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DV Rescue:

Innovations in the Preservation

of Digital Videotape

Libby Hopfauf & Dave Rice

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DV Rescue

presentation outline

DV: Overview & Significance

Lack of Available Tools

DVRescue: Project Scope

Tools for All Skill Levels

Documentation for All Skill Levels

Next steps

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DV: Overview & Significance

DAVE

Hi everyone, I'm Dave Rice and my pronouns are he/him/his

This project focuses exclusively on a particular family of tapes: DV tapes. DV tapes can be played like videotapes, however we can also just copy the data from a tape player to a file, so the preservation opportunities are different than they are for other videotapes. Usually we play back a videotape and record a digital file of its presentation, but this project is about developing workflows to approach DV tape preservation as a controlled data migration from tape to file rather than audiovisual digitization. An analogy here would be how with Audio CDs we generally rip the data from the CD to a file rather than record the sound the CD makes when its played, this project is about making something like an CD ripper but for DV tapes.

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DV Capture & Ripping Software

Current (not ideal)

AVHSCap
Adobe Premiere Pro
iMovie
QuickTime

Past

Live Capture Plus
dvgrab

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Development - FFmpeg's libavdevice & avfoundation

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Grant Funding: NEH

LIBBY

In 2018, MIPoPS and RiceCapades received a Research and Development grant from the National Endowment for the Humanities to fund the collaborative project, DV Rescue. Which is why this slide features the NEH logo and a celebration, noise-maker emoji. The project is working to develop procedures and tools that support migrating data from DV tapes into digital files suitable for long-term preservation. As we have laid out, this will fill an urgent need for DV tape transfer tools that can rescue content from at-risk digital videotape formats. The DV Rescue project will entail two years of work (which started in May 2019 and was originally set to conclude in April 2021, but due to COVID restrictions, will now run until October 2021). During this time we have been and will continue working to develop open source and freely available software, user research and testing, and create documentation to help define and perform comprehensive, automated, and easy-to-use data migration techniques.

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Participants

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Scope & Scale

LIBBY

At the beginning of the project, we took an initial survey of our participants to gather data to aid in the development process based on this sample groups specific needs. We collected information related to what formats were in their collections, what access they had to equipment for playback and transfer of DV tapes, what operating systems were currently part of their digitizing workflow and what types of training would be the most helpful so that we could tailor the documentation and tools accordingly. This slide features two graphs from our initial survey, showing the types of training the participants would find most beneficial and the current operating systems the organizations are using.

Initially this project was supposed to include a retreat after the first year in Seattle to gather feedback and provide hands-on training with the tools. Unfortunately due to COVID, we had to postpone until further notice. However, we have been able to adjust and provide several remote workshops for the participating institutions over the summer.

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DVRescue

DV Capture
DV Play
DV Merge
DV Analysis
DV Packager
DV Guidance

DAVE

So the components of our project plan are like this.

We want to develop cross-platform tools and workflows to support capturing data from DV tapes.

We want to create players to support viewing and inspecting the resulting data, to highlight errors and concealment that may have occurred because of tape damage or issues with the tape player.

We want to create an analyzer tool to review the datastream, discover how it was recorded, quantify and classify errors, and determine how to make use of metadata, captions, timecode, and other data within the resulting file.

We want to make a packaging tool we're making takes the resulting DV stream and packages it in Matroska or QuickTime to make the video more accessible, and to make use of DV data to add helpful things like chapters and subtitle tracks.

And lastly the guidance section of the project intends to inform those working to preserve DV tapes with the 'how': how to clean decks, repair tapes, and handle transfer issues.

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dvcapture with vrecord

Captures raw DV stream via FireWire input.

Creates metadata logs

Now featuring deck control!

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dvcapture

LIBBY

The main goal of DVRescue is to develop open source software to facilitate the most complete and accurate transfer of DV video from tapes to files, including video, audio, captioning, timecode, camera metadata, and preservation metadata. This dvcapture instructional video is an example of one of the training videos we are currently working on. Since we’re short on time, I won’t play the whole thing, but this is available currently on the MIPoPS blog. Once the voice over and captions are added, it will be integrated into the documentation website.

VOICEOVER:

To capture DV formats in vrecord, you will need to have your DV deck connected directly to your computer via FireWire input. Make sure your deck is in “Local” mode. At this time, vrecord is not equipped with tape control, so you will need to manually start and stop the tape just like with analog capture in vrecord.

