Re-animating archives: Action Space’s V30H / V60H EIAJ 1/2″ video tapes

May 20th, 2015

One of the most interesting aspects of digitising magnetic tapes is what happens to them after they leave the Great Bear studio.

Often transfers are done for private or personal interest, such as listening to the recording of loved ones, or for straightforward archival reasons.

Yet in some cases material is re-used in a new creative project, thereby translating recordings within a different technical and historical context.

Walter Benjamin described such acts as the ‘afterlife’ of translation: ‘a translation issues from the original not so much for its life as from its afterlife […] translation marks their stage of continued life.’ [1]

A child stands on top of an inflatable structure, black and white image.

Stills from the Action Space tapes

So it was with a collection of ½ inch EIAJ SONY V30H and V60H video tapes that recently landed in the Great Bear studio which documented the antics of Action Space.

Part of the vanguard movement of radical arts organisations that emerged in the late 1960s, Action Space described themselves as ‘necessarily experimental, devious, ambiguous, and always changing in order to find a new situation. In the short term the objectives are to continually question and demonstrate through the actions of all kinds new relationships between artists and public, teachers and taught, drop-outs and society, performers and audiences, and to question current attitudes of the possibility of creativity for everyone.’ [2]

Such creative shape-shifting, which took its impulsive artistic action in a range of public spaces can so often be the enemy of documentation.

Yet Ken Turner, who founded Action Space alongside Mary Turner and Alan Nisbet, told me that ‘Super Eight film and transparency slides were our main documentation tools, so we were aware of recording events and their importance.’

Introduced in 1969, EIAJ 1/2″ was the first format to make video tape recording accessible to people outside the professional broadcast industry.

Action Space were part of this wave of audiovisual adoption (minor of course by today’s standards!)

After ‘accidentally’ inheriting a portapak recorder from the Marquis of Bath, Ken explained, Action Space ‘took the portapak in our stride into events and dramas of the community festivals and neighbourhood gatherings, and adventure playgrounds. We did not have an editing deck; as far as I can remember played back footage through a TV, but even then it had white noise, if that’s the term, probably it was dirty recording heads. We were not to know.’

Preservation issues

Yes those dirty recording heads make things more difficult when it comes to re-formatting the material.

While some of the recordings replay almost perfectly, some have odd tracking problems and emit noise, which are evidence of a faulty recorder and/or dirty tape path or heads. Because such imperfections were embedded at the time of recording, there is little that can be done to ‘clean up’ the signal.

Other problems with the Action Space collection arise from the chemical composition of the tapes. The recordings are mainly on Sony branded V30H and high density V60H tape which always suffer from binder hydrolysis. The tapes therefore needed ‘baking’ treatment prior to transfer usually (we have found) in a more controlled and longer way from Ampex branded tapes.

And that old foe of magnetic tape strikes again: mould. Due to being stored in an inappropriate environment over a prolonged period, many of the tapes have mould growth that has damaged the binder.

Despite these imperfections, or even because of them, Ken appreciates the unique value of these recordings: ‘the footage I have now of the community use reminds me of the rawness of the events, the people and the atmosphere of noise and constant movement. I am extremely glad to have these tapes transposed into digital footage as they vividly remind me of earlier times. I think this is essential to understanding the history and past experiences that might otherwise escape the memories of events.’

People sliding down an inflatable structure, joyful expressions on their faces.Historical translation

While the footage of Action Space is in itself a valuable historical document, the recordings will be subject a further act of translation, courtesy of Ken’s film maker son, Huw Wahl.

Fresh from the success of his film about anarchist art critic and poet Herbert Read, Huw is using the digitised tapes as inspiration for a new work.

This new film will reflect on the legacies of Action Space, examing how the group’s interventions can speak to our current historical context.

Huw told me he wants to re-animate Action Space’s ethos of free play, education and art in order ‘to question what actions could shape a democratic and creative society. In terms of the rhetoric of creativity we hear now from the arts council and artistic institutions, it’s important to look at where that developed from. Once we see how radical those beginnings really were, maybe we will see more clearly where we are heading if we continue to look at creativity as a commodity, rather than a potent force for a different kind of society.’

Inflatable action

Part of such re-animation will entail re-visiting Action Space’s work with large inflatable structures, or what Ken prefers to call ‘air or pneumatic structures.’

Huw intends to make a new inflatable structure that will act as the container for a range of artistic, academic, musical and nostalgic responses to Action Space’s history. The finished film will then be screened inside the inflatable, creating what promises to be an unruly and unpredictable spectacle.

Ken spoke fondly about the video footage which recorded ‘the urgency of “performance” of the people who are responding to the inflatables. Today inflatable making and use is more controlled, in the 60s control was only minimally observed, to prevent injuries. But in all our activities over 10 years of air structure events, we had only one fractured limb.’Young people sliding down the side of an inflatable structure - Action Space archive

Great Bear cameo!

Another great thing about the film is that the Great Bear Studio will have an important cameo role.

Huw came to visit us to shoot footage of the transfers. He explains his reasons:

‘I’d like viewers to see the set up for the capturing of the footage used in the film. Personally it’s very different seeing the reel played on a deck rather than scanning through a quicktime file. You pay a different kind of attention to it. I don’t want to be too nostalgic about a format I have never shot with, yet there seems to be an amateur quality inherent to the portapak which I assume is because the reels could be re-recorded over. Seeing material shot by children is something the super 8mm footage just doesn’t have, it would have been too expensive. Whereas watching children grabbing a portapack camera and running about with it is pretty exciting. Seeing the reels and machines for playing it all brings me closer to the experience of using the actual portapak cameras. Hopefully this will inform the filming and editing process of this film.’

We wish Huw the very best for his work on this project and look forward to seeing the results!

***Big thanks to Ken Turner and Huw Wahl for answering questions for this article.***

Notes

[1] Walter Benjamin, ‘The Task of the Translator,’ Selected Writings: 1913-1926, Volume 1, Harvard University Press, 2006, 253-264, 254.

[2] Action Space Annual Report, 1972, accessed http://www.unfinishedhistories.com/history/companies/action-space/action-space-annual-report-extract/.

Protected: Analogue to analogue – the Courtyard Music Group

May 18th, 2015

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Videokunstarkivet’s Mouldy U-Matic Video Tapes

May 15th, 2015

Lives and VideotapesLast year we featured the pioneering Norwegian Videokunstarkivet (Video Art Archive) on the Great Bear tape blog.

In one of our most popular posts, we discussed how Videokunstarkivet has created a state of the video art archive using open source software to preserve, manage and disseminate Norway’s video art histories for contemporary audiences and beyond.

In Lives and Videotapes, the beautiful collection of artist’s oral histories collected as part of the Videokunstarkivet project, the history of Norweigen video art is framed as ‘inconsistent’.

This is because, Mike Sperlinger eloquently writes, ‘in such a history, you have navigate by the gaps and contradictions and make these silences themselves eloquent. Videotapes themselves are like lives in that regard, the product of gaps and dropout—the shedding not only of their material substance, but of the cultural categories which originally sustained them’ (8).

The question of shedding, and how best to preserve the integrity of audiovisual archive object is of course a vexed one that we have discussed at length on this blog.

It is certainly an issue for the last collection of tapes that we received from Videokunstarkivet—a number of very mouldy U-Matic tapes.

umatic-dry-mould-inside-cassette-shellAccording to the Preservation Self-Assessment Program website, ‘due to media and hardware obsolescence’ U-Matic ‘should be considered at high preservation risk.’

At Great Bear we have stockpiled quite a few different U-Matic machines which reacted differently to the Videokunstarkivet tapes.

As you can see from the photo, they were in a pretty bad way.

 Note the white, dusty-flaky quality of the mould in the images. This is what tape mould looks like after it has been rendered inactive, or ‘driven into dormancy.’ If mould is active it will be wet, smudging if it is touched. In this state it poses the greatest risk of infection, and items need to be immediately isolated from other items in the collection.

Once the mould has become dormant it is fairly easy to get the mould off the tape using brushes, vacuums with HEPA filters and cleaning solutions. We also used a machine specifically for the cleaning process, which was cleaned thoroughly afterwards to kill off any lingering mould.

The video tape being played back on vo9800 U-Matic

This extract  demonstrates how the VO9800 replayed the whole tape yet the quality wasn’t perfect. The tell-tale signs of mould infestation are present in the transferred signal.

Visual imperfections, which begin as tracking lines and escalate into a fuzzy black out of the image, is evidence of how mould has extended across the surface of the tape, preventing a clear reading of the recorded information.

Despite this range of problems, the V09800 replayed the whole tape in one go with no head clogs.

SONY BVU 950

The video tape being played back on SONY BVU 950

In its day, the BVU950 was a much higher specced U-Matic machine than the VO9800. As the video extract demonstrates, it replayed some of the tape without the artefacts produced by the V09800 transfer, probably due to the deeper head tip penetration.

Yet this deeper head penetration also meant extreme tape head clogs on the sections that were affected badly by mould—even after extensive cleaning.

