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New Contributor

Get input for webinar from vMix via NDI Virtual input - video issues

Hello,

 

we are using GoToWebinar to host our on-line events and decided to create a little studio for that purpose.

 

We have 3 PCs involved:

PC1) speaker's PC (view questions and sends slides via NDI tools to PC2)

PC2) director's PC with vMix software (get input from cameras, mics and PC1 and sends output to PC3 via NDI tools)

PC3) GoToWebinar PC (launches the GTW client and get audio and video input from PC2 via NDI - as if it was a webcam)

 

The system works, but we have issues when playing videos. Speaker's audio and video are good, but videos are jerky. 

 

We did a  lot of troubleshooting on our LAN and WAN trying to prioritize GTW traffic (we have a 1GB LAN and 100MB fiber optic connection to the Internet).

 

Then, upon a techinician's suggestion, we tried to send the same input to other video/communication software (i.e. Zoom): videos were perfect.

 

It seems that the GTW client or the GTW protocol cannot handle NDI input as efficiently as other software - is it possible?

 

Are there some specific arrangement for this situation?

 

Thanks in advance for your support.

 

5 REPLIES 5
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LogMeIn Contributor

Re: Get input for webinar from vMix via NDI Virtual input - video issues

@FRIDLE  Were you playing the videos from your desktop or using the pre-loaded video stream from your webinar schedule?

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New Contributor

Re: Get input for webinar from vMix via NDI Virtual input - video issues

Hello AshC,

 

I am playing the videos from the webcam input. The videos were not played sharing the presenter's screen.

 

The webcam input is an Newtek NDI virtual input. The NDI stream is perfect when monitored inside the LAN.

 

The same video is OK if it is preloaded and played from the "share" tool of GoToWebinar and it is OK.

 

I tought this could be a network issue, but I made a test with the same software and devices exception made for GoToWebinar - I used Zoom instead. The video in this case was OK.

 

Maybe we need to change some setting on the firewall ?

 

 

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LogMeIn Contributor

Re: Get input for webinar from vMix via NDI Virtual input - video issues

I haven't personally worked with that set up, though we have had success with ManyCam inputing various devices through the GoTo webcam port.  It may be that you have to lower the quality some, before it will stream successfully in GoToWebinar (720P is the current max quality).

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New Contributor

Re: Get input for webinar from vMix via NDI Virtual input - video issues

Hello AshC.

 

I think I have 2 issues to deal with.

 

The first is related to the encoding algorithm that GoToWebinar uses to process the input of the webcam, mix it with the audio from the mic and send the resulting stream to the audience.  If the input contains many frames the video received by the attendees is choopy and jerky, and, worst, the audio is degraded (loss of fragments, varying volume). The client software does not have any option related to video quality. It would be great if GoToWebinar could have something like a "high quality" option. It would be also great to have a native NDI compatibility (like Skype).

 

The second is related to networking. It seems that the same configuration (same computers, webcams, microphones) can "play" the same webinar (same content) with different quality when connected to different networks (different providers) - even if the networks should have the same performance (bandwith and latency). I have not yet understood which could be the cause... I think it is some firewall setting. By the way, other applications (i.e.Zoom) seems not to be affected by this issue.

 

I am performing various tests. Every suggestion is welcome.

 

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LogMeIn Contributor

Re: Get input for webinar from vMix via NDI Virtual input - video issues

Currently there is a maximum of 30 f/s transfer rate for all webcam feeds, which also caps the proportions at 720p.  If you can dial back your video feeds under this limit, then you may have better success displaying them to your audience.

 

I can't say exactly why different networks would be giving you different quality, besides latency on the LAN or throttling by the ISP there.  This article may be of help: https://support.goto.com/meeting/help/test-your-network-settings-windows-g2m050025