Analog Video Recording in Windows

Analog Video Recording in Windows

Current generation windows PCs can easily record (capture) analog video.  Although many video capture setups record the video with MP4 or similar codecs, these codecs are lossy (lower quality).  To preserve as much signal as possible when recording occultation data, we use lossless codecs.  For this reason, we do not recommend the software shipped with most video capture hardware.  This guide explains the hardware configuration, software configuration, and steps for recording high quality analog video with a PC.

Please be aware that the product and techniques described on this website are changing frequently. For the very latest advice we suggest you post a query on IOTAoccultations<at>

PC Hardware

Any recent generation Windows PC should be able to record high quality video without dropping frames.  Windows 7, 8, or 10 is best but Windows XP systems also work.  The PC must have a USB port available for the video capture device and it should have roughly 10GB of free space on the hard drive. Laptop or desktop is fine.  Obviously, laptops and tablets are more portable and therefore a better option than a desktop if you will be observing (and recording) away from home (or observatory).  The most portable option is a “compute stick” (e.g. the Kangaroo Mobile Desktop and the Intel Compute Stick).  The Kangaroo Mobile Desktop is the most convenient since it has a built in battery.  Compute sticks are very small but do not have a built-in monitor or keyboard.  See the section below on Advanced Topics for more information on using a compute stick for recording.

Analog Video Capture Hardware

We currently recommend the StarTech SVID2USB23 analog video capture device.  The older SVID2USB2 is also a good option but tends to be more expensive.  Much of this guide will refer to the SVID2USB2 but they are interchangeable.  These devices are generally available on Amazon for less than $50.  NOTE: You will still need an IOTA-VTI or similar video time inserter to provide accurate time stamps for your video recording BEFORE it is recorded with a PC.

Video codec

We recommend the Lagarith video codec (losssless compression).  The resulting AVI files will be about 4GB for a 10 min recording.

Video Capture Software

For Windows 7, 8, and 10 we can recommend three options for video capture software: “IOTA_VideoCapture”,  “OccuRec”, and LiMovie.  Both the IOTA_VideoCapture program and LiMovie generate an AVI file which can be viewed with a wide variety of software programs.  OccuRec generates an AAV file which can be viewed and analyzed by the program “Tangra”.

For Windows XP we recommend “VirtualDub”.  note: VirtualDub does not work on many Windows 8 or Windows 10 systems.  VirtualDub generates an AVI file.


  • Install the Lagarith video codec
    • You will find the Lagarith installer via the Lagarith website (use the installer version rather than the manual install version).
  • Install the device drivers
  • General PC configuration for video recording : notes
  • Installing the video capture software (choose one)
    • IOTA_VideoCapture Install – download the install file from the software page.
    • OccuRec Install – visit the OccuRec website
    • LiMovie (download the zip file from the LiMovie section of this Resources page)
    • VirtualDub Install  – VirtualDub guide


Practice and Prepare – before recording an important occultation event, do a test run with your setup to eliminate problems beforehand.  Lunar occultations are a good test for recording occultations.  Total lunar occultations occur on most nights of an early moon and do not require travel (you can observe from home).  Asteroid occultations are usually more challenging and much less frequent for any given location.

Here are a few suggestions:

Before leaving home for a remote observation:

  • Verify that the system time on your recording computer is accurate
  • Verify that you have enough free space on your hard drive for your expected recording duration
  • Optional – setup/schedule the event timer for recording

Before recording

  • Put the computer in Airplane mode
  • Shut down all programs other than your application for capturing video

After recording

  • Shut down your recording computer – avoid any data loss due to improper power down.

Back home

  • Transfer video file to main computer for analyzing the data.  If you recorded onto a tablet or stick computer, it is generally much easier to copy the video file from the recording computer a USB stick , then transfer from the USB stick to the main computer.

View / Analyze Captured Video Files

If you recorded your video with a small computer, transfer it to a “main computer” (larger screen, faster processor) to analyze the video.

  • If you recorded with the Lagarith codec (IOTA_VideoCapture or VirtualDub), you must also install the Lagarith codec on the computer used to analyze your video.
  • If you recorded your video with OccuRec, you must use the free program Tangra to analyze the Video.

More Information

  • A document with more details on preparing a small Windows 10/11 computer (laptop, stick, tablet, NUC) to be an analog video recorder is available at this url.

Page history:

2016 Jul 20 (Steve Preston) Initial version

2021 Jan 29 (Joan Dunham) Added comment

2021 July 1 (Joan Dunham) Added link

2022 July 28 (Joan Dunham) Changed link