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-   -   How to remove audio static/buzz and hiss? (https://www.digitalfaq.com/forum/video-restore/1163-how-remove-audio.html)

lordsmurf 01-08-2008 09:49 AM

How to remove audio static/buzz and hiss?
 
7 Attachment(s)
I was e-mailed a test clip by a member here today, asked what could be done to restore the audio and video problem.
.... And EVERYTHING could be fixed, and with only a minimal to medium amount of effort!

This video portion of this is heavily based on this video post: http://www.tvpreservation.com/forum/...-vhs-7161.html

In fact, everything is the same, aside from lowering the chroma filtering, as there was minimal (but still present) chroma noise going on. It appears to have been pre-filtered pretty well there, during the VHS-to-DVD process.

Software required:
  • AUDIO - SoundForge 6 to de-hiss
  • AUDIO - Goldwave 5 to restore audio fuzz, maybe de-hiss
  • AUDIO - BeSweet, BeLight or FFMPEG to convert audio to WAV
  • DEMUX - TMPGEnc 2.5 or TMPGEnc Plus 2.5
  • VIDEO - VirtualDub (version that reads MPEG files) to filter video
  • VIDEO - AVI Synth 2.5 for frameserving (not something you use, just has to be installed for system)
  • VIDEO - Procoder 2 to encode final

First, demux the video/audio from one another. I did it in TMPGEnc Plus. Go to FILE - MPEG TOOLS and then SIMPLE DEMUX (assuming your source is from homemade DVD sources, and NOT a commercial release).

Remember that the goal of restoring something is to not make it perfect! You want to remove as much noise as you can, while retaining as much "good" video/audio as possible. You may lose a little "good" to destroy a lot of bad. With audio, you might lose a little bit of the perfect tone/pitch, but it would still be at least as good as FM radio (just not audiophile perfect). The noise should be reduced to an acceptable level. In this sample, the static noise makes the entire clip unviewable.

The audio needs to have the fuzzy noises removed first. One easy way to do it is to take advantage of technology developed for removing noise from vinyl records. The one in Goldwave works best, in my experience. Go to EFFECT - FILTER - POP/CLICK. It started the default at 1000, but that left some noise still. The LOWER number is more filtering, so I reduced it to 750 (still not enough), then 500. The 500 removed almost everything, and the original audio was virtually unaffected.

That left hiss. Both Goldwave and SoundForge has hiss reduction abilities, but Goldwave requires a perfect noise sample (often during black screens before or after the show, or during the few seconds of black at scene changes or commercial breaks (if off tv) . The sample clip was 100% audio samples mixed with 100% noise samples, so Goldwave was not possible.

I opened the clip in SoundForge and tried several pre-made SF6 filters that I created (download them at digitalFAQ.com, from the SoundForge 6 guides page), and the Flescher-Munson Hiss Removal 4 filter worked perfectly. It removed all hiss, and minimally affected the output audio tones.

I used the attached VCF file (VirtualDub processing settings) for filters. It's the same as the Moo Mesa one, aside from a lower chroma removal setting mentioned above. The original clip was 720x480, and the restored version uses 352x480 for a good reason. The very nature of 352 is still above that of the VHS source, so no detail will be lost. Next, the 352 will maintain image detail, yet hide pixel noises, so the very act of using 352 has some restorative properties.

When encoding in Procoder, during the setup of the project, I used the frameserved video as the video source, and then my restored WAV file was the "alternate audio" that was encoded to MP2 by Procoder. So my final PC2 output file was a .M2P (rename to .MPG).

BEFORE and AFTER files attached.
Because MPEG files are rather large, I've had to split up the videos into smaller under-8MB segments. It should be obvious. You can re-merge these in most MPEG editors, such as Womble MPEG VCR, Womble MPEG Video Wizard, TMPG MPEG Editor, etc. Or listen to each smaller piece, either way is fine.

VCF file attached.

A good exercise for you is to download the BEFORE clip, and then see if you can match (or even surpass!) the quality of my AFTER clip.

Premium Members of this site are always welcome to attach some samples, and get advice on how it can be fixed. Remember that EVERY VIDEO and EVERY AUDIO clip is different. I've been doing this long enough that I can quickly guess what filters might work, and I need only a few minutes of experimentation to fix audio. It might not be a studio-perfect fix, but it's still very nice!


NOTE: If you're not sure what to do with these ZIP or RAR files, then read this help post.
.

Konfusion 01-10-2008 06:16 PM

this isnt in the pack
Flescher-Munson Hiss Removal 4 filter

only
removal 1 and removal 2. no removal 3 or 4.

lordsmurf 01-12-2008 11:15 AM

Here is the current SF presets file: http://www.digitalfaq.com/forum/show...lter-1605.html

The top dozen or so number-only presets are for temp projects, yet unsorted.

Guide at http://www.digitalfaq.com/guides/vid...soundforge.htm

32pennies 02-10-2022 10:18 AM

I feel that Sony Oxford DeNoise is the best for hiss. I havent heard anything better and running to twice on middle and sides makes it a whole lot better. And dont use the hiss function on DeNoise because it takes a brickwall to the highs. If you want a tutorial on it lmk.

Heres a video I made comparing the differences: https://drive.google.com/file/d/1cRJ...ew?usp=sharing

timtape 02-10-2022 05:48 PM

Your movie clip is too low definition for us to see which icons you are clicking.

But also your example has little hiss. Why not give the tool a real test with some serious hiss, serious hum, serious clicks etc? Then we can know how good it is tackling the difficult stuff, where help is most needed.

32pennies 02-11-2022 06:37 AM

Quote:

Originally Posted by timtape (Post 82778)
Your movie clip is too low definition for us to see which icons you are clicking.

But also your example has little hiss. Why not give the tool a real test with some serious hiss, serious hum, serious clicks etc? Then we can know how good it is tackling the difficult stuff, where help is most needed.

Its blurry because you are watching the google drive preview. If you want I'll transfer a tape with super low signal and denoise.

timtape 02-11-2022 03:51 PM

OK thanks.


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