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Preservation & Digitization
Low quality
Since the middle of 2003 the formats, systems and procedures for encoding at low quality have been investigated and worked out. A test film was produced for the streaming video test from frequently used video material which included sequences that were potentially problematic for conversion into streaming formats (for example, noise, rapidly blinking images, slow movements, graphic material, digital images, amateur material). The material was first encoded to MPEG-2 and subsequently transcoded to the four most popular streaming formats (Windows Media, Real, Quicktime, MPEG-4) in three qualities for various connection speeds. Not entirely unexpectedly, it emerged from this test that the quality of the source material is the most important factor for the quality of the stream. The differences in quality among the four formats were examined primarily for the highest resolution, because that is where the differences were most obvious. In general, all the formats were good. Quicktime and MPEG-4 were somewhat less successful in handling fast movements (especially blinking images), and Windows Media produced clearly smaller files. Disregarding cost, Windows Media turned out to be the best. But Windows Media needs Windows Media server software, and that runs only on a Microsoft Windows server. The Netherlands Media Art Institute prefers to work with an open system, and does not use Windows but instead Linux servers. Because of its somewhat better quality, and the fact that Real has a Surestream option (that is to say, if the connection deteriorates anywhere, the Real server automatically switches to a lower quality image), Real was initially chosen.
The Artlab of the Netherlands Media Art Institute produced thirty-second MPEG-2 fragments and stills of works in the distribution collection. These were converted to RealMedia. Everything was stored on the server. During the process the fragments were cropped, meaning that a part of the image frame was reduced or cut away. This is not necessary for presentation on television sets or monitors for video presentation; these are made in such a way that they show no edges (underscan). But the edges are seen on computer monitors (overscan), and these edges would be intrusive when viewing the fragments on the Internet via the catalogue. In order to be able to convert the fragments easily to another format in the future, the MPEG-2 fragments were preserved as well. Previously it was thought that MPEG-4 would provide the best results. The MPEG-4 codices can be used freely, the source is available, and an active Internet community and a commission supervise the maintenance of the standard. Moreover, the necessary server, Darwin, is open source and thus free.
For live streaming of events of the Netherlands Media Art Institute we already use the Darwin streaming server software. A Linux station captures the video signal with Mp4Live and sends the stream to the Darwin server which distributes the mpeg4 stream to the clients. The same stream is transmitted to the video file server to be stored. Later this stream is available on demand on the website of the Netherlands Media Art Institute.
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To extend the lifespan of video tapes, they often get → digitised. To maintain as much information as possible and not to alienate the work, it needs special attention and care.
Digital rendering → formats usually condense the image information. You can find general information → here.
The internal algorithms involved in the process of digitisation and condensation can lead to image modifications. We tested a series of → Codecs and condensation methods.
Visit the → HfG Codec Test Site.
→ Sustainable Storage is directed at institutions that would like to build up a digital media archive, and are looking for a financially and ideally appropriate storage solution.
Back to → OASIS Platform
Additional resources:
AktiveArchive
The Conservation Awards
DOCAM | Documentation and Conservation of Electronic Media Arts Heritage
IMAP | Independent Media Art Preservation
Montevideo Guideline
EAI Online Resource Guide for Exhibiting, Collecting & Preserving Media Art
→ Curatorial Tools
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