Removing camera shutter noise from video

kevinm wrote on 10/10/2011, 6:47 AM

Hi All,

I'm on MEP15+.

Can anybody give me some advice/help...

I recently recorded a play with my daughter in. At the play there was a "real" photographer (somebody with a super expensive DSLR), problem is the shutter on their camera made a very loud shutter noise everytime they took a picture (and the happened to be right near me).

Now I know that I can manually go through the audio and using volume curve lower the volume at ever click from the camera (the spike it very obvious in the waveform display).

However is there an easier way (audio restoration doesn't help)?

I was thinking the good audio (without the clicks) is at about -6bd, the clicks from the cameras shutter go right up to 0db, so is their a filter I can use that can take anything above -6db and drop it down to -6db (or there abouts)? This would effectively lower the volume of the shutter noises to the same as the plays sound and make it not so jarring.

Thanks!

Comments

emmrecs wrote on 10/10/2011, 12:42 PM

Hi.

If the difference in audio level is about 6dB, then one possible method which will require an external audio program, I think (i.e. don't think you can do this in MEP, any version) is as follows:

Export the Audio as .wav, open the exported file in the external audio program (Audacity, a freebie, should be able to do this for you). Raise the level of the whole track by 6dB, thus making most of it to be 0dB but set a brickwall limiter to operate with Fast Attack and Release at 0dB. Thus no sound above 0dB will be allowed through.

The overall effect will be that the level of the wanted audio will be increased but the level of the unwanted clicks will be no louder than any other sound.

Alternatively, Export the audio as above, set the brickwall limiter at -6dB (assuming that to be the peak level of the wanted audio) and process the file. Again the unwanted noises will be at the same level as the wanted and so slightly masked, I hope!

If you don't have access to an external audio editor program or don't want the hassle of exporting, processing and then reimporting you might try the Audio Cleaning>Compressor. A compressor is a somewhat "gentler" version of a limiter; you will need to set the compression level quite high. Unfortunately as a far as I can see you have no control over the Attack And Release times so results will be variable, to say the least.

HTH

johnebaker wrote on 10/10/2011, 4:33 PM

If I read emmrecs technique correctly this can be done in MEP as follows -

Right click the audio track, select Edit wave externally this should open Music Editor.

In Music Editor select Effects, Dynamics

Set the try different settings for Threshold and Ratio and set Attack and Release to minimum set Gain to 0 to start with then adjust as necessary.

When you have got the effect you need then save the audio and import back into MEP - it should transfer back to MEP but for some reason mine gives an error.

You should be able to reduce the camera noise to an acceptable level.

John

kevinm wrote on 10/11/2011, 3:18 AM

Thanks for the advice, I will try the suggested...

terrypin wrote on 10/11/2011, 11:21 AM

I thought that maybe an alternative method would work, using the Denoiser section of Audio cleaner, but to my surprise it failed.

I made a test recording, talking into the PC mic while I snapped my fingers. Part of the recording was only that finger snapping, and that's the 'noise' that I want to try reducing. It seemed logical to me that if that worked then it should be able to deal with the unwanted shutter noise (providing you could find at least one section of your recording that includes mainly that noise).

Anyway, I then r-clicked the clip and opened the Audio cleaning window, enabled the DeNoiser , and opened the 'DeNoiser - Advanced settings' dialog window.

My first aim was to get a sample of the noise. I don't really follow the first method described, 'Search for noise sample'. So I tried the other one, 'Take noise sample from start'. To do this I closed the dialogs and made a copy of my recording, then extracted a small section of it containing just a single click. (More of a 'thump' really.) Then I repeated the above procedure using this small clip.

I clicked 'Create noise sample', then 'Save noise sample' as 'ThumbClick'.

Then I opened the original target in the Audio Cleaner and chose 'ThumbClick' as the noise to remove.

However, it didn't sound any different!

I'm sure I have used this method before months ago to reduce wind noise, so I'm puzzled why it didn't work on this occasion. Maybe my procedure was flawed? Any ideas anyone?

--
Terry, East Grinstead, UK

johnebaker wrote on 10/11/2011, 2:01 PM

Hi Terry

I agree with you that your procedure is flawed - not the way you did it, but what the De-noiser is capable of. Most 'de-noisers are looking for 'white' noise in its various forms eg electronic noise, wind, hiss etc which are fairly broad spectrum and may be biased to the lower or higher frequencies.

The problem with thinks like claps etc is that they can be of narrow frequency spectrum, with fast attack and decay times which is why you need a dynamic compressor or brick wall filter, as emmrec's recommended, to limit the audio peaks.

John.

terrypin wrote on 10/12/2011, 4:27 AM

Thanks John, understood. That makes sense now that I listen more carefully to my finger 'thumping'.

I'm pleased to know that my technique was OK - it took me ages to get it right when I first tried it!

Edit: BTW, my posts this morning are generating a 'site down for maintenance' message, but that seems an error, as they're getting sent OK.

--
Terry, East Grinstead, UK