Audio Cassette Parallel Ingests

July 27th, 2015

The scale of digitisation jobs we do at Great Bear often varies. We are asked by our customers to reformat single items to large quantities of tape and everything else inbetween.

Reformatting magnetic tape-based media always takes time and care.

Transfers have to be done in real time; if you want a good quality recording there is no way to reformat tape-based media quickly.

Some jobs are so big, however, that you need to find ways of speeding up the process. This is known as a parallel ingest – when you transfer a batch of tapes at the same time.

Realistically, parallel ingest is not possible with all formats.

An obvious issue is machine scarcity. To playback tapes at the same time you need multiple playback machines that are in fairly good condition. This becomes difficult with rarer formats like early digital video tape, such as D1 or D2, where you are extremely lucky if you have two machines working at any given time.

Audio Cassettes

Audio cassette tapes are one of few formats where archival standard parallel ingest is possible if tapes are in good condition and the equipment is working well.

Stack of professional tape machines, including Marantz PMD 502 and Tascam 322

Great Bear Parallel Ingest Stack

We were recently approached by Jim Shields of the Zion, Sovereign Grace Baptists Church in Glasgow to do a large scale transfer of 5000 audio cassettes and over 100 open reels.

Jim explains that these ‘tapes represent the ministry of Pastor Jack Glass, who was the founder of Zion, Sovereign Grace Baptists Church, located at Calder St.Polmadie, Glasgow. The church was founded in 1965. All early recordings are on reel but the audio tapes represent his ministry dating from the beginning of 1977 through to the end of 2003. The Pastor passed away on the 24th Feb 2004 [you can read obituaries here and here]. It is estimated there are in the region of 5,000 ministry tapes varying in length from 60 mins to 120 mins, with many of the sermons being across 2 tapes as the Pastor’s messages tended to be in the region of 90 minutes plus.’

Sermons were recorded using ‘semi domestic to professional cassette decks. From late Sept 1990 a TEAC X-2000 reel recorder was used [to make master copies] on 10 inch reels then transposed onto various length cassettes [when ordered by people]’ chief recordist Mike Hawkins explains.

Although audio cassettes were a common consumer format it is still possible to get high quality digital transfers from them, even when transferred en masse. Recordings of speech, particularly of male voices which have a lower frequency range, are easier to manage.

Hugh Robjohns, writing in 1997 for the audio technology magazine Sound on Sound, explains that lower frequency recordings are mechanically more compatible with the chemical composition of magnetic tape: ‘high-frequency signals tend to be retained by the top surface of the magnetic layer, whilst lower-frequency components tend to be recorded throughout its full depth. This has a bearing on the requirements of the recording heads and the longevity of recordings.'[1]

Preparation

In order to manage a large scale job we had to increase our operational capacity.

We acquired several professional quality cassette machines with auto reverse functions, such as the Marantz PMD 502 and the Tascam 322.

Although these were the high end audio cassette recorders of their time, we found that important components, such as the tape transport which is ‘critical to the performance of the entire tape recorder'[2], were in poor shape across all the models. Pitch and timing errors, or wow (low speed variations) and flutter (high speed variations), were frequently evident during test playbacks.

Because of irregular machine specifications, a lot of time was spent going through all the tape decks ensuring they were working in a standardised manner.

In some cases it was necessary to rebuild the tape transport using spares or even buying a new tape transport. Both of these restoration methods will become increasingly difficult in years to come as parts become more and more scarce.

Assessing the options

There are certainly good reasons to do parallel ingests if you have a large collection of tapes. Nevertheless it is important to go into large scale transfers with your eyes open.

There is no quick fix and there are only so many hours in the working day to do the transfers, even if you do have eight tapes playing back simultaneously.

To assess the viability of a large scale parallel ingest you may want to consider the following issues: condition of tapes, how they were originally recorded and the material stored on them.

It may well be that parts of your collection can be reformatted via parallel ingest, but other elements need to be selected for more specialist attention.

As ever we can help with discussing the options so do contact us if you want some specific advice.

