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Digitizing video
Thomas May edited this page Sep 19, 2025
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Currently, the machines which can complete video digitization are the four Macs in the front of the primary lab (the "video lab"). There are a few things you need to make sure of before you digitize the tape (and this is, of course, after inspection and any necessary remediation).
- Power on all necessary equipment. This includes the surge protector mounted on the back of Rack B (the rack on the right side if you're facing them), the Time Base Correctors, the S-Video Switchers (if digitizing on Rack B), and the playback machine the item requires.
- On the machine you will be digitizing to, enter
vrecord -ein a new Terminal window to edit the vrecord settings before beginning the capture. - Most options in this window will stay the same. Pay attention to the following:
- Audio Input: This will be Analog or SDI Embedded Audio depending on the deck (navigate to format notes below).
- Audio Channel Mapping: Some formats may not have 1 Stereo Track (From Channels 1 & 2), which is the norm, so see notes below.
- Playback options: This determines what the monitoring windows will look like. You can change these to suit your preferences. A good place to start is "Audio + Video."
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Select a recording directory: This directory should always be the
/capturedirectory on the drive that is connected to the machine. Drives rotate around so this will occasionally change. - Name of Recording: Enter the Unique ID of the item in this field.
- Name of the person digitizing this tape: It's fine to just use your initials here.
- Hit "Record."
- The Terminal window will now prep the vrecord session to begin, but it hasn't started yet.
- Load the tape into the deck, and rewind it completely if it is not already.
When you're ready to capture the tape, you'll hit ENTER in the Terminal window and then play the tape in the deck. There are two phases of the capture, a calibration phase, and a continuity phase.
During the calibration phase, you will let the tape play and watch the levels and audio. There are three key things to watch (other than also making sure that video and audio are coming through):
- Luma and Black: Luma, also called "Video" sometimes, is the brightness values of the video signal. Black, sometimes called "Set-up" is the base, bottom value (the darkest). A useful comparison is a train and a tunnel. We want the train cars to be as large as possible to fit as much freight as possible, but it also must make it through the tunnel. The train car is the video signal. The Luma and Black adjustments can make the train car bigger to include more of the signal, but if it gets too big, then the car can't fit into the tunnel (which is the maximum resolution of video signal that the video file can have). This results in clipped highs or lows where we're losing definition. Usually calibration is simple if there are bars on the tape, as there will be a bar to correspond to the historic maximum and minimum values, and you can line them up fairly easily. If there are no bars, you want your black value as low as possible without begin clipped by the bottom of the video signal, and you want the luma as high as possible without being clipped. _As an additional complication, even if there are bars you calibrated to, they could have aged differently than the video signal, and you may need to adjust values more to get it within range. If you are running the deck through a Time Base Corrector (see notes below) make these adjustments using the "Luma" and "Black" knobs, but if you're not, some decks also have knobs to control these values.
- Chroma: Chroma, or saturation, is similar to luminance values but where those values control the amount of light in the signal, chroma controls the amount of color. Like luma, there is a limit to the amount of color a video signal can contain without clipping, but chroma also has an ideal value. If there are bars, you can calibrate the chroma level (also found on the Time Base Corrector, or the deck if not using a TBC) using the hexagonal spirograph that has target points for each color's chroma level. There is an outer ring and an inner ring, and during bars, colors should hit the inner ring of targets. If there are no bars, you will just have to watch for clipping, as with luminance.
- Audio Channels: The last thing to monitor is the audio signal, as you a) want to make sure you're getting all the audio, but also b) that you have the channel layout correctly configured. Most decks have audio monitors that will clearly show you how many channels audio is being picked up on. It's as straightforward as matching that to the audio layout that you choose in vrecord. Notes pertaining to specific formats' likely audio layouts are below.
- Always SDI-embedded audio, running through the switching board but NOT a Time Base Corrector. Adjustments can be made on the deck.
- Audio can be up to two tracks with four channels, but is often a traditional two channel/one track layout.
- Very rarely issues with playback.
- All of these can be played in the Digital Betacam machines.
- Always SDI-embedded audio, running through the switching board but NOT a Time Base Corrector. Adjustments can be made on the deck.
- Audio can be up to two tracks with four channels, but is often a traditional two channel/one track layout.
- Very rarely issues with playback, but more than other Betacam varieties.
- Requires Betacam SX machine.
- Component video and audio signals that we will typically route through a VCR. This means it goes through a TBC, through the S-Video Switcher and will be Analog audio.
- Audio is usually one track/two channels.
- Rarely do these. Issues not well-defined.
- Requires Betamax machine.
- Usually captured via Handbrake as a digital file, which is an entirely different process. See Disc Capture.
- Requires an external Blu-ray drive.
- Captured with playback on a camcorder using the audio jack and S-video output. This means it goes through a TBC, through the S-Video Switcher and will be Analog audio routed through a VCR slot.
- Audio is standard.
- Can have issues with playback as heads in camcorders become dirty quickly. Cleaning the head in the camcorder or swapping tapes is a good way to verify issues. Occasionally tapes need baking, but it is a different stickiness than the usually sticky-shed.
- Requires camcorder.
- Always SDI-embedded audio, running through the switching board but NOT a Time Base Corrector. Adjustments can be made on the deck.
- Audio can be up to two tracks with four channels, but is often a traditional two channel/one track layout.
- Very rarely issues with playback.
- Requires DVCAM deck which can play both.
- Always SDI-embedded audio, running through the switching board but NOT a Time Base Corrector. Adjustments can be made on the deck.
- Audio can be up to two tracks with four channels, but is often a traditional two channel/one track layout.
- Very rarely issues with playback.
- Requires DVCPro deck.
- Usually captured via Handbrake as a digital file, which is an entirely different process. See Disc Capture.
- Requires an external Blu-ray drive.
- Goes through a TBC, through the S-Video Switcher and will be Analog audio.
- Audio is standard.
- Usually no issues.
- All playback on a VCR, but VHS-C requires an adaptor.
- Goes through a TBC, through the S-Video Switcher and will be Analog audio.
- Audio is usually two channel/one track, but sometimes one channel will be static or unusable, and you will need to capture the good channel as mono audio.
- Issues very common. Decks can malfunction. Tapes often need baking, which can result in signal dropout if it wasn't caught in inspection and remediated. Top lines of video can also skew, but aside from the very small adjustments that the skew slider on the machine can make, there is little that can be done.
- All playback on U-matic SP decks.