This, in turn, took a significant amount of time to remove the shedded material from the machine before the transfer could continue.

Mould problems

The play back of the tapes certainly underscores how deeply damaging damp conditions are for magnetic tape collections, particularly when they lead to endemic mould growth.

Yet the quality of the playback we managed to achieve also underlines how a signal can be retrieved, even from the most mould-mangled analogue tapes. The same cannot be said of digital video and audio, which of course is subject to catastrophic signal loss under similar conditions.

As Mike Sperlinger writes above, the shedding and drop outs are important artefacts in themselves. They mark the life-history of magnetic tapes, objects which so-often exist at the apex of neglect and recovery.

The question we may ask is: which transfer is better and more authentic? Yet this question is maddeningly difficult to answer in an analogue world defined by the continuous variation of the played back signal. And this variation is certainly amplified within the context of archival transfers when damage to tape has become accelerated, if not beyond repair.

At Great Bear we are in the good position of having a number of machines which enables us to test and experiment different approaches.

One thing is clear: for challenging collections, such as these items from the Videokunstarkivet, there is no one-size-fits-all answer to achieve the optimal transfer.

Mouldy DATs

May 5th, 2015

We have previously written on this blog about the problems that can occur when transferring Digital Audio Tapes (DATs).

According to preliminary findings from the British Library’s important survey of the UK’s sound collections, there are 3353 DAT tapes in the UK’s archives.

While this is by no means a final figure (and does not include the holdings of record companies and DATheads), it does suggest there is a significant amount of audio recorded on this obsolete format which, under certain conditions, is subject to catastrophic signal loss.

The conditions we are referring to is that old foe of magnetic tape: mould.

In contrast with existing research about threats to DAT, which emphasise how the format is threatened by ‘known playback problems that are typically related to mechanical alignment’, the biggest challenges we consistently face with DATs is connected to mould.

It is certainly acknowledged that ‘environmental conditions, especially heat, dust, and humidity, may also affect cassettes.’

Nevertheless, the specific ways mould growth compromise the very possibility of successfully playing back a DAT tape have not yet been fully explored. This in turn shapes the kinds of preservation advice offered about the format.

What follows is an attempt to outline the problem of mould growth on DATs which, even in minimal form, can pretty much guarantee the loss of several seconds of recording.

DAT Tape SizeTape width issues

The first problem with DATs is that they are 4mm wide, and very thin in comparison to other forms of magnetic tape.

The size of the tape is compounded by the helical method used in the format, which records the signal as a diagonal stripe across the tape. Because tracks are written onto the tape at an angle, if the tape splits it is not a neat split that can be easily spliced together.

The only way to deal with splits is to wind the tape back on to the tape transport or use leder tape to stick the tape back together at the breaking point.

Either way, you are guaranteed to lose a section of the tape because the helical scan has imprinted the recorded signal at a sharp, diagonal angle. If a DAT tape splits, in other words, it cuts through the diagonal signal, and because it is digital rather than analogue audio, this results in irreversible signal loss.

And why does the tape split? Because of the mould!

If you play back a DAT displaying signs of dormant mould-growth it is pretty much guaranteed to split in a horrible way. The tape therefore needs to be disassembled and wound by hand. This means you can spend a lot of time restoring DATs to a playable condition.

Rewinding by hand is however not 100% full proof, and this really highlights the challenges of working with mouldy DAT tape.

Often mould on DATs is visible on the edge of the tape pack because the tape has been so tightly wound it doesn’t spread to the full tape surface.

In most cases with magnetic tape, mould on the edge is good news because it means it has not spread and infected the whole of the tape. Not so with DAT.

Even with tiny bits of mould on the edge of the tape there is enough to stick it to the next bit of tape as it is rewound.

When greater tension is applied in an attempt to release the mould, due to stickiness, the tape rips.

A possible and plausible explanation for DAT tape ripping is that due to the width and thinness of the tape the mould is structurally stronger than the tape itself, making it easier for the mould growth to stick together.

When tape is thicker, for example with a 1/4 ” open reel tape, it is easier to brush off the dormant mould which is why we don’t see the ripping problem with all kinds of tape.

Our experience confirms that brushing off dormant mould is not always possible with DATs which, despite best efforts, can literally peel apart because of sticky mould.

What, then, is to be done to ensure that the 3353 (and counting) DAT tapes in existence remain in a playable condition?

One tangible form of action is to check that your DATs are stored at the appropriate temperature (40–54°F [4.5–12°C]) so that no mould growth develops on the tape pack.

The other thing to do is simple: get your DAT recordings reformatted as soon as possible.

While we want to highlight the often overlooked issue of mould growth on DATs, the problems with machine obsolescence, a lack of tape head hours and mechanical alignment problems remain very real threats to successful transfer of this format.

Our aim at the Great Bear is to continue our research in the area of DAT mould growth and publish it as we learn more.

As ever, we’d love to hear about your experiences of transferring mouldy DATs, so please leave a comment below if you have a story to share.

 

Codecs and Wrappers for Digital Video

April 9th, 2015

In the last Great Bear article we quoted sage advice from the International Association of Audiovisual Archivists: ‘Optimal preservation measures are always a compromise between many, often conflicting parameters.’ [1]

While this statement is true in general for many different multi-format collections, the issue of compromise and conflicting parameters becomes especially apparent with the preservation of digitized and born-digital video. The reasons for this are complex, and we shall outline why below.

Lack of standards (or are there too many formats?)

Carl Fleischhauer writes, reflecting on the Federal Agencies Digitization Guidelines Initiative (FADGI) research exploring Digital File Formats for Videotape Reformatting (2014), ‘practices and technology for video reformatting are still emergent, and there are many schools of thought. Beyond the variation in practice, an archive’s choice may also depend on the types of video they wish to reformat.’ [2]

We have written in depth on this blog about the labour intensity of digital information management in relation to reformatting and migration processes (which are of course Great Bear’s bread and butter). We have also discussed how the lack of settled standards tends to make preservation decisions radically provisional.

In contrast, we have written about default standards that have emerged over time through common use and wide adoption, highlighting how parsimonious, non-interventionist approaches may be more practical in the long term.

The problem for those charged with preserving video (as opposed to digital audio or images) is that ‘video, however, is not only relatively more complex but also offers more opportunities for mixing and matching. The various uncompressed-video bitstream encodings, for example, may be wrapped in AVI, QuickTime, Matroska, and MXF.’ [3]

What then, is this ‘mixing and matching’ all about?

It refers to all the possible combinations of bitsteam encodings (‘codecs’) and ‘wrappers’ that are available as target formats for digital video files. Want to mix your JPEG2000 – Lossless with your MXF, or ffv1 with your AVI? Well, go ahead!

What then is the difference between a codec and wrapper?.

As the FADGI report states: ‘Wrappers are distinct from encodings and typically play a different role in a preservation context.’ [4]

The wrapper or ‘file envelope’ stores key information about the technical life or structural properties of the digital object. Such information is essential for long term preservation because it helps to identify, contextualize and outline the significant properties of the digital object.

Information stored in wrappers can include:

  • Content (number of video streams, length of frames),
  • Context (title of object, who created it, description of contents, re-formatting history),
  • Video rendering (Width, Height and Bit-depth, Colour Model within a given Colour Space, Pixel Aspect Ratio, Frame Rate and Compression Type, Compression Ratio and Codec),
  • Audio Rendering – Bit depth and Sample Rate, Bit Rate and compression codec, type of uncompressed sampling.
  • Structure – relationship between audio, video and metadata content. (adapted from the Jisc infokit on High Level Digitisation for Audiovisual Resources)

Codecs, on the other hand, define the parameters of the captured video signal. They are a ‘set of rules which defines how the data is encoded and packaged,’ [5] encompassing Width, Height and Bit-depth, Colour Model within a given Colour Space, Pixel Aspect Ratio and Frame Rate; the bit depth and sample rate and bit rate of the audio.

Although the wrapper is distinct from the encoded file, the encoded file cannot be read without its wrapper. The digital video file, then, comprises of wrapper and at least one codec, often two, to account for audio and images, as this illustration from AV Preserve makes clear.

Codecs and Wrappers

Diagram taken from AV Preserve’s A Primer on Codecs for Moving Image and Sound Archives

Pick and mix complexity

Why then, are there so many possible combinations of wrappers and codecs for video files, and why has a settled standard not been agreed upon?

Fleischhauer at The Signal does an excellent job outlining the different preferences within practitioner communities, in particular relating to the adoption of ‘open’ and commercial/ proprietary formats.

Compellingly, he articulates a geopolitical divergence between these two camps, with those based in the US allegedly opting for commercial formats, and those in Europe opting for ‘open.’ This observation is all the more surprising because of the advice in FADGI’s Creating and Archiving Born Digital Video: ‘choose formats that are open and non-proprietary. Non-proprietary formats are less likely to change dramatically without user input, be pulled from the marketplace or have patent or licensing restrictions.’ [6]

One answer to the question: why so many different formats can be explained by different approaches to information management in this information-driven economy. The combination of competition and innovation results in a proliferation of open source and their proprietary doubles (or triplets, quadruples, etc) that are constantly evolving in response to market ‘demand’.

