Many organisations have archive material stored on video tape. The tapes themselves have no commercial value but the recordings on them may be very valuable. Most of us are aware that video cassettes deteriorate with age but there is another issue. Your old tapes could be in great condition but the playback equipment will almost certainly be obsolete. As times goes on the chances of finding a working player for older video tapes is reducing.
In the following paragraphs we’ll look at some file storage options for commercial archiving of analogue and digital video tape recordings for companies and organisations. This information may also be of interest to the general public looking for better quality digital copies of their home video recordings.
We’re keen to avoid jargon in this article and will try to offer plain English explanations where possible.
DVDs – Good enough?
A common request we receive from businesses is to back-up old tape recordings onto DVD Video discs. For some purposes such as viewing copies this is perfectly reasonable. It’s cheap, convenient and provides decent quality copies of the content. However that ‘decent quality’ needs to be quantified.
DVD Video is a domestic viewing format containing compressed audio and video. It’s pretty good and for most people it’s completely acceptable. Those viewing the DVD copies we’ve made of their tapes often perceive a genuine improvement in picture quality compared what they were used to seeing from the original tapes. There are a couple of very good technical reasons for this. Firstly, the equipment we use to make the copies is good quality and well maintained. Secondly, most DVD and Blu-ray players are connected to televisions using either component video or HDMI with upscaling to HD providing a much better quality signal compared to older connections such as composite.
We’ve explained that DVDs offer a decent quality, good enough for domestic viewing. If you just want viewable copies then DVD is a good solution. Visually you may not notice any quality loss compared to the original material, especially in a living room sitting ten feet away from a 32″ TV. However, on close inspection there will be compression artefacts which are visible as a fine ‘moving grain’ in the image. It’s important to say again that DVDs are cost effective and good enough quality for many people but it’s not the best possible and much better quality digital copies can be made.
If you would like to have your video tapes archived onto DVD then we recommend using archival grade media. It’s not very much more expensive than standard discs but has been specifically manufactured for long term data storage. We will be happy to speak with you about these options.
Bigger Files, Better Quality
Analogue video tapes do not contain data – the magnetic tape carries analogue signals which are interpreted by the electronics in the player as video and audio. The best quality copies of analogue recordings are described as ‘uncompressed’. The problem with uncompressed video files is the amount of data generated by the files. Put simply they can take up lots of hard drive space which makes them difficult to move around or view over a network or via an internet connection. A wide range of compression formats are available to reduce the file size to much more manageable levels. Most of these are ‘lossy’ which means that some quality is lost during the file size reduction process but the average viewer may not notice any drop in quality.
Compression ratio is a way of expressing how much a file size has been reduced. In broad terms an uncompressed standard definition video file takes around 20 Megabytes per second. This can be compressed to just 4 Megabytes per second and will therefore reduce the file size to 1/5th of the original. This is described as 5:1 compression.
It’s often an advantage to have multiple versions of analogue tapes made:
- Uncompressed video file – highest quality – a 1:1 copy of the original tape with minimal quality loss
- MPEG2 25Mbit or DV compressed around 5:1 – good quality but 1/5th the size of uncompressed
- H.264 MPEG4 – still quite good quality but relatively tiny file sizes – ideal for the web or network use
Big files need to be stored on either a hard drive, optical disc or backup tape (yes – tape backup drives are still going strong). Putting a hard drive full of your precious footage in a cupboard for a few years and expecting all the data to be there when you need it is not good practice. It’s wise to make at least one backup copy of everything initially and then have regular backups made over time taking advantage of new, bigger and better data storage options as they are developed.
Apple ProRes – A great option for production
ProRes is a high quality video compression format developed by Apple Inc for their own editing software. It offers very good quality at modest file sizes and is easy to edit compared to many other formats. Although originally intended to be an intermediate compression system (for editing only) it’s been widely adopted in the professional and broadcast video world as one of the main digital video compression formats and has also become an acquisition format used in cameras and digital video recorders such as the Atomos Ninja. Apple continue to develop ProRes and it’s now available in several different versions and works on both Windows and Mac computers.
If you’re working in video or television production then conversion to ProRes is a sensible option for analogue video conversions. This is especially true if you’re editing in high definition and need to use older standard definition archive material. We can upscale at the point of ingest (copying to a digital file) to the exact frame rate and frame size that your project demands.
We see ProRes as a viable long term video storage format. The quality is excellent whilst taking less storage space than uncompressed video file otherwise would.
Video Archiving – Further help and advice
We’ve provided some basic information about some aspects of video archiving and we hope that this has been helpful to you. There’s a lot more to the process of archiving legacy analogue and digital video tapes in terms of maintaining and improving image quality. For more specific advice about your own video archiving requirements please contact Gavin Gration on 0800 228 9422 or use this contact form to get in touch. We’ll listen and do our best to help.