Notes

[1] The gendered implications of this statement are briefly worth reflecting on here. Robjohns suggests that voices which command the higher frequencies, i.e., female or feminine voices, are apparently incompatible with the chemical composition of magnetic tape. If higher frequencies are retained by the top layer of magnetic tape only, but do not penetrate its full depth, does this make high frequencies more vulnerable in a preservation context because they never were never substantially captured in the first place? What does this say about how technical conditions, whose design has often been authored by people with low frequency voices (i.e., men), privilege the transmission of particular frequencies over others, at least in terms of ‘depth’?

[2] Hugh Robjohns ‘Analogue Tape Recorders: Exploration’ Sound on Sound, May 1997. Available: http://www.soundonsound.com/sos/1997_articles/may97/analysinganalogue.html.

*** Many thanks to Jim Shields, Martyn Glass and Mike Hawkins for sharing their tape stories***

British Stand Up Comedy Archive’s audiovisual collections

July 13th, 2015

Great Bear have recently worked with the British Stand Up Comedy Archive (BSUCA) to reformat a number of Digital Audio Tapes (DATs) and U-Matic video tapes from their collection.

Established in 2013 and based at the University of Kent’s Special Collections, the BSUCA aims ‘to celebrate, preserve, and provide access to the archives and records of British stand-up comedy and stand-up comedians.’

A hand holding a microphine superimposed on a red circle

In 2014 the BSUCA became one of the University of Kent’s 50th anniversary ‘Beacon Projects‘.

Beacon Project funding will support work to ‘catalogue, preserve, digitise, and make accessible the existing collections, and identify new relevant collections.’

They will also hold a number of events which engage comedians ‘in conversation’ about their archives, excerpts from these events are documented here.

We are honoured that project archivist Elspeth Millar took time out of her busy archiving schedule to tell us a bit more about the BSUCA.

She told us:

‘I’m really enjoying the variety of material that I get to work on, including printed material (posters, flyers, letters, notebooks), audio-visual material on a range of formats (audio cassettes, VHS, DAT, MiniDisc, U-matic), and also born-digital records held on obsolete formats (such as 3.5” floppy disks).

In addition the content of the material is, of course, really interesting, and I feel that I am learning a lot from our collections, including about the history of stand-up comedy (from the alternative cabaret movement, to alternative comedy, to the comedy ‘industry’ today) but also political and social topics (for example Mark Thomas’ collection includes a lot of material on the arms trade and large corporations). We are also holding events with some fantastic comedians (Richard Herring, Stewart Lee, Mark Thomas, and at the Edinburgh Festival Fringe, Jo Brand, Alexei Sayle, Susan Calman) so it is wonderful to hear comedians themselves reflecting on their work and on material that they have deposited with the archive.’

You can keep up to date with the latest news from the BSUCA archive on twitter and view images from their collections on flickr.

Read on for more from Elspeth. Her answers cover issues such as selection and appraisal decisions, metadata and dissemination plans for the BSUCA.

They also provide useful insight into the digital preservation tools BSUCA use to manage their digitised and born-digital assets.

Once again, massive thanks to her for responding to our questions and best of luck to BSUCA in the future.

 BSCUA Responses to Great Bear Questions

1. What motivated you to get the tapes you sent to us re-formatted now? i.e., what kinds of selection and appraisal processes were behind the decision?

The British Stand-Up Comedy Archive has AV material on a number of audio and moving image formats, magnetic and optical, including audio compact cassettes, MiniDiscs, DATs (Digital Audio Tapes), VHS, DVCams, Audio CD and U-matic tapes. None of these formats are suitable for archival storage and all material will need to be digitised or transferred from their original carrier to digital files. We can carry out the digitisation (or digital transfer) of some audio in-house and we have started our project by transferring material originally captured or stored on MiniDiscs, Audio CDs, and audio compact cassettes1. After assessing all the formats we currently have it was decided to outsource the digitisation of DATs and U-matic tapes. Both of these are priority formats for transfer from a preservation perspective2 and after some research I learnt that DATs can be problematic to transfer due to ‘DAT compatibility’ and dropout problems3. In addition, we have neither a DAT machine or U-matic machine already within Special Collections or within the University, and with the number of recordings on these formats currently limited, it was felt that it would not make sense to purchase already obsolete equipment, which would then need to be professionally maintained.

The other important reason for transferring the tapes of course was for accessibility, so that we can make the recordings accessible to researchers. In addition, our funding is currently only for one year4, so it is vital to ensure that audio-visual material on obsolete formats are transferred during this first phase of the project.

