Long-term storage of information. Pictures and sound stored in digital form can be archived and recovered without loss or distortion. The storage medium must be both reliable and stable and, as large quantities of information need to be stored, cost is of major importance. Currently the lowest cost is magnetic tape but there is increasing interest in optical disks and especially DVDs – more expensive but with far better access.

VTRs offer the most cost-effective storage, highest packing density and instant viewing
– even while spooling. Non-compressed component digital formats: D1, D5 (SD) and D6 (HD) give the best quality and 50 Mb/s 3:1 compression for SD is also used (DVCPRO 50, IMX). However, VTRs are format dependent so their long-term use is limited for the world which is increasingly format co-existent.

For stills and graphics compression should be avoided as full detail is required for viewing still images. CDs, DVDs and Magneto-optical (MO) disks are convenient, giving instant access to all pictures.

Today, networking, the proliferation of video formats and the use of digital film have meant a move away from VTRs toward data recorders. DTF-2 is increasingly used for archiving.

Archiving an editing or compositing session, requiring data on all aspects of the session to be stored, becomes practical with integrated equipment (e.g. non-linear suites).Beyond an EDL this may include parameters for colour correction, DVE, keying, layering etc. This metadata can be transferred to a removable medium such as a floppy disk or an MO. Quantel has introduced an archiving system based on AAF – a format designed for the media industry that carries both essence and metadata.

Traditionally, material is archived after its initial use – at the end of the process. More recently some archiving has moved to the beginning. An example is news where, in some cases, new material is archived and subsequent editing, etc., accesses this. This reflects the high value of video assets where rapidly increasing numbers of channels are seeking material.

See also: AAF, Data recorders, DTF, Optical disks