Blackmagic Forum

Hi,

I'm having a rather severe audio issue:

1080p25 timeline.
Video: MXF footage audio+video from SONY PXW-FS7 camera, an after effects ProRes444 render and a PNG graphic.
Audio: mono audio track from video MXF, being processed in the fairlight page, by three VST plugins (SONNOX denoiser and compressor, fabfilter EQ)

Playback in EDL: all audio is fine.

Exporting timeline IN to OUT to MXF OP1A DNxHD 1080p 220/185/175 10 bit
Audio PCM 16 bit stereo.

Video is ok. Audio NOT: random audio glitches in exported file. Tried exporting again a few times, each time the same sort of artifacts occur but in different places.

Tried exporting with disabled VST plugins -> still glitches in audio output
Tried exporting audio only -> still glitches in audio output
Tried exporting with lower gain (eliminating a few small inter-plugin overloads) -> still glitches in audio output
Tried exporting other codec (h.264 NVENC) -> still glitches in audio output
Tried exporting audio as 24bit -> still glitches in audio output

The glitches sound like small segments of audio that are missing/repeated

Seemed to have been fine in Beta1?

Anyway now it's broken

BTW: I'm on Windows 10.0.17134 Build 17134
Is that enough info?

Carl.

Same problem here. Sad to hear it was fixed in v15 but is back in 16.1.

Same problem. 16.1 Beta2. Frustrating.

Similar behaviour is if I insert two Waves plugins on bus. Exported audio has glitches.
My resolve is insert effect plugins to timeline track (not to bus) but I'd like preferred correct behaviour of DaVinci. I hope Blackmagic developers fix it.

I haven't seen this issue yet in Studio 16.1b2 for Windows.

Have you tested other audio sources, other timelines, other frame rates, other projects?

Yes I did.
Had to go back to 16.0 for a clean export.

Jim Simon wrote:I haven't seen this issue yet in Studio 16.1b2 for Windows.

Really? This is good to hear because there is a possibility that it can be fixed for Mac.

Jim Simon wrote:Have you tested other audio sources, other timelines, other frame rates, other projects?

This behavior has been tested in dozens of different projects.

OK.

You guys are all using .wav audio as source? No compressed formats?

Corrupted audio with third-party VST plugins goes back forever. Has any version been free of it? For sure?

(That's one reason why I don't like plug-ins, wanting such functionality built in and high quality.)

The same timeline with same source files exports just fine in DR 16.0. It is definitely a Beta bug.

With what VST plugins?

No VST plugins.

Jim Simon wrote:You guys are all using .wav audio as source? No compressed formats?

Of course. PCM 24-bit.

TomasM wrote:The same timeline with same source files exports just fine in DR 16.0. It is definitely a Beta bug.

I never had 16.0 installed, but the problem was also in DaVinci 15.

TomasM wrote:It is definitely a Beta bug.

Hard to pinpoint, though. I can't think of any more variables that might cause it to not work for you, while audio exports are working just fine for me.

Well... as usual it seems to be a combination of things.

When I REMOVE the plugins from the audio channel, the result is a bit better, less artefacts.
But still NOT ok.

An export from the same EDL but with the audio muted and other audio from some random WAV file on another track is clean.

So it seems the problem occurs with the audio from the camera file: this is the first audio track out of the eight that are in the MXF. As I said the footage originates from a SONY FS7: XAVC Intra 3840x2160 at 25fps, S-Log3, with 8 channels of 24bit PCM at 48kHz.

I take my audio to an external application for processing but for some smaller projects it would be very efficient to keep it all inside Resolve including the audio processing. But unfortunately we're not there yet..
Can't spend any more time on this, hope that maybe I have pointed in the right direction.

Will check again with the next beta!

Cheers,
Carl.

Maybe the length of a timeline?
I'm exporting a ~1hr final file. And glitches appear very irregulary.

I've exported two hour timelines without issue. I don't think that's it.

Have you any way of extracting the audio out of the files and then import them into Davinci to test if it works?

No time for such an extensive testing, unfortunately.
Switched to 16.0 until next stable release.

Daz Wood wrote:Have you any way of extracting the audio out of the files and then import them into Davinci to test if it works?

This brings the same result. This is not a way to solve this problem.

Vit Reiter wrote:This is not a way to solve this problem.

At this point, I think the effort is to try and find the variable that's causing a problem for some, but not others. Knowing that variable would give BMD somewhere to look.

Jim Simon wrote:At this point, I think the effort is to try and find the variable that's causing a problem for some, but not others. Knowing that variable would give BMD somewhere to look.

For me, the solution is only to insert effect plugins on the track on the timeline, not on the bus.
Extracting the audio out of the files and then import them into Davinci doesn't work

Still present in 16.1 b3, so for the moment this still makes DR unusable for me.

I, too, am getting this huge bug. Glad I'm not the only one, but it'd be REALLY nice to see an official response to it.

The only workaround I have found is to do a bounce of your mix within Fairlight, and go find that generated file and use that externally to encode with, by multiplexing it with your video file.

I can also confirm that this bug is still present in beta 3...

Does anybody from Blackmagic look at this forum at all?
Or do I need to additionally submit a bug report?

Some kind of reaction would be nice...

Can confirm that 16.1b3 is causing delivery errors with audio while using some Waves plugins. Plays fine on the timeline but upon delivery export I'm hearing artifacts of other random portions of the main bus playing for a few seconds before the main finally begins to play properly. The projects that have this problem all have submix busses FYI. Bouncing is a temp fix the problem as far as I can tell.

Jeffrey Hahn wrote:Can confirm that 16.1b3 is causing delivery errors with audio while using some Waves plugins. Plays fine on the timeline but upon delivery export I'm hearing artifacts of other random portions of the main bus playing for a few seconds before the main finally begins to play properly. The projects that have this problem all have submix busses FYI. Bouncing is a temp fix the problem as far as I can tell.

Yes, I confirm. Two or more Waves plugins applied to buses cause errors in the exported audio. One plugin is fine.

Apply them to the track, not to the bus. I hope the BM team can make it right.

Can you please check on 16.1 released today and let us know if you still see the issue?

Rohit,

Thanks for the response. Issue is still a problem in 16.1 final.

I have uploaded the DRP file to Dropbox for you in case that might help.

https://www.dropbox.com/s/g2lfc948w441q ... 0.drp?dl=0

Let us know if you need any other info and please keep us informed as to when this will be fixed.

Yeah I’m running 16.1.1 madly trying to prepare a DCP for cinema and I get these audio glitches.

I’m breaking up the 30 min DCP into 11 parts to minimise the amount of outputting I’m doing.

But it’s so hit or miss.

Sometimes a restart can fix it. But now it’s getting to the point where it’s always glitching.

Things that didn’t glitch - now do. It’s a massive problem for me.

My workstation specs should be in signature

Hello
Same problem here on every versions since 16
Even when I just put a MP3 song in audio, the output glitches ! I can't work !

remiphoto wrote:Hello
Same problem here on every versions since 16
Even when I just put a MP3 song in audio, the output glitches ! I can't work !

There is another thread with the same problem. Workaround is to set the NVidia encoder speed to 100 or lower from MAX.

This problems seems to manifest itself if the render speed is set to Max. Try a lower speed and see if it makes a difference.

Yes I've found changing that setting from MAX to 100 solves the issue for me with no noticeable slow down in rendering.