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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: charles on March 11, 2005, 12:55:08 AM

Title: Clip removal
Post by: charles on March 11, 2005, 12:55:08 AM

Anyone know how to mask minor clips throughout a track using Wavelab 5?

Title: Re: Clip removal
Post by: charles on March 11, 2005, 01:54:48 PM

So...nobody has any reccomendations? There's got to be something that can be done here.

Title: Re: Clip removal
Post by: macroint on March 11, 2005, 02:09:09 PM

Quote from: charles on March 11, 2005, 01:54:48 PM

So...nobody has any reccomendations? There's got to be something that can be done here.

If they're minor (and not causing distortion), why not leave it?

Title: Re: Clip removal
Post by: charles on March 11, 2005, 02:14:53 PM

Well....they're not that minor. They are causing some occasional distortion.

Title: Re: Clip removal
Post by: Lil Kim Jong-Il on March 11, 2005, 02:39:41 PM

I assume that the clips are longer than a few samples.  This is tedious and may not be what you want to do but it will work.  You may still hear some distortion of the sound but it will sound a lot better than clipping sounds.

Bring your recording into an audio editor. Using the waveform shaping tool, manipulate each instance of clipping so that the plateau region is reshaped to have a curve that matches the curve you would expect to see if the clipping had not occured.   Your goal is to eliminate all those sharp corners and to reconstruct the original wave as closely as possible.

This does work.  I've done it and got good results.  It is tedious and you would be better served to get another source. But if this is the only tape of the performance, then you can do it and get satisfying results.


Assuming a 16-bit source

1) import the 16-bit source to a project that uses 32-flt data
2) massage all the clipped regions as described above
3) export the waveform as a normalized 16-bit recording

Title: Re: Clip removal
Post by: charles on March 11, 2005, 02:54:58 PM

Thanks a lot man. + T. I'll give it a try. Do you know the name of the waveform reshaping tool in Wavelab?

Title: Re: Clip removal
Post by: macroint on March 11, 2005, 02:59:42 PM

Quote from: El Barto on March 11, 2005, 02:39:41 PM

Bring your recording into an audio editor. Using the waveform shaping tool, manipulate each instance of clipping so that the plateau region is reshaped to have a curve that matches the curve you would expect to see if the clipping had not occured.   Your goal is to eliminate all those sharp corners and to reconstruct the original wave as closely as possible.

Depending on the number of occurances, that can be alot of work...you can always decrease the volume a hair. As long as you don't increase/decrease too much, you won't have any problems.

Title: Re: Clip removal
Post by: Lil Kim Jong-Il on March 11, 2005, 03:26:37 PM

I agree that it is a great deal of tedious work.  But just decreasing the volume isn't going to repair the main fault of the recording, which is the discontinuity of the wave form at the points where it hits the rail and goes DC.


Charles, I don't use wavelab so I can'thelp you with that.  Audacity should work for this.  I used cool edit.

Title: Re: Clip removal
Post by: charles on March 11, 2005, 03:30:27 PM

Yeah...I went the volume route many moons ago.....to no avail. I'm working on the reshaping now.

Title: Re: Clip removal
Post by: lds490 on March 11, 2005, 03:40:58 PM

I don't use wavelab, but I have had good results using the clip restoration function in Adobe Audition.  You can download a 30-day trial version for free.

Title: Re: Clip removal
Post by: charles on March 11, 2005, 03:45:28 PM

I have Adobe Audition....but I never use it. It has a "clip restoration" function? Damn...I'll have to check that out. +T

Title: Re: Clip removal
Post by: Lil Kim Jong-Il on March 11, 2005, 04:00:33 PM

Quote from: lds490 on March 11, 2005, 03:40:58 PM

I don't use wavelab, but I have had good results using the clip restoration function in Adobe Audition.  You can download a 30-day trial version for free.

Nice.

Title: Re: Clip removal
Post by: charles on March 11, 2005, 04:46:38 PM

hey lds.....got any specific instructions on using that clip restoration function?

