Archive for the ‘Video Transfer’ Category

Digitising Shedding Magnetic Multi-track Tape & the history of John Peel favourites BOB

Wednesday, November 13th, 2013

An important part of digitisation work we do is tape restoration. Often customers send us tape that have been stored in less than ideal conditions that are either too hot, cold or damp, which can lead to degradation.

In the excellent Council on Library and Information Sources’ report on Magnetic Storage and Handling (1995), they set the ideal archival storage conditions for magnetic tape at ‘significantly lower than room ambient (as low as 5 centrigade)’, with no less than 4 degrees variation in temperature at 20% room humidity. They suggest that ‘the conditions are specifically designed to reduce the rate of media deterioration through a lowering of the temperature and humidity content of the media.’

8 Track Headshot 1 Digitising Shedding Magnetic Multi track Tape & the history of John Peel favourites BOB

Of course most people do not have access to such temperature controlled environments, or are necessarily thinking about the future when they store their tape at home. Sometimes manufacturers recommended to store tape in a ‘cool, dark place’, but often tape is not adorned with any such advice. This leads to us receiving a lot of damaged tape!

As we are keen to emphasise to customers, it is possible to salvage most recordings made on magnetic analogue tape that appear to be seriously damaged, it just requires a lot more time and attention.

For example, we were recently sent a collection of 3” multi-track tapes that had been stored in fairly bad conditions. Nearly all the tapes were degraded and needed to be treated. A significant number of these tapes were AMPEX so were suffering from binder hydrolysis, a.k.a. sticky shed syndrome in the digitisation world. This is a chemical process where binder polymers used in magnetic tape constructions become fragmented because the tape has absorbed water from its immediate environment. When this happens tapes become sticky and sheds when it is played back.

Baking the AMPEX tapes is a temporary treatment for binder hydrolysis, and after baking they need to be migrated to digital format as soon as possible (no more than two weeks is recommended). Baking is by no means a universal treatment for all tapes – sticky shed occurs due to the specific chemicals AMPEX used in their magnetic tape.

Cleaning shedding tape

Other problems occur that require different kinds of treatment. For example, some of the 3” collection weren’t suffering from sticky shed syndrome but were still shedding. We were forewarned by notes on the box:

Shedder Digitising Shedding Magnetic Multi track Tape & the history of John Peel favourites BOB

The tapes recorded on TDK were particularly bad, largely because of poor storage conditions. There was so much loose binder on these tapes that they needed cleaning 5 or 6 times before we could get a good playback.

We use an adapted Studer A 80 solely for cleaning purposes. Tape is carefully wound and rewound and interlining curtain fabric is used to clean each section of the tape. The photo below demonstrates the extent of the tape shedding, both by the dirty marks on fabric, and the amount we have used to clean the collection.

Studer A 80 Digitising Shedding Magnetic Multi track Tape & the history of John Peel favourites BOB

You might think rigorous cleaning risks severely damaging the quality of the tape, but it is surprising how clear all the tapes have sounded on playback. The simple truth is, the only way to deal with dry shedding is to apply such treatment because it simply won’t be able to playback clearly through the machine if it is dirty.

Loss of lubricant

Another problem we have dealt with has been the loss of lubricant in the tape binder. Tape binder is made up of a number of chemicals that include lubricant reservoirs, polymers and magnetic particles.

Dirty Cloth Digitising Shedding Magnetic Multi track Tape & the history of John Peel favourites BOB

Lubricants are normally added to the binder to reduce the friction of the magnetic topcoat layer of the tape. Over time, the level of the lubricant decreases because it is worn down every time the tape is played, potentially leading to tape seizures in the transport device due to high friction.

In such circumstances it is necessary to carefully re-lubricate the tape to ensure that it can run smoothly past the tape heads and play back. Lubrication must be done sparingly because the tape needs to be moist enough to function effectively, but not too wet so it exacerbates clogging in the tape head mechanism.

Restoration work can be very time consuming. Even though each 3″ tape plays for around 20 minutes, the preparation of tapes can take a lot longer.

Another thing to consider is these are multi-track recordings: eight tracks are being squeezed onto a 1/4″ tape. This means that it only takes  a small amount of debris to come off, block the tape heads, dull the high frequencies and ultimately compromise the transfer quality.

It is important, therefore, to ensure tapes are baked, lubricated or cleaned, and heads are clear on the playback mechanism so the clarity of the recording can realised in the transfer process.

Now we’ve explored the technical life of the tape in detail, what about the content? If you are a regular visitor to this blog you will know we get a lot of really interesting tape to transfer that often has a great story behind it. We contacted Richard Blackborow, who sent the tapes, to tell us more. We were taken back to the world of late 80s indie-pop, John Peel Sessions, do it yourself record labels and a loving relationship with an 8 track recorder.

A Short History of BOB by Richard Blackborow

RichardInBanwellStudio Digitising Shedding Magnetic Multi track Tape & the history of John Peel favourites BOB Back in 1983 I was a 17 year old aspiring drummer, still at school in North London and in an amateur band. Happily for me, at that time, my eldest brother, also a keen musician, bought a small cottage in a village called Banwell, which is 20 or so miles outside of Bristol, near Weston Super Mare. He moved there to be near his work. The cottage had a big attic room and he installed a modest 8-track studio into it so that he could record his own music during his spare time. The studio was based around a new Fostex A8 reel-to-reel machine and the little mixing desk that came with it.

The equipment fascinated me and I was a regular visitor to his place to learn how to use it and to start recording my own music when he wasn’t using it.

Skip forward a couple of years and I am now 19, out of school, deferring my place at university and in a new band with an old friend, Simon Armstrong. My brother’s work now takes him increasingly abroad, so the studio is just sitting there doing nothing. Simon and I begin to write songs with the express intention of going to Banwell every time we had a decent number of tunes to record. Over the next ten years it becomes part of the routine of our lives! We formed a band called BOB in 1986, and although we still lived in London, we spent a lot of time in that small studio in Banwell – writing, recording demos, having wild parties! By this time my brother had moved to the US, leaving me with open access to his little studio.

The band BOB had modest success. John Peel was a keen fan and a great supporter, we toured loads around the UK and Europe and made lots of singles and an album or two, as well as recording 5 BBC sessions.

