{"id":866,"date":"2019-04-14T17:16:46","date_gmt":"2019-04-14T21:16:46","guid":{"rendered":"http:\/\/resources.culturalheritage.org\/emg-review\/?page_id=866"},"modified":"2019-04-14T17:16:46","modified_gmt":"2019-04-14T21:16:46","slug":"turkus-2","status":"publish","type":"page","link":"https:\/\/resources.culturalheritage.org\/emg-review\/volume-4-2015-2016\/turkus-2\/","title":{"rendered":"Drop Video File(s) Here: The Emergence of Free Quality Control Tools for Video Preservation"},"content":{"rendered":"\n

Benjamin Turkus
The Electronic Media Review, Volume Four: 2015-2016<\/em>\u00a0<\/p>\n\n\n\n

ABSTRACT<\/h2>\n\n\n\n

From 2013-2015, members of the Bay Area Video\nCoalition\u2019s Preservation Department worked closely with a technical team led by\nDave Rice on a National Endowment for the Humanities-funded research and\ndevelopment project. The result of this work was QCTools, free and open source\nquality control software designed to aid in the analysis of reformatted analog\nvideo materials. The following essay, adapted from a white paper, describes the\nmotivations, technical developments, challenges, and future prospects for the\nQCTools effort. Adopted widely within the audiovisual preservation community,\nQCTools is significant both for the functions its serves, and for what it\nrepresents: that we can, and should, design these tools for ourselves, rather\nthan relying on proprietary, stretched-to-fit, corporate solutions. And, given\nthe inevitable decline of magnetic media, there is no time to delay.<\/p>\n\n\n\n

INTRODUCTION<\/h2>\n\n\n\n

“The BAVC QC Tool Set is perhaps the most significant recent tool development for those working in the preservation of video. This tool set has provided a means of examining video material that previously would not have been possible for the majority of conservators and archivists. It therefore now forms a cornerstone to ensuring that the new generation of those who are caring for our collections are equipped with the skills and training to respond to a file based environment.\u201d (Laurenson 2015)<\/p><\/blockquote>\n\n\n\n

The\nQuality Control Tools for Video Preservation (QCTools) project was born of a\nsimple, yet singular idea: that video preservationists must not cede their own\ninterest in the development of software tools designed to suit their own needs.\nThis push for more self-determination\u2014for an assertion of control over the\nquality control process, rather than reliance upon proprietary systems or\noutdated methods\u2014has resulted in free and open source software that allows\nusers to better understand and analyze their digital video files, whether\nborn-digital or the result of analog-to-digital reformatting.<\/p>\n\n\n\n

With\nfunding from the National Endowment for the Humanities\u2019 Preservation and Access\nResearch and Development Program, the Bay Area Video Coalition (BAVC)\nspearheaded this effort to develop and create a sustainable body of users for\nQCTools. While specifically targeting those at work in cultural heritage\ninstitutions (libraries, archives, and museums), the eclectic nature of QCTools\ngenerated an unexpectedly broad base of users, from media artists to software\ndevelopers. Not only did these diverse communities bring new ideas to the\ntable, helping to refine and expand the goals of the project, but they also\nserved as a powerful reminder that it is inclusiveness that will ultimately\ndictate the long-term prospects of all such efforts.<\/p>\n\n\n\n

As\nwith free and open source software communities more broadly, the true successes\nof QCTools lie not in its source code, but rather in the political, economic,\nand institutional implications that erupt from its new forms of social\norganization. In particular, QCTools reveals productive pathways through its\ncompanionship with the Audio\/Visual Artifact Atlas (AVAA), its incorporation\ninto the world of FFmpeg, and its dissemination through the web-based Git-repository\nGithub. In a wider sense, QCTools marks the continuing spread of a free or open\nsource ethos into the audiovisual preservation community, one that is giving\nrise to new infrastructural models, new relational modes, and new ways of\nsharing knowledge.1<\/sup> While this could be easily dismissed as mere\noverstatement or romanticizing, as Steven Weber describes in The Success of\nOpen Source<\/em> (2004), the unlikely phenomenon of free and open source\nsoftware is \u201cin some ways the first and certainly one of the most prominent\nindigenous political statements of the digital world\u201d (7). It is a \u201cstory of\nhow social organization can change the meaning of property, and conversely, how\nshifting notions of property can alter the possibilities of social\norganization;\u201d adopting this perspective allows us to recast quality control\nitself, thinking of it as more than a set of tools and processes, rather, as a\npublic good: something that should be shared, cared for collectively, and made\nwidely available to all (Weber 2004, 1).<\/p>\n\n\n\n

Given the intense pressures and demands of audiovisual preservation, this radical reorientation could not be timelier. Our future abilities to safeguard audiovisual materials\u2014and to guarantee access over the long-term\u2014will hinge in large part upon the continued support of projects that are striving to remove the barriers and obstacles impeding the progress of our time-sensitive, yet critical mission. Maximizing efficiency, yielding new and unexpected insights, and establishing an ever-evolving community committed to the very idea of free software playing an integral role in the future of this work\u2014these are the lessons of QCTools.<\/p>\n\n\n\n

MOTIVATION: THE NEED FOR FREE QUALITY CONTROL TOOLS <\/h2>\n\n\n\n

Leaders\nin the field of audiovisual preservation are united in their predictions. Whether\ninvoking metaphors of catastrophe, crisis, or \u201cgathering storms,\u201d this much is\nclear: the combination of deteriorating or degrading analog physical media\ncarriers and obsolete playback and peripheral equipment have made the task of protecting\nand preserving our audiovisual cultural heritage both immediate and immensely\ndifficult (Casey 2015, 14). But, though the challenges of digitization and\ndigital preservation may make some yearn for the relatively more stable days of\ntape-to-tape preservation, the end of an entire industry (the Sony Corporation\nrecently announced plans to \u201ccease sales and distribution of Professional Video\nTape Recorders\/Players\/Camcorders\u201d by March 2016, with repair services offered\nuntil March 2023) makes even this nostalgia a luxury that few can truly afford (www.sony.co.uk\/pro\/article\/broadcast-products-vtr-announcement).<\/p>\n\n\n\n

