Audio Crackle AAC Audio (mp4) Video Exports

For large files, you might have to use a file sharing service like google drive.

I too have been experiencing crackling in the project as well as the export. I tried all of the tricks to no avail. The only resolution I got was to export all of the edited audio into a single file (in this case, I chose WAV) then imported that file into my sound editor (I use audacity). I also imported into audacity all of the audio clips used for my shotcut project then edited them as needed using the sound clip from shotcut to assist with the timing. I then used the newly created sound file to put back into shotcut as a single file and the crackling issues are no longer evident. It seems there is an issue with handling audio clips that are sliced within shotcut. To experiment, I took the good working audio clip then split it at a random spot. As soon as I did this, the crackling was back. Just wanted to share this in case it can help someone get their project completed or maybe even to help the devs figure out what is going on with shotcut. Still love the platform. Happy editing all!

This bug makes the program unusable for me. Glad I recently got something else.

The bug is now happening even when I select ‘Default for format’ as Codec.

The audio does not crackle in the project. Only once it has been exported.

Luckily, tried again with a higher bitrate (384k is extremely high)

Also, disabled the video. This time no crackle.

I recall in the past that disabling the video did not make a difference in the crackle. I was also able to get glitch free audio at 192 k when selecting ‘Default for Format’ Audio Codec.

That’s telling me this is an intermittent thing that happens across a variety of conditions.

New users can only embed one media into each post. That’s a wrench in the way of productivity.

To admins - audio files cannot be attached here. I can post the glitch vs no glitch audio segments if you allow permissions for .wav and .mp3.

I am still interested in helping. Have you made any progress to make a simple example project?

Correct. An external file sharing service like GoogleDrive is the best way to share media files for this site. It would be great if you could provide links to a single audio file and mlt project file and step-by-step instructions to use those files to hear the problem.

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Hello Brian, I made a minimal example where cracks in the audio of the exported file appear.

Thank you!

Thank you for providing the example project. I think this is going to be a difficult problem to nail down. I think I hear what you are describing. But I am not sure.

The reason that I am unsure is because in my listening test the preview in Shotcut sounds the same as the exported file. I am using noise canceling headphones to listen, but maybe I am not able to discern a difference between preview and exported file. Also, I find the distortion (if I am indeed hearing what you hear) to be very subtle.

A couple of points for clarification:

Have you also tried the latest version 22.12.21? Both versions sound the same to me, but I am not sure if I am hearing the problem correctly.

In my listening, I think I would describe the distortion as “clicks”. I agree that they do not sound like clipping. Also, very subtle to my ears, but maybe more pronounced to experienced listeners.

When I play the source .wav file and turn my computer volume up very loud, I feel like I can hear the clicks in the source file. Maybe I am not listening for the right distortion?

The file you provided is .wav. I assume you performed a conversion as suggested by another user above.

You have an equalizer filter applied with -20db on the low end. So I think that would explain the low end? There is basically no low end in the preview when I listen.


AAC is the default when I choose any of the H.264 presets. Which preset are you starting from?

What program are you using to listen to the exported file? Windows media player? How does it sound it you open the exported file and play it in Shotcut?

I apologize if the questions seem futile and distortion is so obvious to you. Hopefully I am not missing something. Or maybe another reader will download your project and will be able to hear the different between preview and exported file.

Hello Brian. Right, there are some filters applied to the audio - that is not optimal to find out what the problem is. I prepare another example with is even more minimal. My system:

Host: erde Kernel: 6.0.0-6-amd64 arch: x86_64 bits: 64 Console: pty pts/4
Distro: Debian GNU/Linux bookworm/sid

I tried different versions of shotcut, the clicks in the exported file remain. Yes, it’s subtle. I played with vlc and gnome video player and tried other computers too. I make a picture of the original waveform in comparison with the clicky one. I can do that tonight. Thanks for your effort!

Perhaps it is not necessary to upload another project: I removed all the audiofilters in the project (also the ones in the master-track “output”) and the clicks still remain.

i noticed something else when analysing the audio (original vs. exported): the exported audio is slightly shortened/squeezed together as if shotcut resamples it (i’m just guessing).

This is good progress to make the most minimal example possible.

Shotcut is not resampling because the source sample rate matches the output sample rate. And there would be messages in the log if sample rate conversion were occurring. Maybe samples are being dropped for some reason.

Here is the version without filters. One more thing I noticed is, that when I use the whole original wav-file it does not click. It clicks when cutted it in parts within shotcut (in the exported video).

Thanks for the minimal project.

I’ve been “squinting” my ears on these files and I am really struggling. In all my listening tests, the original WAV file, the Shotcut preview playback and the exported file all sound the same. I’m afraid that my perception is not good enough to hear any difference. Hopefully someone else will be able to hear a difference in the example you provided.

Can you explain this more? In the minimal project, there is only one clip from the WAV file. There are not multiple parts.

Hello Brian, right, I cutted the original source only into one short part. The most (at least to me) noticable clicks are right at the beginning of the exported file.

Does the click disappear if you put a 1 video frame length audio fade in and out? Is it just a discontinuity caused by cutting?

Hi, it appears with and without a fader. I tried several lenghts of fades but it didn’t work. If I put in a one-frame-fade in audio, the audio completly disappears (another bug?). With a 2-frame-fader it works, but the cracklings and noises are still here.

Hi Brian. Here I have another minimal example which has even more noticeable noises in the export that are not in the sourcefile. (4.9 MB)

Thanks for your effort!

Your project contains raw flac files. Unfortunately, that is known to be problematic in Shotcut. The underlying FFMPEG library does not seek well with raw flac. And we have not found a solution. FLAC in MKV in works better.

Use Properties > menu > Convert to Edit-friendly.

Alternatively, I suggest to remux that to a mkv file using ffmpeg ffmpeg -i your.flac -c copy your.mkv.

Additional reading:

Thank you, I’ll try it with that and avoid flac.