To cut a long story short, we loved that little studio and wrote and recorded some 300 songs over the ensuing 10 years…the studio gear finally dying in about 1995. Most recordings were for/by BOB, but I also recorded bands called The Siddeleys and Reserve (amongst others).

The tapes we recorded have been lying around for years, waiting to be saved!

GroupShot MK1 Banwell Digitising Shedding Magnetic Multi track Tape & the history of John Peel favourites BOB

Recent interest in BOB has resulted in plans to release two double CDs. The first contains a re-issued album, all the BBC sessions and a few rarities. The second CD, planned for next year, will contain all of the BOB singles, plus a whole CD of the best of those demos we recorded. It was for this reason that all of those old tapes were sent to Adrian to be transferred to digital. I now have a studio near my home in West Cornwall, close to Land’s End, where I will be mixing all the material that Great Bear have been working on. The demos map our progression from pretty rubbish schoolboy aspirants to reasonably accomplished songwriters. Some of the material is just embarrassing, but a good chunk is work I am still proud of. We were very prolific and the sheer number of reels that Adrian has transferred is testament to that. There is enough material there for a number of CDs, and only time will tell how much is finally released.

Listen to the recently transferred Convenience demo

This is a bit of a rarity! It’s the demo (recorded on the little 8-track machine in Banwell) for a BOB single that came out in 1989. It’s called Convenience and I wrote and sang it. This early version is on one of the tapes that Adrian has transferred, so, like many of the rest of the songs, it will be re-mixed this winter for digital formats and released next year.

This is a link to the video we made for the song back in 1989 in a freezing warehouse in Hull! It appeared on Kats Karavan – The History of John Peel on the Radio compilation that was released in 2009.

***

If you want the latest news from BOB you can follow them on twitter. You can also pre-order the expanded edition of their 1991 album Leave the Straight Life Behind from Rough Trade. It will be available from the end of January 2014. A big thank you to Richard for sending us the photos, his writing and letting us include the recording too!

Transfer Digital Betacam (DigiBeta) to Quicktime or AVI now, one day they will be obsolete

Monday, November 4th, 2013

Even relatively recent born digital formats like Digital Betacam or DigiBeta, as it’s often referred to, should be viewed as a potentially obsolete format. This Standard Definition (SD) format while very popular for many years is not the preferred delivery format now the industry has embraced High Definition (HD). When serviced these machines are very reliable and would be worked hard in a production environment. Designed to be serviced with little expense spared these were some of Sony’s most expensive decks and even if second hand values of machines have dropped recently, new spares have not. As with most video formats though as they become less popular the spares availability will become a problem as parts inventory dry up. One day and it may not be that far away a popular format like DigiBeta will become a threatened, obsolete format.

Digibeta full frontal Transfer Digital Betacam (DigiBeta) to Quicktime or AVI now, one day they will be obsolete

Digital Betacam recorders  were introduced in 1993, superseding the Betacam and Betacam SP, while costing significantly less, and being dramatically smaller than (!), the D-1.

We are particularly pleased with this machine because there are relatively low hours on its original head drum (1000 hours). The average headlife for this format is up to three times that or more, depending on the environment it was used in.

If the machine was used in a heavy production environment, for example, it would be constantly drawing in air to cool the electronics and, potentially, large amounts of dust and debris with it. This is one of the factors affecting head life.

Part of the service kit installed on the digi-beta is designed to counter such damage because it allows you to replace the filters around the head drum area should they become clogged.

dvw a510 digital betacam loading gear Transfer Digital Betacam (DigiBeta) to Quicktime or AVI now, one day they will be obsolete

The big problem, as with so many of these machines, is acquiring relevant parts to ensure they can be serviced when they break down. Spare parts for digi-beta machines can be expensive, costing several thousand pounds for a replacement head drum.

This machine has needed some work recently to keep it running smoothly. The loading gear had split which meant it couldn’t load tapes and gave reel motor errors. These were fixed easily by replacing the broken parts. After these repairs were completed the picture was still however displaying errors. This was because the bearing on the pinch roller was worn resulting in too much movement in the tape path. With the problem diagnosed a new pinch roller was installed and our new machine is working beautifully!

So send us your digi-beta tapes!

UNESCO World Audiovisual Heritage Day – 27 October

Monday, October 28th, 2013

In 2005 UNESCO (United Nations Education, Scientific and Cultural Organisation) decided to commemorate 27 October as World Audiovisual Heritage Day. The theme for 2013 was ‘Saving Our Heritage for the Next Generation’. Even though we are a day late, we wanted to write a post to mark the occasion.

UNESCO argue that audiovisual heritage is a unique vehicle for cultural memory because it can transcend ‘language and cultural boundaries’ and appeal ‘immediately to the eye and the ear.’

27th October world day of audiovisual heritage UNESCO World Audiovisual Heritage Day   27 October

World Audiovisual Heritage Day aims to recognise both the value and vulnerability of audiovisual heritage. It aims to raise awareness that much important material will be lost unless ‘resources, skills, and structures’ are established and ‘international action’ taken.

Many important records of the 20th and 21st century are captured on film, yet digitally preserving this material generates specific problems, which we often discuss on this blog. Andrea Zarza Canova emphasises this point on the British Library’s blog:

‘World Day for Audiovisual Heritage is an important moment to celebrate and draw attention to the efforts currently being made in audiovisual preservation. But the story doesn’t end here as the digital environment raises its own preservation challenges concerning the ephemerality of websites and digital formats. Saving our heritage for the next generation involves engaging with the ongoing complexities of preservation in a rapidly changing environment.’

World Audiovisual Heritage Day is an  ideal opportunity to delve into UNESCO’s Memory of the World collection whose audiovisual register features rare footage including photo and film documentation of Palestinian refugees, footage of Fritz Lang’s motion picture Metropolis (1927), documentary heritage of Los olvidados (“The Young and the Damned”), made in 1950 by Spanish-Mexican director Luis Buñuel, documentary heritage of Aram Khachaturian the world renowned Armenian composer and many others. Of the 301 items in the Memory of the World collection, 57 are audiovisual or have significant audiovisual elements.

