practically implement VOD services at around 2 Mbps 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 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 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 ICL media server to set-top boxes designed by Acorn Online Media. The trial commenced at a speed of 2 Mbit/s to the home, subsequently increased to 25 Mbit/s. The content was provided by the BBC and Anglia Television. Although a technical success, difficulty in sourcing content was a major issue and the project closed in 1996.
In 1997, Enron Corporation had entered the broadband market, constructing and purchasing thousands of miles of fiber-optic cables throughout the United States. In 2001, Enron and Blockbuster Inc. attempted to create a 20-year deal to stream movies on demand over Enron's fiber-optic network. The heavily promoted deal fell through, with Enron's share prices dropping following the announcement.
In 1998, Kingston Communications became the first UK company to launch a fully commercial VOD service and the first to integrate broadcast television and Internet access through a single set-top box using IP delivery over ADSL. By 2001, Kingston Interactive TV had attracted 15,000 subscribers. After several trials, Home Choice followed in 1999 but was restricted to London. After attracting 40,000 customers, they were bought by Tiscali in 2006 which was, in turn, bought by Talk Talk in 2009. Cable TV providers Telewest and NTL (now Virgin Media) launched their VOD services in the United Kingdom in 2005, competing with the leading traditional pay-TV distributor BSkyB, which responded by launching Sky by broadband, later renamed Sky Anytime on PC. The service went live on 2 January 2006. Sky Anytime on PC uses a legal peer-to-peer approach based on Kontiki technology to provide very-high-capacity multi-point downloads of the video content. Instead of the video content all being downloaded from Sky's servers, the content comes from multiple users of the system who have already downloaded the content. Other UK television broadcasters implemented their own versions of the same technology, such as the BBC's iPlayer, which was launched on 25 December 2007, and Channel 4's 4oD (4 on Demand), which was launched in late 2006. Another example of online video publishers using legal peer-to-peer technology is based on Giraffic technology, which was launched in early 2011, with large online VOD publishers such as US-based VEOH and UK based Craze's Online Movies Box movie rental service.
The BBC, ITV and Channel 4 planned to launch a joint platform provisionally called Kangaroo in 2008. This was abandoned in 2009 following complaints, which were investigated by the Competition Commission. In that same year, the assets of the now-defunct Kangaroo project were acquired by Arqiva, who used the technology to launch the SeeSaw service in February 2010. A year later, however, SeeSaw was shut down due to a lack of funding.
VOD services are now available in all parts of the United States, which has the highest global take-up rate of VOD. In 2010, 80% of American Internet users had watched video online, and 42% of mobile users who downloaded video preferred apps to a normal browser. Streaming VOD systems are available on desktop and mobile platforms from cable providers (in tandem with cable modem technology). They use the large downstream bandwidth present on their cable systems to deliver movies and television shows to end-users. These viewers can typically pause, fast-forward, and rewind VOD movies due to the low latency and random-access nature of cable technology. The large distribution of a single signal makes streaming VOD impractical for most satellite television systems. Both EchoStar/Dish Network and DirecTV offer VOD programming to PVR-owning subscribers of their satellite TV service. In Demand is a cable VOD service that also offers pay-per-view. Once the programs have been downloaded onto a user's PVR, he or she can watch, play, pause, and seek at their convenience. VOD is also common in expensive hotels.
According to the European Audiovisual Observatory, 142 paying VOD services were operational in Europe at the end of 2006. The number increased to 650 by 2009. At the 2010 Consumer Electronics Show in Las Vegas, Nevada, Sezmi CEO Buno Pati and president Phil Wiser showed a set-top box with a one-terabyte hard drive that could be used for video-on-demand services previously offered through cable television and broadband. A movie, for example, could be sent out once using a broadcast signal rather than numerous times over cable or fiber-optic lines, and this would not involve the expense of adding many miles of lines. Sezmi planned to lease part of the broadcast spectrum to offer a subscription service that National Association of Broadcasters President Gordon H. Smith said would provide a superior picture to that of cable or satellite at a lower cost.
Developing VOD requires extensive negotiations to identify a financial model that would serve both content creators and cable providers while providing desirable content for viewers at an acceptable price point. Key factors identified for determining the economic viability of the VOD model include VOD movie buy-rates and setting Hollywood and cable operator revenue splits. Cable providers offered VOD as part of digital subscription packages, which by 2005 primarily allowed cable subscribers to only access an on-demand version of the content that was already provided in the linear traditional broadcasting distribution. These on-demand packages sometimes include extras and bonus footage in addition to the regular content.
Role of peer-to-peer file sharing
Peer-to-peer (P2P) file-sharing software allows the distribution of content without the linear costs associated with centralized 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 centralized 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 providers.
Transactional 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 Apple iTunes online store and Google Play service.