For\nthe caretakers of magnetic media (audio and videotape) collections, prompt and\ndecisive action is<\/em> required<\/em>,\nand the only way to save this part of our cultural heritage is to play back\ntapes on obsolete equipment, creating digital surrogates through a process\nalternatively referred to as reformatting, migration, digitization, or\nanalog-to-digital conversion. Unlike celluloid film, which is composed of\ndiscrete frames that are visible to the naked eye, magnetic media show nothing\nof their inner nature without functioning playback equipment; they are\ndependent, their existence utterly intertwined with the technologies that gave\nbirth to them.<\/p>\n\n\n\n

In\na 2013 presentation, \u201cTo Outsource or Not to Outsource,\u201d Jonah Volk, Media\nPreservation Coordinator at the New York Public Library, sketched a telling\nportrait of quality control, situating Quality\nControl: The Ideal<\/em> on one end of a spectrum, and Quality Control: The Reality<\/em> near the far opposite end. For Volk,\nquality control\u2014the effort to confirm that digital files have been created\naccording to pre-determined specifications\u2014has become an unfortunate risk\/reward\nscenario. Due to limitations of time and resources, many institutions have been\nforced into a weighing of the odds, potentially sacrificing thorough and\ncomplete quality control simply to get by. And even for these\ninstitutions\u2014which are the lucky ones, blessed with the resources to embark\nupon digitization projects\u2014it remains difficult to justify the additional\nexpense of proprietary quality control software designed for the needs (and\nbudgets) of the broadcast industry. <\/p>\n\n\n\n

For\ninstitutions pursuing in-house digitization, QCTools offers a means of ensuring\nthe creation of consistent, high-quality files. For institutions working with\noutside vendors, QCTools offers a means of verifying that digital files meet\ndesired expectations\/thresholds for quality. In both circumstances, QCTools\nserves an important communicative function, one that transcends institutional\nboundaries.<\/p>\n\n\n\n

BACKGROUND AND DEVELOPMENT<\/h2>\n\n\n\n

As\na leader in the field of video preservation, BAVC has had a front-row seat to\nthe acceleration of this impending crisis. Working with the oldest and most\ndecrepit of magnetic media formats, BAVC was able to witness firsthand the\nmultiplying (and compounding) challenges that are associated with reformatting\ndegrading tapes. It was this awareness\u2014this acute understanding of the\ndifficulties ahead\u2014that prompted BAVC to develop quality control software\ncapable of reducing some of the burdens placed upon the underserved, overlooked\npreservation community. For magnetic media to be granted a second life, they\nmust undergo a complex, error-prone, time- and resource-intensive process.\nBefore this project, extraordinary amounts of time were required to:<\/p>\n\n\n\n

  1. Transfer\nvideotape recordings to digital file formats, meticulously documenting\nerrors\/artifacts\/adjustments<\/li>
  2. Review,\nin full, potentially problematic files, identifying compromises in tape\nplayback or digitization tools<\/li>
  3. Analyze\nand identify problem areas and their sources<\/li>
  4. Develop\npotential solutions to tape degradation, malfunctioning playback equipment, and\ncomputer hardware\/software incompatibilities.<\/li><\/ol>\n\n\n\n

    The\nurgent need to transform culturally significant tape-based materials into forms\ncapable of standing the test of time is matched only by the need to do so in an\nefficient, high quality manner. The incongruities of preservation workflows\nprompted Lauren Sorenson, a former member of BAVC\u2019s Preservation Department, to\nask the question that has served as a beacon for the entire QCTools effort: \u201chow\nmight the archival and conservation community re-imagine software\nfunctionality\u201d (2013, 143). From the beginning, QCTools was about more than\nrefusing to rely upon commercial software companies whose interests may one day\ndiverge from our own; as BAVC imagined it, the imperative in quality control\nwas to question the implications of allowing private, for-profit interests to dictate\nwhat this software looks like, how it functions, and who it is designed to\nserve.<\/p>\n\n\n\n

    The\nvision for QCTools emerged out of the collaborative work of BAVC, the Dance\nHeritage Coalition (DHC), and a technical team lead by independent consultant\nDave Rice. Working to create the DHC\u2019s Secure Media Network (SMN), a digital\npreservation system made up of multiple digitization hubs (\u201cdigihubs\u201d)\noperating simultaneously throughout the country, it became immediately apparent\nthat the DHC would benefit from adopting a coherent method for analyzing the\ndigital video files produced by these various stations. In tackling the\ninfrastructural, technical, and organizational challenges attendant to this\ndigital preservation network, all three groups came to see that quality control\nwas more than a local problem; it was endemic to entire field of audiovisual\npreservation. Regardless of institutional alliances, preservationists of all kinds<\/em> require the means to assess\ntheir digital video materials, whether created in-house or by outside vendors.\nWithout proper protocols in place, the lack of quality control tools and\nexpertise can result in technical compromises that go undetected, with minor\nflaws undermining all resulting digital media. <\/p>\n\n\n\n

    By\ntaking a data-driven approach to the analysis of digital video, QCTools fills\nan important gap in the preservation community, becoming the \u201ccomputer\nprocessable\u201d companion to the more \u201chuman readable\u201d Audio\/Visual Artifact Atlas\n(AVAA), a web-based dictionary and repository for the most frequently occurring\nerrors and anomalies of the digitization process. As with the AVAA\u2014a\npartnership of BAVC, New York University\u2019s Digital Library Technology Services,\nand the Stanford Media Preservation Lab\u2014QCTools is guided by the\ncommunity-driven belief that:<\/p>\n\n\n\n

    Users can improve the outcomes of their media preservation efforts if they can properly identify and characterize signal issues and anomalies. With a tool to facilitate building a vocabulary of terms and supporting examples, users will be able to learn and communicate about problems with more clarity and understanding. With this understanding, it is more likely that fixable problems will be fixed, limited resources will be directed more appropriately, and the products of reformatting workflows will be of higher quality. <\/p>

    (http:\/\/avaa.bavc.org\/artifactatlas\/index.php\/About_the_AV_Artifact_Atlas).<\/p><\/blockquote>\n\n\n\n