Digital preservation is central to our work at the Great Bear. We see ourselves as an integral part of the wider preservation process, offering a service for archive professionals who may not always have access to obsolete playback machines, or expert technical knowledge about how best to transfer analogue tape to digital formats. So if you need help with a digitisation project why not get in touch?

UNESCO would surely approve of our work because we help keep the audiovisual memory of the world alive.

 

Digital Preservation and Copyright

Monday, October 21st, 2013

Most customers who send us tape to digitise own the copyright of their recording: it is material they have created themselves, be it music, spoken word or film.

Occasionally customers are not so sure if they own the full copyright to their recordings. This is because a single piece of work can have multiple copyright holders.

For example, films and songs can have many different contributors, such as the person who made the recording, the songwriter and performers. There are performing rights royalties which are paid to a songwriter, composer or publisher whenever their music is played or performed in any public space or place; mechanical rights royalties which are paid to the songwriter, composer or publisher when music is reproduced as a physical product or for broadcast or online, and performers rights royalties which are paid to the people performing on the record. It can seem like a bit of a minefield, and you do have to be really careful, particularly if want to re-publish the works in a commercial context.

DSC02576 Digital Preservation and Copyright

A collection of tapes that include original recordings made by the customer

The simple truth is, if you do not have full permission of all copyright holders, you would break the law if you digitised a tape and re-published it commercially.

Copyright, Intellectual Property and Digital Preservation is a tricky area to negotiate. Currently ‘there is still no exception in UK law for preservation copying. For materials which are still in copyright, permissions should be sought from copyright holders prior to any copying being done. This area is under consideration though with museums, libraries and archives lobbying for change’ (Jisc Digital Media).

What this means basically is that archives, libraries and museums are effectively restricted in how much material they can legally preserve in digital form. Andrew Charlesworth explains in a very useful report for the Digital Preservation Coalition on ‘Intellectual Property Rights for Digital Preservation’ (2012)

‘In “Chapter III: Acts permitted in relation to copyright works”, the Copyright Designs and Patents Act 1988 provides for a series of permissible activities that would otherwise be barred for breach of a rights holder’s exclusive rights. These include the “fair dealing provisions” which, for example, state that making transient copies is an integral and essential part of certain technological processes (s.28), and using all or part of a copyright work for non-commercial research or private study (s.29), criticism or review, or reporting current events (s.30), do not constitute infringements’ (11).

Clearly copyright law as it stands places immense restrictions in a digital environment where copying and sharing all kinds of things is pretty much the norm. What are the arguments then for changing copyright laws? In Imagine there is no copyright and cultural conglomerates too by Joost Smiers and Marieke Van Schinjdel, published by the Institute of Network CulturesTheory on Demand series, they argue that removing copyright from cultural products will ensure that ‘our past and present heritage of cultural expression, our public domain of artistic creativity and knowledge will no longer be privatised’ (6).

Making cultural heritage publicly available is an argument for transforming current copyright laws across the range of political positions. While Smiers and Van Schinjdel interpret privatisation embedded in copyright law as linked to commercial power, the implicit argument in the DPC report is that opening up current restrictions can only be good for business. In this particular domain we see how the value of archival information has shifted in the digital landscape, so that it is increasingly seen as a resource through which money can be made.

Copyright Protection Digital Preservation and CopyrightA transformation of copyright laws would not necessarily lead to a weakening of commercial interests as Smiers and Van Schinjdel speculate, but would most probably enable the re-use of information across a range of profit and profit-making initiatives. Charlesworth insists we are ‘clinging to copyright practices that reflect outdated business models rather than attempting to establish new practices to address the prevailing mixed analogue/digital environment’ (7).

The digital information revolution has required all sectors of society to change how they relate to, use, record, save and consume information. While we have all become, to a lesser or more degree, record keepers, this brief survey of copyright law may help us appreciate the challenges professional archivists face in negotiating this complex area. After all, ‘life would be much simpler for archivists if the law relating to the preservation of copyright works in general, and digital works in particular, was both clarified and, where necessary, extended to permit more robust strategies for collection, preservation and reuse of copyright works’ (5).

 

Digitise VHS Tapes – Bristol’s Meet Your Feet

Monday, October 14th, 2013

We recently digitised some VHS tapes from when Bristol-based band Meet Your Feet performed on HTV in 1990. Meet Your Feet

‘formed in 1988 as a result of three of the women getting together to start a women’s music workshop, Meet Your Feet played its first gig in June 1988, when asked to get a set together for a Benefit Gig against section 28. This gig was so successful that the band decided to stay together and gradually the original line-up of the early years of the band evolved: Carol Thomas, vocals; Diana Milstein, founder member, bass and lyricist; Diggy, percussion; Heie Gelhaus, founder member, keyboards and songwriter; Julie Lockhart, vocals; Karen Keen, sax; Sue Hewitt, founder member, drums and songwriter; Vicki Burke, sax’ (taken from the  Women’s Liberation Music Archive).

During the 80s the band achieved great success and performed at prestigious festivals such as Glastonbury and WOMAD, as well as appearing on Radio 4′s Women’s Hour. They played together until 1992 before disbanding, reformed in 2010 and continue to play shows in Bristol and beyond. Meet Your Feet’s style, which draws from Latin, Jazz and Soul influences, interspersed with passionate, upbeat political lyrics, align them with other ‘women’s music’ bands from the 1980s, such as The Guest Stars and Hi-Jinx.

Meet Your Feet from Adrian Finn on Vimeo.

The video clip we digitised is interesting because it indicates how novel women’s bands were in 1990.

After the band finish performing their new single, they take part in a short interview where they are asked:

‘Its an obvious question, but I am going to ask it, why all women?’

Julie Lockhart, one of the singers, responds wittily, but not without a tinge of bewilderment, ‘Um, we were born that way!’

Can you imagine an all male group being asked a similar question in a television interview, either now or in the early 1990s?! It just wouldn’t happen because no one notices if all the members of a group are male, it just seems completely normal.

The interview goes on to emphasise gender issues, rather than focus on other aspects, such as themes in their music or that it is a large group (there are nine people in the band after all, which is a lot!)

