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  CEDAR Tools
 
     
 
 

CEDAR Tools™ is a suite of processes that brings the highest standards of audio restoration to the Pro Tools™ (PC) platform. Offering high resolution processing of up to forty-eight tracks simultaneously, CEDAR Tools provides excellent results, quickly, and with the minimum of user intervention.

Note: Auto Dehiss, Declip and Retouch™ work on versions of Pro Tools from v6.9 - v8. Declick, Decrackle and Dethump require Pro Tools v7.0 - v8, Windows XP only.

For further details on each of these packages, please click on the links below:

Auto Dehiss
Declip
Retouch
Auto and Manual Declickers
Decrackle
Dethump

 
     
  CT3/A: Auto Dehiss      
         
 

auto_dehiss

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Automatic dehissing that works is now a reality

The Problem
In the past, digital dehissers that used no fingerprinting or noise reduction profiling were prone to side-effects known variously as 'twittering' and 'glugging'. On earlier CEDAR processes, it was possible to avoid these unwanted sounds by careful and judicious use of the controls, but it has never been possible - until now - to remove broadband noise correctly with almost no user intervention.

The solution

"The first so-called 'automatic' dehisser that works! And it really does..."

Auto Dehiss embodies a more advanced algorithm than any previous dehisser. It offers significantly improved performance and has a unique "Auto" mode that enables the software to determine the broadband noise content, removing this without the introduction of unwanted side-effects or artefacts.

We have even retained a manual mode that allows you to control all parameters and fine-tune the noise reduction.

The Plaudits
CEDAR's original DH-1 Dehisser - the world's first mastering quality digital dehisser that did not require a noise fingerprint - was voted "Best Of Show" by the editors and readers of EQ Magazine.
 
         
 
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  CT8: Declip      
         
  Adaptive Lattice
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Eliminating clipping from overloaded audio

The Problem
Clipping occurs when a piece of equipment or a medium carrying a signal is unable to handle a high level presented at its input, and will usually be heard as a harsh distortion that increases in intensity as the clipping becomes heavier. In all cases of clipping, it is the portions of the waveform near its extremities that are affected, while portions of the waveform closer to zero are unaffected. Examples of clipping include:
  • Digital clipping
    The signal contains many false samples. Viewing the audio waveform would reveal 'flat tops', at which points the genuine signal is destroyed and replaced by false samples at the maximum amplitude.

  • Clipping of analogue equipment and media
    There are many different types of analogue clipping, and these will usually be less obvious than digital clipping. This means that the hard edges visible in the former case are replaced by a more rounded profile.
The Solution
Declip is a genuine declipping algorithm that allows you to identify and remove most instances of clipping in a single real-time pass. It does so by presenting a visual indication of the density of sample values in the signal. If the Signal Analysis window displays 'hard' vertical edges, this demonstrates that the signal has been clipped at that sample value. It is then simple to remove the offending samples and reconstruct the signal. If you wish to inspect a region of the display more closely, you can use zoom to increase the resolution, allowing you to see finer detail within the signal. Furthermore, Declip offers multiple display modes that help you to analyse the audio correctly.

Two processing modes are provided, and these allow you to choose between an algorithm optimised for light clipping, and one optimised for heavy amounts of clipping. This ensures that you remove the problem without causing damage to the genuine signal.

 
 
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  CT13: Retouch™      
         
  Time Align
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The science of eliminating coughs, scuffs, page turns, creaky piano pedals, and even car horns

The Problem
Until now, audio restoration systems have been limited as to the types of noises that they can remove: clicks and scratches, crackle and buzz, pops and thumps. But today, CEDAR Retouch offers a huge leap forward in processing technology, allowing you to identify and eliminate sounds as varied as coughs, record scuffs, squeaky chairs, page turns, the creak of a piano pedal, and even a car horn.

There are no conventional methods available for removing these types of noise. Nonetheless, some engineers have attempted to use techniques such as severe EQ which, in addition to being completely inappropriate to such short duration problems, introduces ringing. Retouch does not suffer from this type of side-effect. Others have used (and misused) harsh compression, tight editing, and signal interpolators that affect the whole frequency spectrum. These damage good signal that should be left untouched, and can introduce unwanted side-effects such as drop-outs.

