provenance

Sep

2016

Digital Video in Mixed-Content Archives

On a recent trip to one of Britain’s most significant community archives, I was lucky enough to watch a rare piece of digitised video footage from the late 1970s.

As the footage played it raised many questions in my mind: who shot it originally? What format was it originally created on? How was it edited? How was it distributed? What was the ‘life’ of the artefact after it ceased to actively circulate within communities of interest/ use? How and who digitised it?

As someone familiar with the grain of video images, I could make an educated guess about the format. I also made other assumptions about the video. I imagined there was a limited amount of tape available to capture the live events, for example, because a number of still images were used to sustain the rolling audio footage. This was unlikely to be an aesthetic decision given that the aim of the video was to document a historic event. I could be wrong about this, of course.

When I asked the archivist the questions flitting through my mind she had no answers. She knew who the donor of the digital copy was, but nothing about the file’s significant properties. Nor was this important information included in the artefact’s record.

This struck me as a hugely significant problem with the status of digitised material – and especially perhaps video – in mixed-content archives where the specificities of AV content are not accounted for.

Due to the haphazard and hand-to-mouth way mixed-content archives have acquired digital items, it seems more than likely this situation is the rule rather than the exception: acquired bit by bit (no pun intended), maintaining access is often privileged over preserving the context and context of the digitised video artefact.

As a researcher I was able to access the video footage, and this of course is better than nothing.

Yet I was viewing the item in an ahistoric black hole. It was profoundly decontextualised; an artefact extracted to its most barest of essences.

Standard instabilities

This is not in any way a criticism of the archive in question. In fact, this situation is wholly understandable given that digital video are examples of ‘media formats that exist in crisis.’

Video digitisation remains a complex and unstable area of digital preservation. It is, as we have written elsewhere on this blog, the final frontier of audiovisual archiving. This seems particularly true within the UK context where there is currently no systematic plan to digitise video collections, unlike film and audio.

The challenge with digital video preservation remains the bewildering number of potential codec/ wrapper combinations that can be used to preserve video content.

There are signs, however, that file-format stabilities are emerging. The No Time to Wait: Standardizing FFV1 & Matroska for Preservation symposium (Berlin, July 2016) brought together software developers and archivists who want to make the shared dream of an open source lossless video standard, fit for archival purpose, a reality.

It seems like the very best minds are working together to solve this problem, so Greatbear are quietly optimistic that a workable, open source standard for video digital preservation is in reach in the not too distant future.

Metadata

Yet as my experience in the archive makes clear, the challenge of video digitisation is not about file format alone.

There is a pressing need to think very carefully about the kind of metadata and other contextual material that need to be preserved within and alongside the digitised file.

Due to limited funding and dwindling technical capacity, there is likely to be only one opportunity to transfer material currently recorded on magnetic tape. This means that in 2016 there really can be no dress rehearsal for your video digitisation plans.

As Joshua Ranger strongly emphasises:

‘Digitization is preservation…For audiovisual materials. And this bears repeating over and over because the anti-digitization voice is much stronger and generally doesn’t include any nuance in regards to media type because the assumption is towards paper. When we speak about digitization for audio and video, we now are not speaking about simple online access. We are speaking about the continued viability, about the persistence and the existence of the media content.’

What information will future generations need to understand the digitised archive materials we produce?

An important point to reckon with here is that not all media are the same. The affordances of particular technologies, within specific historical contexts, have enabled new forms of community and communicative practice to emerge. Media are also disruptive (if not deterministic) – they influence how we see the world and what we can do.

On this blog, for example, Peter Sachs Collopy discussed how porta-pak technology enabled video artists and activists in the late 1960s/ early 1970s to document and re-play events quickly.

Such use of video is also evident in the 1975 documentary Les prostituées de Lyon parlent (The prostitutes of Lyon speak).

Les prostituées documents a wave of church occupations by feminist activists in France.

The film demonstrates how women used emergent videotape technology to transmit footage recorded within the church onto TV screens positioned outside. Here videotape technology, and in particular its capacity to broadcast uni-directional messages, was used to protect and project the integrity of the group’s political statements. Video, in this sense, was an important tool that enabled the women – many of whom were prostitutes and therefore without a voice in French society – to ‘speak’.

Peter’s interview and Les prostituées de Lyon parlent are specific examples of how AV formats are concretely embedded within a social-historical and technical context. The signal captured – when reduced to bit stream alone – is simply not an adequate archival source. Without sufficient context too much historical substance is shed.

In this respect I disagree with Ranger’s claim that ‘all that really may be needed moving ahead [for videotape digitisation] is a note in the record for the new digital preservation master that documents the source.’ To really preserve the material, the metadata record needs to be rich enough for a future researcher to understand how a format was used, and what it enabled users to do.

‘Rich enough’ will always be down to subjective judgement, but such judgements can be usefully informed by understanding what makes AV archive material unique, especially within the context of mixed-content archives.

Moving Forward

So, to think about this practically. How could the archive item I discuss at the beginning of the article be contextualised in a way that was useful to me, as a researcher?

At the most basic level the description would need to include:

The format it was recorded on, including details of tape stock and machine used to record material
When it was digitised
Who digitised it (an individual, an institution)

In an ideal world the metadata would include:

Images of the original artefact – particularly important if digital version is now the only remaining copy
Storage history (of original and copy)
Accompanying information (e.g., production sheets, distribution history – anything that can illuminate the ‘life’ of artefact, how it was used)

This information could be embedded in the container file or be stored in associated metadata records.

These suggestions may seem obvious, but it is surprising the extent to which they are overlooked, especially when the most pressing concern during digitisation is access alone.

