How to apply filter reduction noise on audio?

Hi! I want to apply filter of reduction of noise on audio, is it available from shotcut?



Bienvenue dans ce forum

welcome to this forum

Malheureusement, il n’existe pas de filtre de réduction du bruit audio dans shotcut.
Pour cela j’utilise le logiciel libre (opensource) audacity

Pour ce faire :

  • Il faut exprter le film sur lequel vous voulez travailler le son en mp3.
  • ouvrir audacity et retravailler votre son.
  • enregistrer une nouvelle version de ce mp3
  • ouvrir shocut avec le film dont le son a Ă©tĂ© retravaillĂ©.
  • importer la nouvelle bande son retravaillĂ©e
  • exporter votre clip avec un nouveau nom.

Cette méthode peut paraitre fastidieuse, mais si on est rigoureux c’est assez facile à mettre en place
(conseil) Pensez à laisser 2 secondes de silence en commençant le tournage de vos film.

Unfortunately, there is no noise reduction filter in shotcut.
For this I use the open source software audacity

To do this :

  • You have to express the film on which you want to work the sound in mp3.
  • open audacity and rework your sound.
  • save a new version of this mp3
  • open shocut with the movie whose sound has been reworked.
  • import the new reworked soundtrack
  • export your clip with a new name.

This method can seem tedious, but if you are rigorous it’s easy enough to set up
(advice) Remember to leave 2 seconds of silence when you begin shooting your movie.

Je vous souhaite beaucoup de plaisir avec shotcut
I wish you a lot of fun with shotcut

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In my opinion Audacity is not a good tool for real noise reduction. The filter is bad and very complicated to use and you can’t hear the diffence at once by looping a file while playing!
You’ll always have to render it and that takes time.

If you are a lucky to have Wavelab or Reaper, then a VST-Plugin filter can afford these advantages.

Maybe later there could be an audiofilter, called “VST-Plugin” in the audiofilter section of SC.

Dans Audacity, il suffit d’avoir enregistrer un peu de silence afin que le filtre analyse ce dernier pour faire la différence avec le bruit. C’est le volet pré-analyse de ce filtre.

De toutes les manières si le son enregistré est mauvais, on ne pourra jamais en faire un bon son., même avec un très bon logiciel.

Est ce que Wavelab ou Reaper sont gratuits ?

In Audacity, you only need to record a little silence so that the filter analyzes it to make the difference with the noise. This is the pre-analysis part of this filter.

Anyway, if the recorded sound is bad, we can never make a good sound, even with very good software.

Are Wavelab or Reaper free?

The noise reduction is enormously good at eliminating noise; I am baffled that you find it ineffective :astonished:. I use it all the time and it does a perfect job with the standard settings. As @Galipe pointed out, you need to record the background for some seconds, determine the noise profile and then apply the profile onto the track. I usually record 10-15 s of background and the tracks are mostly 4-5 min long which makes it easier to apply the noise reduction, since I can select the whole track instead of cutting one track into several bits with similar background noise.
But perhaps you have tried it with quickly changing background noises, because for that case I cannot judge its performance.
But I agree that the UI is not very good. Only being able to hear length restricted sound parts is not very user-friendly. I fortunately can use it without checking, since it exactly does the task without any distortion or newly introduced noise.
@Tomas_Gonzalez If Galipe’s reply anwers your question, you could mark it as the answer :slight_smile:.

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I used Audacity briefly. UI is horrible. The horrible mic I was using took in so much noise, and after finding the right tutorial on YouTube explaining how to use the noise reduction, I got it to work like a charm. I applied about 2 more filters beyond noise reduction, but that was personal preference.

Despite all of the filter work with Audacity, I still considered it be “ok”, but nothing great as to what I get now with my current mic.

But the price is free, and I’m not really willing to pay nor learn another software.


If you want to stay completely inside Shotcut, you could use the High Pass filter on a speech track and raise the cutoff frequency just to the point that it starts to affect the speech. If there are other background noises at specific frequencies you can locate (look for bars on the Spectrum Analyzer graph that are taller than they should be outside the speech range), you could add a Notch filter at those frequencies with a bandwidth of 150 Hz or less and a rolloff of around 6.

