Potential Solution to pop/click at audio breaks

Ubuntu 22.04.2 LTS
Shotcut 22.12.21 64 bit

Resurrecting an old issue here but I got the pop/click issue at splits in audio/video clips.

My resolution was to add a 00:00:00:02 Fade In Audio and Fade out Audio to each clip and it worked perfectly.

A question then…

Is it possible to make Fade In/Out Audio work at the track level? Then I just have to add it once.


Is it possible to add it behind the scenes so it is done by the software all the time for every clip as part of how audio is interpreted?

Would a fade in/out of this duration have a negative impact anywhere else if it was built into the way the software interprets the audio?

This was already addressed in version 23.05.07 but you might want to wait for the next version to switch over completely. Of course, you are welcome to test this. It is not possible to automatically fade in/out each clip.

Sounds good.
I’ll give it a try when I’m feeling risky or the update rolls out :slightly_smiling_face:

Out of curiosity what was the fix? Broadly speaking that is…

To be clear the “fix” was only about audio resampling. The default for Shotcut is 48000. So, if all your sources were 48 KHz, then your issue may not be addressed. The audio resampling now operates at a level higher than per clip and join. Another workaround people use is to reprocess the export result with ffmpeg’s adeclick filter.

Looks like most of what I have is 48KHz
Well…I have something that seems to work without postprocessing.
I don’t understand why it works though. It’s just clipping 1/50 of a second off the beginning and ending of an audio clip I think. Does it create a virtually lower sampling rate?

If you take two arbitrary waves and simply join them, the wave is not going to be continuous. It is like taking two arbitrary puzzle pieces and smashing them together and expecting it to look seamless. The fade in/out technique brings the wave of each piece smoothly down to the same point 0 to make it continuous. Going back to the puzzle analogy, it would be like trimming one side of each piece to a perfectly flat line. Now these pieces can be joined seamlessly.

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That is a great analogy!

Also highlights the potential problem - there is a tiny but sudden drop in the audio. I guess a better solution would be to fade to a mid point between the end of the one wave and the beginning of the next.

Thanks for taking the time to help me get my head around this.

I see the snap store has 23.05.07 (deb is old for some reason)

I’ll upgrade after this project is wrapped up.

Thanks again

@brian I think my previous idea to make a track filter (maybe automatically added and hidden by Shotcut) that observes a frame before and after a cut would help here - perhaps not by fade in/out but porting the technique in adeclick.

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The two most common reasons for clicks are:

  • Samplerate mismatch (which has been greatly improved in the 23.05 release)
  • Poor audio seeking (which was also improved in 23.05 release)

Both of those two reasons result in discontinuities lasting many samples.

In my testing and experimenting, a single sample discontinuity between two clips is very hard to hear and rarely worth mitigating. But I am open minded about researching it if someone can provide a simple example project that demonstrates a problem.

I recommend saving your project with a new name and trying it with 23.05 to see if things improve.

I looked into this and it will not port over because it relies on modifying past/future samples to smooth out discontinuities (modify samples at the end of one frame and the beginning of the next). Filters can not look ahead or backwards. It could be made into a link - but we can not put links on playlists. I have some ideas for a different algorithm that only does smoothing at the beginning of a frame. But I need some good test cases to develop it with.

Tested the project file in 23.05.14
All the clicks are still present in between audio clips.

It’s always really noticeable when it happens so it’s more than a single sample discontinuity I guess.

I’ve recreated the exact sequence in another open source software and I get the same issue. The same solution I’ve used solves the problem: add a fade out/fade in in between clips. fwiw the other software lets me set the fade time to 00:00:00:01 rather than 00:00:00:02. Probably not a noticeable difference.

In any case, how can I send you my sample project with the video file?
It’s all in one folder.

Just popping a bit of feedback from my projects: I’ve always had random pops in between clips, both from vfr phone clips and gopro videos. The latest release greatly improved this but I can still hear them every now and then.

I think some kind of per track/output filter that does 1 frame fade (or whatever it takes to get rid of it) would be a very good addition, I’d even go with doing this by default on any project as it’s pretty annoying when it happens especially when the sound is low.

It would be great if you could zip it up and then share it with a cloud sharing service like Google Drive or OneDrive.

The break between each clip has a click.
Each clip has a fade in and fade out filter that are unchecked.
Turning the filters on eliminates the clicks.

The latest beta build has two new filters that can be applied to a track to automatically reduce the pop/click.

Here is the beta thread on the forum:

Here is announcement:

From the notes:

Added Track Auto Fade and Track Seam audio filters. These filters address an old problem where clicks and pops may be heard in export when switching between clips due to discontinuities in the audio stream. A recommended technique was to add a 2 frame Fade Audio Out and Fade Audio in filters on clips. Track Auto Fade automates that. Track Seam works on a similar level but rather attempts to do a smoothing between outgoing and incoming samples around edit points. Both of these new filters may ONLY be added to individual tracks—audio or video.

Would you be willing to test these new filters to see if they work for you?

I’d like to test it but I’m travelling for a couple of weeks and then in the process of a move. If my editing computer is not packed I can maybe test towards the end of the month.