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{{Short description|Standard for mastering and localising media}}
{{About|1=the video format|2=other uses|3=IMF (disambiguation)}}
{{Distinguish|Id Software#IMF Music File Format{{!}}IMF (file format)}}
{{Use dmy dates|date=August 2021}}
{{Infobox file format
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'''Interoperable Master Format (IMF)''' is a [[Container format (computing)|container format]] for the [[Standardization|standardized]] 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, ST 2067, is maintained by [[Society of Motion Picture and Television Engineers|SMPTE]].<ref name=":0">{{Cite journal |date=August 2021
IMF is closely related to [[Digital Cinema Package]] (“DCP”), leveraging several of the same standards for packaging and architecture.
== Architecture ==
The core 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 specific essence corresponding to a single aspect of the presentation. Track Files are both organized and limited by parameters such as resolution, color space, frame rate, audio sound field, etc. Track Files of disparate parameters may not be mixed in a Composition. 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=May 2020 |title=ST 2067-3:2020 - SMPTE Standard - Interoperable Master Format — Composition Playlist |url=https://ieeexplore.ieee.org/document/9097510 |archive-url=https://web.archive.org/web/20201025204418/https://ieeexplore.ieee.org/document/9097510 |url-status=dead |archive-date=25 October 2020 |journal=St 2067-3:2020 |pages=1–35 |doi=10.5594/SMPTE.ST2067-3.2020|isbn=978-1-68303-214-4 |doi-access=free }}</ref> It assembles the Track Files<ref>{{Cite journal |date=May 2020 |title=ST 2067-5:2020 - SMPTE Standard - Interoperable Master Format — Essence Component |url=https://ieeexplore.ieee.org/document/9099734 |archive-url=https://web.archive.org/web/20201021025124/https://ieeexplore.ieee.org/document/9099734 |url-status=dead |archive-date=21 October 2020 |journal=St 2067-5:2020 |pages=1–15 |doi=10.5594/SMPTE.ST2067-5.2020|isbn=978-1-68303-213-7 |doi-access=free |url-access=subscription }}</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.
Each Composition represents a different version of an audio-visual work. Separating the Composition Playlist from the Track Files allows reuse of Track Files across multiple Compositions, as shown in the reuse example diagram. [[File:IMF Track File Re-use Example.svg|alt=IMF can re-use Track Files to minimize resource usage for versions of audio-viual works.|thumb|IMF Track File Reuse]]
== Specifications ==
IMF is specified in the ST 2067 family of standards managed by [[Society of Motion Picture and Television Engineers|SMPTE]].<ref name=":0" />
IMF is organized into three main categories:
* core constraints,<ref name=":1" /> to which all IMF implementations conform and representing the bulk of the IMF standard;
* applications, which target specific use cases; and
* plug-ins, which contain optional technology that can be used across multiple applications.
The core constraints are specified in SMPTE ST 2067-2 (Core Constraints).<ref name=":1">{{Cite journal |date=May 2020 |title=ST 2067-2:2020 - SMPTE Standard - Interoperable Master Format — Core Constraints |url=https://ieeexplore.ieee.org/document/9097478 |archive-url=https://web.archive.org/web/20201025194936/https://ieeexplore.ieee.org/document/9097478 |url-status=dead |archive-date=25 October 2020 |journal=St 2067-2:2020 |pages=1–43 |doi=10.5594/SMPTE.ST2067-2.2020|isbn=978-1-68303-211-3 |doi-access=free }}</ref> An example of an application is Application #2E, which is specified in SMPTE ST 2067-21<ref name=":2">{{Cite journal |date=May 2020 |title=ST 2067-21:2020 - SMPTE Standard - Interoperable Master Format — Application #2E |url=https://ieeexplore.ieee.org/document/9097487 |archive-url=https://web.archive.org/web/20200929152305/https://ieeexplore.ieee.org/document/9097487 |url-status=dead |archive-date=29 September 2020 |journal=St 2067-21:2021 |pages=1–34 |doi=10.5594/SMPTE.ST2067-21.2020|isbn=978-1-68303-212-0 |doi-access=free }}</ref> and targets studio masters. One of the plugins is the Immersive Audio Bitstream Level 0 Plug-in, which is specified in SMPTE ST 2067-201<ref>{{Cite journal |date=January 2021 |title=ST 2067-201:2021 - SMPTE Standard - Immersive Audio Bitstream Level 0 Plug-in |url=https://ieeexplore.ieee.org/document/9343937 |archive-url=https://web.archive.org/web/20210203090109/https://ieeexplore.ieee.org/document/9343937/ |url-status=dead |archive-date=3 February 2021 |journal=St 2067-201:2021 |pages=1–14 |doi=10.5594/SMPTE.ST2067-201.2021|isbn=978-1-68303-238-0 |url-access=subscription }}</ref> and adds support for immersive sound.
