what is VOD
Video on demand
(VOD) are systems which allow users to select and watch/listen to video or
audio content when they choose to, rather than having to watch at a specific
broadcast time. IPTV technology is often used to bring video on demand to
televisions and personal computers.
Television
VOD systems can either stream content through a set-top box, a computer or
other device, allowing viewing in real time, or download it to a device such as
a computer, digital video recorder (also called a personal video recorder) or
portable media player for viewing at any time. The majority of cable- and
telco-based television providers offer both VOD streaming, including
pay-per-view and free content, whereby a user buys or selects a movie or
television program and it begins to play on the television set almost
instantaneously, or downloading to a DVR rented from the provider, or
downloaded onto a PC, for viewing in the future. Internet television, using the
Internet, is an increasingly popular form of video on demand.
Some airlines offer VOD as in-flight entertainment
to passengers through individually controlled video screens embedded in
seatbacks or armrests or offered via portable media players. Some video on
demand services such as Netflix use a subscription model that requires users to
pay a monthly fee to access a bundled set of content. Other services use an
advertising-based model, where access is free for users, and the platforms rely
on selling advertisements as a main revenue stream.
Early development
Early development
Developing VOD required extensive negotiations to
identify a financial model that would serve both content creators and cable
providers while providing desirable content for viewers. Key factors identified
for determining the economic viability of the VOD model included VOD movie buy
rates, 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 content that was already provided in linear
distribution. Included in these packages were “extras” and “bonus footage”
rather than full episodes of television shows.
Functionality
Functionality
Download and streaming video on demand systems
provide the user with all of the features of Portable media players and DVD
players. Some VOD systems that store and stream programs from hard disk drives
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, in which case they can provide very rapid response to users.
Streaming video servers can also serve a wider community via a WAN, in which
case the responsiveness may be reduced. Download VOD services are practical to
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 as well as 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).
History
History
From September 1994, a VOD service formed a major
part of the Cambridge Digital Interactive Television Trial in England. This
provided video and data to 250 homes and a number of 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 1998, Kingston Communications became the first
UK company to launch a fully commercial VOD service and the first to integrate
broadcast TV 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 a number of trials, HomeChoice followed in 1999, but were restricted to
London. After attracting 40,000 customers, they were bought by Tiscali in 2006
who were 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. BSkyB
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 same content.
Other UK TV broadcasters have implemented their own versions of the same
technology, such as the BBC’s iPlayer, which launched on 25 December 2007, and
Channel 4’s 4oD (4 On Demand) which 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
Video-on-Demand publishers such as US based VEOH and UK based Craze’s
OnlineMoviesBox 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 investigated by the Competition Commission.
That same year, the assets of the defunct Kangaroo project were bought by
Arqiva. who used the technology behind Kangaroo to launch the SeeSaw service in
February 2010. A year later, however, SeeSaw was shut down from 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) who use the large downstream bandwidth
present on cable systems to deliver movies and television shows to end users,
who 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 TV systems.
Both EchoStar/Dish Network and DirecTV offer video on demand programming to
PVR-owning subscribers of their satellite TV service. 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 quite common in more expensive hotels. VOD
systems that store and provide a user interface for content downloaded directly
from the Internet are widely available.[citation needed]
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 January 2010 Consumer Electronic Show in Las
Vegas, Sezmi CEO Buno Pati and president Phil Wiser showed a set-top box with a
one-terabyte hard drive which could be used for video on demand services
previously offered through cable TV or 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 broadcast spectrum to offer a
subscription service which National Association of Broadcasters president
Gordon H. Smith said would provide a superior picture to that of cable or
satellite, at a lower cost. Role of piracy and peer to peer
Although video on demand generally refers to
delivery mechanisms operating in accordance with applicable laws, the
motivation for the development of video on demand services can be traced back
to peer-to-peer networking and the development of file sharing software. These
innovations proved that it was technically possible to offer the consumer
potentially every film ever made, in a way that does not burden the original
provider without the linear costs associated with centralised streaming media.
Many legal services such as Spotify use peer to
peer distribution to better scale their platforms with the likes of Netflix
considering doing so to cope with net neutrality problems from downstream
providers.
Torrenting is a popular alternative to legal
streaming with 6% of global internet traffic involved in file sharing
applications.
A growing number of TV stations offer Catch up TV
as a way to watch TV shows though their VOD service for a period of days after
the original television broadcast.
Subscription models
Subscription models
Subscription VOD services use a subscription
business model, where subscribers are charged a monthly fee to access unlimited
programs. These services include Netflix, Hulu Plus, Amazon Instant Video and
HBO Go. Near video on demand
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The examples and perspective in this section may not represent a worldwide view of the subject. Please improve this article or discuss the issue on the talk page. (February 2015)
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The examples and perspective in this section may not represent a worldwide view of the subject. Please improve this article or discuss the issue on the talk page. (February 2015)
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
10–20 minutes) providing convenience for viewers, who can watch the program
without needing to tune in at a scheduled point in time. This form is bandwidth
intensive and is generally provided only by large operators with a great deal
of redundant capacity and has been reduced in popularity as video on demand is
implemented; only the satellite services Dish Network and DirecTV continue to
seriously provide NVOD experiences out of necessity as many of their customers
have no access to their broadband VOD servies. Before the rise of video on
demand, pay-per-view provider In Demand facilitated this need by providing up
to 40 channels in 2002, with several films receiving up to four channels on the
staggered schedule to provide the NVOD experience. As of 2014, only four
channels (2 in high definition, two in standard definition) are provided to
facilitate live and event coverage, along with existing league out-of-market
sports coverage channels (varied by provider) by the service.
Push video on demand
Push video on demand
Push video on demand is a technique used by a
number of broadcasters on systems that lack connectivity to provide true video
on demand or by broadcasters who want to optimize their video streaming
infrastructure by pre-loading the most popular contents to the consumer device.
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 issue. As content occupies space on the
PVR hard drive, downloaded content is usually deleted after a week to make way
for newer programs. The limited space on a PVR hard drive means that the
selection of programs is usually restricted to most popular content. A new
generation of Push VOD solution recently appeared on the market which, by using
efficient error correction mechanisms, can free significant amount of bandwidth
and that can deliver more than video e.g. magazines, interactive applications.
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