This is not a criticism of the interviewer’s questions as such. Yet the fact it was necessary to asks them about their gender speaks volumes about how surprising it was to see women playing music together. The interview continues as follows:

Presenter: Are there any real advantages to being an all female group?

Sue Hewitt: We listen to each other more, and spin ideas of each other a lot more easily

Julie Lockhart: We giggle a lot more

Presenter: Do you row a lot because you are on the road, its a hard life isn’t it, very intense?

Julie Lockhart: No, that’s the obvious difference we never row!

Presenter: Do you find it hard to be taken seriously by men who come to see an all girl band?

Sue Hewitt: Well no, not all the time. I think initially some men take the view of ‘oh well, its just a bunch of girls on stage’ but when we get up there and start playing they think, ohhh [they can play as well]

It is frustrating that such questions had to be asked, and maybe they wouldn’t be now – although it is still often the case that in music, as in other areas of cultural life, women’s gender is marked, while male gender is not. We have all heard, for example, the phrase ‘female-fronted band’. When do we ever hear of bands that are ‘male-fronted’?

It is really valuable to have access to recordings such as those of Meet Your Feet, not only as a documentation of their performances, but also to demonstrate the attitudes and assumptions that women faced when they participated in a male dominated cultural field.

It is also good to know that Meet Your Feet are still performing and undoubtedly upsetting a few stereotypes and expectations along the way, so make sure you catch them at a show soon!

1/2 inch EIAJ skipfield reel to reel videos transferred for Stephen Bell

Monday, October 7th, 2013

We recently digitised a collection of 1/2 inch EIAJ skipfield reel to reel videos for Dr Stephen Bell, Lecturer in Computer Animation at Bournemouth University.

CLEWS SB 01 from Stephen Bell on Vimeo.

Stephen wrote about the piece:

‘The participatory art installation that I called “Clews” took place in “The White Room”, a bookable studio space at the Slade School of Art, over three days in 1979. People entering the space found that the room had been divided in half by a wooden wall that they could not see beyond, but they could enter the part nearest the entrance. In that half of the room there was a video monitor on a table with a camera above it pointing in the direction of anyone viewing the screen. There was also some seating so that they could comfortably view the monitor. Pinned to the wall next to the monitor was a notice including cryptic instructions that referred to part of a maze that could be seen on the screen. Participants could instruct the person with the video camera to change the view by giving simple verbal instructions, such as ‘up’, “down”, “left”, “right”, “stop”, etc. until they found a symbol that indicated an “exit”.’

My plan was to edit the video recordings of the event into a separate, dual screen piece but it was too technically challenging for me at the time. I kept the tapes though, with the intention of completing the piece when time and resources became available. This eventually happened in 2012 when, researching ways to get the tapes digitized, I discovered Greatbear in Bristol. They have done a great job of digitizing the material and this is the first version of piece I envisaged all those years ago.’

Nice to have a satisfied customer!

A word about metadata and digital collections

Monday, September 23rd, 2013

Metadata is data about data. Maybe that sounds pretty boring, but archivists love it, and it is really important for digitisation work.

As mentioned in the previous post that focused on the British Library’s digital preservation strategies, as well as many other features on this blog, it is fairly easy to change a digital file without knowing because you can’t see the changes. Sometimes changing a file is reversible (as in non-destructive editing) but sometimes it is not (destructive editing). What is important to realise is changing a digital file irrevocably, or applying lossy instead of lossless compression, will affect the integrity and authenticity of the data.

What is perhaps worse in the professional archive sector than changing the structure of the data, is not making a record of it in the metadata.

Metadata is a way to record all the journeys a data object has gone through in its lifetime. It can be used to highlight preservation concerns if, for example, a file has undergone several cycles of coding and decoding that potentially make it vulnerable to degradation.

schema A word about metadata and digital collections

Metadata can in fact be split into three kinds, as Ian Ireland writes in this article:

technical data (info on resolution, image size, file format, version, size), structural metadata (describes how digital objects are put together such as a structure of files in different folders) and descriptive (info on title, subject, description and covering dates) with each type providing important information about the digital object.’

As the previous blog entry detailed, digital preservation is a dynamic, constantly changing sector. Furthermore, digital data requires far greater intervention to manage collections than physical objects and even analogue media. In such a context data objects undergo rapid changes as they adapt to the technical systems they are opened by and moved between. This would produce, one would speculate, a large stream of metadata.

What is most revealing about metadata surrounding digital objects, is they create a trail of information not only about the objects themselves. They also document our changing relationship to, and knowledge about, digital preservation. Metadata can help tell the story about how a digital object is transformed as different technical systems are adopted and then left behind. The marks of those changes are carried in the data object’s file structure, and the metadata that further elaborate those changes.

Like those who preserve physical heritage collections, a practice of minimal intervention is the ideal for maintaining both the integrity and authenticity of digital collections. But mistakes are made, and attempts to ‘clean up’ or otherwise clarify digital data do happen, so when they do, it is important to record those changes because they help guide how we look after archives in the long term.

Digitisation strategies – back up, bit rot, decay and long term preservation

Monday, September 23rd, 2013

In a blog post a few weeks ago we reflected on several practical and ethical questions emerging from our digitisation work. To explore these issues further we decided to take an in-depth look at the British Library’s Digital Preservation Strategy 2013-2016 that was launched in March 2013. The British Library is an interesting case study because they were an ‘early adopter’ of digital technology (2002), and are also committed to ensuring their digital archives are accessible in the long term.

Making sure the UK’s digital archives are available for subsequent generations seems like an obvious aim for an institution like the British Library. That’s what they should be doing, right? Yet it is clear from reading the strategy report that digital preservation is an unsettled and complex field, one that is certainly ‘not straightforward. It requires action and intervention throughout the lifecycle, far earlier and more frequently than does our physical collection (3).’

The British Library’s collection is huge and therefore requires coherent systems capable of managing its vast quantities of information.

‘In all, we estimate we already have over 280 terabytes of collection content – or over 11,500,000 million items – stored in our long term digital library system, with more awaiting ingest. The onset of non-print legal deposit legislation will significantly increase our annual digital acquisitions: 4.8 million websites, 120,000 e-journal articles and 12,000 e-books will be collected in the first year alone (FY 13/14). We expect that the total size of our collection will increase massively in future years to around 5 petabytes [that's 5000 terabytes] by 2020.’