If you’re willing to jump outside of Shotcut and use Audacity for noise reduction, be sure to take a look at the notes in the Audacity manual about how and when to apply the filter. The final sound can be very bad if filtering is done in the wrong order. Any artefacts generated can get unnecessarily amplified.

Audacity noise reduction filter manual:

If you are willing to jump outside of Shotcut but you want even better results, and you’re willing to pay money for it, then take a look at iZotope RX Elements for $129. This is the same denoiser that major studios use, and I personally feel this is one area of the processing chain where open source software has miles to go before it catches up with commercial offerings. I paid money for iZotope because I felt it was that much better. I am not affiliated with them in any way.

The iZotope Elements Suite is only $199 if you also want Ozone for mastering. The transient shaper tool is especially useful for customizing snare drum sounds, if you’re into recording music performances.

The difference between Audacity and iZotope is that Audacity’s noise reduction method is basically a glorified graphic EQ filter. It uses spectral noise gating, which basically means it divides the frequency spectrum into 1025 bands like an old-school graphic equalizer on steroids. It is trained by analyzing a patch of noise to see how much energy is in each band. Once applied to your real audio (speech), if the energy in each band is not significantly higher than the noise fingerprint, the band gets reduced because the filter assumes there is no signal (speech) currently happening. Obviously, there will be artefacts because there isn’t a smooth transition between the 1025 bands, and the human ear is sensitive enough to hear any major changes applied between neighboring bands that wide. Also, this technique is rendered useless if the noise profile pulses or changes over time, like vehicle traffic or crowd noise.

This isn’t to say Audacity’s NR is bad. I’m just saying that once you know how it works, you now know how to get the best results out of it. It works best in a controlled recording environment where any background noise is extremely consistent. Then Audacity’s method can provide great results.

If a controlled environment isn’t possible, then iZotope is your only real option. It uses a learning algorithm rather than static EQ binning, and is enormously more sophisticated which produces much better results.


Nope, thats why I mean, when you’re “lucky”.

Another “free” way in realtime-editing is to use OBS-Studio.
Loop your content and add filters.

There is also a way to add professionell VST-Plugs for refining.

By setting all your parameters, you only have to “record” your contend in OBS and cut it later in SC.

I have made a tutorial about this a time ago, - but sorry, only german.


And that explains why it works so well in my case. Fortunately, I am able to use a room which provides consistent background noise and splitting into tracks helps as well. I did not know that Audacity’s method is that simple.
I use a compressor (TDR Kotelnikov) and an equaliser plug-in (TDR Nova), which are more sophisticated, due to the limitations of the in-built ones.

I know this has nothing to do with post, but I personally put the gain of the mic down a bit, put it a bit closer to my mouth and then use a sock or something to reduce plosive distortion. That should make recordings slightly less noisy.

I did not realize OBS could be used as a VST host. That opens up a lot of possibilities! Especially for voice-over work in well-known rooms, the VSTs could be applied at the time of recording and totally skip the post-production step to save time. I like it.

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@Austin, thank you for liking it!

Very interesting thanks you

Comme le disait samth dans le post précédent, et ce que vous surligner avec votre intervention.
La question est l’environnement sonore existant, mais aussi le matériel d’enregistrement.
C’est pourquoi, la plus part du temps je n’utilise pas le son existant en direct, mais la post production pour la bande sonore.
Comme je ne possède pas de matériel d’enregistrement pro, j’utilise le micro de mon appareil photo reflex, et j’enregistre en même temps avec un smartphone, puis je synchronise les 2 pistes.
d’où l’importance des secondes de silence puis du clap.


As samth said in the previous post, and what you highlight with your intervention.
The question is the existing sound environment, but also the recording material.
That’s why, most of the time I do not use the existing live sound, but the post-production for the soundtrack.
Since I do not have professional recording equipment, I use the microphone of my SLR camera, and I record at the same time with a smartphone, then I synchronize the 2 tracks.
hence the importance of the seconds of silence then the clap.

Merci pour toutes ces informations.

thank you for all those informations


Is there any updated video in English?

Sorry, - no! :frowning:

Thank you for your reply, its a pity about that. :cry:

The automatic noise filter in Ocenaudio is good. It’s a free audio editing software.