Audio glitches when playing back several simultaneous video clips

bryan-quarrie wrote on 2/2/2021, 6:40 PM

Hello all,

I have been tasked with putting together a virtual choir video with 36 choristers. The issue I am experiencing is that sometimes the audio from some of the simultaneously played video clips cut out intermittently, even though the video clips are still playing back ok. The clips were a mixture of 1080p and 480p clips (mp4s), which were converted to 480p mp4s (30 frames per second) with Wondershare, then imported into Vegas Pro. Also the clips were played back from a USB3 external hard drive.

Another thing I've noticed is that as I continue to add the video clips / tracks to the timeline, the audio waveforms for subsequent tracks do not appear, unless you zoom into the track a few times. Of course the problem with that is that it is almost impossible to sync the tracks correctly without the waveforms on the screen without zooming to microscopic levels (see pics below)

(without zoom)

 

(zoomed in)

 

Regarding the audio playback issue, I've tried defragging the external harddrive where the clips are stored, but still no joy.

Any ideas why this is happening?

 

Thanks.

 

Machine specs:

RAM 64GB 3200 DDR4

CPU: Ryzen 9 3900x 12-Core processor

GPU: Radeon RX580 (8GB VRAM)

External Drive: USB3 1TB Seagate Expansion Desk drive

Windows 10, Version 20H2 (Build no 19042.746)

Vegas Pro 18 Build 434 (but the problem was present on the previous build as well).

Comments

Musicvid wrote on 2/2/2021, 8:04 PM

There is a Search Box at the top of every forum start page.

Type in "virtual choir" on the Vegas Pro start page.

Subsequently, you find a wealth of discussion including a couple of recent marathon threads.

Feel free to ask a question there, or perhaps IM one of the principles.

 

bryan-quarrie wrote on 2/3/2021, 2:29 AM

Thanks @Musicvid 👍. I found some great threads on the VC due to the search - Some methods like “Cookie Cutter” I never even thought about 😀👍.

 

How about the audio issue? Any ideas about that? (this is the real issue that is doing my head in 😕😕).

 

If my memory serves me, I used to use Cubase VST 5 back in the day, and if you intended to use more audio tracks than the default you had to mess about with memory buffer settings and set track counts etc. Does Vegas Pro operate on the same principle (but for audio tracks only)?

 

Thanks again 😀

 

bryan-quarrie wrote on 2/3/2021, 4:46 AM

OK Just an update...

 

Ocaasionally I would surf the web while doing this sort of thing on Vegas Pro, and I believe that Vegas Pro can occasionally conflict with the audio shared with the Chrome web-browser.

 

To prove this, I made sure there were no browser windows open (Chrome in this case - I don't use any other browser like Edge etc), then opened Vegas Pro and loaded the Virtual Choir project. I then played it back and heard no audio glitches from that point onwards.

 

So far so good.

 

Thanks for your patience 👍

Musicvid wrote on 2/3/2021, 8:20 AM

Sounds like a little buffer overflow that is being aggravated by system activity -- network use isn't as innocuous as it seems.

In Preferences->Audio Device, what drivers are available to you in the drop-down?

bryan-quarrie wrote on 2/3/2021, 8:44 AM

 

Hi @Musicvid

It lists the following:

 

Microsoft Sound Mapper

Direct Sound Surround Mapper

Windows Classic Wave Driver

M-Audio Delta ASIO

Magix Low Latency 2016

Realtek ASIO

 

 

I know - Quite a few drivers! The computer is also used for music production in Pro Tools etc.

 

At the time of the issue, I was using the Microsoft Sound Mapper driver. I haven’t changed it since then 👍

Musicvid wrote on 2/3/2021, 9:02 AM

Yeah, Mapper is older technology. I would run through the others (but not Windows Classic), and pick the one that seems like the lowest latency to you. They should also be less prone to dropouts. And as you probably know, avoid competition for audio from other applications. "Direct Surround..." is your onboard ASIO (Realtek?)

bryan-quarrie wrote on 2/3/2021, 1:43 PM

The Realtek ASIO driver is the on-board chip on the motherboard (ASUS B350 plus). I haven't used the Direct Sound Mapper so I'm not sure how that one works.

Musicvid wrote on 2/4/2021, 10:42 AM

Doesn't hurt a thing to try ...