QCTools (Quality Control Tools for Video Preservation) is a software tool that helps users analyze and understand their digitized video files through use of audiovisual analytics and filtering to help users detect corruptions or compromises in the results of analog video digitization. The goal of the project is to cut down the time it takes to perform high-quality video preservation and direct time towards preservation issues that are solvable, for example identifying tapes that would benefit from a second transfer, saving not only the precious time of preservationists and institutional resources, but giving collections a necessary advantage in the bigger race against time to preserve their significant cultural artifacts. QCTools incorporates archival standards and best practices for reformatting and capturing metadata that enables the long-term preservation and of and access to the original artifact, the digital object, and the associated catalog record.
Potential users of the quality control tools include specialists and non-specialists:
Moving image archives that collect digital video may receive digitized content with undiagnosed playback problems and errors. QCTools can help archivists understand what is wrong with certain files and then take steps to correct or explain these errors. Archivists need to be able to trust that the digitized files are up to a certain level of quality, and have quantifiable data to prove it. QCTools allows archivists to not be required to overly rely on visual queues and guesswork for the acknowledgment of problematic video quality.
QCTools will benefit not only moving image collections but also traditional archives that include video collections that may fall into neglect. The rapid rate of deterioration makes the preservation of magnetic media-based archival elements of foremost import when deciding on preservation strategies; however, because the knowledge base is so specialized, many archivists lack a way to evaluate digitization measures. QCTools will make it easier and more approachable for these archives to preserve and maintain digitized moving image materials.
Users working in this industry can use QCTools to perform quality checks on incoming media, as well as existing stored media. Work on large video collections can be done in-house and via spot-checking, instead of outsourcing much of the material. Furthermore, quality of video can be assured suitable for broadcast environments.
For example, if a production company is working with editing footage, it is better to know early on if there is a problem with any of the video files, so that they can be retransferred or discarded from use.
Preservation technicians and moving image digitization specialists need to maintain a high level of quality for all materials they are processing. QCTools assists with these projects. Instead of having to do a full visual check of video files to monitor for errors, technicians can use QCTools to identify problem areas for more efficient spot-checking. When integrated into a digitization workflow, QCTools can reduce time and increase the discovery of errors.
For example, using QCTools regularly to verify audiovisual artifacts caused by VHS Head Switching Noise or a U-Matic machine's Video Head Clog can prevent the need for additional transfers due to a machine that needs cleaning.
Artists digitizing their work, or having their work digitized for them, may not have the background knowledge necessary to understand why their videos look the way they do. QCTools can help artists interpret these errors so the necessary steps can be taken to keep digitized video looking as close to as they originally did.
For example, a performance artist may have stored her performances on VHS tapes in a non-ideal location, resulting in some damage to the magnetic tape's structure. She is working with a friend to digitize the tapes, but they keep noticing errors. However, not expecting problems with the tapes, they have no budget for paying an expert to explain and fix the problem. Using QCTools, the artist can assess the collection, pinpoint errors, understand what the problems are, and come up with solutions without requiring outsourcing of all of the tapes.
Historians and collection managers that do not usually work with audiovisual historical documents may not know how to proceed with preserving video formats, and additionally not have the standard tools that may be found in archives equipped to handle audiovisual materials. QCTools can work in lieu of access to expensive proprietary software
For example, a small state historical society may have a collection of tapes, but because they are a small staff and cannot afford to outsource digitization, the tapes have been neglected. If the staff is able to get the equipment to digitize the tapes in-house, QCTools can help them diagnose issues and make the digitization process less intimidating while ensuring high quality digital files.
Initial development within this project will span two years (2013 and 2014). The first part will focus on the development of tools for use in the repository workflow and archival digitization environments. The central piece of the tool set is the development of a data format to document and express quality control, analytical, and visual qualitative data across the frames of a digital video, QCTools report. The data format will be designed to be transparent, understandable, plottable, flexible, and efficient to store analytical data on a frame-by-frame basis. Alongside the development of the data format will be the design, testing, and release of an open source, multi-platform tool to generate this report from referenced digital video files as well as tools to analyze and visualize the collected data according to locally defined priorities and thresholds.
The second part of the development will focus on designing a software application to simplify generation of QCTools reports for batches of digitized video. The software applications will enable the archivist to depict the contents of the QCTools report as graphed data, revealing trends, averages, and extremes of the signals stored within the digitized video. The applications can also be used to set thresholds of tolerance for the extent to which the reported digitized video signal can veer from expected trends of best practices (such as video out of a legal range, extended drop-outs, changes in). The QCTools will also facilitate sorting of collections of digitized video according to the presence of digitization issues to enable the archivist to focus quality control and assessment of video on the digitized content most deserving of attention.
An ongoing focus of the project will be the deployment of the full toolset and dissemination of findings and training materials to archivists, media and preservation specialists, as well as all areas of the humanities where access to reliable information on digital preservation standards and practices is not easily accessible.
QCTools accepts a variety of video formats, including *.avi, *.mkv, *.mov, and *.mp4, as well as a diverse selection of codecs. Uncompressed 8-bit formats are ideal for the most accurate interpretation of the video. QCTools relies on FFmpeg's libavcodec and libformat libraries to analyze and playback video which allows QCTools to support a wide variety of digital audiovisual formats.
QCTools currently a frame-by-frame analysis in CSV format. These files can be integrated into your preservation metadata. Later versions of QCTools will support more comprehensive reporting.
QCTools is licensed under a Free BSD License. Please see the License tab for more information about this license and what it means.
QCTools does not support audio at this time, but will in future releases.
You may be able to find the answer in the A/V Artifact Atlas, which is closely associated with QCTools. The AV Artifact Atlas is for use in the identification and definition of the technical issues and anomalies that can afflict audio and video signals.
The YUV and Diffs (Y values, U values, V values, YDiff, YDiffX) are beneficial to all video formats. The TOUT (Temporal Outliers) filter is targeted to detecting white noise such as white speckle pattern you may find in damaged VHS tape. The HEAD (Head Switching) filter is meant to quantify visible playback issues at the bottom of analog frames of video caused by head switching.
YUV are channels that hold data about video. The Y channel carries the luma. This is the information on the brightness of a video. Mostly white images will have a high number and mostly dark images will have a low number. The U and V channels both carry information about the chrominance, or the color of the video. The range in these fields while change as the colors of the image changes.