    The\nsheer variety of formats in the sixty-odd year history of video has presented\nAVAA contributors with a unique challenge: can errors identified in one format\ncorrespond in any noticeable way to their equivalents in different formats?\nWhile QCTools may not be able to overcome the challenge of getting a diverse\ngroup to adhere to a common set of terms, especially given the substantial\ndistinctions differentiating video recording technologies, it does point to an\nalternate possibility, the big data future of audiovisual preservation, with\ninformation gathered and arranged in provocative new ways. If widely\nimplemented, QCTools can help identify field-wide areas of concern, pinpointing\nthe most problematic formats, or brands\/stocks, and perhaps even the efficacy\nof tape treatment methods (such as baking tapes, a widely used means of\ncountering \u201csticky shed syndrome,\u201d or binder hydrolysis). Though this would depend\nupon a metadata model capable of bridging institutional gaps, what is most\nexciting about QCTools is that it spurs this type of thinking, removing it from\nthe realm of impossibility.<\/p>\n\n\n\n

    QCTOOLS: ORGANIZING CONCEPTS AND PRINCIPLES<\/h2>\n\n\n\n

    In\nits current incarnation, QCTools strikes a fascinating balance, alleviating\nsome pressures through automation while simultaneously prompting a deeper dive\ninto the depths of digital video signals. At its core, QCTools reduces our need\nto rely so heavily upon human subjectivity and perception, bringing a concrete\nconsistency to the task at hand, whether that be communicating about common\nproblems or performing quality control on a batch of digital video files.<\/p>\n\n\n\n

    After\na 2014 QCTools workshop, Erik Piil, Time-Based Media Conservator for the\nKramlich Collection\/New Art Trust, struck upon two of QCTools\u2019 strongest\nmerits, its ability to catch what might be missed, and its unanticipated status\nas a new educational platform:<\/p>\n\n\n\n

    When feeding [QCTools] newly-created digital assets, it picks up almost imperceptible field-level errors and chrominance noise that could easily be overlooked by the fatigued eyes of a video technician and engineer. From a pedagogical standpoint, however, feeding files with known video artifacts through QCTools allows the user to learn a wealth of information about the signals themselves, through the patterns that the artifacts reveal. Since viewing and interpreting moving images is a complex process, observing the recurring patterns gives the user base a better, well-structured sensitivity to the problems.<\/p><\/blockquote>\n\n\n\n

    Here, Piil points to an exciting reversal: for many, QCTools is most noteworthy for its archaeological nature, for the ways it allows users to sift through layer upon pixelated layer of digital video signals, learning to think of digitization\u2014and problems occurring during the digitization process\u2014in new and different ways. By challenging our preconceived notions about digitization, QCTools encourages us to think more critically about the digital surrogates we are creating. And this unexpected use of QCTools can be instrumental in efforts to convince the preservation community to embrace ideas that are at first uncomfortable. While QCTools may not end debates about the best way to encode or wrap digital video bit-streams, it can make these debates more informed, allowing preservationists to visualize the underlying differences between methods of encoding (figs. 1, 2). <\/p>\n\n\n\n

    \"\"
    Fig. 1. The analytical playback window of QCTools, \u201cNormal\u201d view on the left; \u201cBit Plane\u201d view of the fourth Y bit on the right, 10-bit uncompressed V210 encoding
    <\/figcaption><\/figure>\n\n\n\n
    \"\"
    Fig. 2. The same side-by-side, with H.264 encoding. Note the level of fine-grained detail. <\/figcaption><\/figure>\n\n\n\n

    As\nPiil explains:<\/p>\n\n\n\n

    To take just one example, using the \u201cbit [plane]\u201d filter to examine sets of bits corresponding to a given bit position, one could ascertain whether a file had been made using a compressed (lossy) or an uncompressed (lossless) source. This information is crucial for the archivist and conservator, who can now sufficiently move statements of file fidelity through time with the proper documentation. (2014)<\/p><\/blockquote>\n\n\n\n

    When\nwe speak of video, whether analog or digital, we are speaking of the\ntransmission of visual and aural information. Video is an electronic medium,\none that flows, moving constantly. Descriptions of the underlying mechanisms of\nanalog video\u2014electron guns and cathode ray tubes\u2014can make the familiar feel\nforeign. In How Video Works<\/em> (2007),\nMarcus Weise and Diana Weynand describe a process that astounds with its speed\nand immediacy: \u201cthe electron beam inside a video camera transforms a light\nimage into an electronic signal. Then, an electron beam within a video receiver\nor monitor causes chemicals called phosphors to glow so they transform the\nsignal back into light\u201d (15).<\/p>\n\n\n\n

    Despite\ntheir fluidity, video signals are composed of standardized, discrete units\n(lines, fields, and frames) that lend themselves to digitization. Charles Poynton\n(1996), breaks down this two-part process into sampling\u2014\u201cthe value of a\nbandlimited, continuous signal at an instant of time\/and or space\u201d\u2014 and\nquantization\u2014the assignment of an \u201cinteger to the amplitude of the signal in each\ninterval or region (294, 2). QCTools offers the digital video novice a better\nunderstanding of what a vast and comprehensive world this is; in a crude\napproximation of the National Digital Stewardship Alliance\u2019s Levels of Digital Preservation<\/em> (2013),\nthis could be thought of as a super-charged version of \u201cLevel Two: Know Your\nData.\u201d <\/p>\n\n\n\n

    The\ndifficulties that some users have reported in adapting to QCTools point to a\nfocus of future educational efforts: video preservationists must be as fluent\nin the language of digital video as they are in the language of analog video.\nWhile the under the hood nature of QCTools has granted users an unprecedented\nability to deconstruct digital video streams, analyzing them from different\nperspectives, in certain cases practitioners have continued to struggle with\nthe complexity of analog-to-digital conversion, particularly the mapping of\nanalog standards onto the digital realm. For example, many expressed confusion\nregarding the correspondence between the IRE scale, an analog mode of measuring\nvideo-specific units of voltage, from black (7.5 IRE) to white (100 IRE), and\nits 8-bit, Y\u2019CbCr (color difference component digital video) equivalent\n(0-255).<\/p>\n\n\n\n

