From terminology to processes, your questions about BAVC’s preservation services answered.
Video preservation transfer is the conditioning and digitization of an analog video recording to a robust digital file format which captures as much information, and is as true to the original recording, as possible. A digital preservation master is produced and stored with any necessary codecs and associated metadata functioning as the archival file.
Analog video preservation is necessary because of two central factors: technical obsolescence and deterioration. Analog video was originally manufactured without durability in mind; experts say that magnetic media has an estimated lifespan for playback of 10-15 years, and companies have already ceased manufacture of analog playback decks, the devices required to digitize and preserve analog video.
The preservation master is the robust file that results from a transfer from analog video; it contains a maximum amount of data from the original recording. These files tend to be large and, as a result, are not meant for playback. The preservation master file is designed for archiving and long-term storage, and serves as the source from which smaller, compressed files can be made for editing and playback.
A production file is a lightly compressed file that can be used in video production, editing and to make additional compressed versions. An access file is a highly compressed, lower resolution version which is suitable for web streaming and is easily shared and accessed.
Preservation master files are meant for storage; they are large and require a robust computer set-up with specific software for playback. You should use your production or access files for playback.
We recommend specifications developed by the California Audiovisual Preservation Project which can be found here.
When we receive your tape, we label it with a unique ID, inspect and evaluate its condition and log this information in a transfer log. Tapes are stored in a secure, temperature- and humidity-regulated space. If necessary, the tape will be cleaned and/or baked to prepare it for transfer. We will then digitize from your analog video recording to an uncompressed or losslessly compressed high-quality preservation master file. Production and access files are produced from this file on request. Each resulting file is checked by a quality control technician before delivery.
BAVC has tape cleaning machines which run your tape over a cloth-based cleaning tape to safely remove any debris from its surface. If a tape exhibits signs of “sticky-shed syndrome” it is incubated in a low temperature convection oven at 120-degree Fahrenheit for twenty hours, resting for 48 hours before transfer.
At least two copies of the files should be stored in geographically distinct locations or on a server with a regular backup system. Please be aware of data corruption and the dangers of bit rot; anyone storing preservation masters should put into place a system to check the quality of your files over time. There are many great resources on the web about digital preservation of your files.
What is included in the transfer log is what is called metadata, which is ancillary information about the provenance of the preservation master files. Metadata is a way to keep track of information about the file produced, a way of having a “label” for files. Metadata is essential for preservationists in the future who need to know on what operating system your file was made, and on what software program it can be played back. For example, do you remember Real Player or Word Star? These software programs produced many files that are now difficult for digital archivists and family historians to recover.
A codec is a computer program that can read the data in a digital file and allow it to be played back. The codecs necessary to playback your files are included on your hard drive, along with instructions for installing them on your computer. It is a good idea to store this folder with your preservation master files.
The overall process requires time not only for the transfer, but also for tape inspection and treatment, documentation and quality control of resulting files. Analog to digital transfers have to take place in real time and each preservation transfer at BAVC is fully supervised by a trained technician. Additionally, the equipment we are working with is very old, often rare, and requires specialized care and servicing.
Yes, as long as you follow some guidelines. We recommend using a major shipping company, such as FedEx or UPS, which allows tracking and insurance.
We recommend you consider the Internet Archive, a non-profit organization dedicated to archiving media for researchers and the general public.