2. Can you tell us how metadata helps you to describe, preserve and aid discovery of the Stand Up Comedy archive.

Providing information about our audiovisual items (and resulting digital items) is incredibly important from both an access and preservation perspective. Metadata about analogue items (and subsequent digital files) and born-digital files will be included in the cataloguing collections management system used by the British Stand-Up Comedy Archive (which is part of the University of Kent’s Special Collections & Archives). The catalogue records will include descriptive metadata and administrative metadata. Metadata which comes under the ‘descriptive metadata’ heading describes the item/file and includes a summary of the contents of the recording, all of which helps to make recordings discoverable for researchers. This metadata is also vital from a preservation perspective as it allows archivists to retrieve and identify files. Metadata which comes under the ‘administrative metadata’ heading provides information to help manage the file(s)/recordings, and includes information related to Intellectual Property Rights (including copyright) and preservation information such as the file format and the digitisation/digital transfer. Researchers will be interested in some of these issues (e.g. copyright, as this determines how archived recordings can be used) but from a digital preservation perspective this metadata is extremely important as it records information about the format of the digital file, information about the original carrier, as well as fixity information, to measure whether the file has changed over time.

This metadata will be recorded in our catalogue and will be searchable via the University of Kent’s website and in the future some archive aggregators. However, we are also experimenting with different processes and tools for embedding metadata in files, and researching different metadata standards for this. The benefits of embedding some metadata within the file include the removal of the risk of losing the link between the metadata and the digital file that it is describing. In addition, metadata embedded in born-digital master and digitised master files can also be transferred to ‘access’ copies (generated at a lower specification/resolution) which will also assist in user accessibility. Embedded metadata has its limitations and it is not that flexible, which is why we are using a dual approach of embedding some metadata, but also keeping this information externally in our catalogue.Two cassettes from 1982 and 1982

3. How do you manage, and plan to manage digital audio and audio visual materials in the Stand Up Archive? What digital preservation tools do you use?

The first process in managing digital AV materials in the BSUCA is to think about the file formats that we will use for long-term preservation and access. For audio material we are digitising as LPCM (Linear Pulse Code Modulation) in a Wave format (.wav) wrapper. The addition of embedding metadata into these wave files extends the file to become BWF .wav files, the standard recommended by the International Association of Audiovisual Archives (IASA).5

Deciding upon a file format for digitising moving image has been trickier, as the Greatbear team have already written about on this blog; we hope to get underway with digitisation of VHS in September and we are looking at using the FFv1 codec (an open-source lossless compressed codec) wrapped as either AVI or Matroska (MKV).

We are also experimenting with a number of digital preservation tools; one directory that has proved great for discovering such tools is the COPTR wiki (Community Owned digital Preservation Tool Registry), a really useful collated list of various digital preservation tools . One aspect of our digital preservation planning is the creation of checksums as early in the lifecycle of the digital file as possible. We are using a tool called Blackbush, which is a checksum tool6 which generates MD5 hash files which was developed for the British Library’s Sound Archive. To embed metadata into .wav files we are using the BWF MetaEdit tool, a free open-source tool developed by AV Preserve and the Federal Agencies Digitization Guidelines Initiative. When our archival master is a compressed format (such as an mp3 on a data or audio CD which has been deposited), we are using tools such as Adobe Bridge to embed metadata in the ID3 format (or Adobe Audition’s metadata tools as we transfer audio). The advantage of BWF MetaEdit for wav files is that it is a free open-source tool, which also has other functions such as batch editing (we can edit multiple wav files at once) and batch import and export functions, which will be useful for when we catalogue this material to item level.

Other tools that we have found useful include DROID (Digital Record Object Identification), developed by The National Archives, and, for other digital material we are using forensic imaging tools such as FTK Imager and ImDisk to mount virtual images of disk images.

4. How do you think the material will be used by future researchers? As a Stand Up Archive I imagine you get a lot of requests for material from broadcasters. How do you manage requests and expectations from different user communities?

The British Stand-Up Comedy Archive is still in its infancy; although we have had material since 2013, it has only been since the beginning of this year that we have been funded to digitise and preserve the material already deposited, start to catalogue it, make it accessible, and publicise what we have and what we are aiming to do.