A growing number of television stations offer "catch-up TV" as a way for viewers to watch programs though their VOD services after the original television broadcast. Some studies show catch-up television is starting to represent a large amount of the views and hours watched and that users tend to watch catch up TV programs for longer when compared to live television watching.
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Subscription VOD (SVOD) services use a subscription business model in which subscribers are charged a regular fee to access unlimited programs. Examples of these services include Netflix, Amazon Prime Video, Disney+ and Hulu.
Near video on demand
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Near 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 program 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 program 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 and non-5G wireless and 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 organizations (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 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 demand
Push 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 demand
Advertising 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 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, Sony Crackle, Tubi, Vudu, and YouTube. Walmart is adding ASVOD original programming to Vudu, and YouTube Originals will be ASVOD by 2020.
- Comparison of video hosting services
- Electronic sell-through
- Music on demand
- Over-the-top media service
- Streaming media
- "Advertising Terminology: A Primer for the Uninitiated or Confused". Videa. 16 May 2016. Retrieved 24 December 2018.
- Martínez-del-Amor, Miguel Á.; Martínez-del-Amor, Miguel Á; Bruns, Volker; Sparenberg, Heiko (2017). "Parallel efficient rate control methods for JPEG 2000". Applications of Digital Image Processing XL: Paper 103960R, 16.
- "Digital Cinema Initiatives (DCI) - DIGITAL CINEMA SYSTEM SPECIFICATION, VERSION 1.2". www.dcimovies.com. Retrieved 4 September 2019.
- Bouma, Luke (23 December 2018). "The Roku Channel Is the Most Popular FREE Streaming Service Beating Out Pluto TV, Sony Crackle, & Tubi (2018 Cordie Awards)". Cord Cutters News. Retrieved 24 December 2018.
- Lea, William (1994). Video on demand: Research Paper 94/68. 9 May 1994: House of Commons Library. Retrieved 20 September 2019.CS1 maint: location (link)
- Ahmed, Nasir (January 1991). "How I Came Up With the Discrete Cosine Transform". Digital Signal Processing. 1 (1): 4–5. doi:10.1016/1051-2004(91)90086-Z.
- Ghanbari, Mohammed (2003). Standard Codecs: Image Compression to Advanced Video Coding. Institution of Engineering and Technology. pp. 1–2. ISBN 9780852967102.
- Li, Jian Ping (2006). Proceedings of the International Computer Conference 2006 on Wavelet Active Media Technology and Information Processing: Chongqing, China, 29-31 August 2006. World Scientific. p. 847. ISBN 9789812709998.
- "Brand Playbook: What you need to know about ad-supported video-on-demand". Ad Age. Retrieved 24 December 2018.
- "S. Rept. 104-357 - THE NATIONAL INFORMATION INFRASTRUCTURE PROTECTION ACT OF 1995". www.congress.gov. Retrieved 4 September 2019.
- , "Service delivery using broadband", issued 1995-02-16
- "The potential of ad-supported, on-demand video". SmartBrief. Retrieved 24 December 2018.
- "SGI Ready Opposing Video-Server Architectures: Video on Demand Battle", Electronic Engineering Times, 4 October 1993, p. 1.
- "Video Servers: nCube and Oracle Challenge IBM", Computergram International, 29 October 1993, p. 17.
- Daniel Minoli, Video Dialtone Technology, 1995, pp. 441–485.
- Daniel Minoli, Video Dialtone Technology, 1995, p. 233.
- "Building the Data Highway", Byte, March 1994, p. 46.
- "Cambridge iTV Trial". University of Cambridge. Retrieved 31 August 2017.
- "Cambridge Corners the Future in Networking", TUANZ Topics, Volume 05, No. 10, November 1995.
- Schiesel, Seth (11 July 1999). "Jumping Off the Bandwidth Wagon". The New York Times. Retrieved 17 February 2017.
- "Montana Power, Williams Communications, Enron Units Announce Fiber Providers for Portland-to-Los Angeles Network" (Press release). PR Newswire. 17 December 1997. Archived from the original on 17 February 2017. Retrieved 17 February 2017.
- Behr, Peter (1 January 2001). "Broadband Strategy Got Enron in Trouble; Bid to Create Market for Fiber-Optic Space Included Aggressive Accounting". The Washington Post. p. E01.
- "UPDATE KC Bringing Fibre Optic Broadband to 105,000 Hull UK Premises - ISPreview UK". www.ispreview.co.uk. Retrieved 1 November 2019.
- "Sky by Broadband rebrands as Sky Anytime on PC". www.campaignlive.co.uk. Retrieved 1 November 2019.
- Sweney, Mark (27 November 2007). "Broadcasters to launch joint VoD service". The Guardian. London. Retrieved 13 January 2008.
- "Arqiva to launch video-on-demand service using Kangaroo technology". BBC. 23 July 2009. Retrieved 25 September 2012.
