QCTools

Introduction

This Activity involves downloading and installing a software tool, QCTools, to your computer. If you do not wish to install a software program, please scroll to the bottom of the Activity description to find an alternative Activity to follow. Either Activity works!

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In this activity you will be downloading, installing and using QCTools, a program that provides a way to analyze audio/visual transfer “artifacts”.

Setup steps

• Install the QCTools program (GUI): https://bavc.org/programs/preservation/preservation-tools/ target="_blank"
• Download the video clip in the A/V Preservation shared folder locally. Note: this video was transcoded from a VHS tape.
• Open the Moving Image Preservation of Puget Sound (MIPoPS) QCTools Manual.
• Open the terminal/command line and QCTools in another.

Activity steps

Analyze the video file in QCTools using graphs

• Open the QCTools program and drag/drop the video file you downloaded. This may take a few seconds to import.

• Play the file back by pressing your Space bar.

• Click the Filters layout button.

• Read Ashley Blewer’s slides on filters starting from page #14 to 31 (https://training.ashleyblewer.com/presentations/qctools.html#14) (use your right arrow key to navigate). Keep this information handy as you apply more filters to the video file.

• On the left-hand side of the Filters layout, click the filters drop-down and select “Broadcast Range Pixels”. Play the video back and notice what the filter does to the video.

• Apply other filters to your video, such as the Histogram, Oscilloscope, Vectorscope and Waveform (hint: you can check off multiple filters and view them side-by-side, including the original video by selecting “Normal” in the drop-down).

• Notice how the clip has some issues, especially to do with tracking near the beginning.

Look up a transfer artifact: tracking

• Open the A/V Artifact Atlas (http://www.avartifactatlas.com/tags.html) and click “Browse by format”. Select VHS.

• Click and read through the page about tracking errors, and how to use the QCTools graphs to detect tracking issues (Click the Setup Filters button in the top-left of the graphs screen to make sure the appropriate graphs are showing).

• Apply other filters and replay the video. Pay special attention to the parts of the clip with tracking issues. What do the other filters show you when tracking issues occur?

Review the file’s metadata

• In QCTools, click the File list button to open up a table of data results for your file.

• Open the QCTools cheat sheet: https://github.com/bavc/qctools-documentation/blob/master/qctools/QCToolsWorkshopCheatSheet.pdf

• Review the results. Note whether your QCTools report counts were way under, over or average, as far as the QCTools cheat sheet indicates are ideal limits/ranges for certain aspects of the video signal.

Activity Steps - Alternative

If you prefer, you can perform an alternative activity that does not involve installing QCTools.

• Download the video clip in the A/V Preservation shared folder locally. Note: this video was transcoded from a VHS tape.
• Using a video player, watch the video. You will notice immediately that there are some issues with the tape. Note what you observe.
• Open the A/V Artifact Atlas (http://www.avartifactatlas.com/tags.html) and click “Browse by Formats”. Select VHS.
• In the list of artifacts that appear, try and find at least 2 artifacts listed that appear in the video. Make note of each.
• Next, visit the XFR Collective collection on the Internet Archive. Click around and try and find a digital video transferred from VHS that contains at least one additional artifact. Make note of that as well.

Prepare to share your findings Next class, we will speak together as a group about your experience either using QCTools and/or the A/V Artifact Atlas. In Brightspace, please submit a brief reflection on your experience with this Activity.