Blackmagic Forum

kalpox wrote:From the very moment you can do exactly the same with any other video editor with no issues (using PPro right now)

Premiere Pro doesn't use the GPU for encoding purposes. If hardware encoding is checked in the Export Settings dialog, it's using the Intel QuickSync feature, not the GPU.

As noted, crackle is occurring with other formats, including DNxHD. Crackle and other audio distortion may also be apparent when playing timelines in the Deliver page.

Much as these proposed solutions are appreciated, it could be that they're more of a distraction than a help at this point.

The work around of rendering at less then max works, doesn't it? It did in my case anyway.

It would be nice to see it fixed though.

Yes, that workaround works. It's the suggestion that something else is wrong, user error, etc. which is not working.

Yes... I see little point in striving to have a fast (most productive) workstation if you then have to manually throttle it in order to work around bugs.

I haven't observed this problem using an NVIDIA GPU but I'm still on Resolve 15 (too many issues remaining in 16 and I value reliability and productivity over "features"). Since it doesn't happen on Resolve 15 but does happen in Resolve 16 then clearly it is a Resolve 16 issue, not an NVIDIA issue.

RCModelReviews wrote: Since it doesn't happen on Resolve 15 but does happen in Resolve 16 then clearly it is a Resolve 16 issue, not an NVIDIA issue.

Are you running the latest nVidia driver?
I had not noticed the problem in 431.70 only since 431.86
I am hoping that this is sorted before I have to do delivery H.264s

I am experiencing this too in Resolve Studio 16.1 Public Beta 3 on Windows 10.

Exporting to DNxHQX 10-bit Linear 24bit 48khz audio. Crackle is apparent on audio channels of the exported file.

The source WAVs sound fine and do not have same crackle.

Roen Davis wrote:Are you running the latest nVidia driver?
I had not noticed the problem in 431.70 only since 431.86
I am hoping that this is sorted before I have to do delivery H.264s

Absolutely not. I work on the old adage "If it works, don't fix it" so unless the upgrade is an important security one, I give it a miss.

This allows me to work day in, day out without having to face unexpected problems because someone tried to "fix" something that wasn't broken in the first place.

I also drive a 1994 Toyota pickup truck... and it does everything I ask it to do in return for a little gas and oil from time to time.

Call me old, call me conservative but (in my mind) I'm just very wise

It's looking like the nVidia driver isn't the cause here, as exports which don't use that are still having problems.

So the other thing to look at is USB audio. I don't use it, and don't have any issues. Are the folks with problems using any USB audio devices?

No audio usb here. FireWire card to MOTU device.

IMHO audio device shouldn't matter in export chain.

Interesting.

So maybe the question should be is anyone having a problem using any kind of external audio device?

Creative Sound Blaster X-Fi HD here and the bug is killing me. Please, it's been almost one month since the last beta. Just a hotfix or something.

I'm using neither NVIDIA or a sound card for rendering.

Setting the Render Speed to 50fps did the trick.

A workaround until BM can fix this bug!

Horrible issue. I wasn't able to render a 6 minute video without crackles (there were always at least 3-4), even if I rendered WAV audio only. They always occurred in different places, and not a single render of more than ten of them without noticeable crackles.

Lowering Render Speed to 50 did the trick for me also.

Some people suggested that it has something to do with Nvidia cards. Does Resolve use GPU when dealing with audio? Because when rendering audio only, no video is processed, so it should not matter what GPU one has. (I have Nvidia GTX 770 card, and second to last Game Ready drivers)

Can't wait for beta 4. Hope the problem with crackling audio will be resolved.

Hello!

signed up specifically to report this issue. Tried everything but audio crackles/corruption happens no matter what format, render speed or even PC I tried (tried 3 different ones, all Windows 10, very high spec workstations). As far as I can tell it has nothing to do with mass storage, video cards, or audio interface. It appears to be just a bug in the audio rendering - it does not even need multiple audio clips or video to show up. I took my project, deleted everything except the music track, rendered and still got corruption.

One thing that's true is that reducing the render speed *mitigates* the problem, and you might not notice it anymore, but there could still be corruption. In one of my tests at render speed 50 the crackles were gone, but there were definite artifacts in two locations that I could have easily missed had I not specifically been looking for problems. And no, these were not compression artifacts, but definite digital distortion.