To select the deck you would like to use, go into the configuration mode either by:

run vrecord -e
clicking on the “Edit Settings” button in the GUI (run vrecord -g)

Switch from the "Decklink" tab to the "DV" tab under “Input Options” at the top of the configuration window.
Select the name of the DV device you want to use from the list.
Specify the playback, sidecar, file naming, recording event and directory options as you normally would for vrecord. For details see Editing Settings
Click “OK” to save.
You can then run passthrough and record modes the same as you would with analog videotape. Please note that if the timecode does not start at the very beginning of the tape, the record mode viewer will not open until the timecode is detected (as soon as the counter starts moving on your deck, the viewer window should pop-up)

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dvplay

Plays back and visualizes the DV errors as a stack of images.

Running with the -x flag will produce JPEGs of frames containing artifacts with timecode marked

L

Another goal of dvrescue was to build a player to support visualization of uncorrected DV data, including categorizing DV transfer errors, illuminating when selective re-transfer may be most likely to offer improvements, and providing a method to easily distinguish authentic DV data, from error concealment techniques, and unconcealed damage. Dvplay is a function of dvrescue that allows users to run QC on their DV files in order to identify errors and artifacts. I won’t get too far into the weeds here, but Plays back and visualizes the DV errors as a stack of images. Running dvplay in another mode (with the -x flag) will scan the file for errors and produce JPEGs of frames containing artifacts with timecode marked for the user to examine and review for possible solutions or the need to recapture.

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dvplay -x

JPEG created in dvplay -x mode

Screenshot from QuickTime of same frame

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dvplay -x

Screenshot of same frame from Quicktime playback

dvplay -x JPEG of

problem frame

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dvpackager

Rewraps one DV stream into two or more MOV files.

Used for splitting DV files when the significant characteristics change.

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dvpackager

variable aspect ratio?

variable audio channel count?

variable interlacement settings?

variable sample rate?

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Audio Issues

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Reporting the Analysis as Graphs

Thanks @tomackroyd https://github.com/mipops/dvrescue/issues/34#issuecomment-667447850

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Reporting the Analysis as Graphs

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GUI

Transfer

-> Analysis

-> Package

-> Playback

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DV Guidance

training & education

Background/history of DV

DV formats guide

Training videos & documentation

Transfer station set-up instructions

Shopping lists

Deck guide

File care (post capture best practices)

Capturing best practices

Artifacts: identification & solutions

Glossary

Additional resources

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Shopping List

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Shopping List

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Set-up & Transfer Recommendations: Mac

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Set-up & Transfer Recommendations: Windows/Linux

LIBBY

With our equipment budget we were able to purchase a Windows set-up that Andrew Weaver has been testing. The whole set up was just under $250, which provides an exciting opportunity for small institutions where funding creates a huge barrier in their AV preservation efforts.

****SHOUTOUT TO ANDREW****

Dell Optiplex 7010 Business Desktop Computer (Intel Quad Core i5 up to 3.8GHz Processor), 8GB RAM, 500GB HDD, DVD, Windows 10 Professional

the main difference is that thunderbolt is a PITA on non-macs

and the multiple adapters don't work on linux

so basically it all is the same EXCEPT it is best to go through a dedicated DV card

(or I should say firewire card)

so basically replacing the adapters with a card is what ya gotta do, and other than that it's the same (and like I said, the card I have even comes with the right cable)

but needing the card kinda bones you for laptop applications

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Deck Guide

https://mipops.github.io/dvrescue/

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A/V Artifact Atlas

What is it?
What does it look like?
How can you check?
Can you fix it? If so, how?

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Example: Headclog

How can you fix it/how can you check?

You can fix a headclog by cleaning the deck you are using to transfer the tape manually or with a cleaning tape (depending on how you feel about that). If this doesn’t resolve the issue, your head may be damaged or the artifact might be missing information from the tape.

LIBBY

For example, this is an excerpt from an entry for a dv head clog, where we were able to use dvplay to identify the artifact, which informed our decision to clean the deck and recapture the tape, which you can see worked!

What it looks like and how to fix it.Typically, a head clog will appear as wide alternating lines of frozen video or an alternating pattern of color indicating a loss of read/write capability at the video head. Two head clogs cause loss of picture altogether or a freeze-frame of the last decodable frame.

For example, this is an excerpt from an entry for a dv head clog: What it looks like and how to fix it.

Typically, a head clog will appear as wide alternating lines of frozen video or an alternating pattern of color indicating a loss of read/write capability at the video head. Two head clogs cause loss of picture altogether or a freeze-frame of the last decodable frame.

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Additional Resources

DVRescue: h ttps://github.com/mipops/dvrescue

https://mipops.github.io/dvrescue/index.html

DV Capture (vrecord): https://github.com/amiaopensource/vrecord

MIPoPS website: https://www.mipops.org/dvrescue/

MediaArea daily builds: https://mediaarea.net/DVRescue

mipops.tumblr.com

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Questions?