Impact of the Broadcast Industry

An important area to highlight driving change in this area is the role of the broadcast industry.

Format selections in this sector have a profound impact on the creation of digital video files that will later become digital archive objects.

In the world of video, Kummer et al explain in an article in the IASA journal, ‘a codec’s suitability for use in production often dictates the chosen archive format, especially for public broadcasting companies who, by their very nature, focus on the level of productivity of the archive.’ [7] Broadcast production companies create content that needs to be able to be retrieved, often in targeted segments, with ease and accuracy. They approach the creation of digital video objects differently to how an archivist would, who would be concerned with maintaining file integrity rather ensuring the source material’s productivity.

Furthermore, production contexts in the broadcast world have a very short life span: ‘a sustainable archiving decision will have to made again in ten years’ time, since the life cycle of a production system tends to be between 3 and 5 years, and the production formats prevalent at that time may well be different to those in use now.’ [8]

Take, for example, H.264/ AVC ‘by far the most ubiquitous video coding standard to date. It will remain so probably until 2015 when volume production and infrastructure changes enable a major shift to H.265/ HEVC […] H.264/ AVC has played a key role in enabling internet video, mobile services, OTT services, IPTV and HDTV. H.264/ AVC is a mandatory format for Blu-ray players and is used by most internet streaming sites including Vimeo, youtube and iTunes. It is also used in Adobe Flash Player and Microsoft Silverlight and it has also been adopted for HDTV cable, satellite, and terrestrial broadcasting,’ writes David Bull in his book Communicating Pictures.

HEVC, which is ‘poised to make a major impact on the video industry […] offers to the potential for up to 50% compression efficiency improvement over AVC.’ Furthermore, HEVC has a ‘specific focus on bit rate reduction for increased video resolutions and on support for parallel processing as well as loss resilience and ease if integration with appropriate transport mechanisms.’ [9]

CODEC Quality Chart3Increased compression

The development of codecs for use in the broadcast industry deploy increasingly sophisticated compression that reduce bit rate but retain image quality. As AV Preserve explain in their codec primer paper, ‘we can think of compression as a second encoding process, taking coded information and transferring or constraining it to a different, generally more efficient code.’ [10]

The explosion of mobile, video data in the current media moment is one of the main reasons why sophisticated compression codecs are being developed. This should not pose any particular problems for the audiovisual archivist per se—if a file is ‘born’ with high degrees of compression the authenticity of the file should not ideally, be compromised in subsequent migrations.

Nevertheless, the influence of the broadcast industry tells us a lot about the types of files that will be entering the archive in the next 10-20 years. On a perceptual level, we might note an endearing irony: the rise of super HD and ultra HD goes hand in hand with increased compression applied to the captured signal. While compression cannot, necessarily, be understood as a simple ‘taking away’ of data, its increased use in ubiquitous media environments underlines how the perception of high definition is engineered in very specific ways, and this engineering does not automatically correlate with capturing more, or better quality, data.

Like error correction that we have discussed elsewhere on the blog, it is often the anticipation of malfunction that is factored into the design of digital media objects. These, in turn, create the impression of smooth, continuous playback—despite the chaos operating under the surface. The greater clarity of the visual image, the more the signal has been squeezed and manipulated so that it can be transmitted with speed and accuracy. [11]

MXF

Staying with the broadcast world, we will finish this article by focussing on the MXF wrapper that was ‘specifically designed to aid interoperability and interchange between different vendor systems, especially within the media and entertainment production communities. [MXF] allows different variations of files to be created for specific production environments and can act as a wrapper for metadata & other types of associated data including complex timecode, closed captions and multiple audio tracks.’ [12]

The Presto Centre’s latest TechWatch report (December 2014) asserts ‘it is very rare to meet a workflow provider that isn’t committed to using MXF,’ making it ‘the exchange format of choice.’ [13]MXF

We can see such adoption in action with the Digital Production Partnership’s AS-11 standard, which came into operation October 2014 to streamline digital file-based workflows in the UK broadcast industry.

While the FADGI reports highlights the instability of archival practices for video, the Presto Centre argue that practices are ‘currently in a state of evolution rather than revolution, and that changes are arriving step-by-step rather than with new technologies.’

They also highlight the key role of the broadcast industry as future archival ‘content producers,’ and the necessity of developing technical processes that can be complimentary for both sectors: ‘we need to look towards a world where archiving is more closely coupled to the content production process, rather than being a post-process, and this is something that is not yet being considered.’ [14]

The world of archiving and reformatting digital video is undoubtedly complex. As the quote used at the beginning of the article states, any decision can only ever be a compromise that takes into account organizational capacities and available resources.

What is positive is the amount of research openly available that can empower people with the basics, or help them to delve into the technical depths of codecs and wrappers if so desired. We hope this article will give you access to many of the interesting resources available and some key issues.

As ever, if you have a video digitization project you need to discuss, contact us—we are happy to help!

References:

[1] IASA Technical Committee (2014) Handling and Storage of Audio and Video Carriers, 6. 

[2] Carl Fleischhauer, ‘Comparing Formats for Video Digitization.’ http://blogs.loc.gov/digitalpreservation/2014/12/comparing-formats-for-video-digitization/.

[3] Federal Agencies Digital Guidelines Initiative (FADGI), Digital File Formats for Videotape Reformatting Part 5. Narrative and Summary Tables. http://www.digitizationguidelines.gov/guidelines/FADGI_VideoReFormatCompare_pt5_20141202.pdf, 4.

[4] FADGI, Digital File Formats for Videotape, 4.

[5] AV Preserve (2010) A Primer on Codecs for Moving Image and Sound Archives & 10 Recommendations for Codec Selection and Managementwww.avpreserve.com/wp-content/…/04/AVPS_Codec_Primer.pdf, 1.

‎[6] FADGI (2014) Creating and Archiving Born Digital Video Part III. High Level Recommended Practices, http://www.digitizationguidelines.gov/guidelines/FADGI_BDV_p3_20141202.pdf, 24.
[7] Jean-Christophe Kummer, Peter Kuhnle and Sebastian Gabler (2015) ‘Broadcast Archives: Between Productivity and Preservation’, IASA Journal, vol 44, 35.

[8] Kummer et al, ‘Broadcast Archives: Between Productivity and Preservation,’ 38.

[9] David Bull (2014) Communicating Pictures, Academic Press, 435-437.

[10] Av Preserve, A Primer on Codecs for Moving Image and Sound Archives, 2.

[11] For more reflections on compression, check out this fascinating talk from software theorist Alexander Galloway. The more practically bent can download and play with VISTRA, a video compression demonstrator developed at the University of Bristol ‘which provides an interactive overview of the some of the key principles of image and video compression.

[12] ‘FADGI, Digital File Formats for Videotape, 11.

[13] Presto Centre, AV Digitisation and Digital Preservation TechWatch Report #3, https://www.prestocentre.org/, 9.

[14] Presto Centre, AV Digitisation and Digital Preservation TechWatch Report #3, 10-11.

IASA – Resources and Research

March 27th, 2015

There are an astonishing amount of online resources relating to the preservation and re-formatting of magnetic tape collections.

Whether you need help identifying and assessing your collection, getting to grips with the latest video codec saga or trying to uncover esoteric technical information relating to particular formats, the internet turns up trumps 95% of the time.

Marvel at the people who put together the U-Matic web resource, for example, which has been online since 1999, a comprehensive outline of the different models in the U-Matic ‘family.’ The site also hosts ‘chat pages’ relating to Betamax, Betacam, U-Matic and V2000, which are still very much active, with archives dating back to 1999. For video tape nerds willing to trawl the depths of these forums, nuggets of machine maintenance wisdom await you.

 International Association of Sound and Audiovisual Archives

Sometimes you need to turn to rigorous, peer-reviewed research in order to learn from AV archive specialists.

Fortunately such material exists, and a good amount of it is collected and published by the International Association of Sound and Audiovisual Archives (IASA).

Three IASA journals laid out on the floor

‘Established in 1969 in Amsterdam to function as a medium for international co-operation between archives that preserve recorded sound and audiovisual documents’, IASA holds expertise relating to the many different and specialist issues attached to the care of AV archives.

Comprised of several committees dealing with issues such as standards and best practices; National Archive policies; Broadcast archives; Technical Issues; Research Archives; Training and Education, IASA reflects the diverse communities of practice involved in this professional field.

As well as hosting a yearly international conference (check out this post on The Signal for a review of the 2014 meeting), IASA publish a bi-annual journal and many in-depth specialist reports.

Their Guidelines on the Production and Preservation of Digital Audio Objects (2nd edition, 2009), written by the IASA Technical Committee, is available as a web resource, and provides advice on key issues such as small scale approaches to digital storage systems, metadata and signal extraction from original carriers, to name a few.

Most of the key IASA publications are accessible to members only, and therefore remain behind a paywall. It is definitely worth taking the plunge though, because there are comparably few specialist resources relating to AV archives written with an interdisciplinary—and international—audience in mind.