In every other area of archival life, preserving the context of item is deemed important. The difference with AV material is that the context of use is often complex, and in the case of video, is always changing.

As stressed earlier: in 2016 and beyond you will probably only get one chance to transfer collections stored on magnetic tape, so it is important to integrate rich descriptions as part of the transfer.

Capturing the content alone is not sufficient to preserve the integrity of the video artefact. Creating a richer metadata record will take more planning and time, but it will definitely be worth it, especially if we try to imagine how future researchers might want to view and understand the material.

May

2015

Analogue to analogue – the Courtyard Music Group

Greatbear 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 Greatbear 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.***

Jun

2014

Digitisation: methodologies, processing and archival practices

We work with a range of customers at Greatbear, digitising anything from personal collections to the content of institutional archives. Because of this, what customers need from a digitisation service can be very different.

A key issue relates to the question of how much we process the digital file, both as part of the transfer and in post-production. In other words, to what extent do we make alterations to the form of the recording when it becomes a digitised artifact. While this may seem like an innocuous problem, the question of whether or not to apply processing, and therefore radically transform the original recording, is a fraught, and for some people, ethical, consideration.

There are times when applying processing technologies is desirable and appropriate. With the transfer of video tape, for example, we always use time-based correctors or frame synchronisers to reduce or eliminate errors during play back. Some better quality video tape machines, such as the U-matic BVU-950P, already have time-based correctors built in which makes external processing unnecessary. As the AV Artifact Atlas explains however, time-based correction errors are very common with video tape:

‘When a different VTR is used to playback the same signal, there can be slight mechanical and electronic differences that prevent the tape from being read in the same way it was written. Perhaps the motors driving the tape in a playback VTR move slightly slower than they did in the camera that recorded the tape, or maybe the head of the playback VTR rotates a fraction quicker than the video head in the machine that recorded the tape. These tiny changes in timing can dramatically affect stability in a video image.’

We also utilise built in processes that are part of machine’s circuitry, such as drop out compensation and noise reduction. We use these, however, not in order to make the tape ‘look better.’ We do it rather as a standard calibration set up, which is necessary for the successful playback of the tape in a manner appropriate to its original operating environment.

After all, video tape machines were designed to be interchangeable. It is likely such stabilising processing would have been regularly used to play back tapes in machines that were different to those they were recorded on. Time-based correction and frame synchronisation are therefore integral to the machine/ playback circuitry, and using such processing tools is central to how we successfully migrate tape-based collections to digital files.

Digital processing tools

Our visual environment has changed dramatically since the days when domestic video tape was first introduced, let alone since the hay day of VHS. The only certainty is that it will continue to change. Once it was acceptable for images to be a bit grainy and low resolution, now only the crisp clarity of a 4K Ultra HD image will do. There is perhaps the assumption that ‘clearer is better’, that being able to watch moving images in minute detail is a marker of progress. Yet should this principle be applied to the kinds of digitisation work we do at Great Bear? There are processors that can transform the questionable analogue image into a bright, high definition, colour enriched digital copy. The teranex processor, for example, ‘includes extremely high quality de-interlacing, up conversion, down conversion, SD and HD cross/standards conversion, automatic cadence detection and removal even with edited content, noise reduction, adjustable scaling and aspect ratio conversion.’ ‘Upgrading’ analogue images in this way does come with certain ethical risks.

Talking about ethics in conjunction with video or audio tape might seem a bit melodramatic, but it is at the point of intervention/ non-intervention where the needs of our customers diverge the most. This is not to say that people who do want to process their tapes are unethical – far from it! We understand that for some customers it may be preferable for such processing to occur, or to apply other editing techniques such as noise reduction or amplification, so that audio can be heard with greater clarity.

Instead we want to emphasise that our priority is getting the best out of the tape and our playback machines, rather than relying on the latest processing technology that is also at risk from obsolescence. After all, a heavily processed file will always require further processing at an unknown point in future so that it can maintain visually relevant to whatever format is commercially dominant at the time. Such transformations of the digital file, which are necessarily destructive and permanent, contribute to the further circulation of what Hito Steyerl calls ‘poor images‘, ‘a rag or a rip; an AVI or a JPEG…The poor image has been uploaded, downloaded, shared, reformatted, and reedited. It transforms quality into accessibility, exhibition value into cult value, films into clips, contemplation into distraction.’

Maintaining the integrity, and as far as possible authenticity of the original recordings, is a core part of our methodology. In this way our approach corresponds with Jisc’s mantra of ‘reproduction not optimisation’ where they write:

‘Improving, altering or modifying media for optimisation may seem logical when presenting works to a public or maintaining perceived consistency. It should be remembered that following an often natural inclination to enhance what we perceive to be a poor level of quality is a subjective process prescribed by personal preference, technological trends and cultural influences. In many cases the intentions of a creator are likely to be unknown and this can cause difficulties in interpreting levels of quality. In these instances common sense alongside trepidation should prevail. On the one end of the spectrum unintelligible recordings may be of little use to anyone, whereas at the opposite end recordings from previous eras were not produced with modern standards of clarity in mind.’

It is important to bear in mind, however, that even if a file is subject to destructive editing there may come a time when the metadata created about the artefact can help to illuminate its context and provenance, and therefore help it maintain its authenticity. The debates regarding digital authenticity and archiving will of course shift as time passes and practices evolve.

In the meantime, we will continue to do what we are most skilled at: restoring, repairing and migrating magnetic tape to digital files in a manner that maintains both the integrity of the original operating environment and the recorded signal.

provenance