Choppy Audio on Zoom via HDMI output and capture card

[Robertjdavies]

Hi everyone,

I'm hoping to find a solution here, as I am all out of ideas personally. Long story short, our stake center AV install was recently upgraded to the latest and greatest. As such, I have an HDMI out port in the back of the chapel that hooks into the AV rack running all the video inputs (PTZ mounted cam, input from podium HDMI, etc). I purchased an HDMI capture card (EVGA XR1 lite) to pull the video and audio from that port to be sent out on Zoom for our stake conferences. So far, using that to pull the video works fine, but getting audio along with it is an issue. The audio I get on the other end of the Zoom broadcast is very choppy, very similar to UDP packets arriving late on your video game chat app of choice. It is designed to carry both, as I can hook TVs into the other ports in the building and receive the accompanying audio with no issues. I have tried pulling both audio and video from other ports in the building with the capture card and have the same result. The capture card is running the latest firmware, and I have purchased a beefier (personal) laptop to see if the processing power was the issue, to no improvement. My work around for the moment is to pull the audio from the hearing assist broadcast via an RTLSDR USB stick and antenna to send that into Zoom for the broadcast, but ideally, I'd like to figure this out/have it fixed so that the wards in the building can use the hardware for their sacrament meeting broadcasts without needing me to be there to run/assist. The long and short of my question is, what am I missing here? I can come up with no reason this should be happening.

Thanks in advance!

[Mikerowaved]

Zoom can sometimes chop up music because it treats it as background noise. See: viewtopic.php?t=41960

Not sure if this is your problem, but it's easy to try.

[Robertjdavies]

I'll give this a shot next time I get a chance. Thanks!

[Robertjdavies]

I have tried changing this setting, including turning off echo cancellation, to the same effect. I've included a gif of the audio through Zoom in case this offers any additional insight.

EDIT: Just realized that the gif doesn't include sound, so that isn't going to help.
EDIT2: Forgive me if this is against the forum rules, but here's a link to the video from my drive. https://drive.google.com/file/d/1CBT09n ... share_link

[russellhltn]

The video does help, as it's clear you're talking about just trying to capture the speaker at the podium and not the much softer music.

Have you tried connecting the capture card to other sources? That may be tricky as it may be designed to reject copyrighted content.

You might also go looking for forums or support that deal with that card. My guess is that the church system is encoding the sound in a way the capture card doesn't like.

[brad_p]

I'd continue to learn and rule out issues.


Can you use your capture device on an HDMI cable you know provides both video and audio, such as a DVD player? If the capture device is giving you the same problems on a DVD player, then it's very likely either the computer's fault or the capture device's fault.

What happens if you use your capture card on another laptop or computer? Same issues? What happens if you use a tool like OBS to view the video source and listen to the audio source (OBS has audio monitoring of "monitor only (mute ouput)" and "monitor and output mode" to help you hear exactly what it's capturing.)

[russellhltn]

Can you use your capture device on an HDMI cable you know provides both video and audio, such as a DVD player? If the capture device is giving you the same problems on a DVD player, then it's very likely either the computer's fault or the capture device's fault.

The problem with using a DVD or Blu-ray player is the capture card may sense copyrighted content and refuse to work. You need to test with a non-copyrighted source, like a camera.

[Robertjdavies]

Rather than trying to find a non-HDCP source, I bought a card from another brand to try out. I'm getting the same issue with that one, so I'm guessing that the issue may lie in the AV system somewhere, but I'm not confident in that.

[russellhltn]

I see you've successfully plugged in a TV into a source that the capture card won't work with.

So it would appear the data is there, the card just isn't working with it.

If the camera outputs sound on the HDMI output, you could try plugging that into the capture card directly.

[Mikerowaved]

My work around for the moment is to pull the audio from the hearing assist broadcast via an RTLSDR USB stick and antenna to send that into Zoom for the broadcast...

Our building's A/V was revamped about a year or two before yours, and now that I think of it, I've never been able to get audio over the HDMI to work as expected either. Our current solution is to pull the audio directly from the hearing assist transmitter using its headphone jack. A 3.5mm cable plugs that into either our PC's line-in or our capture card's stereo input jack and we get super clean audio from it. Unfortunately, it appears your EVGA XR1 lite doesn't have an audio-in port. If your notebook doesn't have a dual mic/line level jack, USB soundcards are dirt cheap, and for the most part, work pretty well.

We stream almost exclusively to YouTube Live using OBS, so I'm not familiar with how well Zoom handles audio and video from different sources. Of course, one can combine the A/V in OBS then output that to Zoom, but that adds another layer of complexity.