Examples of issues covered in member-only publications include Selection in Sound Archives, Decay of Polymers, Deterioration of Polymers and Ethical Principles for Sound and Audiovisual Archives.

The latest publication from the IASA Technical Committee, Handling and Storage of Audio and Video Carriers (2014) or TC05, provides detailed outlines of types of recording carriers, physical and chemical stability, environmental factors and ‘passive preservation,’ storage facilities and disaster planning.

The report comes with this important caveat:

 ‘TC 05 is not a catalogue of mere Dos and Don’ts. Optimal preservation measures are always a compromise between many, often conflicting parameters, superimposed by the individual situation of a collection in terms of climatic conditions, the available premises, personnel, and the financial situation. No meaningful advice can be given for all possible situations. TC 05 explains the principal problems and provides a basis for the archivist to take a responsible decision in accordance with a specific situation […] A general “Code of Practice” […] would hardly fit the diversity of structures, contents, tasks, environmental and financial circumstances of collections’ (6).

Member benefits

Being an IASA member gives Great Bear access to research and practitioner communities that enable us to understand, and respond to, the different needs of our customers.

Typically we work with a range of people such as individuals whose collections have complex preservation needs, large institutions, small-to-medium sized archives or those working in the broadcast industry.

Our main concern is reformatting the tapes you send us, and delivering high quality digital files that are appropriate for your plans to manage and re-use the data in the future.

If you have a collection that needs to be reformatted to digital files, do contact us to discuss how we can help.

1″ type A Video Tape – The Old Grey Whistle Test

March 5th, 2015

Sometimes genuine rarities turn up at the Great Bear studio. Our recent acquisition of four reels of ‘missing, believed wiped’ test recordings of cult BBC TV show The Old Grey Whistle Test is one such example.Old Grey Whistle Test Ampex reel

It is not only the content of these recordings that are interesting, but their form too, because they were made on 1” type A videotape.

The Ampex Corporation introduced 1” Society of Motion Picture and Television Engineers (SMPTE) type A videotape in 1965.

The 1″ type A was ‘one of the first standardized reel-to-reel magnetic tape formats in the 1 inch (25 mm) width.’ In the US it had greatest success as an institutional and industrial format. It was not widely adopted in the broadcast world because it did not meet Federal Communications Commission (FCC) specifications for broadcast videotape formats—it was capable of 350 lines, while the NTSC standard was 525, PAL and SECAM were 625 (for more information on television standards visit this page, also note the upcoming conference ‘Standards, Disruptions and Values in Digital Culture and Communication‘ taking place November 2015).

According the VT Old Boys website, created by ex-BBC engineers in order to document the history of videotape used at the organisation, 2″ Quadruplex tape remained very much the norm for production until the end of the 1970s.

Yet the very existence of the Old Grey Whistle Test tapes suggests type A videotape was being used in some capacity in the broadcast world. Perhaps ADAPT, a project researching British television production technology from 1960-present, could help us solve this mystery?

Old Grey Whistle Test ReelFrom type A, to type B….

As these things go, type A was followed by type B, with this model developed by the German company Bosch. Introduced in 1976, type B was widely adopted in continental Europe, but not in UK and USA which gravitated toward the type C model, introduced by SONY/ Ampex, also in 1976. Type C then became the professional broadcast standard and was still being used well into the 1990s. It was able to record high quality composite video, and therefore had an advantage over component videos such as Betacam and MII that were ‘notoriously fussy and trouble-prone.‘ Type C also had fancy functions like still, shuttle, variable-speed playback and slow motion.

From a preservation assessment point of view, ‘one-inch open reel is especially susceptible to risks associated with age, hardware, and equipment obsolescence. It is also prone to risks common to other types of magnetic media, such as mould, binder deterioration, physical damage, and signal drop-outs.’

1" Type A Machine

The Preservation Self-Assessment Programme advise that ‘this format is especially vulnerable, and, based on content assessment, it should be a priority for reformatting.’

AMPEX made over 30 SMPTE type A models, the majority of which are listed here. Yet the number of working machines we have access to today is few and far between.

In years to come it will be common for people to say ‘it takes four 1” type A tape recorders to make a working one’, but remember where you heard the truism first.

Harvesting several of these hulking, table-top machines for spares and working parts is exactly how we are finding a way to transfer these rare tapes—further evidence that we need to take the threat of equipment obsolescence very seriously.

Digitising small audiovisual collections: making decisions and taking action

February 24th, 2015

Deciding when to digitise your magnetic tape collections can be daunting.

The Presto Centre, an advocacy organisation working to help ‘keep audiovisual content alive,’ have a graphic on their website which asks: ‘how digital are our members?’

They chart the different stages of ‘uncertainty,’ ‘awakening’, ‘enlightenment’, ‘wisdom’ and ‘certainty’ that organisations move through as they appraise their collections and decide when to re-format to digital files.

Similarly, the folks at AV Preserve offer their opinion on the ‘Cost of Inaction‘ (COI), arguing that ‘incorporating the COI model and analyses into the decision making process around digitization of legacy physical audiovisual media helps organizations understand the implications and make well-informed decisions.’

They have even developed a COI calculator tool that organisations can use to analyse their collections. Their message is clear: ‘the cost of digitization may great, but the cost of inaction may be greater.’

Digitising small-medium audiovisual collections

For small to medium size archives, digitising collections may provoke worries about a lack of specialist support or technical infrastructure. It may be felt that resources could be better used elsewhere in the organisation. Yet as we, and many other people working with audiovisual archives often stress, the decision to transfer material stored on magnetic tape has to be made sooner or later. With smaller archives, where funding is limited, the question of ‘later’ is not really a practical option.

Furthermore, the financial cost of re-formatting audiovisual archives is likely to increase significantly in the next five-ten years; machine obsolescence will become an aggravated problem and it is likely to take longer to restore tapes prior to transfer if the condition of carriers has dramatically deteriorated. The question has to be asked: can you afford not to take action now?

If this describes your situation, you might want to hear about other small to medium sized archives facing similar problems. We asked one of our customers who recently sent in a comparatively small collection of magnetic tapes to share their experience of deciding to take the digital plunge.

We are extremely grateful for Annaig from the Medical Mission Sisters for answering the questions below. We hope that it will be useful for other archives with similar issues.

threadimg-eiaj-half-inch-video-tape1. First off, please tell us a little bit about the Medical Mission Sisters Archive, what kind of materials are in the collection?

The Medical Mission Sisters General Archives include the central archives of the congregation. They gather all the documents relating to the foundation and history of the congregation and also documents relating to the life of the foundress, Anna Dengel. The documents are mainly paper but there is a good collection of photographs, slides, films and audio documents. Some born digital documents are starting to enter the archives but they are still few.

2. As an archive with a modest collection of magnetic tapes, why did you decide to get the materials digitised now? Was it a question of resources, preservation concerns, access request (or a mixture of all these things!)

The main reason was accessibility. The documents on video tapes or audio tapes were the only usable ones because we still had machines to read them but all the older ones, or those with specific formats,  where lost to the archives as there was no way to read them and know what was really on the tapes. Plus the Medical Mission Sisters is a congregation where Sisters are spread out on 5 continents and most of the time readers don’t come to the archives but send me queries by emails where I have to respond with scanned documents or digital files. Plus it was obvious that some of the tapes were degrading as that we’d better have the digitisation sooner than later if we wanted to still be able to read what was on them. Space and preservation was another issue. With a small collection but varied in formats, I had no resources to properly preserve every tape and some of the older formats had huge boxes and were consuming a lot of space on the shelves. Now, we have a reasonably sized collection of CDs and DVDs, which is easy to store in good conditions and is accessible everywhere as we can read them on computer here and I can send them to readers via email.

3. Digital preservation is a notoriously complex, and rapidly evolving field. As a small archive, how do you plan to manage your digital assets in the long term? What kinds of support, services and systems are your drawing on to design a system which is robust and resilient?

At the moment the digital collection is so small that it cannot justify any support service or system. So I have to build up my own home made system. I am using the archives management software (CALM) to enter data relating to the conservation of the CDs or DVDs, dates of creation, dates to check them and I plan to have regular checks on them and migrations or copies made when it will prove necessary.

4. Aside from the preservation issue, what are your plans to use the digitised material that Great Bear recently transferred?

It all depends on the content of the tapes. But I’ve already spotted a few documents of interest, and I haven’t been through everything yet. My main concern now is to make the documents known and used for their content. I was already able to deliver a file to one of the Sisters who was working on a person related to the foundation of the congregation, the most important document on her was an audio file that I had just received from Great Bear, I was able to send it to her. The document would have been unusable a few weeks before. I’ve come across small treasures, like a film, probably made by the foundress herself, which nobody was aware of. The Sisters are celebrating this year the 90th anniversary of their foundation. I plan to use as many audio or video documents as I can to support the events the archives are going to be involved into.

***

What is illuminating about Annaig’s answers is that her archive has no high tech plan in place to manage the collection – her solutions for managing the material very much draw on non-digital information management practices.