    Has\nQCTools firmly and thoroughly straddled the specialist\/novice divide? Not quite\nyet, but this is an ambition of the project. In many ways, the pedagogical\npotential of QCTools caught the development team by surprise, and though it has\nbeen secondary to the desire to create a robust, functioning program, they\nenvision actively working to build upon this potential through future\neducational outreach. <\/p>\n\n\n\n

    FFMPEG AND THE FREE AND OPEN SOURCE SOFTWARE MOVEMENTS<\/h2>\n\n\n\n

    QCTools greets users with a clean, light grey interface; within, a file folder bisected by a downward facing arrow points to the simple dictum that could serve as symbol for the entire QCTools project: \u201cDrop video file(s) here\u201d (fig. 3). <\/p>\n\n\n\n

    \"\"
    Fig. 3. The QCTools User Interface <\/figcaption><\/figure>\n\n\n\n

    Follow this command, and QCTools will kick into multi-colored action, quickly analyzing the pixel information of a digital video file, spitting out multiple levels of crawling red, green, blue and black graphs (fig. 4). <\/p>\n\n\n\n

    \"\"
    Fig. 4. QCTools in graph mode<\/figcaption><\/figure>\n\n\n\n

    This is the first of QCTools\u2019 three core analytical components, a macro view of the digital video and audio bit-streams, read from left (the beginning of a recording) to right (the end of a recording). At the bottom of the screen, a series of frame-level preview windows allows users to gain an instant impression of problematic areas requiring closer review. In an effort to make the program more approachable, QCTools defaults to a limited number of audiovisual metrics. YUV Values plot brightness (luma, Y) and color information (chroma, U\/V) and YUV Difference Values document the extent of visual (YUV) change from one frame to the next. Saturation offers an overview of the color saturation, or vibrancy, of the video and R.128, is a measurement the overall loudness of the audio stream, following European Broadcast Union (EBU) specifications).<\/p>\n\n\n\n

    In\nthis macro-analytic view, users can also select from a number of other filter\ngraphs: Hue, a plot of the average color value for each frame; Temporal\nOutliers (TOUT), which identifies pixels that vary drastically from their closest\nneighbors; Vertical Line Repetitions (VREP), a measurement of similar or\nduplicate rows of pixel data; Broadcast Range (BRNG), which detects pixels\nwhose values are outside \u201clegal\u201d limits (16-235 for Y; 16-240 for U\/V); and\nMean Square Error per Field (MSEf) and Peak Signal to Noise Ratio (PSNRf), two\ngraphs that specialize in tracking differences at the field level.<\/p>\n\n\n\n

    QCTools\ndraws much of its strength from FFmpeg, a free software project self-described\nas \u201ca complete, cross-platform solution to record, convert, and stream audio\nand video\u201d (https:\/\/ffmpeg.org). Just as Linux often exists behind the scenes,\npowering many contemporary operating systems, FFmpeg forms a foundational layer\nfor a number of media platforms, such as Google Chrome, YouTube, MPlayer, VLC,\nand xine. Written in the programming language C, FFmpeg\u2019s speed, reliability,\nand high functionality have made it an ever-increasing part of audiovisual\npreservation workflows, particularly for the following tasks:<\/p>\n\n\n\n