But two of our core purposes are to ensure access (that these archives are universally discoverable and accessible), and to ensure that the archives are used, and used in a variety of ways (popular culture, academic research, teaching, journalism, general enjoyment). Our main user group at the moment is actually students studying stand-up and popular performance at the University of Kent (at BA and MA level) who have used AV material as part of their course, and we also have a number volunteering with the project, doing summaries of recorded interviews and stand-up performances.

Notes

[1] We have purchased an audio cassette deck (Denon DN-790R) and are using a MiniDisc deck on loan from colleagues within the University, and have also purchased an external audio capture card/A-D converter.

[2] https://psap.library.illinois.edu/format-id-guide/audiotape#dat and https://psap.library.illinois.edu/format-id-guide/videotape#umatic.

[3] https://siarchives.si.edu/sites/default/files/pdfs/digitalAudioTapesPreservation2010_0.pdf (page 5-8) and http://www.thegreatbear.net/audio-tape/transferring-dats-to-digital-files/.

[4] The British Stand-Up Comedy Archive is part of the University of Kent’s Special Collections and Archives, but it currently has specific funding for one year (as a Beacon Project) to digitise and make accessible its current holdings; more about the Beacon projects can be found at http://www.kent.ac.uk/beacon/about.html.

[5] Guidelines on the Production and Preservation of Digital Audio Objects, IASA-TC 04, 2.8.2

[6] A checksum is ‘an algorithmically-computed numeric value for a file or a set of files used to validate the state and content of the file for the purpose of detecting accidental errors that may have been introduced during its transmission or storage. The integrity of the data can be checked at any later time by recomputing the checksum and comparing it with the stored one. If the checksums match, the data was almost certainly not altered’. National Digital Stewardship Alliance Glossary, http://www.digitalpreservation.gov/ndsa/ndsa-glossary.html.

Save Our Sounds’ £9.5 million boost

July 7th, 2015

british-library-sound-archivesThis article is a bit late to break this news, but it is worth highlighting again in case you missed it first time round.

In May 2015 the British Library were awarded over £9.5 million pounds by the Heritage Lottery Fund to help them deliver their hugely important Save Our Sounds project.

We told you about Save Our Sounds earlier in the year.

As stated in a press release, ‘the funding will enable the British Library to digitise and make available 500,000 rare, unique and at-risk sound recordings from its own archive and other key collections around the country over 5 years (2017-2022).’

Funding will also help ‘develop a national preservation network via ten regional centres of archival excellence which will digitise, preserve and share the unique audio heritage found in their local area.’

Living Knowledge

Also worth a read is the recently published Living Knowledge: The British Library 2015-2023, which sets out the strategic priorities of the organisation in its 50th anniversary year.

The short text outlines ‘what it means to be a national library in a digital age and what the British Library’s role is as one of the UK’s great public assets.’

These are set out in ‘a framework of six purposes which explain, as simply and clearly as we can, the enduring ways in which the public funding we receive helps to deliver tangible public value – in custodianship, research, business, culture, learning and international partnership.’

Within the strategy digitising ‘the 42 different physical formats which hold our 6.5 million audio items’ is highlighted as ‘the next great preservation challenge’ for the British Library.

As ever, we will keep you up to date with updates from the British Library’s Save Our Sounds project as it evolves.

Phil Johnson’s the Wild Bunch VHS video

June 24th, 2015
wildbunch-arnolfini-screen-grab-dancing

Screen shots from the Wild Bunch film

As a business situated in the heart of Bristol, Great Bear is often called upon by Bristol’s artists to re-format their magnetic tape collections.

Previously we have transferred documentaries about the St. Paul’s Carnival and films from the Bristol-based Women in Moving Pictures archive. We also regularly digitise tapes for Bristol Archive Records.

We were recently approached by author Phil Johnson to transfer a unique VHS recording.

As Bristol countercultural folklore goes, the video tape is a bit of a gem: it documents the Wild Bunch performing at Arnolfini in 1985.

For the uninitiated, the Wild Bunch were the genesis of what became internationally known as trip-hop, a.k.a. ‘the Bristol-sound.’

Members went on to form Massive Attack, while Tricky and producer Nellee Hooper continue to have successful careers in the music industry. And that’s just the short-hand version of events.