The main issues driving the decision to migrate the materials are fairly common to all archives: limited storage space and accessibility for the user-community.

What lesson can be learnt from this? Largely, that if you are trained as an archivist, you are likely to already have the skills you need to manage your digital collection.

So don’t let the more bewildering aspects of digital preservation put you off. But do take note of the changing conditions for playing back and accessing material stored on magnetic tape. There will come a time when it will be too costly to preserve recordings on a wide variety of formats – many of such formats we can help you with today.

If you want to discuss how Great Bear can help you re-format your audiovisual collections, get in touch and we can explore the options.

If you are a small-medium size archive and want to share your experiences of deciding to digitise, please do so in the comment box below.

Save our Sounds – 2030 and the threat of audiovisual extinction

February 9th, 2015

At the beginning of 2015, the British Library launched the landmark Save Our Sounds project.

The press release explained:

‘The nation’s sound collections are under threat, both from physical degradation and as the means of playing them disappear from production. Archival consensus internationally is that we have approximately 15 years in which to save our sound collections by digitising them before they become unreadable and are effectively lost.’

dvw-a510-digital-betacam-loading-gearYes you have read that correctly dear reader: by 2030 it is likely that we simply will not be able to play many, if not all of the tape we currently support at Great Bear. A combination of machine obsolescence, tape deterioration and, crucially, the widespread loss of skills necessary to repair, service and maintain playback machines are responsible for this astounding situation. They will make it ‘costly, difficult and, in many cases, impossible’ to preserve our recorded audio heritage beyond the proposed cut-off date.

While such news might (understandably) usher in a culture of utter panic, and, let’s face it, you’d have to have a strong disposition if you were charged with managing the Save Our Sounds project, the British Library are responding with stoic pragmatism. They are currently undertaking a national audit to map the conditions of sound archives which your organisation can contribute to.

Yet whatever way you look at it, there is need to take action to migrate any collections currently stored on obsolete media, particular if you are part of a small organisation with limited resources. The reality is it will become more expensive to transfer material as we move closer to 2030. The British Library project relates particularly to audio heritage, but the same principles apply to audiovisual collections too.

Yes that rumbling you can hear is the sound of archivists the world over engaged in flurry of selection and appraisal activities….

Extinction

One of the most interesting things about discussions of obsolete media is that the question of operability is often framed as a matter of life or death.

Formats are graded according to their ‘endangered statuses’ in more or less explicit terms, as demonstrated on this Video Preservation website which offers the following ‘obsolescence ratings':

‘Extinct: Only one or two playback machines may exist at specialist laboratories. The tape itself is more than 20 years old.

Critically endangered: There is a small population of ageing playback machinery, with no or little engineering or manufacturing support. Anecdotal evidence indicates that there are fewer working machine-hours than total population of tapes. Tapes may range in age from 40 years to 10 years.

Endangered: The machine population may be robust, but the manufacture of the machinery has stopped. Manufacturing support for the machines and the tapes becomes unavailable. The tapes are often less expensive, and more vulnerable to deterioration.

Threatened: The playback machines are available; however, either the tape format itself is unstable or has less integrity than other available formats, or it is known that a more popular or updated format will be replacing this one in a short period of time.

Vulnerable: This is a current but highly proprietary format.

Lower risk: This format will be in use over the next five years (1998-2002).’

The ratings on the video preservation website were made over ten years ago. A more comprehensive and regularly updated resource to consult is the Preservation Self-Assessment Program (PSAP), ‘a free online tool that helps collection managers prioritize efforts to improve conditions of collections. Through guided evaluation of materials, storage/exhibit environments, and institutional policies, the PSAP produces reports on the factors that impact the health of cultural heritage materials, and defines the points from which to begin care.’ As well as audiovisual media, the resource covers photo and image material, paper and book preservation. It also has advice about disaster planning, metadata, access and a comprehensive bibliography.

The good news is that fantastic resources do exist to help archivists make informed decisions about reformatting collections.

dcc-backview

A Digital Compact Cassette

The bad news, of course, is that the problem faced by audiovisual archivists is a time-limited one, exacerbated no doubt by the fact that digital preservation practices on the ‘output end’ are far from stable. Finding machines to playback your Digital Compact Cassette collection, in other words, will only be a small part of the preservation puzzle. A life of file migrations in yet to be designed wrappers and content-management systems awaits all kinds of reformatted audiovisual media in their life-to-come as a digital archival object.

Depending on the ‘content value’ of any collection stored on obsolete media, vexed decisions will need to be made about what to keep and what to throw away at this clinical moment in the history of recorded sound.

Sounding the fifteen-year warning

At such a juncture, when the fifteen year warning has been sounded, perhaps we can pause for a second to reflect on the potential extinction of large swathes of audio visual memory.

If we accept that any kind of recording both contains memory (of a particular historical event, or performance) and helps us to remember as an aide-mémoire, what are the consequences when memory storage devices which are, according to UNESCO, ‘the primary records of the 20th and 21st centuries’, can no longer be played back?

These questions are of course profound, and emerge in response to what are consequential historical circumstances. They are questions that we will continue to ponder on the blog as we reflect on our own work transferring obsolete media, and maintaining the machines that play them back. There are no easy answers!

As the 2030 deadline looms, our audiovisual context is a sobering retort to critics who framed the widespread availability of digitisation technologies in the first decade of the 21st century as indicative of cultural malaise—evidence of a culture infatuated with its ‘past’, rather than concerned with inventing the ‘future’.

Perhaps we will come to understand the 00s as a point of audiovisual transition, when mechanical operators still functioned and tape was still in fairly good shape. When it was an easy, almost throw away decision to make a digital copy, rather than an immense preservation conundrum. So where once there was a glut of archival data—and the potential to produce it—is now the threat of abrupt and irreversible dropout.

Play those tapes back while you can!

1/2″ EIAJ video tape – aesthetic glitches

January 16th, 2015

In an article on the BBC website Temple reflected on the recordings: ‘we affectionately called the format “Glorious Bogroll Vision” but really it was murksville. Today monochrome footage would be perfectly graded with high-contrast effects. But the 1970s format has a dropout-ridden, glitchy feel which I enjoy now.’ 

Note the visible drop out in the image

Note the visible drop out in the image

The glitches of 1/2″ video were perfect for Temple’s film, which aimed to capture the apocalyptic feeling of Britain on the eve of 1977. Indeed, Temple reveals that ‘we cut in a couple of extra glitches we liked them so much.

Does the cutting in of additional imperfection signal a kind-of fetishisation of the analogue video, a form of wanton nostalgia that enables only a self-referential wallowing on a time when things were gloriously a lot worse than they are now?

Perhaps the corrupted image interrupts the enhanced definition and clarity of contemporary digital video.

Indeed, Temple’s film demonstrates how visual perception is always produced by the transmission devices that playback moving images, sound and images, whether that be the 1/2″ video tape or the super HD television.

It is reminder, in other words, that there are always other ways of seeing, and underlines how punk, as a mode of aesthetic address in this case, maintains its capacity to intervene into the business-as-usual ordering of reality.

What to do with your 1/2″ video tapes?

hitachi_reel_to_reel_eiaj_vtr1

While Temple’s film was made to look worse than it could have been, EIAJ 1/2″ video tapes are most definitely a vulnerable format and action therefore needs to be taken if they are to be preserved effectively.

In a week where the British Library launched their Save Our Sounds campaign, which stated that ‘archival consensus internationally is that we have approximately 15 years in which to save our sound collections by digitising them before they become unreadable and are effectively lost,’ the same timeframes should be applied to magnetic tape-based video collections.

So if your 1/2″ tapes are rotting in your shed as Temple’s Clash footage was, you know that you need to get in there, fish them out, and send them to us pronto!

DVCAM transfers, error correction coding & misaligned machines

December 17th, 2014

This article is inspired by a collection of DVCAM tapes sent in by London-based cultural heritage organisation Sweet Patootee. Below we will explore several issues that arise from the transfer of DVCAM tapes, one of the many Digital Video formats that emerged in the mid-1990s. A second article will follow soon which focuses on the content of the Sweet Patootee archive, which is a fascinating collection of video-taped oral histories of 1 World War veterans from the Caribbean.

The main issue we want to explore below is the role error correction coding performs both in the composition of the digital video signal and during the preservation playback. We want to highlight this issue because it is often assumed that DVCAM, which first appeared on the market in 1996, is a fairly robust format.

The work we have done to transfer tapes to digital files indicates that error correction coding is working overdrive to ensure we can see and hear these recordings. The implication is that DVCAM collections, and wider DV-based archives, should really be a preservation priority for institutions, organisations and individuals.

Before we examine this in detail, let’s learn a bit about the technical aspects of error correction coding.

Error error error

DVFormat7Error correction coding is a staple part of audio and audio-visual digital media. It is of great important in the digital world of today where the higher volume of transmitted signals require greater degrees of compression, and therefore sophisticated error correction schemes, as this article argues.

