Content deleted Content added
m improved images |
m added a few more citations to the first & second section for completeness |
||
Line 35:
'''Interoperable Master Format (IMF)''' is a [[Container format (computing)|container format]] for the digital delivery and storage of finished audio-visual masters, including movies, episodic content and advertisements.
In IMF, each kind of [[Essence (media)|essence]] (video, audio, subtitles, etc.) is stored in individual media files (“Track Files”) and the instructions for synchronizing these media files are stored in a separate playlist file (“Composition Playlist”)<ref name=":3" />. This component-based approach allows the large media files to be reused across multiple playlists, each representing a different version of the content<ref>{{Cite web |last=2018-09-16T11:26:00+01:00 |title=IMF: A gateway to component-based workflows |url=https://www.ibc.org/thought-leadership/imf-a-gateway-to-component-based-workflows/3204.article |access-date=2022-05-20 |website=IBC |language=en}}</ref>.
The IMF family of standards is maintained by [[Society of Motion Picture and Television Engineers|SMPTE]].<ref name=":0">{{Cite journal |date=August 2021 |title=OV 2067-0-2021 - SMPTE Overview Document - Interoperable Master Format |url=https://ieeexplore.ieee.org/document/9521128/ |journal=OV 2067-0-2021 |pages=1–4 |doi=10.5594/SMPTE.OV2067-0-2021}}</ref> Its first edition was published in 2013.
Line 42:
At the heart of IMF is the Composition, illustrated in the first image, which consists of a single Composition Playlist and a collection of Track Files. Each Composition corresponds to a single audio-visual master.
[[File:IMF Composition (CPL) Example.png|alt=An IMF Composition is defined by a Composition Play List|thumb|IMF Composition Example]]
Each Track File contains a single kind of essence corresponding to a single aspect of the presentation. For example, a first Track File might contain the primary video program while a second might contain Spanish stereo audio and a third English subtitles. Track Files use a constrained version of the MXF OP1a format [[Material Exchange Format]]<ref name=":1" />
The Composition Playlist is an [[XML]] document<ref>{{Cite journal |date=2020-05 |title=ST 2067-3:2020 - SMPTE Standard - Interoperable Master Format — Composition Playlist |url=https://ieeexplore.ieee.org/document/9097510/ |journal=ST 2067-3:2020 |pages=1–35 |doi=10.5594/SMPTE.ST2067-3.2020}}</ref>. It assembles the Track Files<ref>{{Cite journal |date=2020-05 |title=ST 2067-5:2020 - SMPTE Standard - Interoperable Master Format — Essence Component |url=https://ieeexplore.ieee.org/document/9099734/ |journal=ST 2067-5:2020 |pages=1–15 |doi=10.5594/SMPTE.ST2067-5.2020}}</ref> onto virtual tracks that are synchronized onto a timeline. It also contains metadata associated with that timeline.The combination of a Composition Playlist and the Track Files it references is called a Composition.
The primary benefit of separating the Composition Playlist from the Track Files is that a Track File can be reused across multiple Compositions as shown in the second image. Each Composition represents a different version of an audio-visual work. Since different versions of a title typically differ in small ways and this component-based approach results in smaller files, fewer quality control passes and fewer resources expended on mastering the multiple versions. For example, a censored version of a movie might differ in only a few video frames from the original. Instead of having to deliver or store two largely identical versions, IMF allows the censored version to reuse the Track Files of the original version.
Line 72:
== History ==
The need for IMF arose from various projects in the film and television industries<ref>{{Cite web |title=© 2011 AmberFin Limited Loose Coupling for Multipurpose Distribution Bruce Devlin Chief Technical Officer. - ppt download |url=https://slideplayer.com/slide/7416420/ |access-date=2022-04-01 |website=slideplayer.com}}</ref> that identified component-based working as a more efficient mechanism for handling the very large volumes of very large files created when delivering cinema and television content around the globe<ref>{{Cite web |last=Blog |first=Netflix Technology |date=2017-04-19 |title=The Netflix IMF Workflow |url=https://netflixtechblog.com/the-netflix-imf-workflow-f45dd72ed700 |access-date=2022-04-01 |website=Medium |language=en}}</ref>. With help from the [[Entertainment Technology Center]]<ref>{{Cite web |title=ETC |url=https://www.etcenter.org/imf-version-1-0-launches/ |access-date=2022-04-01 |website=www.etcenter.org}}</ref>, the [[Society of Motion Picture and Television Engineers|SMPTE]] created the first version of the standard in 2013. The IMF User Group (IMF UG) was created by the [[Hollywood Professional Association]] shortly after and the IMF UG fosters active discussions between content owners, technologists, logistics specialists and software providers on best current practise for delivering large volumes of localised content in a resource efficient way. The IMF UG has created an IMF explainer in miultiple languages<ref name=":3">{{Cite web |title=EXPLAINER: Interoperable Master Format (IMF) – IMF UG |url=https://www.imfug.com/explainer/ |access-date=2022-04-01 |language=en-US}}</ref>.
== References ==
| |||