Editing Digital preservation (section)

===Moving image preservation===
The term "moving images" includes analog film and video and their born-digital forms: digital video, digital motion picture materials, and digital cinema. As analog videotape and film become obsolete, digitization has become a key preservation strategy, although many archives do continue to perform photochemical preservation of film stock.<ref>{{cite book|title=The Digital Dilemma: Strategic Issues in Archiving and Accessing Digital Motion Picture Materials. |year=2007 |publisher=Academy of Motion Picture Arts and Sciences Science and Technology Council |page=19 |url=http://www.oscars.org/science-technology/council/projects/digitaldilemma/ |url-status=live |archive-url=https://web.archive.org/web/20130218075928/http://www.oscars.org/science-technology/council/projects/digitaldilemma/ |archive-date=2013-02-18 }}</ref><ref>{{cite book|title=Commission Staff Working Document on the challenges for European film heritage from the analogue and the digital era: Third implementation report of the 2005 EP and Council Recommendation on Film Heritage |year=2012 |location=Brussels |pages=11, 17, 93–114 |url=http://ec.europa.eu/avpolicy/docs/reg/cinema/report_3/swd_2012_431_en.pdf |url-status=dead |archive-url=https://web.archive.org/web/20131007171056/http://ec.europa.eu/avpolicy/docs/reg/cinema/report_3/swd_2012_431_en.pdf |archive-date=October 7, 2013 }}</ref>

"Digital preservation" has a double meaning for audiovisual collections:  analog originals are preserved through digital reformatting, with the resulting digital files preserved; and born-digital content is collected, most often in proprietary formats that pose problems for future digital preservation.

There is currently no broadly accepted standard target digital preservation format for analog moving images.<ref name="Science and Technology Council">{{cite book|title=The Digital Dilemma 2: Perspectives from Independent Filmmakers, Documentarians and Nonprofit Audiovisual Archives: Nonprofit Audiovisual Archives section|year=2012|publisher=Science and Technology Council, the Academy of Motion Picture Arts and Sciences|url=http://www.oscars.org/tdd2}}</ref> The complexity of digital video as well as the varying needs and capabilities of an archival institution are reasons why no "one-size-fits-all" format standard for long-term preservation exists for digital video like there is for other types of digital records "(e.g., word-processing converted to [[PDF/A]] or [[TIFF]] for images)".<ref name=":12">{{Cite web|url=https://siarchives.si.edu/what-we-do/digital-curation/digital-video-preservation|title=Digital Video Preservation|last=bradyh|date=2017-04-26|website=Smithsonian Institution Archives|access-date=2019-04-29}}</ref><ref name=":64">{{Cite web|url=https://www.scart.be/?q=en/content/short-guide-choosing-digital-format-video-archiving-masters|title=A short guide to choosing a digital format for video archiving masters {{!}} Scart - a website on audiovisual heritage by packed|website=www.scart.be|access-date=2019-05-06}}</ref>

Library and archival institutions, such as the Library of Congress and [[New York University]], have made significant efforts to preserve moving images; however, a national movement to preserve video has not yet materialized".<ref name=":34">{{Cite journal|last=Frick|first=Caroline|date=April 2014|title='Separate but Equal?': Bolstering Audiovisual Preservation.|url=https://www.degruyter.com/view/j/pdtc.2014.43.issue-1-2/pdtc-2014-1004/pdtc-2014-1004.xml|journal=Preservation, Digital Technology & Culture|volume=43|issue=1–2|pages=20–25|doi=10.1515/pdtc-2014-1004|s2cid=199576183 |url-access=subscription}}</ref> The preservation of audiovisual materials "requires much more than merely putting objects in cold storage".<ref name=":34" /> Moving image media must be projected and played, moved and shown. Born-digital materials require a similar approach".<ref name=":34" />

The following resources offer information on analog to digital reformatting and preserving born-digital audiovisual content.