Error correction works through a process of prediction and calculation known as interpolation or concealment. It takes an estimation of the original recorded signal in order to re-construct parts of the data that have been corrupted. Corruption can occur due either to wear and tear, or insufficiencies in the original recorded signal.

Yet as Hugh Robjohns explains in the article ‘All About Digital Audio’ from 1998:

 ‘With any error protection system, if too many erroneous bits occur in the same sample, there is a risk of the error detection system failing, and in practice, most media failures (such as dropouts on tape or dirt on a CD), will result in a large chunk of data being lost, not just the odd data bit here and there. So a technique called interleaving is used to scatter data around the medium in such a way that if a large section is lost or damaged, when the data is reordered many smaller, manageable data losses are formed, which the detection and correction systems can hopefully deal with.’

There are many different types of error correction, and ‘like CD-ROMs, DV uses Reed-Solomon (RS) error detection and correction coding. RS can correct localized errors, but seldom can reconstruct data damaged by a dropout of significant size (burst error),’ explains this wonderfully detailed article about DV video formats archived on web archive.

The difference correction makes

Digital technology’s error correction is one of the key things that differentiate it from their analogue counterparts. As the IASA‘s Guidelines on the Production and Preservation of Digital Audio Objects (2009) explains:

‘Unlike copying analogue sound recordings, which results in inevitable loss of quality due to generational loss, different copying processes for digital recordings can have results ranging from degraded copies due to re-sampling or standards conversion, to identical “clones” which can be considered even better (due to error correction) than the original.’ (65)

To think that digital copies can, at times, exceed the quality of the original digital recording is both an astonishing and paradoxical proposition. After all we are talking about a recording that improves at the perceptual level, despite being compositionally damaged. It is important to remember that error correction coding cannot work miracles, and there are limits to what it can do.

Dietrich Schüller and Albrecht Häfner argue in the International Association of Sound and Audiovisual Archives’s (IASA) Handling and Storage of Audio and Video Carriers (2014) that ‘a perfect, almost error free recording leaves more correction capacity to compensate for handling and ageing effects and, therefore, enhances the life expectancy.’ If a recording is made however ‘with a high error rate, then there is little capacity left to compensate for further errors’ (28-29).

The bizarre thing about error-correction coding then is the appearance of clarity it can create. And if there are no other recordings to compare with the transferred file, it is really hard to know what the recorded signal is supposed to look and sound like were its errors not being corrected.

DVCAM PRO

When we watch the successfully migrated, error corrected file post-transfer, it matters little whether the original was damaged. If a clear signal is transmitted with high levels of error correction, the errors will not be transferred, only the clear image and sound.

Contrast this with a damaged analogue tape it would be clearly discernible on playback. The plus point of analogue tape is they do degrade gracefully: it is possible to play back an analogue tape recording with real physical deterioration and still get surprisingly good results.

Digital challenges

The big challenge working with any digital recordings on magnetic tape is to know when a tape is in poor condition prior to playback. Often tape will look fine and, because of error correction, will sound fine too until it stops working entirely.

How then did we know that the Sweet Patootee tapes were experiencing difficulties?

Professional DV machines such as our DVC PRO have a warning function that flashes when the error-correction coding is working at heightened levels. With our first attempt to play back the tapes we noticed that regular sections on most of the tapes could not be fixed by error correction.

The ingest software we use is designed to automatically retry sections of the tape with higher levels of data corruption until a signal can be retrieved. Imagine a process where a tape automatically goes through a playing-rewinding loop until the signal can be read. We were able to play back the tapes eventually, but the high level of error correction was concerning.

DVFormat6

As this diagram makes clear, around 25% of the recorded signal in DVCAM is composed of subcode data, error detection and error correction.

DVCAM & Mis-alignment

It is not just the over-active error correction on DVCAMs that should send the alarm bells ringing.

Alan Griffiths from Bristol Broadcast Engineering, a trained SONY engineer with over 40 years experience working in the television industry, told us that early DVCAM machines pose particular preservation challenges. The main problem here is that the ‘mechanisms are completely different’ for earlier DVCAM machines which means that there is ‘no guarantee’ they will play back effectively on later models.

Recordings made on early DVCAM machines exhibit back tensions problems and tracking issues. This increases the likelihood of DV dropout on playback because a loss of information was recorded onto the original tape. The IASA confirm that ‘misalignment of recording equipment leads to recording imperfections, which can take manifold form. While many of them are not or hardly correctable, some of them can objectively be detected and compensated for.’

One possible solution to this problem, as with DAT tapes, is to ‘misalign’ the replay digital video tape recorder to match the misaligned recordings. However ‘adjustment of magnetic digital replay equipment to match misaligned recordings requires high levels of engineering expertise and equipment’ (2009; 72), and must therefore not be ‘tried at home,’ so to speak.

Our experience with the Sweet Patootee tapes indicates that DVCAM tapes are a more fragile format than is commonly thought, particularly if your DVCAM collection was recorded on early machines. If you have a large collection of DVCAM tapes we strongly recommend that you begin to assess the contents and make plans to transfer them to digital files. As always, do get in touch if you need any advice to develop your plans for migration and preservation.

 

Reel-to-reel transfer of Anthony Rye, Selborne’s nature poet

November 25th, 2014

We have recently transferred a number of recordings of the poet, Anthony Rye, reading his work. The tapes were sent by his Grandson Gabriel who was kind enough to tell us a bit more about Anthony’s life and work.

‘Anthony Francis Rye is intimately associated with the Hampshire village of Selborne, a village made famous by Gilbert White and his book, Natural History of Selborne.

The Rye family has been here since the end of the 19th century and Anthony came to live here in the 1940s with his wife, in the house I now live in.

Among his books of poems are The Inn of the Birds (1947), Poems from Selborne (1961) and To A Modern Hero (1957). He was an illustrator and trained as an engraver and illustrated The Inn of the Birds himself, of which he said the poems “…were written to make people more alive to the spirit of bird-life and to the nature of birds generally. It was hoped to communicate something of the intense pleasure in birds felt by the author, and at the same time, by emphasizing their strange remote quality without destroying the sense of their being our fellow creatures…”Jacket cover depicting a hand drawn rural scene with people walking

His poem ‘The Shadow on the Lyth’ from Poems from Selborne, invokes a dark moment in Selborne’s history when it was proposed by the council to put a much needed sewage works at the bottom of Church Meadow, thus ruining one of the most beautiful settings in Hampshire – one beloved of natural historian Gilbert White. Anthony Rye fought this and after a long struggle managed to have the works re-sited out of sight.’

Gilbert White’s life and work was a significant influence on Rye’s work and in 1970 he published the book Gilbert White and his Selborne.

Although the BBC has previously broadcast Rye’s poems, Gabriel tell us that these particular recordings have not been. Until now the recordings have been stored in Arthur’s house; migrating them to digital files is an exciting opportunity for family members, but also hopefully wider audiences, to access Rye’s work.

 

Listen to Anthony Rye reading his poems, with thanks to Gabriel for granting permission

Recording technologies in history

75SonyBrochure02

Arthur Jolland, a nature photographer and friend of the poet made the recordings on a SONY 800B, a portable reel-to-reel tape machine described by SONY as ‘compact, convenient and capable, a natural for both business and pleasure.’

The machine, which used a ‘ServoControl Motor; the same type of motor used is missile guidance control systems where critical timing accuracy is a must,’ is historically notorious for its use by US President Richard Nixon who racked up 3,700-4,000 hours of recordings that would later implicate him during the Watergate Scandal.

Sahr Conway-Lanz explains that ‘room noise may constitute roughly one quarter of the total hours of recorded sound’ because tape machines recorded at the super slow speed of 15/16 of an inch per second ‘in order to maximize the recording time on each tape’ (547-549).

Decreasing the speed of a tape recording causes a uniform reduction in the linearity of response, resulting in more hiss and dropouts. If you listen to the recordings made by Nixon, it is pretty hard to discern what is being said without reference to the transcripts.

The transfer process

There were no big issues with the condition of the Anthony Rye tapes other than a small amount of loose binder shedding. This was easily solved by dry cleaning with pellon fabric prior to digitization.

Although in some cases playing back tapes on exactly the same machine as it was recorded on is desirable (particularly so with DAT transfers), we migrated the recordings using our SONY APR 5003. Sony APR 5003v headblock closeup, with tape laced up

Using a technically superior model, one of the few large format professional reel-to-reel machines SONY manufactured, mitigates the extent errors are added to the recording as part of the transfer process. Furthermore, the greater flexibility and control offered with the 5003 makes it easier to accurately replay tapes recorded on machines that had lower specifications.

Another slight adjustment was attaching longer leader tape to the front and end of the tape. This is because the Sony APR 5003 has a much longer tape path than the 800B, and if this isn’t done material can be lost from the beginning and end of the recording.

***

The journeys we have been on above – from the natural history of a Hampshire village seen through the eyes of largely unknown poet to the Watergate scandal – is another example of the diverse technical, cultural and historical worlds that are opened up by the ‘mysterious little reddish-brown ribbon‘ and its playback mechanisms.