- "Internet TV service Seesaw launches beta trial". BBC. 26 January 2010. Retrieved 25 September 2012.
- Clover, Julian (27 May 2011). "Arqiva to close SeeSaW". Broadband TV News. Retrieved 25 September 2012.
- "Percentage of subscribers who use video on demand on the TV by country in 2010 and 2011". Statista. Retrieved 30 August 2012.
- "Archived copy". Archived from the original on 26 November 2010. Retrieved 16 November 2010.CS1 maint: archived copy as title (link)
- Saylor, Michael (2012). The Mobile Wave: How Mobile Intelligence Will Change Everything. Perseus Books/Vanguard Press. p. 86. ISBN 978-1593157203.
- Video on demand and catch-up TV in Europe Archived 3 October 2011 at the Wayback Machine
- Dickson, Glen (9 January 2010). "NAB Shows Off New Spectrum Applications". Broadcasting & Cable. Retrieved 13 January 2010.
- Rizzuto, Ronald J.Wirth (2002). "The Economics of Video on Demand: A Simulation Analysis". Journal of Media Economics. 15 (3): 209. doi:10.1207/s15327736me1503_5.
- Johnson, James (8 February 2019). "VOD vs OTT: Seriously, what's the difference? [Infographic]". Uscreen. Retrieved 1 November 2019.
- Ernesto. "Spotify: A Massive P2P Network, Blessed by Record Labels". Retrieved 22 March 2014.
- Brinkmann, Martin. "Could Netflix switch to P2P to lower ISP pressure?". Retrieved 22 March 2014.
- Kehoe, Keith. "VOD Rights Models". Retrieved 9 December 2015.
- Kaysen, Mads (24 August 2015). "Understand the "SVOD", "TVOD" and "AVOD" terms and business models of streaming services like Netflix". LinkedIn. Retrieved 9 December 2015.
- Brodkin, Jon (4 March 2020). "Struggling AT&T plans "tens of billions" in cost cuts, more layoffs". Ars Technica. Retrieved 4 March 2020.
- "Echelon Studios". Echelon Studios.
- Foxtel Support. "Rent Store + Box Office titles – Store + Box Office". foxtel.com.au. Retrieved 9 December 2015.
- EdgeSpectrum.com, retrieved February 19, 2020.
- Anderson, Casey. "What Is VOD Technology?". Houston Chronicle.
- Baysinger, Tim (15 August 2016). "For Ad VOD Players, Success Is Blend of Linear, Digital Models". Broadcasting & Cable: 18.
- "Tech Tweets". Broadcasting & Cable: 23. 15 August 2016.
- Bouma, Luke (23 December 2018). "The Roku Channel Is the Most Popular FREE Streaming Service Beating Out Pluto TV, Sony Crackle, & Tubi (2018 Cordie Awards)". Cord Cutters News. Retrieved 24 December 2018.
- Petley, Julian (July 2014). "The regulation of pornography on video-on-demand in the United Kingdom". Porn Studies. 1 (3): 260–284. doi:10.1080/23268743.2014.927705.
- What is Broadcaster VOD. Broadcaster Video On Demand is an exciting and evolving landscape which offers advertisers a host of premium advertising opportunities around trusted, quality content. It’s an important part of the new TV ecosystem that is helping people to watch more of the TV they love.
- Broadcaster VOD services. There are a host of different VOD services from the UK broadcasters all brimming with opportunities for advertisers. Here you’ll find an overview of the key players and their on-demand services by platform
- Broadcaster VOD advertising formats. From clickable pre-rolls to full interactivity, broadcaster VOD advertising is always innovating. Here you can get the low down on the various VOD formats currently available from the UK TV companies
- Marriott, Michel (6 August 2007). "Nothing to Watch on TV? Streaming Video Appeals to Niche Audiences". The New York Times. Retrieved 1 April 2008.
- "Google entering video-on-demand business". CNET News. 9 January 2006. Retrieved 23 May 2016.
- "On-demand media: Re-inventing the retail business model". Screen Digest. March 2008. Archived from the original on 18 March 2008. Retrieved 1 April 2008.
- "Pioneer Optical Disc Expertise Advances On-Demand DVD Entertainment". Reuters. 6 January 2008. Retrieved 1 April 2008.
- Lotz, Amanda D. (2007) "The Television Will Be Revolutionized". New York, NY: New York City University Press. p. 59
- McGregor, Michael A., Driscoll, Paul D., McDowell, Walter (2010) “Head’s Broadcasting in America: A Survey of Electronic Media”. Boston, Massachusetts: Allyn & Bacon p. 47–48.
- "The Video on Demand Business Index". Archived from the original on 18 April 2016. Retrieved 27 April 2011.
- "MAVISE, Database on television and on-demand audiovisual services in Europe (European Audiovisual Observatory)".
- "Market intelligence on the VoD markets in Europe (European Audiovisual Observatory)".