* The Library of Congress tracks the sustainability of digital formats, including moving images.<ref>{{cite web|url=http://www.digitalpreservation.gov/formats/content/video.shtml |title=Moving Images |work=digitalpreservation.gov |url-status=live |archive-url=https://web.archive.org/web/20130425032848/http://digitalpreservation.gov/formats/content/video.shtml |archive-date=2013-04-25 }}</ref>
* ''The Digital Dilemma 2: Perspectives from Independent Filmmakers, Documentarians and Nonprofit Audiovisual Archives (2012)''.<ref name="Science and Technology Council" /> The section on nonprofit archives reviews common practices on digital reformatting, metadata, and storage. There are four case studies.
* [http://www.digitizationguidelines.gov/about/ Federal Agencies Digitization Guidelines Initiative (FADGI)]. Started in 2007, this is a collaborative effort by federal agencies to define common guidelines, methods, and practices for digitizing historical content. As part of this, two working groups are studying issues specific to two major areas, Still Image and Audio Visual.<ref>{{cite web|last=Federal Agencies Digitization Guidelines Initiative |title=Federal Agencies Digitization Guidelines Initiative |url=http://www.digitizationguidelines.gov |access-date=5 March 2013 |year=2013 |url-status=live |archive-url=https://web.archive.org/web/20130204231349/http://www.digitizationguidelines.gov/ |archive-date=4 February 2013 }}</ref>
* PrestoCenter publishes general audiovisual information and advice at a European level. Its online library has research and white papers on digital preservation costs and formats.<ref>{{cite web|url=https://www.prestocentre.org/library |title=PrestoCentre |work=prestocentre.org |url-status=live |archive-url=https://web.archive.org/web/20121130064826/http://www.prestocentre.org/library |archive-date=2012-11-30 }}</ref>
* The [[Association of Moving Image Archivists]] (AMIA) sponsors conferences, symposia, and events on all aspects of moving image preservation, including digital. The [http://www.amiatechreview.com/ ''AMIA Tech Review''] contains articles reflecting current thoughts and practices from the archivists' perspectives. ''Video Preservation for the Millennia (2012)'', published in the ''AMIA Tech Review'', details the various strategies and ideas behind the current state of video preservation.<ref>{{cite journal |last=Tadic |first=Linda |title=Video Preservation for the Millennia |journal=AMIA Tech Review Journal |year=2012 |issue=4 |url=http://www.amiatechreview.org/V12-05/papers/tadic.pdf |access-date=21 March 2013 |url-status=dead |archive-url=https://web.archive.org/web/20150510054430/http://www.amiatechreview.org/V12-05/papers/tadic.pdf |archive-date=10 May 2015 }}</ref>
*The [[National Archives of Australia]] produced the Preservation Digitisation Standards which set out the technical requirements for digitisation outputs produced under the National Digitisation Plan. This includes video and audio formats, as well as non-audiovisual formats.<ref>{{Cite web|title=Preservation Digitisation Standards {{!}} naa.gov.au|url=https://www.naa.gov.au/about-us/our-organisation/accountability-and-reporting/archival-policy-and-planning/preservation-digitisation-standards|access-date=2021-11-10|website=www.naa.gov.au}}</ref>
*The [[Smithsonian Institution Archives]] published guidelines regarding file formats used for the long-term preservation of electronic records, which are regarded as open, standard, non-proprietary, and well-established. The guidelines are used for video and audio formats, and other non-audiovisual materials.<ref name=":03"/>