All that data needs to be backed up as well. In some cases valuable digital collections are backed up in different locations/ servers seven times (amounting to 35 petabytes/ 3500 terabytes). So imagine it is 2020, and you walk into a large room crammed full of rack upon rack of hard drives bursting with digital information. The data files – which include everything from a BWAV audio file of a speech by Natalie Bennett, leader of the Green Party after her election victory in 2015, to 3-D data files of cunieform scripts from Mesopotamia, are constantly being monitored by algorithms designed to maintain the integrity of data objects. The algorithms measure bit rot and data decay and produce further volumes of metadata as each wave of file validation is initiated. The back up systems consume large amounts of energy and are costly, but in beholding them you stand in the same room as the memory of the world, automatically checked, corrected and repaired in monthly cycles.

Such a scenario is gestured toward in the British Library’s long term preservation strategy, but it is clear that it remains a work in progress, largely because the field of digital preservation is always changing. While the British Library has well-established procedures in place to manage their physical collections, they have not yet achieved this with their digital ones. Not surprisingly ‘technological obsolescence is often regarded as the greatest technical threat to preserving digital material: as technology changes, it becomes increasingly difficult to reliably access content created on and intended to be accessed on older computing platforms.’ An article from The Economist in 2012 reflected on this problem too: ‘The stakes are high. Mistakes 30 years ago mean that much of the early digital age is already a closed book (or no book at all) to historians.’

DSC02325 Digitisation strategies   back up, bit rot, decay and long term preservation

There are also shorter term digital preservation challenges, which encompass ‘everything from media integrity and bit rot to digital rights management and metadata.’ Bit rot is one of those terms capable of inducing widespread panic. It refers to how storage media, in particular optical media like CDs and DVDs, decay over time often because they have not been stored correctly. When bit rot occurs, a small electric charge of a ‘bit’ in memory disperses, possibly altering program code or stored data, making the media difficult to read and at worst, unreadable. Higher level software systems used by large institutional archives mitigate the risk of such underlying failures by implementing integrity checking and self-repairing algorithms (as imagined in the 2020 digital archive fantasy above). These technological processes help maintain ‘integrity and fixity checking, content stabilisation, format validation and file characterisation.’

DDCD R SA 100 1 Digitisation strategies   back up, bit rot, decay and long term preservation

300 years, are you sure?

Preservation differences between analogue and digital media

The British Library isolate three main areas where digital technologies differ from their analogue counterparts. Firstly there is the issue of ‘proactive lifestyle management‘. This refers to how preservation interventions for digital data need to happen earlier, and be reviewed more frequently, than analogue data. Secondly there is the issue of file ‘integrity and validation.’ This refers to how it is far easier to make changes to a digital file without noticing, while with a physical object it is usually clear if it has decayed or a bit has fallen off. This means there are greater risks to the authenticity and integrity of digital objects, and any changes need to be carefully managed and recorded properly in metadata.

Finally, and perhaps most worrying, is the ‘fragility of storage media‘. Here the British Library explain:

‘The media upon which digital materials are stored is often unstable and its reliability diminishes over time. This can be exacerbated by unsuitable storage conditions and handling. The resulting bit rot can prevent files from rendering correctly if at all; this can happen with no notice and within just a few years, sometimes less, of the media being produced’.

A holistic approach to digital preservation involves taking and assessing significant risks, as well as adapting to vast technological change. ‘The strategies we implement must be regularly re-assessed: technologies and technical infrastructures will continue to evolve, so preservation solutions may themselves become obsolete if not regularly re-validated in each new technological environment.’

Establishing best practice for digital preservation remains a bit of an experiment, and different strategies such as migration, emulation and normalisation are tested to find out what model best helps counter the real threats of inaccessibility and obsolescence we may face in 5-10 years from now. What is encouraging about the British Library’s strategic vision is they are committed to ensuring digital archives are accessible for years to come despite the very clear challenges they face.

Remembering Ray Dolby pioneer of analogue noise reduction

Monday, September 16th, 2013

We have already written about noise reduction this week, but did so without acknowledging the life of Ray Dolby, one of the inventors of video tape recording while working at Ampex and the inventor and founder of Dolby Noise Reduction, who died on 12 September 2013.

An obituary in The Guardian described how:

‘His noise-reduction system worked by applying a pre-emphasis to the audio recording, usually boosting the quieter passages. The reverse process was used on playback. Removing the boost – lowering the level – also removed most of the tape hiss that accompanied all analogue recordings. Of course, people did not care how it worked: they could hear the difference.’

 Dolby managed to solve a clear problem blighting analogue tape recording: the high frequency noise or tape hiss inherent when recording on magnetic tape.

Dolby A Rack Remembering Ray Dolby pioneer of analogue noise reduction

Like many professional recording studios from the 1960s onwards, the Great Bear Studio uses the Dolby A noise-reduction system that we use to play back Dolby A encoded tape. On the Dolby A the input signal is split into four individual frequency bands and provided 10 dB of broadband noise reduction overall.

Dolby SR Board Remembering Ray Dolby pioneer of analogue noise reduction

We also have a Dolby SR system that was introduced in 1986 to improve upon analogue systems and in some cases surpass rapidly innovating digital sound technologies. Dolby SR maximises the recorded signal at all times using a complex series of filters that change according to the input signal and can account for up to 25dB noise reduction.

Measuring signals – challenges for the digitisation of sound and video

Monday, September 9th, 2013

In a 2012 report entitled ‘Preserving Sound and Moving Pictures’ for the Digital Preservation Coalition’s Technology Watch Report series, Richard Wright outlines the unique challenges involved in digitising audio and audiovisual material. ‘Preserving the quality of the digitized signal’ across a range of migration processes that can negotiate ‘cycles of lossy encoding, decoding and reformatting is one major digital preservation challenge for audiovisual files’ (1).

Wright highlights a key issue: understanding how data changes as it is played back, or moved from location to location, is important for thinking about digitisation as a long term project. When data is encoded, decoded or reformatted it alters shape, therefore potentially leading to a compromise in quality. This is a technical way of describing how elements of a data object are added to, taken away or otherwise transformed when they are played back across a range of systems and software that are different from the original data object.