    Encoding: \u201cThe process of converting\none or more signals into a more complex representation, with the goal of\nreducing data rate for transmission or recording.\u201d (Poynton 2012, 617)<\/pre>\n\n\n\n
    Decoding: \u201cConverting one or more\ncoded signals into uncompressed form, reversing a previous encoding operation\nthat was applied to reduce data rate for transmission or recording.\u201d (Poynton 2012,\n612)<\/pre>\n\n\n\n
    Transcoding: \u201cVarious methods of\nrecording a compressed bitstream, or decompressing then recompressing.\u201d\n(Poynton 2012, 661)<\/pre>\n\n\n\n
    It\nwas lead developer, Dave Rice, who had the critical foresight to align QCTools\nwith this much larger, well-established effort. A contrarian in the sense that\nhe brings a technical understanding to conversations and debates that\nstudiously avoid technical specifics, preferring to remain surface-level, Rice\nimmediately recognized that the sustainability and growth of the QCTools\nproject would depend in large part upon our ability to reach outside of our\ncircle, finding compatriots in communities other than our own.<\/p>\n\n\n\n
    Though\nit emerged out of the world audiovisual preservation, QCTools is not exclusive,\nor exclusionary, and can notably serve the needs of anyone working with digital\nvideo. This inclusiveness speaks to the long-term prospects of QCTools, and one\nof the signature achievements of the project was the incorporation of a\nQCTools-designed filter set, signalstats<\/em>(http:\/\/ffmpeg.org\/ffmpeg-filters.html#signalstats),\ninto the release of FFmpeg 2.3. By complementing the core technical team\n(J\u00e9r\u00f4me Martinez, Devon Landes, Ashley Blewer, Mark Heath, and Erik Piil) with\nan FFmpeg libavfilter specialist (Cl\u00e9ment B\u0153sch), we were able to optimize the\nsignalstats filter set, ensuring that a broad base of users would be able to\ntake advantage of QCTools-style reports and features directly through FFmpeg\u2019s\ncommand line interface.<\/p>\n\n\n\n
    This\ngive-and-take is typical of free and open source software development, and a\ncloser look at the licenses underlying QCTools2<\/sup> reveals a true\nhodge-podge, one that reflects the diversity of the free and open source\nsoftware movements themselves:<\/p>\n\n\n\n
    -QCTools is licensed under a GPLv3 license\u00a0 
    -QCTools GUI and FFmpeg statistics filter are licensed under a the 3-Clause BSD license\u00a0 
    -Libraries from the FFmpeg project are licensed under a GPLv3 license
    -The QT GUI Toolkit is licensed under a GPLv2.1 license 
    -The QWT Library is licensed under a LGPL license 
    -Tiny XML-2 is licensed under a zlib license <\/p>\n\n\n\n
    Rather than review the well-trodden, overhyped ground of frenzied\nargument and flame wars that has characterized the relationship between the\nFree Software Foundation (FSF) and the Open Source Initiative (OSI), it is more\nproductive to see these movements as partners in practices, and to consider how\nthese practices have begun infiltrating the audiovisual preservation community\n(Kelty 2008, 112). The core of both movements is software licensing that\ninsists upon the following:<\/p>\n\n\n\n
    1. Source code must be distributed with the software\n     or otherwise made available for no more than the cost of distribution;<\/li>
    2. Anyone may distribute the software for free,\n     without royalties or licensing fees to the author; and<\/li>
    3. Anyone may modify or derive other software from\n     it, and then distribute the modified software under the same terms (Weber 2004,\n     5).<\/li><\/ol>\n\n\n\n
      The singular genius of the free and open source software movements\nwas to invert a copyright system that had become hell-bent on locking up\nculture, tipping too far in the direction of protecting intellectual property\n(Boyle 2008, 9). In a paradoxical way, the\nexpansive force of copyright stimulated its own counterforce, giving rise to\nnew ways of conceptualizing intellectual property and new social practices\nbased upon the belief that knowledge should always be unfettered, and freely\ndistributed. <\/p>\n\n\n\n
      This radical reshaping of the politics of information would\nultimately ripple outward, proving the power and simple effectiveness of\n\u201chorizontal, informal cooperation\u201d (Streeter 2011, 186). In both its creation\nand execution, QCTools is vivid evidence that the preservation community has\ngained more from the free and open source software movements than merely tools\nand a means of distributing them.<\/p>\n\n\n\n
      THE SHIFT TOWARD ADVANCED VISUALIZATION FEATURES<\/h2>\n\n\n\n
      As\noriginally conceived, QCTools was a statistical analysis engine, offering\ngraphs and numbers that would allow users to collect and maintain quality\ncontrol data in standardized ways. However, over a series of cross-country\nSkype video sessions, Rice and BAVC\u2019s then-Director of Preservation, Moriah\nUlinskas, began to weigh the benefits and compromises that would be associated\nwith incorporating enhanced visualization features into QCTools. An educator at\nheart, Ulinskas understood that QCTools had the potential to intimidate\nnon-specialists; to counteract this possibility, she believed the software had\nto evolve, taking on a more visual nature. Though it was difficult to alter\ncourse (relying more heavily upon FFmpeg\u2019s application programming interface\n(API) led to mini-roadblocks, such as reworking QCTools\u2019 original source code,\nand having to wait for FFmpeg improvements in order to proceed), all involved\nrecognized that a preview window environment held the key to allowing users to\nbetter explore and understand digital video errors and anomalies.<\/p>\n\n\n\n
      If\nthe first of QCTools\u2019 three core analytical components offers an overview of\nthe audiovisual essence of a digital video file, breaking it down into its\nconstituent parts, the second\u2014a playback window for manual spot checking and\nin-depth analysis\u2014offers the possibility of field-level, side-by-side visual\ncomparisons. Taking as its launching pad traditional analog measurement devices\n(video monitor, waveform monitor, and vectorscope), this playback window lets\nusers drill down deeper into problems first identified by the graphs.<\/p>\n\n\n\n
      Double-clicking on any of the frame-level thumbnail images that line the bottom of the screen in the graph mode of QCTools launches the playback window, which offers two viewing windows that can be set to different combinations of filters. This split-screen view defaults to Normal on the left, a simple presentation of the video signal as QCTools interprets it, without any special effects or filters added, and Vectorscope on the right, a digital representation of the analog oscilloscope used to monitor the chrominance of a video signal (fig.5).<\/p>\n\n\n\n
      \"\"
      Fig. 5. The QCTools Playback Window, \u201cNormal\u201d view of a color bar pattern on the left; \u201cWaveform Monitor\u201d on the right<\/figcaption><\/figure>\n\n\n\n