==== Codecs and containers ====
Moving images require a [[codec]] for the decoding process; therefore, determining a codec is essential to digital preservation.<ref name=":3">{{Cite web |url=https://www.ischool.utexas.edu/~galloway/spring2017/INF392K2017/AVPS_Codec_Primer.pdf |title=A Primer on Codecs for Moving Image and Sound Archives & 10 Recommendations for Codec Selection and Management |last=Lacinak |first=Chris |date=April 2010 |website=UTexas |access-date=March 28, 2022}}</ref><ref name=":2" /> In ''"A Primer on Codecs for Moving Image and Sound Archives: 10 Recommendations for Codec Selection and Management"'' written by Chris Lacinak and published by AudioVisual Preservation Solutions, Lacinak stresses the importance of archivists choosing the correct codec as this can "impact the ability to preserve the digital object".<ref name=":2">{{Cite journal|date=April 1, 2010|title=Codecs primer for archives|journal=Information Standards Quarterly|volume=22|pages=1/3|via=EBSCOhost}}</ref><ref name=":3" /> Therefore, the codec selection process is critical, "whether dealing with [[Born-digital|born digital]] content, reformatting older content, or converting analog materials".<ref name=":2" /><ref name=":3" /> Lacinak's ten recommendations for codec selection and management are the following: adoption, disclosure, transparency, external dependencies, documentation and metadata, pre-planning, maintenance, obsolescence monitoring, maintenance of the original, and avoidance of unnecessary trans-coding or re-encoding.<ref name=":2" /><ref name=":3" /> There is a lack of consensus to date among the archival community as to what standard codec should be used for the digitization of analog video and the long-term preservation of digital video nor is there a single "right" codec for a digital object; each archival institution must "make the decision as part of an overall preservation strategy".<ref name=":2" /><ref name=":43">{{Cite web|url=https://www.records.nsw.gov.au/recordkeeping/advice/choosing-codec-for-digitising-audio-or-video|title=Choosing a format/codec for digitising audio or video|date=2015-11-10|website=records.nsw.gov.au|language=en|access-date=2019-05-06|archive-date=2019-05-06|archive-url=https://web.archive.org/web/20190506092455/https://www.records.nsw.gov.au/recordkeeping/advice/choosing-codec-for-digitising-audio-or-video|url-status=dead}}</ref><ref name=":64"/><ref name=":3" />

A [[digital container format]] or wrapper is also required for moving images and must be chosen carefully just like the codec.<ref name=":43"/> According to an international survey conducted in 2010 of over 50 institutions involved with film and video reformatting, "the three main choices for preservation products were [[Audio Video Interleave|AVI]], [[QuickTime File Format|QuickTime]] (.MOV) or [[Material Exchange Format|MXF]] (Material Exchange Format)".<ref name=":52">{{Cite web|url=https://www.archives.gov/preservation/products/definitions/video-opt.html|title=Video Digital Product Options|website=archives.gov|access-date=2019-05-06}}</ref> These are just a few examples of containers. The [[National Archives and Records Administration]] (NARA) has chosen the AVI wrapper as its standard container format for several reasons including that AVI files are compatible with numerous open source tools such as [[VLC media player|VLC]].<ref name=":52"/>

Uncertainty about which formats will or will not become obsolete or become the future standard makes it difficult to commit to one codec and one container."<ref name=":64"/> Choosing a format should "be a trade off for which the best quality requirements and long-term sustainability are ensured."<ref name=":64"/>

==== Considerations for content creators ====
By considering the following steps, content creators and archivists can ensure better accessibility and preservation of moving images in the long term:

* Create uncompressed video if possible. While this does create large files, their quality will be retained. Storage must be considered with this approach.<ref name=":12"/><ref name=":7">{{Cite web |url=http://www.digitizationguidelines.gov/guidelines/FADGI_BDV_p3_20141202.pdf |title=Creating and Archiving Born Digital Video Part III. High Level Recommended Practices |date=December 2, 2014 |website=Federal Agencies Digitization Guidelines Initiative |access-date=March 28, 2022}}</ref><ref name=":64"/>
* If uncompressed video is not possible, use lossless instead of lossy compression. The compressed data gets restored while lossy compression alters data and quality is lost.<ref name=":12" /><ref name=":43"/><ref name=":7" /><ref name=":64" />
* Use higher bit rates (This affects resolution of the image and size of file.)<ref name=":12" /><ref name=":7" />
* Use technical and descriptive metadata.<ref name=":12" /><ref name=":7" />
* Use containers and codecs that are stable and widely used within the archival and digital preservation communities.<ref name=":12" /><ref name=":52"/><ref name=":03"/><ref name=":7" />