World Day for Audiovisual Heritage – digitisation and digital preservation policy and research

October 27th, 2014

Today, October 27, has been declared World Day for Audiovisual Heritage by UNESCO. We also blogged about it last year.

Since 2005, UNESCO have used the landmark to highlight the importance of audiovisual archives to ‘our common heritage’ which  contain ‘the primary records of the 20th and 21st centuries.’ Increasingly, however, the day is used to highlight how audio and moving image archives are particularly threatened with by ‘neglect, natural decay to technological obsolescence, as well as deliberate destruction’.

Indeed, the theme for 2014 is ‘Archives at Risk: Much More to Do.’ The Swiss National Sound Archives have made this rather dramatic short film to promote awareness of the imminent threat to audiovisual formats, which is echoed by UNESCO’s insistence that ‘all of the world’s audiovisual heritage is endangered.’

As it is World Audiovisual Heritage Day, we thought it would be a good idea to take a look at some of the recent research and policy that has been collected and published relating to digitisation and digital preservation.

While the UNESCO anniversary is useful for raising awareness of the fragility of audiovisual mediums, what is the situation for organisations and institutions grappling with these challenges in practice?

Recent published research – NDSA

The first to consider are preliminary results from a survey published by the US-based NDSA Standards and Practices Working Group, full details can be accessed here.

The survey asked a range of organisations, institutions and collections to rank issues that are critical for the preservation of video collections. Respondents ‘identified the top three stumbling blocks in preserving video as:

  • Getting funding and other resources to start preserving video (18%)
  • Supporting appropriate digital storage to accommodate large and complex video files (14%)
  • Locating trustworthy technical guidance on video file formats including standards and best practices (11%)’

Interestingly in relation to the work we do at Great Bear, which often reveal the fragilities of digital recordings made on magnetic tape, ‘respondents report that analog/physical media is the most challenging type of video (73%) followed by born digital (42%) and digital on physical media (34%).’

It may well be that there is simply more video on analogue/ physical media than other mediums which can account for the higher response, and that archives are yet to grapple with the archival problem of digital video stored on physical mediums such as DVD and in particular, consumer grade DVD-Rs. Full details will be published on The Signal, the Library of Congress’ Digital Preservation blog, in due course.

Recent research – Digital Preservation Coalition (DPC)

Another piece of preliminary research published recently was the user consultation for the 2nd edition of the Digital Preservation Coalition’s Digital Preservation Handbook. The first edition of the Handbook was published in 2000 but was regularly updated throughout the 00s. The consultation precedes what will be a fairly substantial overhaul of the resource.

Many respondents to the consultation welcomed that a new edition would be published, stating that much content is now ‘somewhat outdated’ given the rapid change that characterises digital preservation as a technological and professional field.

Survey respondents ranked storage and preservation (1), standards and best practices (2) and metadata and documentation (3) as the biggest challenges involved in digital preservation, and therefore converge with the NDSA findings. It must be stressed, however, that there wasn’t a massive difference across all the categories that included issues such as compression and encryption, access and creating digital materials.

Some of the responses ranged from the pragmatic…

‘digital preservation training etc tend to focus on technical solutions, tools and standards. The wider issues need to be stressed – the business case, the risks, significant properties’ (16)

‘increasingly archives are being approached by community archive groups looking for ways in which to create a digital archive. Some guidance on how archive services can respond effectively and the issues and challenges that must be considered in doing so would be very welcome’ (16)

…to the dramatic…

‘The Cloud is a lethal method of storing anything other than in Lo Res for Access, and the legality of Government access to items stored on The Cloud should make Curators very scared of it. Most digital curators have very little comprehension of the effect of solar flares on digital collections if they were hit by one. In the same way that presently part of the new method of “warfare” is economic hacking and attacks on financial institutions, the risks of cyber attacks on a country’s cultural heritage should be something of massive concern, as little could demoralise a population more rapidly. Large archives seem aware of this, but not many smaller ones that lack the skill to protect themselves’ (17)

…Others stressed legal issues related to rights management…

‘recording the rights to use digital content and ownership of digital content throughout its history/ life is critical. Because of the efforts to share bits of data and the ease of doing so (linked data, Europeana, commercial deals, the poaching of lines of code to be used in various tools/ services/ products etc.) this is increasingly important.’ (17)

It will be fascinating to see how the consultation are further contextualised and placed next to examples of best practice, case studies and innovative technological approaches within the fully revised 2nd edition of the Handbook.

European Parliament Policy on Film Heritage

Our final example relates to the European Parliament and Council Recommendation on Film Heritage. The Recommendation was first decreed in 2005. It invited Member States to offer progress reports every two years about the protection of and access to European film heritage. The 4th implementation report was published on 2 October 2014 and can be read in full here.

The language of the recommendation very much echoes the rationale laid out by UNESCO for establishing World Audiovisual Heritage Day, discussed above:

‘Cinematography is an art form contained on a fragile medium, which therefore requires positive action from the public authorities to ensure its preservation. Cinematographic works are an essential component of our cultural heritage and therefore merit full protection.’

Although the recommendation relates to preservation of cinematic works specifically, the implementation report offers wide ranging insight into the uneven ways ‘the digital revolution’ has affected different countries, at the level of film production/ consumption, archiving and preservation.

The report gravely states that ‘European film heritage risks missing the digital train,‘ a phrase that welcomes a bit more explanation. One way to understand is that it describes how countries, but also Europe as a geo-political space, is currently failing to capitalise on what digital technologies can offer culturally, but also economically.

The report reveals that the theoretical promise of interoperable digital technologies-smooth trading, transmission and distribution across economic, technical and cultural borders-was hindered in practice due to costly and complex copyright laws that make the cross border availability of film heritage, re-use (or ‘mash-up’) and online access difficult to implement. This means that EU member states are not able to monetise their assets or share their cultural worth. Furthermore, this is further emphasised by the fact that ‘85% of Europe’s film heritage is estimated to be out-of-commerce, and therefore, invisible for the European citizen’ (37).

In an age of biting austerity, the report makes very clear that there simply aren’t enough funds to implement robust digitization and digital preservation plans: ‘Financial and human resources devoted to film heritage have generally remained at the same level or have been reduced. The economic situation has indeed pushed Member States to change their priorities’ (38).

There is also the issue of preserving analogue expertise: ‘many private analogue laboratories have closed down following the definitive switch of the industry to digital. This raises the question on how to maintain technology and know-how related to analogue film’ (13).

Production Heritage Budget EUThe report gestures toward what is likely to be a splitting archival-headache-to-come for custodians of born digital films: ‘resources devoted to film heritage […] continue to represent a very small fraction of resources allocated to funding of new film productions by all Member States’ (38). Or, to put it in numerical terms, for every €97 invested by the public sector in the creation of new films, only €3 go to the preservation and digitisation of these films. Some countries, namely Greece and Ireland, are yet to make plans to collect contemporary digital cinema (see opposite infographic).

Keeping up to date

It is extremely useful to have access to the research featured in this article. Consulting these different resources helps us to understand the nuts and bolts of technical practices, but also how different parts of the world are unevenly responding to digitisation. If the clock is ticking to preserve audiovisual heritage in the abrupt manner presented in the Swiss National Archives Film, the EU research in particular indicates that it may well be too late already to preserve a significant proportion of audiovisual archives that we can currently listen to and watch.

As we have explored at other places in this blog, wanting to preserve everything is in many ways unrealistic; making clinical selection decisions is a necessary part of the archival process. The situation facing analogue audiovisual heritage is however both novel and unprecedented in archival history: the threat of catastrophic drop out in ten-fifteen years time looms large and ominous.

All that is left to say is: enjoy the Day for World Audiovisual Heritage! Treasure whatever endangered media species flash past your eyes and ears. Be sure to consider any practical steps you can take to ensure the films and audio recordings that are important to you remain operable for many years to come.

Transferring Digital Audio Tapes (DATs) to digital audio files

October 9th, 2014

This post focuses on the problems that can arise with the transfer of Digital Audio Tapes (DATs).

An immature recording method (digital) on a mature recording format (magnetic tape), the audio digital recording revolution was never going to get it right first time (although DATs were not of course the first digital recordings made on tape).

Indeed, at a meeting of audio archivists held in 1995, there was a consensus even then that DAT was not, and would never be, a reliable archival medium. One participant stated: ‘we have tapes from 1949 that sound wonderful,’ and ‘we have tapes from 1989 that are shot to hell.’ And that was nearly twenty years ago! What chances do the tapes have now?

A little DAT history

Before we explore that, let’s have a little DAT history.

SONY introduced Digital Audio Tapes (DATs) in 1987. At roughly half the size of an analogue cassette tape, DAT has the ability to record at higher, equal or lower sampling rates than a CD (48, 44.1 or 32 kHz sampling rate respectively) at 16 bit quantization.

Although popular in Japan, DATs were never widely adopted by the majority of consumer market because they were more expensive than their analogue counterparts. They were however embraced in professional recording contexts, and in particular for recording live sound.