      Gaining the ability to see a video file as QCTools\nsees it is an illuminating experience that can complement, reinforce, or\npossibly even challenge the assumptions of a human being. Not\nonly does the playback window encourage users to slow down, taking the time to examine\nerrors and anomalies in different fashions, but it also offers views that are\nsimply beyond human perception. The best example of this is the field-split\nfilter, which separates the interleaved fields of the video frame, potentially\nisolating errors to a single field. <\/p>\n\n\n\n
      In the example below, the source of a compromised video signal can be traced back to one of the video heads that determine a videotape recorder\u2019s (VTR) ability to recreate the video signal.3<\/sup> In this case, a single video head has either become clogged with loose oxide, or is damaged beyond cleaning (fig. 6). <\/p>\n\n\n\n
      \"\"
      Fig. 6. The QCTools Playback Window, \u201cField Split\u201d on the left, \u201cNormal\u201d view on the right<\/figcaption><\/figure>\n\n\n\n
      This\nnewfound sight lifts a veil, and opens up a wealth of restorative\npossibilities: what if QCTools could be used to remove these split-second\nerrors and anomalies, improving the condition of the video signal in cases\nwhere an alternate transfer might not be possible or beneficial? While this\nmight be wading into ethically murky waters, again, what is special about\nQCTools is that it sparks new ideas and critical thought that could shape the\nfuture of audiovisual preservation.<\/p>\n\n\n\n
      The\nField-Split and Vectorscope filters are just the beginning of the QCTools\nanalytical playback environment. By harnessing FFmpeg\u2019s libavfilter library,\nQCTools allows users to mix-and-match from a variety of other filters (fig.7).\nThese include: <\/p>\n\n\n\n
      • Histogram- shows the frequency of occurrence      of the YUV or RGB channels<\/li>
      • Waveform- plots the brightness of the video      signal, with color-coded demarcations for \u201clegal limits\u201d or \u201cbroadcast      range\u201d <\/li>
      • Line Select- allows users to select one      line of video to display as a waveform<\/li>
      • Extract Planes- removes the chroma data      from the video, presenting something akin to histogram goggles<\/li>
      • Bit Plane- allows users to see the      underlying structural patterns of YUV encoding methods <\/li>
      • Value\/Saturation Highlight- allows users to      specify ranges of YUV values, highlighting pixels that fall within or      outside these zones <\/li>
      • Chroma Adjust- allows users to adjust the      hue and saturation levels of a video signal <\/li>
      • Color Matrix- allows users to play back the      video in various color spaces, visualizing the subtle yet significant      differences between BT.601, BT. 709, SMPTE240M, and FCC <\/li>
      • Field Difference presents deviations      between fields of video<\/li>
      • Temporal Difference- presents deviations      between frames of video<\/li>
      • Broadcast Range Pixels\/Broadcast Illegal      Focus- offer visualizations of pixels within\/outside broadcast range<\/li>
      • Vertical Line Repetition- highlights repetitive      lines of video data<\/li>
      • Frame Tile- offers a \u201ctiled\u201d mosaic of      successive frames<\/li>
      • Zoom- allows users to zoom to a particular      point in an image on the X and Y coordinates<\/li>
      • <\/li><\/ul>\n\n\n\n
        \"\"
        Fig. 7. The QCTools Playback Window, \u201cNormal\u201d view of a color-imbalanced video on the left; \u201cChroma Adjust\u201d view on the right, with moderate chroma desaturation<\/figcaption><\/figure>\n\n\n\n
        Though focused on in-the-moment analysis, the playback window can also serve a documentation and communication function. As Peter Oleksik, Assistant Media Conservator at The Museum of Modern Art (MoMA), describes: <\/p>\n\n\n\n
        The filtering capabilities of the\nsoftware are where media conservation sees the greatest benefit to our current\ndocumentation process. Using the various filters in QCTools that allow for\nmultiple views of a video signal, errors or aberrations in the video can be\naccurately reported in our conservation reports alongside screen shots of the\nactual errors. In addition, these filters allow one to zero in on the specifics\nof an error, which will allow better communication with vendors to pinpoint and\ncorrect poor transfers. (2014)<\/p>\n\n\n\n
        The\nthird of QCTools\u2019 three core analytical components, the List View<\/em>, complements the statistical graphs and visualization\nfilters by offering technical metadata and summarization statistics (fig. 8).\nIn this mode, users can watch as QCTools processes multiple videos, tracking\nboth the percentage of completion and the accumulation of potentially\nproblematic statistical averages. The technical metadata is similar to an\nabbreviated FFprobe (https:\/\/www.ffmpeg.org\/ffprobe.html) or Mediainfo (https:\/\/mediaarea.net\/en\/MediaInfo)\ntest, while the summarization statistics, introduced in QCTools 0.6.0, offer\nthe following: <\/p>\n\n\n\n
        • Y Average<\/li>
        • Y Range: average of YHIGH-YLOW<\/li>
        • U Average<\/li>
        • V Average<\/li>
        • TOUT (Temporal Outlier) Average<\/li>
        • TOUT (Temporal Outlier) Count<\/li>
        • SAT (Saturation) Broadcast<\/li>
        • SAT \n     (Saturation) Illegal<\/li>
        • BRNG (Broadcast Range) Average<\/li>
        • BRNG (Broadcast Range) Count<\/li>
        • MSEfY (Mean Square Error per Field Y)<\/li><\/ul>\n\n\n\n
          \"\"
          Fig. 8. QCTools in \u201cList View\u201d <\/figcaption><\/figure>\n\n\n\n
          While the primary purpose of QCTools is to display information through graphs, visual side-by-sides, and statistics, the long-term retention of quality control data was also a critical component of the project. The 0.5.0 release of QCTools marked the addition of the \u201cQCTools Document,\u201d a self-descriptive XML document designed to store frame-level quality control metadata (compressed by the free software application gzip (http:\/\/en.wikipedia.org\/wiki\/Gzip), formatted according to FFmpeg\u2019s FFprobe XML schema (http:\/\/ffmpeg.org\/schema\/ffprobe.xsd)).<\/p>\n\n\n\n
          The questions most frequently asked of QCTools\u2014and the\nquestions most difficult to answer\u2014are typically some version of the following:\n\u201cWhat does normal look like?\u201d \u201cWhat does aberrant look like?\u201d \u201cCan QCTools tell\nme when to go back and re-transfer a tape?\u201d Though the answer to the last\nquestion is undoubtedly yes, there is an important qualification to make: as\nwith Nicholas Carr\u2019s description of predictive algorithms, QCTools is\n\u201cindifferent to underlying causes or root phenomena;\u201d false positives come with\nthe territory (2014). Is that tape damage, sync loss, or has the\ncamera panned to a light-filled window? To QCTools, all three phenomena present\nthemselves in the same fashion: spikes of luma, and pixels unlike their\nneighbors (Temporal Outliers) that might veer dangerously close to upper edges\nof \u201clegality\u201d (Broadcast Range). In its current state, QCTools indicates, it\ndoes not diagnose, and though it has made us faster and smarter, the\ncontingency of circumstance will always prevail. While future development will\ncertainly make QCTools itself smarter, we would do well to pay attention to\nskills we are gaining, as well as <\/em>the\nskills we are losing or compromising, as we take audiovisual preservation in\nmore automated, scalable directions. <\/p>\n\n\n\n