At the end, for this project, since the only audio was a stereo music track, I rendered the video with Resolve, then imported into HitFilm, added the audio and rendered with the same settings. No audio problems at all.

Hopefully this gets fixed in the next beta, since b3 is unusable as is.

It is a kind of relief that nVidia is clear and if V16 non beta is ok, I might roll back.

mbaksa wrote: Does Resolve use GPU when dealing with audio? Because when rendering audio only, no video is processed, so it should not matter what GPU one has.

I have been using the nVidia H.264/65 rendering - I assume it has to handle audio at some level, no?

Andrea, are you sure the other computers didn’t have Nvidia GPUs? Nvidia still isn’t out of the woods yet.

Roen Davis wrote:

mbaksa wrote:Does Resolve use GPU when dealing with audio? Because when rendering audio only, no video is processed, so it should not matter what GPU one has.

I have been using the nVidia H.264/65 rendering - I assume it has to handle audio at some level, no?

You are using that for video rendering. Actually, not even for that - you are using it for encoding already rendered video frames. So it would not make sense for that to have any influence on audio, especially since it should happen on GPU and VRAM, instead on CPU and motherboard RAM, where audio rendering should occur. Unless Resolve (in part) uses GPU for audio also.

The whole situation is just weird. Random noise introduced into digital audio pipeline.

A couple things to try that I’ve read from google search.

Disable Fast Start in Windows boot settings.

Disable the Nvidia audio driver.

It might make more sense to revert to an earlier version or wait for the next beta, as the developers are surely aware of the issue by now.

Users may not know if other strategies are actually working, as seems to be the case with the proposed rendering speed workaround, where artifacts may still be present.

Gary Hango wrote:Andrea, are you sure the other computers didn’t have Nvidia GPUs? Nvidia still isn’t out of the woods yet.

You are correct - they all had NVidia cards, very recent ones - but unless Resolve uses the GPU *unconditionally* as a compute platform to render audio, which seems very unlikely since it does not even do that for video, then I don't see how the problem could be related. Still, I can only guess....

Mostly I wanted to stress that just because the audio might not exhibit very obvious glitches when rendered at lower speeds, it does not mean that some distortion might have not been introduced.

Hopefully the team has enough information to track down the issue!

Cheers,

A=

I have an RTX 2080 TI.
I don’t believe I was experiencing this issue prior to 16.1...

Using R 16 and getting MP3 crackle/pops approx. 11 secs after playing from any point in the track. Exported it to wav file and same issue.

I have just rendered out 3 x 30 min 24 bit .wav's to send to a mix.
i didn't listen to every second but 5 - 6 mins at a stretch and found no crackle or pop.
I am still using B.025.

apessino wrote:It appears to be just a bug in the audio rendering

Maybe. But what triggers it, and why only for some?

UHD .mxf render 24 bit stereo from timeline has crackle
?????????????????????????????????????????????

W10 1903
RTX 2080 TI
B.025
32 G RAM

I installed V16 and the crackle seems to be gone.

I can confirm setting render speed to 50 exports a clean audio. Phew!

kalpox wrote:I can confirm setting render speed to 50 exports a clean audio. Phew!

It did not work for me.
it is random. I tried 50% and 75%.
I could find crackle and re-render only to find crackle somewhere else.
V16 seems to be free from this issue.

Speed reduction worked for me (or it seems like so). Even setting it to 100% instead of MAX.
It even helps in solving a problem, described in this thread:
viewtopic.php?f=21&t=95939

Roen Davis wrote:
This crackle and pop might be Nvidia? RTX?

Nope. AMD Radeon VII, here, and I'm getting crackly audio. FUN, ISN'T IT?!

philtimm wrote:

Roen Davis wrote:
This crackle and pop might be Nvidia? RTX?

Nope. AMD Radeon VII, here, and I'm getting crackly audio. FUN, ISN'T IT?!

No, it isn't fun - but it's a BETA for a reason. We find problems, report them, wait for a fix... that's the deal.

TomasM wrote:Speed reduction worked for me (or it seems like so). Even setting it to 100% instead of MAX.
It even helps in solving a problem, described in this thread:
viewtopic.php?f=21&t=95939

Update:
Apparently this "workaround" DOES NOT work for me either...

i tried 16.1 on a project that had the bug and now it is ok.