DSC02160 Measuring signals   challenges for the digitisation of sound and video

To think about this in terms which will be familiar to people today, imagine converting an uncompressed WAV into an MP3 file. You then burn your MP3s onto a CD as a WAV file so it will play back on your friend’s CD player. The WAV file you started off with is not the same as the WAV file you end up with – its been squished and squashed, and in terms of data storage, is far smaller. While smaller file size may be a bonus, the loss of quality isn’t. But this is what happens when files are encoded, decoded and reformatted.

Subjecting data to multiple layers of encoding and decoding does not only apply to digital data. Take Betacam video for instance, a component analogue video format introduced by SONY in 1982. If your video was played back using composite output, the circuity within the Betacam video machine would have needed to encode . The difference may have looked subtle, and you may not have even noticed any change, but the structure of the signal would be altered in a ‘lossy’ way and can not be recovered to it’s original form. The encoding of a component signal, which is split into two or more channels, to a composite signal, which essentially squashes the channels together , is comparable to the lossy compression applied to digital formats such as mp3 audio, mpeg2 video, etc.

DSC02173 Measuring signals   challenges for the digitisation of sound and video

A central part of the work we do at Great Bear is to understand the changes that may have occurred to the signal over time, and try to minimise further losses in the digitisation process. We use a range of specialist equipment so we can carefully measure the quality of the analogue signal, including external time based correctors and wave form monitors. We also make educated decisions about which machine to play back tapes in line with what we expect the original recording was made on.

If we take for granted that any kind of data file, whether analogue or digital, will have been altered in its lifetime in some way, either through changes to the signal, file structure or because of poor storage, an important question arises from an archival point of view. What do we do with the quality of the data customers send us to digitise? If the signal of a video tape is fuzzy, should we try to stabilise the image? If there is hiss and other forms of noise on tape, should we reduce it? Should we apply the same conservation values to audio and film as we do to historic buildings, such as ruins, or great works of art? Should we practice minimal intervention, use appropriate materials and methods that aim to be reversible, while ensuring that full documentation of all work undertaken is made, creating a trail of endless metadata as we go along?

Do we need to preserve the ways magnetic tape, optical media and digital files degrade and deteriorate over time, or are the rules different for media objects that store information which is not necessarily exclusive to them (the same recording can be played back on a vinyl record, a cassette tape, a CD player, an 8 track cartridge or a MP3 file, for example)? Or should we ensure that we can hear and see clearly, and risk altering the original recording so we can watch a digitised VHS on a flat screen HD television, in line with our current expectations of media quality?

DSC02185 1024x360 Measuring signals   challenges for the digitisation of sound and video

Richard Wright suggests it is the data, rather than operating facility, which is the important thing about the digital preservation of audio and audiovisual media.

‘These patterns (for film) and signals (for video and audio) are more like data than like artefacts. The preservation requirement is not to keep the original recording media, but to keep the data, the information, recovered from that media’ (3).

Yet it is not always easy to understand what parts of the data should be discarded, and which parts should kept. Audiovisual and audio data are a production of both form and content, and it is worth taking care over the practices we use to preserve our collections in case we overlook the significance of this point and lose something valuable – culturally, historically and technologically.

Curating Digital Information or What Do You With Your Archive?

Monday, September 2nd, 2013

Today is the first day of iPres 2013, the 10th international conference on the preservation of digital objects held in Lisbon, Portugal. To mark the occasion we want to reflect on an issue that is increasingly important for the long term management of digital data: curation.

Anyone who has lived through the digital transition in the 21st century surely cannot ignore the information revolution they have been part of. In the past ten years, vast archives of analogue media have been migrated to digital formats and everyday we create new digital information that is archived and distributed through networks. Arcomen, who are running a workshop at iPres on ‘Archiving Community Memories’, describe how

‘in addition to the “common” challenges of digital preservation, such as media decay, technological obsolescence, authenticity and integrity issues, web preservation has to deal with the sheer size and ever-increasing growth and change rate of Web data. Hence, selection of content sources becomes a crucial and challenging task for archival organizations.’

As well as the necessary and sometimes difficult choices archival organisations have to make in the process of collecting an archive, there is then the issue of what to do with your data once it has been created. This is where the issue of digital curation comes in.

SONY website 1996 3 Curating Digital Information or What Do You With Your Archive?

Screenshot of the SONY website from 1996

Traditionally, the role of the curator is to ‘take care’ and interpret collections in an art gallery or a museum. In contemporary society, however, there is an increasing need for people to curate collections that are exclusively digital, and can only be accessed through the web. Part of any long term digitisation strategy, particularly if an archive is to be used for education or research purposes, should therefore factor in plans and time for curation.

Curation transforms a digital collection from being the equivalent of a library, which may be searchable, organised and catalogued, into something more akin to an exhibition. Curation helps to select aspects of an archive in order to tell deliberate stories, or simply help the user navigate content in a particular way. Curating material is particularly important if an archive deals with a specialist subject that no one knows about because visitors often need help to manoeuvre large amounts of complex information. Being overwhelmed by content on the internet is an often cited expression, but ensuring digital content is curated carefully means it is more likely that people visiting your site will be able to cope with what they find there, and delve deeper into your digitsed archival treasures.

Like all things digital, there is no one steadfast or established guidelines for how to ensure your collection is curated well. The rapid speed that technology changes, from preferred archival formats, software to interface design, mean that digital curation can never be a static procedure. New multiple web authoring tools such as zeega, klynt and 3WDOC will soon become integrated into web design in a similar fashion to the current Web 2.0 tools we use now, therefore creating further possibilities for the visual, immersive and interactive presentation of digital archive material.

fostex Dec 1998 Curating Digital Information or What Do You With Your Archive?

Screenshot of the Fostex website from Dec 1998

Curation is an important aspect of digital preservation in general because it can facilitate long term use and engagement with your collection. What may be lost when archive sites become pruned and more self-consciously arranged is the spontaneous and sometimes chaotic experience of exploring information on the web.

