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Tape archives are a hot topic

Archiving is becoming an issue as videotape reaches end-of-life for new recordings. Most cameras on sale today shoot to solid-state or optical media. Finished programs and commercials are now delivered via satellite and fiber as files. There will be videotape libraries for decades, but the problem facing content creators is how to archive the files.

The IT sector has many answers, but not all are suitable for the media and entertainment business. Financial and business records must be archived for compliance, but that is generally for less than ten years. Media archives look to equal or exceed the life of film. That means fifty years at a minimum. How many of today’s IT vendors will be around in 50 or 100 years?

The answer lies in the abstraction of the content from the recording medium. Files can be migrated to new media formats before it becomes difficult to recover them from their current medium.

The other important factor is the file format. What wrappers and codecs should be used? What metadata should be wrapped with the essence? The usual answer here is to avoid the proprietary and to use international standards.

I have a good feeling that in a hundred years’ time, someone will be able to open and read MPEG-2 wrapped as MXF OP1a. They will also understand Dublin Core metadata. But, I will be very surprised if the hard drive on which I am storing this document file will be readable in 100 years without specialty equipment. The necessary disk interfaces will not exist, and operating systems will be totally different. All of that depends on whether the disk even spins up.

The current favorite archive media seems to be LTO data tape, used within a hierarchical storage architecture along with SATA and SAS hard drives and possibly SSDs. LTO drives and tapes can be purchased from several vendors, giving users the comfort of multiple sourcing.

The choice of codec is less clear, including MPEG-2 and -4 (AVC), and JPEG-2000, with some companies choosing proprietary editing codecs.

That leaves three other questions: which wrapper, what metadata and what tape format? The MXF standards offer a starting point for the wrappers, but the format need constraining to ease the interoperability of archive files. There are many metadata standards, including MPEG-7, IPTC, Dublin Core — the list is long.

There are several standards for data tape, including TAR, which dates from the POSIX standard of 1988. Very recently, LTFS has been developed for LTO-5 and future LTO standards. There are also proprietary standards, plus AXF (Archive eXchange Format) – an open format which can be used with data tape and other media substrates.

The M&E sector is not the only group looking for very long-term archives. The heritage sector — museums, libraries and archives — would like to store audio-visual material as a historical record. Some commercial organizations need long-lasting archives, like the pharmaceutical sector, which needs to store some records for the life of their patients.

There is much ongoing development of products to manage tape libraries and standards for wrapper and metadata. The demise of videotape is spurring standards development to ensure that our archives will be usable by future generations, and that the cost of maintaining the archive does not exceed the value of the assets.