          TESTING, DISSEMINATION, COMMUNITY-BUILDING <\/h2>\n\n\n\n
          As\nwith the AVAA, the lifeblood of QCTools has been, and will continue to be,\ncommunity involvement and participation. From the beginning, QCTools was\ndesigned to evolve in tandem with the ever-changing needs and requirements of\npreservationists working with digital video materials. While there was never an\nexpectation that novice users would be able to pick up keyboards and begin\ninstantly contributing lines of computer code, we did strive to level the\nplaying field by encouraging users to help us identify problems to-be-fixed and\ndirections for future development.<\/p>\n\n\n\n
          The smartest decision made to solicit more active community engagement was to move QCTools to the web-based Git-repository Github (https:\/\/github.com\/bavc\/qctools). With over nine million registered users, and twenty million regular monthly visitors, Github, founded in 2008, operates as a centralized marketplace for idea sharing in free and open source software development (Metz 2015). Much more than a simple repository for the QCTools source code, Github proved to be an immensely valuable project management tool, allowing us to more easily and efficiently track: (1) the history of the development process, and changes made in successive releases; (2) any problems with the software, or bugs; and (3) user-desired features or enhancements. Github was also, critically, a place to connect QCTools to other free and open source projects, and a place to find unlikely collaborators (fig. 9).<\/p>\n\n\n\n
          \"\"
          Fig. 9. The QCTools Github \u201cIssue Tracker,\u201d with user-identified \u201cbugs\u201d and \u201cenhancements.\u201d<\/figcaption><\/figure>\n\n\n\n
          In\norder to gain in-depth feedback from QCTools\u2019 intended audience, BAVC hosted a\ntwo-day workshop at its headquarters in San Francisco in March 2014. The aim\nwas to present the latest version of QCTools (at the time, version 0.4) to a\nrange of archivists, conservators, and technicians, all specialists in the preservation\nof analog video. By engaging this group of users in training, testing, and\ndiscussion, we were able to set goals for the remainder of the project.<\/p>\n\n\n\n
          CRISIS AND RESPONSE: THE FUTURE OF QCTOOLS <\/h2>\n\n\n\n
          Imagine free quality control software that allows users\nto digitize their video materials to chosen specifications, with real-time\nanalytics, visualization features, and frame level checksums. Imagine free\nquality control software that accommodates large-scale workflows, increasing\nefficiency and reducing human error. Imagine free quality control software that\ncloses the gap between the digital video novice and the digital video expert,\nelevating the quality of work being performed at a range of cultural heritage\ninstitutions.<\/p>\n\n\n\n
          The QCTools project is far closer to reaching these\ngoals than one might expect; it is poised, ready to respond to the increased\ndemands of audiovisual preservation.<\/p>\n\n\n\n
          While\naudiovisual materials of all kinds make up an ever-increasing part of the\narchival and cultural record, a false sense of dormancy masks an inescapable\ninevitability (of degradation, obsolescence, and loss) in many contemporary\naudiovisual archives. Indiana University Bloomington, an exemplar in the realm\nof campus-wide commitment to the cause of audiovisual preservation, offered a\ndire forecast in Meeting the Challenge of Media Preservation: Strategies and\nSolutions<\/em>, a 2011 report detailing its multi-year effort to identify and\npreserve over 560,000 endangered audio, video, and film assets:<\/p>\n\n\n\n
          Media archives have reached a\ncritical point in their history marked by the simultaneous deterioration of\nunique original materials, the development of powerful new digital\ntechnologies, and the consequent decline of analog formats and media. Rapidly\nadvancing obsolescence\u2014of playback machines, spare parts, technical expertise,\ntools, and formats\u2014combined with degradation of carriers multiplied by large\nnumbers of archival recordings have resulted in a necessary race against time<\/em> to preserve\nimportant holdings\u2026It is now widely thought that a fifteen- to twenty-year\nwindow of opportunity exists\u2014even less for some formats\u2014before the combination\nof degradation, obsolescence, and large numbers makes it either impossible or prohibitively expensive<\/em>\nto do this work. (24; italics added)<\/p>\n\n\n\n
          Though\none might object to the specificity of these predictions, or perhaps the\nend-of-times, doomsday, apocalyptic sentiment, IU\u2019s Mike Casey would likely\npush back, pointing out two indisputable facts: (1) tapes are<\/em> degrading,\nand \u201cthere is no guarantee that future playback will achieve the same fidelity\nand accuracy as playback today;\u201d and (2) \u201cthe work ahead to digitally preserve\nmedia recordings is massive, and preservation strategies must scale to\nincorporate very large numbers\u201d (2015, 15). <\/p>\n\n\n\n
          For institutions that are fighting for every preservation\ndollar, the challenges of scaling up can seem insurmountable. With continued support, QCTools will evolve to meet\nthese demands, offering in-depth reporting that will democratize access to the\ntools of large-scale digitization. The future of QCTools will include batch\nprocessing, user-defined thresholds for quality, and various visualizations\nthat allow for the easy identification of suspicious files. BAVC will also\ncontinue pursuing QCTools capture functionality, work that began as part of the\nKnight Foundation\u2019s Prototype Fund in the fall of 2014. The shift from Apple\u2019s\nFinal Cut 7 to Final Cut X was a rude awakening for the preservation community,\na reminder that tape-based workflows have become as obsolete as the tapes\nthemselves. QCTools can step in and fill this gap, bringing control to an\nearlier stage of the digitization process.<\/p>\n\n\n\n
          Projects\nsuch as QCTools emerged out of a sense of shared duty and responsibility, a\nrecognition that the quality of the digital files we will be caring for over\nthe long-term\u2014until we pass that baton on to future generations\u2014will largely be\ndetermined by our actions in this arena. Will we step up to make the twin\npillars of quality and scale attainable, or will we allow them to remain out of\nreach, the domain of the fortunate few? QCTools provides an important vehicle\nenabling us to ensure the quality of the digital files being created to\npreserve our video and audio heritage. At the same time, it also provides the\nability for many more people to engage effectively in this essential and\ncritically time-sensitive preservation effort.<\/p>\n\n\n\n