Title: Re: Clip removal
Post by: Brian Skalinder on March 11, 2005, 04:51:16 PM

FWIW, I've found the CEP/Audition clip restoration works best if applied to a range surrounding the clipped section that starts with the 0 centerline sample closest to the beginning of the clip, and ends with the 0 centerline sample closest to the end of the clip.  For example:

             _____
  ~         /CLIP1\                 ~
 / \       /       \               / \           + dB
/   \     /         \             /   \   /   ____________ <--- 0 center line
     \   /           \           /     \ /     
      \ /             \         /       ~        - dB
       ~               \_______/
                         CLIP2
===========================================
0....|...10....|...20....|...30....|...40.. <--- COUNTER / TIME (arbitrary units)
===========================================

So, for a slight clip, CLIP1, apply clip restoration to the range before and after the clip, starting and ending at the 0 center line.  In this example, the range:  10 - 21.  If, for example, you started your clip restoration range at 8 and ended at 19, it sometimes produces audible artifacts.  More info on heavily clipped areas a little bit later...

Title: Re: Clip removal
Post by: dklein on March 11, 2005, 06:11:15 PM

I've tried a coupla waves plugins for something similar x-click and x-crackle.  They aren't specifically for clipping but if you've heard clipping...

Nice thing is you can test and monitor real time to see how it's doing.

Title: Re: Clip removal
Post by: hexyjones on March 11, 2005, 09:41:25 PM

Here are some samples using SoundForge 7 using the Vinyl Restoration Tools...

Brickwall from a friends MD source:

http://www.pennmar.net/clips/Sound%201.mp3

Cleaned up:

http://www.pennmar.net/clips/Sound%202.mp3

Not perfect - but can make a disaster listenable...

Title: Re: Clip removal
Post by: Lil Kim Jong-Il on March 11, 2005, 09:57:08 PM

Any chance of posting the wav copies of that?  I'd be interested to see the result compared to the original waveform.

Title: Re: Clip removal
Post by: hexyjones on March 11, 2005, 10:50:08 PM

Here's the wavs - - -

Brickwalled:

http://www.pennmar.net/clips/Sound%201.flac

Cleaned up:

http://www.pennmar.net/clips/Sound%202.flac

Title: Re: Clip removal
Post by: F.O.Bean on March 12, 2005, 12:49:42 AM

in soundforge 7.0, i fixed up my ymsb from cbus a few weeks ago in a few tracks :)

1. open track and check 'detect clipping'
2. zoom in and highlight the clips, select only the clipped region, and then go into
3. 'wave hammer' and just make sure 'smooth saturation' is on and the rest of the default settings are fine IMO on it, and simply click
5. OK

 ;D 8)

makes a huge diff IMO and takes nothing away from the music IMO either :) jusat cuts peaks off a bit

Title: Re: Clip removal
Post by: charles on March 12, 2005, 01:54:11 AM

Thanks to all. +T's all around. The particular clip I'm working with is very important to me, so I'm really thankfull for all of this help.

Title: Re: Clip removal
Post by: F.O.Bean on March 12, 2005, 02:28:11 AM

backatcha, i like helping, no worries, hope ya get everything worked out

Title: Re: Clip removal
Post by: F.O.Bean on March 12, 2005, 02:37:16 AM

yeah, i just focus on the clipped parts and a little compression(especially on bluegrass style stuff) can go a LONG way IMO!

Title: Re: Clip removal
Post by: hexyjones on March 12, 2005, 03:22:26 AM

I'm old enough to have spent at least half my life listening to records (vinyl) - and I thought those brickwall "click farts" sounded like a scratch, pop, or click on a record...

For the SF7 Vinyl Tools approach -  I just select the enitre track - adjust the settings a bit in the "preview" mode - then let it roll...

Title: Re: Clip removal
Post by: rerem on March 26, 2005, 06:51:03 AM

Sondforge's SF NR2 plugin includes "clipped peak restoration tool" which is excellent. SFNR2 works as a Direct X plug-in with both Wavelab and Soundforge. The hiss reduction tool is also quite good