Want to know more? This documentary from 1996 is a good place to become acquainted.

 wildbunch-arnolfini-vhs-screen-grabThe newly transferred video will be screened at B-Boys, B-Girls, Breakdancers, Wannabees and Posers: ‘Graffiti Art in Bristol 30th Anniversary Party’, a free event taking place on Sunday 19 July 2015, 14:00 to 23:00 at Arnolfini.

We are delighted to feature a guest blog from Phil Johnson, author of Straight Outta Bristol: Massive Attack, Portishead, Tricky and the Roots of Trip-Hop, who filmed the event.

Below he beautifully evokes the social and technical stories behind why the video was made. Many thanks Phil for putting this together.

***

In 1985 I was a lecturer in Film and Communications at Filton College with an added responsibility for running the Audio Visual Studio, a recording room and edit suite/office that had dropped from the sky as part of a new library and resources building. There was also kit of variable quality and vintage, some new, some inherited. I remember a Sony edit suite for big, chunky u-matic videos and another JVC one for VHS tapes, with a beige plasticky mixer that went in the middle by the edit controller. This also allowed you to do grandiose wipes from one camera to another, although we rarely used the camera set-up in the studio because you really needed to know what you wanted to do in advance, and no one ever did. What students liked using were the portable cameras and recorders, JVC VHS jobs that together with the fancy carry cases and padded camera boxes, plus regulation heavy pivoting tripod, weighed each prospective al fresco film-maker down with the baggage-equivalent of several large suitcases. I remember one aspiring Stanley Kubrick from Foundation Art&Design setting off to get the bus into town carrying everything himself, and returning sweatily later that day, close to collapse. He was wearing a heavy greatcoat, obviously.

We had a ‘professional’ u-matic portable recorder too, and that was seriously heavy, but we didn’t have the requisite three-tube camera to get the quality it was capable of, never entirely understanding the principle of garbage in-garbage out, with the inevitable result that almost everything anyone did was doomed to remain at least as shoddy as the original dodgy signal it depended upon. But hey, this was education: it was the process we were interested in, not the product.

wildbunch-vhs-screen-grab
It was a JVC portable VHS recorder I was using on the night of the Wild Bunch jam at the Arnolfini on Friday 19 July 1985, the case slung over my shoulder while I held a crap Hitachi single-tube camera with a misted-over viewfinder whose murky B&W picture meant you were never entirely sure whether it was on manual or auto focus. There was no tripod, and no lighting; just me and a Foundation student, Jo Evans, helping out. The original camera tape, which I recently found after presuming it lost, is a Scotch 3M 60-minuter and the video document of the event, such as it is, lasts only until the single tape runs out, which is just about the time the Wild Bunch’s rappers, Claude and 3D, are getting started.
The image quality is terrible but when there’s some light in the room – the Arnolfini’s downstairs gallery – you can just about make out what’s happening. When it’s dark – and it generally is – the image is so thin it’s barely an image at all. As this is the camera tape – unimportant in itself, and usually only considered as the raw material for a later edit – the significance of what is shown is very provisional. What I meant to focus on, and what was only being picked up because it was easier to keep recording than it was to switch to ‘pause’, is impossible to say. But what the tape does show – when, of course, there’s enough information there to make out anything at all – is now the stuff of history: a Mitchell and Kenyon type document of the yet-to-emerge ‘Bristol Sound’, and a weirdly innocent time that existed before the camera phone. And there it all is: graffiti on the walls, funk, electro and rap on the muffled boominess of the mono soundtrack, with dancers breaking acrobatically on the floor as rockabilly quiffed boys, big-haired girls and lots and lots of very young kiddies look on. As to why I filmed the event in the first place: it was partly for my master’s dissertation (Black Music, the Arts and Education’ – classic lefty teacher getting down with the kids) and partly for the Arnolfini’s new video library.
If you go down and see it on Sunday July 19: enjoy.

Type IV Metal Cassettes and Robert Chenciner’s Daghestan Collection

June 19th, 2015

We recently received a fascinating collection of tapes from the archive of Robert Chenciner, an ethnographer with over thirty years experience studying the cultures, human rights and current affairs of Daghestan.

Daghestan is located in the north Caucasus region, its neighbouring countries are Azerbaijan, Chechnya and Georgia, while its eastern border is flanked by the Caspian Sea.