The solution
CEDAR Retouch is a huge leap forward in sound processing technology. Unlike conventional restoration tools, it allows you to define the temporal and spectral content of the sound you want to remove. This makes it possible to identify noises as varied as coughs, squeaky chairs, page turns, the creak of a piano pedal and even car horns.

Once identified, unwanted sounds are replaced seamlessly with audio that matches the surrounding signal. All other audio remains untouched.

Retouch is available for Pro Tools HD® and LE v6.9 onwards, operating at high sample rates, and offering 64-bit internal resolution.

In photography, 'retouching' is the art of identifying and removing unwanted blemishes from a picture to produce a perfect image. CEDAR Retouch brings this concept into the audio world, allowing you to remove unwanted acoustic events from a signal.

When all else fails... Retouch gives you complete control.
 
 
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  CT15 Declick - Auto and Manual Declickers  
         
  Adaptive Filter
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  The Problem
Scratches and clicks are encountered on all audio media - film, tape or disk, whether analogue or digital - so CEDAR's processes are invaluable when dealing with master tapes, film soundtracks, videos, interview and surveillance tapes, and vintage recordings.

The Solution
Incorporating both manual and auto declick capabilities, CEDAR Tools Declick comprises two AudioSuite processes that perform at high speed without sacrificing CEDAR quality. The two together ensure that Declick addresses the widest possible range of scratch and click removal problems.

· auto declick... allows the user to process part or all of an audio region as an off-line process. Remarkably, there is no need for controls because the algorithm detects each click, removes it, and then fills the gap with the best estimate of the material that existed (or would have existed) had the click not occurred.

The maximum click length handled is 100 samples at 44.1kHz, or 200 samples at 96kHz.

· manual declick... is ideal for restoring audio that suffers from problems for which auto declick is not ideal. It allows users to specify the audio that constitutes the unwanted noise, and the algorithm - optimised for extended clicks and scratches - will eliminate noises such as those found on optical soundtracks, as well as drop-outs and extended digital errors.

The maximum click length handled is 2,048 samples at 44.1kHz, or 4,096 samples at 96kHz.

 
 
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  CT16 Decrackle  
         
  Adaptive Lattice
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The Problem
Conventional declick processes are unable to identify and eliminate low level crackle without eating into the genuine audio. If misused in this way, they will damage the ambience and remove genuine musical transients.

The solution
CEDAR decrackle doesn't only remove the tiny clicks, crackles and "grunge" from vintage discs and vinyl LPs... it removes many types of buzz, and can be extremely effective at reducing amplitude distortions. It automatically detects the tiny disturbances that comprise the unwanted sounds, removes them, and restores the audio with the best estimate of the material that existed (or would have existed) had the problem not occurred.

With no parameters for you to worry about, CEDAR's adaptive algorithms will identify and remove all of these noises automatically, making Decrackle as applicable to film soundtrack restoration, audio forensics and broadcast as it is to traditional audio restoration jobs such as CD remastering.

 
 
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  CT17 Dethump  
         
  Adaptive Lattice
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  The Problem
Thumps may last for many hundreds of milliseconds, so conventional declicking processes are unsuitable for restoring audio containing them. Furthermore, the spectral content of thumps will usually overlap the genuine signal, so simple filters cannot remove them without degrading the underlying signal.

The solution
Dethump eliminates the low frequency disturbances that cannot be restored using a declick process. It allows the user to identify the audio that constitutes the thump and uses the data in and around this to build up a picture of what the low frequency audio should have been had the thump not occurred. The process then replaces the thump with restored low frequency audio, leaving the undamaged high frequency data unaffected. This makes dethump the world's best tool for removing many of the previously intractible problems associated with optical soundtracks, as well as for restoring damaged cylinders and discs, and for cleaning modern recordings when, for example, microphones and stands are bumped.

The maximum thump length handled is enormous: 50,000 samples (a little over one second) at 44.1kHz, or 100,000 samples at 96kHz.

 
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