Thanx Benoit, good to know
I was really sad about that critical bug in DR and was ready to go back to PP

I have this behaviour also with DNxHD and PCM 24bit audio, stereo, no effects at all.
Tried the 50% mode, but no luck, just once among many failed attempts.

With version 16.1? Could you please provide more details about your system, like I've done in my signature below?

I'm currently on Version 16.1.08.025 and I have this audio crackle problem. I now have to output a feature I originally did in Version 15.

I'm a little confused...

Is the current 16.1 available for download at Blackmagic a new iteration of the software I am running? Is 16.1 out of beta now? Is the audio crackle problem fixed?

Do I need to go back to another release (16? 15?) in order to be confident in a clean audio render?

Thanks

The answer to part of your questions is in the announcement section of the parent forum to this one.

Just got back to the studio after a trip, downloaded 16.1 studio final, opened the project that was failing with huge distortion/errors in the audio, set all export settings back to defaults (max render speed, NVIDIA encoder, etc.), exported, and... all good! No glitches at all.

Bug has been corrected as far as I can tell - whew!

I keep having this problem on the latest version. Seems random. I have to render several times until one goes well

Jean Paul Sneider wrote:I keep having this problem on the latest version. Seems random. I have to render several times until one goes well

Have you tried reducing the Deliver page Render Setting of Render Speed to a lower value? BTW, the numbered values are not percentages, they're FPS. Measure the render speed that you're getting now and then set that number to a lower value. Also, if you're using the NVIDIA encoder, try the native. If those don't work then you should provide your software and hardware configuration in your signature as I have and describe the codecs and resolutions you're using.

Yeah running 16.1.1 on Mac Pro High Sierra 10.13.6 with Dual AMD D500 and had crackling.

In order to mitigate the crackling I broke the 30 min DCP into 11 parts. I couldn't for the life of me get all the crackling out. 2-3 parts in the whole production had crackling.

Massive problem for me. Instead of being able to finesse the final product I had to keep re-rendering output, praying it wouldn't crackle and then re-rendering again if it did.

I ended up having to compromise and live with some crackling in the final product because it was not possible to completely eliminate. Had our theatre screening tonight and just had to grit and bear it.

I'm horrified to having to reduce the speed of rendering to eliminate. I need every bit of performance I can to work on these longer projects and strict deadlines.

I have an audio-only timeline that I want to export to PCM, and I too am getting random glitches at different points when I export repeatedly. All I did in this timeline really was keyframe the clip volumes and use elastic wave to adjust the speed midway through the clip.

I would like to try the render speed trick, but unfortunately I don't see it in my render settings anymore. Have the developers moved this setting away in 16.2?

I am running DaVinci 16.2.2.012 on a 2013 MacBook Pro (no special graphics card!).

POTENTIAL WORKAROUND:
For me, the problem occurred when I tried exporting my project with a limited In-Out range that didn't span the entire timeline (in particular, my IN-point was not at 0:00:00). After playing with the issue, I noticed that when I exported the exact same project with the IN-point of the range set to 0:00:00 (the start of the timeline), all audio glitches disappeared. I could then cut off the beginning of the exported clip in a separate step.

BLACKMAGIC TEAM:
Please fix this bug. It has been around for a while, it seems. The fact that the IN point plays a role may give you a hint at which part of your code causes this glitch. My project only consisted of a single audio clip (no video) with retime controls that modify playback speed along the way. Maybe when your programming code tries to stitch the different retime regions together seamlessly, it makes assumptions on the duration of the clip up until that moment (to achieve smoothness of the transition between retime regions). If there is a bug that accidentally assumes that the export region starts at the beginning of the timeline (0:00:00) instead of at the IN point, that would explain the audio glitches at the retime transition points.

I am using version 16.2.3.015.

Logged in just to bump this thread because the bug still exists. Getting those sharp pops and crackles at random times after exporting. Currently exporting at 100 setting instead of Maximum to see if it fixes the problem for me. Very strange issue, and quite telling that staff haven't commented at ALL on this VERY SERIOUS bug.

JTXPdev wrote:...quite telling that staff haven't commented at ALL on this VERY SERIOUS bug.

Yeah, that seems to happen quite a lot! Hopefully, though, they are at least reading about them...