In the early 1980s Robert had unique access to Daghestan and other parts of the Soviet Caucasus in the twilight years of the USSR.

During visits Robert made recordings of Daghestan’s rich culture. This included music, documenting ethnic instruments such as the Chagana, as well as singing and dancing.

Although Robert believes that claims to authenticity must be treated with suspicion, he nonetheless told me that these recordings document the traditional folk culture that was practiced in the villages of Daghestan.

These tapes also document the 31 mutually unintelligible languages spoken in Daghestan such as Avar which is spoken by 900,000 people.

Listen to excerpt of a tape from the collection. The tape had experienced mould growth and had snapped. It therefore needed to be repaired prior to transfer. Robert explains: ‘The recording was made in Untsukul c.March 1990. You can hear Russian being spoken with a heavy accent, some Kumyk and some Avar. It was joking and talk about who was I and where from.’

Type IV metal cassette with shell open. Visible thin layer of dust on the surface.

Type IV Metal Cassettes

When Robert travelled to Daghestan he was keen to get the most professional recordings he could. For this reason he used type VI metal audio cassette tapes, a tape formula that had been introduced in the late 1970s to offer better quality recordings.

By the mid 1980s, the tape tardis explains, these tapes

‘had been adopted by a lot of enthusiasts. They remained too expensive to be bought in bulk by the average consumer, but if you wanted to record something special – and particularly if you produced music yourself – you’d probably be highly attracted by the exceptional recording quality of a good metal cassette.’

The science behind the type IV cassette, according to the Museum of Obsolete Media, was to use ‘pure metal particles instead of metal oxides. This created a hard-wearing tape with superior frequency response and greater dynamic range.’

Since completing the recordings in the mid 1980s, as with so many of the tapes we receive at Great Bear, they have been tucked away in a drawer and out of circulation.

Due to being stored in poor conditions some of the tapes were displaying signs of mould growth.

Another problem some tapes exhibited was the degradation of the foam pressure pad. This had ‘stuck’ onto the tape and stopped it it from playing. In one case the tape had snapped as a result from a previous attempt at playback. Melted foam pressure pad on a type IV metal tape

Fortunately this issue did not effect our ability to do the transfer. We use Nakamichi tape decks to do optimal audio cassette transfers. The transport design within Nakamichi machines doesn’t use the tape pressure pad to play back the tapes. This is because, Wikipedia tells us,

‘Nakamichi found that this pad provided uneven and fairly inaccurate pressure and was therefore inadequate for reliable tape/head contact. Furthermore, Nakamichi found that the pressure pad was a source of audible noise, particularly scrape flutter (the tape bouncing across the head, a result of uneven pressure), and also contributed to premature head wear. Nakamichi’s dual-capstan tape decks provide such accurate and precise tape tension that, unlike other decks, the cassette’s pressure pad is not needed at all.’

Head pad lifter on a Nakamichi tape machine

The insides of a Nakamichi machine that has no need of a pressure pad to play back tapes.

Re-publication plans

Recent interest from musicologist Stefan Williamson-Fa, the driving force behind getting the tapes transferred to digital files with Great Bear, will enable these unique recordings to be heard by new audiences.

These include what Robert believes to be the only recording of an Andi Zikr ritual. Banned by the Tsar and later the Soviets, the Zikr ritual proved to be a resilient part of Daghestan’s Sufi culture. Zikr involves a group rotating in a circle, stamping the ground and grunting in order to create a mystical and ecstatic experience.

Stefan and Robert have plans to make the transferred digital files available online.

Robert reflected that when he was collecting the tapes in the 1980s his imagined audience for the recordings was pretty small. With the possibility of online publication this audience has substantially increased.

Furthermore, through people uploading material to sites such as YouTube the amount of Daghestan’s culture that can be accessed on the internet continues to grow. Robert’s links with the academic community in Daghestan also means the recordings will gain exposure there as well.

It is no doubt that those interested in the cultural history of Daghestan will await the publication of these recordings with much excitement. When the website is available we will of course let you know!

***Many thanks to Robert Chenciner for talking to us about his collection, and to Stefan for putting us in touch***

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/.