Ultimately though, digital curation will enable more people to navigate archival collections in ways that can foster meaningful, transformative and informative encounters with digitised material.

How sustainable is digitisation?

Monday, July 8th, 2013

Often when we think about the reasons to digitise magnetic tape collections we are considering the future. We digitise to make material accessible so it can be used again, or to preserve it so subsequent generations can benefit or learn from it. But how sustainable is digitisation and digital technology? What is the ecological impact of the widespread and breathtakingly fast adoption of digital technologies since the late 1990s?

At an everyday, consumer level, the use of digital technologies comes with real human and environmental costs, as Professor Toby Miller and Professor Richard Maxwell demonstrate in a recent article in The Guardian. They argue that the very metaphors we use to describe digital media – ‘virtual,’ ‘cloud’, ‘streams’ and ‘mobiles’ – dangerously obscure the fact they come from materials, such as the minerals Tatalun, Tungsten, Tin and Gold, and cover up the exploitative labour conditions, and war torn situations from which they are extracted:

‘Suggestions that we live in a dematerialised world are not only exaggerated; they are doing more harm than good. One person’s cloud is another’s pollution, and one person’s mobile is another’s enslavement. From electronic waste to conflict minerals, the new media leave an indelible mark on bodies and the Earth they inhabit.’

The extent of violence and exploitation that lie at the end of the digital supply chain is hardly a secret. At a consumer level there seems to be very little resistance to the use of mobile digital devices, probably because our very social existence is dependent upon them in a culture where media is pervasive. It is not easy to opt out, and what would you do if you did?

e waste How sustainable is digitisation?

As heavy users of digital technologies we walk with our heads in the clouds, so to speak, unable to access the wider environmental impact of our actions. This impact is intensified by the pressure to continually upgrade our devices, as Dr Chris Priest writes,

‘the regularity with which you replace a device becomes more important in determining the overall footprint of the device. If we take a hypothetical device with a 50% use footprint, and replace it after two years rather than three, then it will increase our overall footprint by 25%. Of course, new devices might be becoming increasingly efficient and this could offset the increase to some extent. Though even if the new device used no power, it could not offset it completely.’

Yet these are speculations not empirical fact. It is hard to know concretely what the environmental consequences of becoming immediate adopters of the latest (fastest, smallest, bestest) digital technologies are. One thing is certain, new goods will appear and people will be told they can’t live without them. This is how an economy driven by innovation works.

Thinking about the uptake of digital technologies at an institutional level, it is clear that within a technological climate pre-disposed to the production of ‘digital waste’ and obsolescence, the mismanagement of energy resources in order to keep digital data ‘alive’ (that is useable, accessible) is a real possibility. One only need turn to the financial and technological waste produced from the BBC’s Digital Media Initiative (DMI) to confirm that the creation of technical systems devised to manage large digital archives are not moving at the same relentless speed as the neoliberal market.

Which begs the question: can there be an ecological solution to the problem of digitisation, and the use of digital technologies in an innovation/ obsolescence economy? Can digitisation ever be energy efficient, non-exploitative and flexible enough to cope with the technological changes that will inevitably happen? What would a sustainable and ethical approach to digital information management look like?

As our world gets increasingly networked these are pressing questions effecting everyone. And clearly understanding the wider impact of the use of technology on people and the earth is a serious issue, usually forgotten when scrolling through data feeds in a voracious, but often distracted, manner. These are admittedly big questions and we welcome comments, links and ideas on how to answer them.

As keen hoarders of mechanical waste from the analogue era who are passionate about making data accessible in digital form, we are contributing to a world that places unprecedented value on technological information.

Need this, however, always be at the expense of people and the world we share as currently it seems to be?

 

Sony V62 EIAJ reel to reel video tape transfer for Barrie Hesketh

Monday, July 8th, 2013

We have recently been sent a Sony V62 high density video tape by Barrie Hesketh. Barrie has had an active career in theatre and in 1966 he set up the Mull Little Theatre on the Isle of Mull off the West Coast of Scotland with his late wife Marianne Hesketh. Specialising in what Barrie calls the ‘imaginative use of nothing’ they toured the UK, Germany and Holland and gained a lot of publicity world wide in the process. Both Marianne and Barrie were awarded MBEs for their services to Scottish Theatre.

You can read a more detailed history of the Mull Little Theatre in this book written by Barrie.

Panosonic VTR NV 8030 1024x800  Sony V62 EIAJ reel to reel video tape transfer for Barrie Hesketh

The video tape Barrie sent us came from when he and Marianne were working as actors in residence at Churchill College at Cambridge University. Barrie and Marianne had what Barrie described as ‘academic leanings,’ gained from their time as students at the Central College of Speech and Drama in London.

In a letter Barrie sent with the tape he wrote:

‘I own a copy of a video tape recording made for me by the University of Cambridge video unit in 1979. I was researching audience/actors responses and the recording shows the audience on the top half of the picture, and the actors on the bottom half – I have not seen the stuff for years, but have recently been asked about it.’

While audience research is a fairly common practice now in the Creative Arts, in 1979 Barrie’s work was pioneering. Barrie was very aware of audience’s interests when he performed, and was keen to identify what he calls ‘the cool part’ of the audience, and find out ways to ‘warm them up.’

Recording audience responses was a means to sharpen the attention of actors. He was particularly interested in the research to identify ‘includers’. These were individuals who influenced the wider audience by picking up intentions of the performers and clearly responding. The movement of this individual (who would look around from time to time to see if other people ‘got it’), would be picked up in the peripheral vision of other audience members and an awareness gradually trickled throughout. Seeing such behaviour helped Barrie to understand how to engage audiences in his subsequent work.

Screenshot of the Audience Reactions 1024x821  Sony V62 EIAJ reel to reel video tape transfer for Barrie Hesketh

Barrie’s tape would have been recorded on one of the later reel-to-reel tape machines that conformed to the EIAJ Standard.

The EIAJ-1 was developed in 1969 by the Electronic Industries Association of Japan. It was the first standardized format for industrial/non-broadcast video tape recording. Once implemented it enabled video tapes to be played on machines made by different manufacturers.