== Example uses ==
IMF is specified by professional content creators for delivery of their content, including: BBC,<ref>{{Cite web |title=TechnicalDeliveryStandardsBBCUHDiPlayerSupplement.pdf |url=https://www.dropbox.com/s/tkvwxksgy3izpca/TechnicalDeliveryStandardsBBCUHDiPlayerSupplement.pdf?dl=0 |access-date=2022-03-04 |website=Dropbox |language=en}}</ref> Netflix<ref>{{Cite web |title=Netflix Branded Delivery Specifications v4.1 |url=https://partnerhelp.netflixstudios.com/hc/en-us/articles/214806618-Netflix-Branded-Delivery-Specifications-v4-1 |access-date=2022-03-04 |website=Netflix {{!}} Partner Help Center |language=en-US}}</ref> and Disney<ref>{{Cite web |date=2021-04-27 |title=Disney Media Tech Specs |url=https://mediatechspecs.disney.com/#/mastering/video/imf-master-packages |access-date=2022-03-04 |website=mediatechspecs.disney.com}}</ref>
In partnership with SMPTE, the DPP has published recommendations for broadcast workflows with IMF<ref>{{Cite web |title=DPP and SMPTE publish major updates to IMF documentation |url=https://www.thedpp.com/news/dpp-and-smpte-publish-major-updates-to-imf-specification |access-date=2022-09-02 |website=The DPP |language=en-GB}}</ref>
== Supported essence ==
IMF supports a wide range of audio-visual essence and metadata, including:
*
* 24-bit 48 kHz channel-based sound, arranged in arbitrary configurations
* Immersive Audio Bitstream (IAB) immersive sound<ref>{{Cite journal |date=June 2019
* Subtitles and captions that conform to the TTML Profiles for Internet Media Subtitles and Captions 1.1 (IMSC 1.1) W3C Recommendation<ref>{{Cite web |title=TTML Profiles for Internet Media Subtitles and Captions 1.1 |url=https://www.w3.org/TR/ttml-imsc1.1/Overview.html |access-date=2022-03-04 |website=www.w3.org
== 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
== System Support ==
Numerous media processing companies support IMF in its various iterations. This section describes several known manufacturers' implementations.
{| class="wikitable"
|+
|Manufacturer
|System
|IMFUG Member
|App#2E (-21)
|App#3 (-30)
|App#4 (-40) Cinema Mezzanine
|App#5 ACES
|ISXD plugin
|IAB plugin
|RDD 45 (ProRes)
|RDD 59-1
(DPP ProRes)
|-
|Blackmagic
|DaVinci Resolve
|
|Yes
|
|
|
|
|
|
|
|-
|Cinecert
|Pakanu
|
|Yes
|
|
|
|
|
|
|
|-
|Marquise
|MIST
|Yes
|Yes
|
|Yes
|Yes
|Yes
|Yes
|Yes
|
|-
|Marquise
|ICE
|Yes
|Yes
|
|Yes
|Yes
|Yes
|Yes
|Yes
|
|-
|Rohde & Schwarz
|Clipster
|
|Yes
|
|
|
|
|
|
|
|-
|Colorfront
|Transkoder
|Yes
|Yes
|
|Yes
|Yes
|Yes
|Yes
|Yes
|
|-
|Colorfront
|QC Player
|Yes
|Yes
|
|Yes
|Yes
|Yes
|Yes
|Yes
|
|-
|MTI
|Cortex
|
|Yes
|
|
|
|
|
|
|
|-
|Telestream
|Vantage
|
|Yes
|
|
|
|
|
|
|
|-
|Venera
|Pulsar
|Yes
|Yes
|
|
|
|
|
|
|
|-
|Venera
|Quasar
|Yes
|Yes
|
|
|
|
|
|
|
|-
|Interra
|Baton
|
|Yes
|
|
|
|
|
|
|
|}
=== Open Source System Support ===
This section describes several known open source IMF implementations.
{| class="wikitable"
|+
|System
|App#2E (-21)
|App#3 (-30)
|App#4 (-40) Cinema Mezzanine
|App#5 ACES
|ISXD plugin
|IAB plugin
|RDD 45 (ProRes)
|RDD 59-1
(DPP ProRes)
|-
|[https://github.com/netflix/photon Photon]
|Yes
|
|
|
|
|
|
|
|-
|[https://github.com/IMFTool IMFTool]
|Yes
|
|
|
|Yes
|
|
|
|-
|[https://ffmpeg.org/ FFMPEG]
|Yes
|
|
|
|
|
|
|
|-
|[https://github.com/bbc/bmx BMX]
|Yes
|
|
|
|
|
|Yes
|Yes
|}
{{SMPTE standards}}
== References ==
<references />
[[Category:Standards]]
{{Improve categories|date=October 2022}}
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