          NOTES<\/h2>\n\n\n\n
          1. QCTools is certainly not\nalone in this regard. Though uniquely focused on quality control and digital\nvideo, QCTools is but one of many open source tools that have been actively\nembraced by archivists and preservationists. For more, see Kara Van Malssen\u2019s\n\u201cTools for Smaller Budgets\u201d in AV Insider 2: Preservation in Times of\nPrecarity<\/em> (2012).<\/p>\n\n\n\n
          2. In the interest of conceptual\nclarity, the free and open source software movements have been treated as a\nsingular entity, despite important differences between the two groups and\ninternal squabbles within each group. Most important is what they share: unique\nlicensing practices that subversively invert traditional notions of\nintellectual property. Though an oversimplification, the Free Software\nFoundation (FSF), founded in 1984 by Richard Stallman, treats software as a\ndeeply political, libertarian concern. For the FSF, the issue is one of liberty\nand freedom of expression, even coming with its own oft-spouted clich\u00e9: \u201cFree\nas in speech, not as in beer\u201d (GNU.org<\/em>). On the other end of the ideological\nspectrum is the Open Source Initiative (OSI), founded in 1998 by Eric Raymond\nand Bruce Perens. Emerging at the same time as the public release of the\nNetscape Navigator search engine source code, the OSI approach, intentionally\ncouched in less overtly political terms, is focused on economics, encouraging\n\u201ccommons-based peer production\u201d (Berry 2008).<\/p>\n\n\n\n
          3. For all tape-based magnetic media, the\ncontent (signal) is captured in electro-magnetic particles that compose a\ncomplex binder matrix affixed to the tape base. Though it varies by video\nformat, playback typically entails a set of electro-magnetic heads rotating at\nhigh speed, \u201creading\u201d the signal as the tape passes over them.\nhttp:\/\/avaa.bavc.org\/artifactatlas\/index.php\/Video_Head_Clog<\/p>\n\n\n\n
          REFERENCES<\/h2>\n\n\n\n
          Berry, D. M.\n2008. Copy, Rip, Burn: The Politics of\nCopyleft and Open Source<\/em>.  London:\nPluto Press.<\/p>\n\n\n\n
          Boyle, J. 2008. The Public Domain: Enclosing the Commons of\nthe Mind<\/em>.  New Haven, Connecticut:\nYale University Press.<\/p>\n\n\n\n
          Carr, N. 2014. The Glass Cage: Automation and Us<\/em>. New\nYork: W.W. Norton & Company.<\/p>\n\n\n\n
          Casey, M. 2015.\nWhy Media Preservation Can’t Wait: The Gathering Storm. The<\/em> International Association\nof Sound and Audiovisual Archives (IASA) Journal<\/em> 44: 14-22.<\/p>\n\n\n\n
          Indiana\nUniversity Bloomington Media Preservation Initiative Task Force. 2014. Meeting\nthe Challenge of Media Preservation: Strategies and Solutions. http:\/\/www.indiana.edu\/~medpres\/documents\/iu_mpi_report_public.pdf\n(accessed 09\/12\/15).<\/p>\n\n\n\n
          Jack, K. 2007. Video Demystified: A Handbook for the\nDigital Engineer<\/em>. Boston: Newnes\/Elsevier.<\/p>\n\n\n\n
          Kelty, C. M.\n2008. Two Bits: The Cultural Significance\nof Free Software<\/em>. Durham: Duke University Press.<\/p>\n\n\n\n
          Laurenson, P.\n2015. Personal Communication.\nhttps:\/\/github.com\/MediaArea\/MediaConch\/blob\/master\/LettersOfSupport\/TateLetterOfSupport.pdf\n(accessed 09\/12\/15).<\/p>\n\n\n\n
          Metz,\nC. 2015. How Github Conquered Google, Microsoft, and Everyone Else. Wired<\/em>. http:\/\/www.wired.com\/2015\/03\/github-conquered-google-microsoft-everyone-else\/\n(accessed 09\/12\/15). <\/p>\n\n\n\n
          Oleksik, P. 2014. Retreat Report. Personal\nCommunication to Devon Landes.<\/p>\n\n\n\n
          Piil, Erik. 2014. Retreat Report. Personal\nCommunication to Devon Landes.<\/p>\n\n\n\n
          Poynton, C. 1996. A\nTechnical Introduction to Digital Video<\/em>. New York: J. Wiley.<\/p>\n\n\n\n
          Poynton, C. 2012. Digital\nVideo and HD: Algorithms and Interfaces<\/em>. New York: Morgan Kaufman.<\/p>\n\n\n\n
          Sorenson, L.\n2013. Capture Software Study for the Preservation of Analog Videotape. The Electronic Media Review <\/em>(2):\n143-156.<\/p>\n\n\n\n
          Streeter, T.\n2011. The Net Effect: Romanticism,\nCapitalism, and the Internet<\/em>.  New\nYork: New York University Press.<\/p>\n\n\n\n
          Van Malssen, K.\n2012. Tools for Smaller Budgets. AV\nInsider 2: Preservation in Times of Precarity<\/em>: 13-21.<\/p>\n\n\n\n
          Weber, S. 2004. The Success of Open Source<\/em>.  Boston: Harvard University Press.<\/p>\n\n\n\n
          Weise, M. and D. Weynand. 2007. How Video Works: From Analog to High Definition<\/em>. Boston: Focal\nPress.<\/p>\n\n\n\n
          About the A\/V\nArtifact Atlas, A\/V Artifact Atlas. https:\/\/bavc.github.io\/avaa\/about.html (accessed\n09\/12\/15).<\/p>\n\n\n\n
          Sony. 2014. Sony\nAnnounces Sales Discontinuation of 1\/2 Inch VTRs and Camcorders. http:\/\/www.sony.co.uk\/pro\/article\/broadcast-products-vtr-announcement<\/a>;\nhttps:\/\/www.sony.com.hk\/notice\/20141008_e.pdf<\/a>\n(accessed 09\/12\/15).<\/p>\n\n\n\n
          CONTACT\nINFORMATION<\/strong><\/h2>\n\n\n\n
          Benjamin Turkus
          Bay Area Video Coalition
          2727 Mariposa St.
          San Francisco, CA 94110
          (415) 558-2158
          benturkus@bavc.org
          @BAVCPreserve<\/p>\n","protected":false},"excerpt":{"rendered":"
          Benjamin TurkusThe Electronic Media Review, Volume Four: 2015-2016\u00a0 ABSTRACT From 2013-2015, members of the Bay Area Video Coalition\u2019s Preservation Department worked closely with a technical team led by Dave Rice on a National Endowment for the Humanities-funded research and development project. The result of this work was QCTools, free and open source quality control software … Continue reading “Drop Video File(s) Here: The Emergence of Free Quality Control Tools for Video Preservation”<\/span><\/a><\/p>\n","protected":false},"author":37,"featured_media":0,"parent":616,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_exactmetrics_skip_tracking":false,"footnotes":""},"class_list":["post-866","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/resources.culturalheritage.org\/emg-review\/wp-json\/wp\/v2\/pages\/866","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/resources.culturalheritage.org\/emg-review\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/resources.culturalheritage.org\/emg-review\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/emg-review\/wp-json\/wp\/v2\/users\/37"}],"replies":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/emg-review\/wp-json\/wp\/v2\/comments?post=866"}],"version-history":[{"count":0,"href":"https:\/\/resources.culturalheritage.org\/emg-review\/wp-json\/wp\/v2\/pages\/866\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/emg-review\/wp-json\/wp\/v2\/pages\/616"}],"wp:attachment":[{"href":"https:\/\/resources.culturalheritage.org\/emg-review\/wp-json\/wp\/v2\/media?parent=866"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}