Prior to the introduction of the standard, tapes could not be interchanged between comparable models made by different manufacturers. The EIAJ standard changed all this, and certainly makes the job of transferring tapes easier for us today! Imagine the difficulties we would face if we had to get exactly the right machine for each tape transfer. It would probably magnify the problem of tape and machine obsolescence effecting magnetic tape collections.

In the Great Bear Studio we have the National Panasonic Time Lapse VTR NV-8030 and Hitachi SV-640.

15  Sony V62 EIAJ reel to reel video tape transfer for Barrie Hesketh

Like Ampex tapes, all the Sony EIAJ tape tend to suffer from sticky shed syndrome caused by absorption of moisture into the binder of the tape. Tapes need to be dehydrated and cleaned before being played back, as we did with Barrie’s tape.

The tape is now being transferred and Barrie intends to give copies to his sons. It will also be used by Dr Richard Trim in an academic research project. In both cases it is gratifying to give the these video tapes a new lease of life through digitisation. No doubt they will be of real interest to Barrie’s family and the wider research community.

What is the future of analogue media?

Monday, July 1st, 2013

In a recent blog article on the Presto Centre website, Richard Wright argues that ‘the audiovisual collections of the 20th century were analogue, and we are now at a critical time for considering the digital future of that analogue content.’ He goes on to say, emphatically:

‘All analogue audio and video formats are obsolete. Digital content walks through walls, travels at the speed of light, can be in many places at the same time, and can (with care) be perfectly copied, again and again. So digitisation has become the solution to the obsolescence of all analogue audio and video formats.’

Although careful not to make too clinical a statement, he bookmarks 15 April 2023 as the date when analogue obsolescence really kicks in.

DSC01263 1024x680 What is the future of analogue media?

We have written extensively on this blog about the problem of obsolescence, and how we collect machines and learn the skills to fix them.

A major problem is finding spare parts for machines after manufacturers stop producing them. Many components were made according to very precise specifications that are hard to make from scratch. When machines and their parts wear out it will therefore be difficult, if not impossible, to keep them working.

This means that the cost of transfers will rise due to machine scarcity. At an institutional level this may lead to selective decisions about what gets digitised and what doesn’t.

DSC01234 1024x680 What is the future of analogue media?

There is one analogue format that has flourished in the 21st century: vinyl.

Writing for music magazine The Wire, Numero Group’s Rob Sevier and Ken Shipley describe how ‘vinyl’s violent sales spike has been a lonely bright spot in what has been a 14 year deterioration in sales of recorded music’.

Yet the resilience of vinyl and other contemporary fringe uses of analogue media, such as the cassette tape and floppy disk, is not enough to stop the march of digitisation. For experts like Wright the digital future for the majority of people is inevitable, irresistible even, given how it enables collections to be open, replicable and accessible.

Yet committing to digital technologies as a preservation and access strategy does not solve our information problems, as we have been keen to stress on this blog. There is also a worrying lack of long term strategy for managing digital information, a problem which is ever more pronounced in film preservation where analogue tape is still marked as the original from which digital copies are made, as this article discusses.

DSC01326 1024x680 What is the future of analogue media?

It is clear that the information we create, store and use is in transition. It probably always has been. The emergence of digital technologies has just made this a pressing issue, not only for large institutions, but for people as we go about our day to day lives.

‘Digitise now!!’ is Richard Wright’s advice – and of course we agree.

copy umatic tape, digitise via dub connector or composite video?

Monday, July 1st, 2013

umatic dub yc converter copy umatic tape, digitise via dub connector or composite video?

Digitising legacy and obsolete video formats in essence is simple but the technical details make the process more complex. Experience and knowledge are therefore needed to make the most appropriate choices for the medium.

The umatic video format usually had two types of video output, composite and a y/c type connector that Sony named ‘Dub’. Originally designed as a higher quality method to make analogue ‘dubs’, or for connections in an edit suite, the Dub connector offers a higher performance signal path for the video signal.

It would make sense to use the higher quality dub output when digitising umatic tapes but here lies the problem. Firstly the connector uses the larger 7 pin y/c type connector that can be quite hard to find connectors for.

Secondly and most significantly, the chrominance subcarrier frequency is not the standard PAL  4.43Mhz but down converted by umatic recorders to 0.686Mhz for low band recordings and 0.984Mhz for high band recordings.

What this means in practice is that you’ll only get a monochrome image using the umatic dub connector unless you can find a way to convert the chroma subcarrier frequency back to 4.43Mhz.

There are several solutions:

  1. Convert this Dub signal chroma frequency using one of a few older Timebase Correctors / Frame Synchronisers  from the umatic era.
    These are now rare and often have other other faults that would degrade the signal.
  2. Take the Luma and Chroma signals at the correct frequency directly from certain test points on the circuit boards inside the machines.
    This can work well but is a slightly ‘messy’ solution and makes it hard to swap machines around, which is a necessity with older hardware.
  3. Convert the dub signal using a dedicated external dub – y/c converter circuit.
    This is our preferred solution that works well technically. It is flexible enough to swap around to different machines easily. It is also a relatively simple circuit that is easy to repair and doesn’t subject the video signal to  unnecessary extra processing.

Below are two stills taken from a Apple ProRes recording from a Low Band Pal u-Matic tape.
The first image is via the Dub connecter but converted to PAL Y/C.
The second images is via the Composite video out.

lb umatic dub kp copy umatic tape, digitise via dub connector or composite video?

 

lb umatic cvbs kp copy umatic tape, digitise via dub connector or composite video?

It’s clear from the images that there is more fine detail in the picture from the u-matic Dub version. The pattern / texture in the jacket and the texture and tone in the face is more detailed.  In contrast, the version digitised through the Composite video connector has less noise but due to the extra encoding and decoding there is less detail and more ‘blurring’.

While less noise may be preferable in some instances, having the option to choose between these two is always better. It’s this kind of attention detail and investment in equipment and knowledge that we are proud of and makes us a preferred supplier of digitising services for umatic video tape.


designed and developed by
greatbear analogue and digital media ltd, 0117 985 0500
Unit 26, The Coach House, 2 Upper York Street, Bristol, BS2 8QN, UK


XHTML | CSS
greatbear analogue and digital media is proudly powered by WordPress
hosted using Debian and Apache