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VHS digitization and clean up
As requested in a separate thread, I recently converted a large number of VHS tapes to DVD, I’ll list the steps I found useful for taking analogue VHS tapes into the final DVD.
I am not by any means an authority, and had the help of some on this forum, and a great deal of help from Technical gurus on Video Help forum.The sequence is in 4 parts
# Capture Analogue video & Audio into digital format – and lining up frame synch & levels
# Post process video to correct for noise, colour bleed, anti-aliasing, ghosting & motion blur etc.
# Edit in Movie Studio for final video and enhance audio
# Render out as MPEG2First off you need to capture the analogue video … as soon as possible – as it will only deteriorate further with age …
I had a reasonably high spec Panasonic 3 head SVHS deck … to start I gave the heads a really good clean.
I captured the video using SVideo output, which was the best I could get out of the deck.
Initially I used an external AVT-8710 TBC correction unit, this was a full frame TBC, but it caused more problems than it fixed (should have got a Line TBC), so instead I used a pass-through technique to clean up frame signals and nail the sync, I used a DVD recorder, you could also use a camcorder to do this.It was worth investing in an ADVC unit,(I used Canopus ADVC300) easy to get from eBay, in fact I sold mine for more than the price I paid for it after completing the job.
This does the hardware conversion from analogue to Digital, it uses professional grade video processing, if picture is way out of whack … you could adjust levels on the ADVC, but I decided to capture ‘as is’ to get all my tapes done.You could also use a Video capture card (Colossus is highly rated) but the USB video to DVD device ‘leads’ are useless, quality is awful.
On the PC I used a free piece of software WINDV this is as basic a capture program as exists, but it is very reliable. I captured as 720 x 576 Lossless AVI at 25fps, I used max Bitrate of 9.8MBs
Chroma Issues
SVHS is about 60% better than VHS on luminance but has the same (poor) Chroma issues of VHS.
If your tape is the original master then you are lucky .. if not you will have the dreaded Chroma Shift .. this moves the chroma I+Q elements out of sync .. by around 1 pixel per generation ………. Giving very bad colour bleed at edges.
Very typical soft smudged VHS image.
Before you start tweaking do not at any point de-interlace, you will be throwing away a lot of information, better to use it.I loaded the files into VirtualDub (free) first step was to use the basic hue/saturation/intensity and/or Levels filters to correct anything that is way off.
If you just want to correct the Chroma Shift then use the Flaxen filter …. Zoom right into a picture and count the number of pixels shift at an edge and enter that in to the Flaxen filter and it will correct really cleaning up the edges … almost akin to a good sharpening effect.
Here is a walk though of how I got to learn to fix Chroma noise on one of my tapes, bad copy as was multi generation and not particularly good – even though commercially paid for tape.
https://tinyurl.com/z68mds6Noise
If you have DigitalNoise .. there are static noise reduction filters for VD, good for removing grain but for anything with movement will end up with an overly softened image, there is a far better filter – Temporal Cleaner.
Set the pre-set filter numbers to halfway as start point … higher the numbers more noise removed but introduces more blur on motion ….. halfway is good start – tweak if necessary ………. You can see result in right hand pane of VD no need to run whole video.
Good explanation here: https://tinyurl.com/okf5t8w
There are alternate options:
CNS (Chroma Noise Reduction) you can run it at Virtual dub point or from within Vegas … installing WAX filter in plugins.
It will 100% fix any Chroma issues .. but is more convoluted to use
NEATvideo will also work but that is not free, and too expensive for me.If you are happy to use AVISynth (another free tool) there is a very highly regarded denoiser script authored by John Meyer, I used that script on almost all of my VHS tapes:
https://tinyurl.com/hq5ykr5For a particular tape (my own wedding) I wanted to try & get the best I could out of it ……… so had a lot of help with customization of scripts from some very experienced guys – the results were amazing, as the steps had to be explained along the way (I had never used AVIsynth before) this could be useful worked example on how to correct VHS post capture.
It uses custom scripts which call filters and other scripts … pretty in-depth stuff, but it builds slowly.
https://tinyurl.com/z7fxsxyOnce complete I dropped the video file into Movie Studio – for NLE edit.
For audio, I rendered audio out as WAV only and dealt with that in SoundForge ……… there are VHS noise filters, but found Sony Noise Reduction 2.0 and taking a noise print of the tape noise and then removing it worked best. I set the overall levels to get to around -3dB
When doing final render out of Movie studio I used MPEG2 at high bitrate and set it to 2-pass encoding, this also cleaned out a lot of noise that you would get using single pass. Audio was rendered out as AC3.
Hope this is of use.
