[audio] Bug: Loud sound glitches on right channel after rendering with Hitfilm

Coincident
Coincident Website User Posts: 13 Just Starting Out
edited November 2020 in HitFilm

Hello everyone.

There's another bug in Hitfilm (15.2.10619.40501) that has been ruining the audio of all the videos I've rendered, and has been taking me hours of work to correct the audio manually, each time it happens.

Randomly across the video, there are very high-pitched and loud sound artifacts appearing on the right channel of my audio. The left channel is always immaculate. If I do a spectrum analysis of the audio before (source file), and after rendering with HitFilm, this is what I see:

The top 2 of those 3 audio artifacts cannot be heard (by me at least), but the one on the bottom (15KHz) can be heard as a very sharp BEEP on my right ear; when loud enough, it even hurts.

This problem happens in any render from Hitfilm: MP4 with AAC audio, MP3 audio, or WAV audio directly; all of them have these glitches at exactly the same moments in time. If I play back the video within HitFilm in the preview window, I can also hear the BEEPs at those moments. If I render the same project multiple times, the moments when this happens are also always the same. But different source videos will have audio glitches at different moments.

To reproduce this problem, I do the following:

  • Record an .mkv using OBS, capturing a single source of audio from a video game (in this case, doom)
  • Use HandBrake to transcode the video into .mp4 (with CFR)
  • Create a new HitFilm project, import and add the .mp4 video into the project timeline
  • Without editing or adding effects, I immediately render a .WAV file with the audio only

Attachment - ZIP with source .mp4 and HitFilm project to create the problem and the resulting .WAV file with the glitches (they happen at several moments; I can hear the ones at: 12s, 20s, and 35s):

Attachment - MediaInfo of the source file:

Because I can hear these audio glitches when previewing inside HitFilm, I believe this might be an audio-decoding problem; but I'm not sure what exactly is the cause.


Has anyone else had this problem? Am I doing something wrong to cause this problem? Is there something wrong with Hitfilm's audio processing?

Any help in understanding/solving this problem is greatly appreciated.


Specs: Win10-64bit (bug happened in Win7-64bit too). Intel i7 7700K @ 4.2GHz. 16GB of RAM. GeForce 1080ti. Samsung SSD 850 EVO, and two other Western-Digital HDD drives for storage. Creative X-Fi Titanium PCI-e sound card.

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Comments

  • EvilDaystar
    EvilDaystar Website User Posts: 301 Enthusiast

    I found something similar when clips are cut too short.

    I'm not at home but I'll dl you project and see.

  • Coincident
    Coincident Website User Posts: 13 Just Starting Out

    Thanks. Let me know if, when you render that same project, you get the same audio glitch as the screenshot I left above (at 35 seconds).

  • EvilDaystar
    EvilDaystar Website User Posts: 301 Enthusiast

    Ok so downloaded the files and had a gander.

    I did an export ... just straight to the default WAV preset and then brought the original wav, your export and my export into Reaper and turned on the Spectograph.


    I also appear to have the same issue but much less intense.

    What I've seen is if you cut the audio using the line in the editor too sharply you get a noise so my issue was not the same as yours. Not sure what is going on here.

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,798 Ambassador

    Most software inserts a quick (1-2ms) fade on audio cuts. Hitfilm doesn't. Best guess is that audio edits are happening off a "zero (amplitude) crossing" and causing the click artifact.

  • EvilDaystar
    EvilDaystar Website User Posts: 301 Enthusiast


    That's probably what is happening to me with my problem (not so much a problem, just something I need to keep in mind) but in @Coincident 's problem is there is no cut. He imported an OBS recording. The recording (last layer in my image) doesn't have that artifact. If we literally just export the file right out .. lietrally no edits at all, import throw on the timeline export ... it adds that click.

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,798 Ambassador

    Ah, my bad. I should have more closely read the thread.

    I don't currently own anything that does spectrographs (but can install Audacity). Still, that shouldn't happen.

    Support ticket?

  • Coincident
    Coincident Website User Posts: 13 Just Starting Out

    Yes, there are no audio cuts or edits in this case. I import the source file and immediately export the audio.

    Audacity is fairly easy to install and use.

    Ok. I can file a support ticket with this information.

  • EvilDaystar
    EvilDaystar Website User Posts: 301 Enthusiast
    edited November 2020

    @Triem23

    Audacity is ok but all changes are destructive. Reaper is only about 60$ US and effects can be added to a chain in a non destructive way. You can even use a audio layer as a grade layer and run your mix througt that grade so if you are mixing a lot of tracks into one you don't have to apply effects to each track individually.

    They have a 60 day trial of the full version.

    It's my go to for audio. I do have a problem with it where I can't get my audio out to be my onboard audio, it insists on outputting to the out of my Behringer UM2 but I have an issue with my UM2 ... it freaked out a while ago and I can't get audio in and out at the same time so I use the audio in for my mic and use the audio out from my built in soundcard.

    So when I use reaper, I have to plug in my headphones into my UM2.