It was recording industry paranoia, particularly in the US, that really sealed the fate of the format. With its threatening promise of perfect replication, DAT tapes were subject to an unsuccessful lobbying campaign by the Recording Industry Association of America (RIAA). RIAA saw DATs as the ultimate attack on copyright law and pressed to introduce the Digital Audio Recorder Copycode Act of 1987.

This law recommended that each DAT machine had a ‘copycode’ chip installed that could detect whether prerecorded copyrighted music was being replicated. The method employed a notch filter that would subtly distort the quality of the copied recording, thus sabotaging the any acts of piracy tacitly enabled by the DAT medium. The law was however not passed, and compromises were made, although the US Audio Home Recording Act of 1992 imposed taxes on DAT machines and blank media.

How did they do ‘dat?

Like video tape recorders, DAT tapes use a rotating head and helical scan method to record data. The helical scan can, however, pose real problems for the preservation transfers of DAT tapes because it makes it difficult to splice the tape together if it becomes sticky and snaps during the tape wind. With analogue audiotape, which records information longitudinally, it is far more possible to splice the tape together and continue the transfer without risking irrevocable information loss.

Another problem posed by the helical scan method is that such tapes are more vulnerable to tape pack and backing deformation, as the CLIR guide explain:

‘Tracks are recorded diagonally on a helical scan tape at small scan angles. When the dimensions of the backing change disproportionately, the track angle will change for a helical scan recording. The scan angle for the record/playback head is fixed. If the angle that the recorded tracks make to the edge of the tape do not correspond with the scan angle of the head, mistracking and information loss can occur.’

When error correction can’t correct anymore

dat-mute-playback-condition-sony-7040Most people will be familiar with the sound of digital audio dropouts even if they don’t know the science behind them. You will know them most probably as those horrible clicking noises produced when the error correction technology on CDs stops working. The clicks indicate that the ‘threshold of intelligibility’ for digital data has been breached and, as theorist Jonathan Sterne reminds us, ‘once their decay becomes palpable, the file is rendered entirely unreadable.’

Our SONY PCM 7030 professional DAT machine, pictured opposite, has a ‘playback condition’ light that flashes if an error is present. On sections of the tape where quality is really bad the ‘mute’ light can flash to indicate that the error correction technology can’t fix the problem. In such cases drop outs are very audible. Most DAT machines did not have such a facility however, and you only knew there was a problem when you heard the glitchy-clickety-crackle during playback when, of course, it was too late do anything about it.

The bad news for people with large, yet to be migrated DAT archives is that the format is ‘particularly susceptible to dropout. Digital audio dropout is caused by a non-uniform magnetic surface, or a malfunctioning tape deck. However, because the magnetically recorded information is in binary code, it results in a momentary loss of data and can produce a loud transient click or worse, muted audio, if the error correction scheme in the playback equipment cannot correct the error,’ the wonderfully informative A/V Artifact Atlas explains.

Given the high density nature of digital recordings on narrow magnetic tape, even the smallest speck of dust can cause digital audio dropouts. Such errors can be very difficult to eliminate. Cleaning playback heads and re-transferring is an option, but if the dropout was recorded at the source or the surface of tape is damaged, then the only way to treat irregularities is through applying audio restoration technologies, which may present a problem if you are concerned with maintaining the authenticity of the original recording.

Listen to this example of what a faulty DAT sounds like

Play back problems and mouldy DATs

Mould growth on the surface of DAT tape

Mould growth on the surface of DAT tape

A big problem with DAT transfers is actually being able to play back the tapes, or what is known in the business as ‘DAT compatibility.’ In an ideal world, to get the most perfect transfer you would play back a tape on the same machine that it was originally recorded on. The chances of doing this are of course pretty slim. While you can play your average audio cassette tape on pretty much any tape machine, the same cannot be said for DAT tapes. Often recordings were made on misaligned machines. The only solution for playback is, Richard Hess suggests, to mis-adjust a working machine to match the alignment of the recording on the tape.

As with any archival collection, if it is not stored in appropriate conditions then mould growth can develop. As mentioned above, DAT tapes are roughly half the size of the common audiocassette and the tape is thin and narrow. This makes them difficult to clean because they are mechanically fragile. Adapting a machine specifically for the purposes of cleaning, as we have done with our Studer machine, would be the most ideal solution. There is, however, not a massive amount of research and information about restoring mouldy DATs available online even though we are seeing more and more DAT tapes exhibiting this problem.

As with much of the work we do, the recommendation is to migrate your collections to digital files as soon as possible. But often it is a matter of priorities and budgets. From a technical point of view, DATs are a particularly vulnerable format. Machine obsolescence means that compared to their analogue counterparts, professional DAT machines will be increasingly hard to service in the long term. As detailed above, glitchy dropouts are almost inevitable given the sensitivity and all or nothing quality of digital data recorded on magnetic tape.

It seems fair to say that despite being meant to supersede analogue formats, DATs are far more likely to drop out of recorded sound history in a clinical and abrupt manner.

They therefore should be a high priority when decisions are made about which formats in your collection should be migrated to digital files immediately, over and above those that can wait just a little bit longer.

Phyllis Tate’s Nocturn for Four Voices 3″ 1/4 inch reel to reel tape transfer

September 19th, 2014

We have recently transferred a previously unpublished 3” ¼ inch tape recording of British 20th century composer Phyllis Tate’s Nocturn for Four Voices. The tape is a 2-track stereo recording made at 7.5 inches per second (in/s) at the Purcell Room in London’s Southbank Centre in 1975, and was broadcast on 16 September 1976.

When migrating magnetic tape recordings to digital files there are several factors that can be considered to assess the quality of recording even before we play back the tape. One of these is the speed at which the tape was originally recorded.

Diagramme of track widths on magnetic tape, and the relative thicknesses of 1, 2 and 4 track recordings

Generally speaking, the faster the speed the better the reproduction quality when making the digital transfer. This is because higher tape speeds spread the recorded signal longitudinally over more tape area, therefore reducing the effects of dropouts and tape noise. The number of tracks recorded on the tape also has an impact on how good it sounds today. Simply put, the more information stored on the tape due to recording speed or track width, the better the transfer will sound.

The tape of Nocturn for Four Voices was however suffering from binder hydrolysis and therefore needed to be baked prior to play back. EMI tape doesn’t normally do this but as the tape was EMI professional it may well have used Ampex stock and / or have been back coated, thus making the binder more susceptible to such problems.

Remembering Phyllis Tate

Nocturn for Four Voices is an example of how Tate ‘composed for unusual combinations of instruments and voice.’ The composition includes ‘Bass Clarinet, Celeste, String Quartet and Double Bass’, music scholar Jane Ballantyne explains.

The tape was brought into us by Tate’s daughter, Celia Frank, who is currently putting the finishing touches to a web archive that, she hopes, will help contemporary audiences (re)discover her mother’s work.

Like many women musicians and artists, Phyllis Tate, who trained at the Royal Academy of Music, remains fairly obscure to the popular cultural ear.

This is not to say, of course, that her work did not receive critical acclaim from her contemporaries or posthumously. Indeed, it is fair to say that she had a very successful composing career. Both the BBC and the Royal Academy of Music, among others, commissioned compositions from Tate, and her work is available to hire or buy from esteemed music publishers Oxford University Press (OUP).

Edmund Whitehouse, who wrote a short biography of the composer, described her as ‘one of the outstanding British composers of her generation, she was truly her own person whose independent creative qualities produced a wide range of music which defy categorisation.’

Her music often comprised of contrasting emotional registers, lyrical sections and unexpected changes of direction. As a writer of operattas and choral music, with a penchant for setting poetry to music, her work is described by the OUP as the product of ‘an unusual imagination and an original approach to conventional musical forms or subjects, but never to the extent of being described as “avant-garde”.’

Tate’s music was very much a hit with iconic suffrage composer Ethel Smyth who, upon hearing Tate’s compositions, reputedly declared: ‘at last, I have heard a real woman composer.’ Such praise was downplayed by Tate, who tended to point to Smyth’s increased loss of hearing in later life as the cause of her enjoyment: ‘My Cello Concerto was performed soon afterwards at Bournemouth with Dame Ethel sitting in the front row banging her umbrella to what she thought was the rhythm of the music.’Open reel tape and box

While the dismissal of Smyth’s appreciation is tender and good humoured, the fact that Tate destroyed significant proportions of her work does suggest that at times she could have doubted her own abilities as a composer. Towards the end of her life she revealed: ‘I must admit to having a sneaking hope that some of my creations may prove to be better than they appear. One can only surmise and it’s not for the composer to judge. All I can vouch is this: writing music can be hell; torture in the extreme; but there’s one thing worse; and that is not writing it.’ As a woman composing in an overwhelmingly male environment, such hesitancies are perhaps an understandable expression of what literary scholars Gilbert and Gubar called ‘the anxiety of authorship.’

Tate’s work is a varied and untapped resource for those interested in twentieth century composition and the wider history of women composers. We wish Celia the best of luck in getting the website up and running, and hope that many more people will be introduced to her mother’s work as a consequence.

Thanks to Jane Ballantyne and Celia Frank for their help in writing this article.


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