Analogue to analogue – the Courtyard Music Group

May 18th, 2015

Great Bear were recently approached by the Courtyard Music Group to help them complete the 100% analogue re-issue of their 1974 acid-folk album Just Our Way of Saying Hello.

Among Britfolk enthusiasts, news of the Courtyard Music Group’s plans to re-issue their album has been greeted with excitement and anticipation.

Just Our Way of Saying Hello was created when ‘an idealistic young teacher cut a lo-fi folk-rock record with a bunch of teenagers in the Utopian rural setting of Kilquhanity School in the Scottish borders.’

100 copies of the album were made in a private pressing, originally intended for family and friends.

Yet this was not the end of the story, as the record went on to become ‘one of the most obscure albums in Britfolk history is now an ultra-rare collector’s item, with copies trading online for over £1000.’

After a hugely successful pledge music campaign, the band are pushing ahead with their re-issue project that will produce a limited pressing of the mono vinyl, a remastered audio CD with outtakes and a 48 page booklet with interviews, photos and drawings. These will all be available in the summer of 2015.

Great Bear’s role in the project was twofold: first to restore the physical condition of tapes in order to achieve the best quality transfer. Second to produce analogue copies of the original master tapes. These second generation masters, originally recorded at a speed of 7½ inches per second, were transferred at the speed of 15 ips in our studio.

These copies were then sent to Timmion Records in Finland to complete the final, analogue only cutting of the re-issue. Even amid the much discussed ‘vinyl revival‘ there are currently no UK-based studios that do pure analogue reproductions. The risk of losing precious cargo in transit to Finland was too great, hence our involvement at the copying stage.

original master tapes - Courtyard Music Group

The original master tapes

Analogue only

Why was it so important to members of the Courtyard Music Group to have an analogue only release? Digital techniques began creeping into the production of audio recordings from the late 1970s onwards, to the situation today where most studios and music makers work in an exclusively digital environment.

Can anyone really tell the difference between an analogue and digital recording, or even a recording that has been subject to a tiny bit of ‘digital interference’?

Frank Swales, member of the Courtyard Music Group, explains how remaining true to analogue was primarily a preference for authenticity.

‘I think in this case it’s really about the JOURNEY that this particular product has had, and the measures taken to keep it as close to the original product as possible. So, I’m not sure anyone can, in a listening context, perceive any real difference between digital and analogue, given that all of us humans are pretty much restricted to the frequency range of 20Hz to 20kHz, if we’re lucky!’

While Richard Jones, also a member of Courtyard Music Group, revealed: ‘Our 1974 recording was made using a selection of microphones, some ribbon, a valve powered four channel mixer and an ancient Ferrograph tape recorder. I cannot claim these decisions about the analogue reissue are soundly based on principles of Acoustics/physics. They are decisions to produce an authentic product. That is, attempting to eliminate the introduction of “colours” into the sound which were not there in 1974.’

The ability to create exact copies is perilously difficult to achieve in an analogue context. Even in the most controlled circumstances analogue transfers are always different from their ‘original.’ The tape might distort at high frequencies for example, or subtle noise will be created as the tape moves through the transport mechanism.

Yet the desire for analogue authenticity is not the same as wanting a replica. It is about preserving historically specific sound production process whose audible traces are becoming far less discernible.

After all, if authenticity was correlated with exact replication, the Courtyard Music Group would not have asked us to make the copies at a higher recording speed than the originals. Yet, Frank explains, ‘the difference in sound quality – the tracks especially having been recorded onto tape travelling at 15ips – will likely be negligible, but it must be said that this was a decision not lightly taken.’

By preserving the historical authenticity of analogue reproduction, the Courtyard Music Group re-issue project converges with the archival concern to maintain the provenance of archival objects. This refers to when the ‘significance of archival materials is heavily dependent on the context of their creation, and that the arrangement and description of these materials should be directly related to their original purpose and function.’

For a range of audiovisual objects made in the late 20th and early 21st centuries, such fidelity to the recording and its context will be increasingly difficult to realise.

As appropriate playback machines and recordable media become increasingly difficult to source, an acceptance of hybridity over purity may well be necessary if a whole range of recordings are to be heard at all.

We are not yet at that stage, thankfully, and Great Bear are delighted to have played a part in helping spread the analogue purity just that little bit further.

***Thanks to Courtyard Music Group members for answering questions for this article.***

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!


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