Inconsistent resolution issues using Screen Capture Alpha>Syphon Stage Output>Syphon Virtual Webcam

  • Hi everyone!

    Reaching out for some help for a daunting virtual theatre project involving three actors in their own homes. The director has asked me to create a POV view of two characters using their computers, the third actor interacts with the others only through video calls and texts.The audience sees their desktops in their entirety - their open tabs, their apps, the time and date, etc. There are scenes that involve live typing through the messages app and video & phone calls happening at the same time. 

    I've taken the time to read through every forum post on these topics and have done some testing, but as far as I can see, no one has posted about this very specific issue yet! Thank you all for your time spent on those posts! 😍

    The system we are currently using is as follows: using Whereby: the actors see each other in real time. We were hoping to use Facetime or something visually similar (lmk if you know something!), but Facetime interrupts the sound settings on lots of different video conferencing software. We are using Discord for all of our audio, calling, and technical chats. 

    I had two of the three actors install Isadora, Screen Capture plugin and Syphon Virtual Webcam in order to send their own desktops as a webcam input (to avoid having them share their screens during the show via Skype). On my device (late 2013 Mac Pro HighSierra 10.13.6), I take their respective Skype inputs via NDI and into Isadora to control the fades/cropping/etc.. From there, I am sending out to OBS via Syphon Client and using Blackhole virtual audio device to send our Discord Voice Channel to OBS. We are streaming on Twitch.


    The signal I am receiving on Skype from one of the actors is extremely low resolution. Neither are great, but I don't know what to tell them to do to improve or test it. Both of their Syphon Virtual Webcam windows are displaying 1920x1080 and 30+fps. Here are screen shots of their feeds directly from Skype:

    The user on the left is using Catalina & has had very little trouble getting everything installed, while the user on the right is using Mojave and has been having some issues getting things installed and up and running. Any ideas? 

    Here are their feeds in OBS:

    User 1 (Catalina Version 10.15.7)

    User 2 (Mojave Version 10.14.6 - 2014 Mac Air)

    As y'all can see, there's a notable difference but neither are ideal. Any ideas on how I can walk them through some tests to get a better image? In all of my testing of this system I didn't have any issues, but I also realise that these people have never used their devices like this before, so there may be some very basic settings and changes that I have neglected to tell them about. 

    Any help or suggestions on this issue (or the entire setup) are welcome and very appreciated! 

    Big love & gratitude to the community always and thanks in advance for any help!

  • @andielloyd Thanks for sharing the project; it looks super interesting!

    You've got quite the CDN here, let me see if I can help simplify a few elements. Right now, if I understand correctly, you have Display-->Isadora-->Syphon Virtual Cam--->Skype as the delivery path for the displays into your Skype server which you then pull NDI ISO feeds from on your end. Rather than booting up a media server and running various frame share / capture / conversion paths on the talent machines, perhaps you could try NDI Scan Covert and NDI virtual input instead of Isadora and the Syphon chain above. Or if the NDI latency is too high, maybe you could use just Syphoner and Syphon Virtual Cam together. Isadora is amazing, but it might be overkill if all you need to do is get their desktops as inputs into Skype. 

    Not a full solution, but some things to think about:

    Gallery Sienna's NDI Scan Convert, which is in many ways a direct upgrade over the NewTek one.

    NDI Tools, which contains the NDI Virtual Input program that converts any NDI source into a webcam input.

    Again, the disadvantage of the above is that NDI will introduce latency to the system, but maybe you are already dealing with sync later in the chain because of the Discord + Skype + Whereby systems needing to be reconciled?


    Years ago I used Syphoner to get a display into the Syphon system. Then you could use the Syphon Virtual Webcam as you have been doing.

    Again, just some food for thought! Looks like you have a great show in progress.

  • Hi,

    could the problem be down to the bandwidth of your performers internet connection? On a recent project where we used Skype we found Skype adjusts the resolution of callers video based on the speed of each connection. This was also reflected in the NDI feeds coming out of Skype which would be different for the different performers and would often change when disconnecting/reconnecting.

    My first test would be an internet speed test under normal operating conditions to see if there's much difference between the two performers connections. The upload speed is especially important. I've always used Ookla for this, I'm sure others are available.

    We found that for some performers they got better upload speeds by tethering their mobiles than they did through their home internet. Obviously, depending on your mobile package doing this can cost anything in the range from 'free' to 'hugely expensive' but it's worth a try.

  • @andielloyd

    I just did a lot of research in order to get good reliable video quality over internet and so far I understood the way to go is a SRT connection (peer to peer) - bird dog cloud is interesting I guess:

    also srt connection from vmix to vmix ....seams to work

  • @bodo looks great, pricy though... 

  • @andielloyd

    I second what @Kathmandale said about bandwidth. What I found even more important is that everyone should be connected via ethernet to their routers. Wifi can drop packets without much notice normally. The lower resolution could be a result of Skype compensating for lost packets. At the start of rehearsals for every show, we get a screenshot of every actor's (ookla) results and we buy them an ethernet cable and adapter for their machine (if they need one). Sometimes they need to string the cable through a hallway, down some stairs and across a few rooms, so 50' and sometimes 100' cables are pretty normal. Actually, if they are stringing it a long way, all the more reason they need it since that usually means they are far from their wifi access point. It's a small investment that can save lots of grief during a show.

    Good luck with the show!


  • Tech Staff


    Yeah my list would be:

    1. Do a speed test for each performer
    2. Get each performer and technician a wired connection to their router (and make sure they're using it properly with wifi disabled)
    3. Have a look around in the Skype settings to make sure that nobody has opted to send or receive video on any settings lower than the maximum. 
    4. Have a look at OBS Ninja, as it might be a better solution for remote desktop capture than Screen Capture Plugin > Isadora > Virtual Webcam > Skype > NDI > Isadora > OBS:

  • @andielloyd Skype has a particularly annoying bandwidth threshold to cut to a lower resolution and no way to influence it. I'm guessing this is the issue.

    Take a look at OBS ninja for free peer to peer video.

  • @fred @Woland @peuclid @Bodo @Kathmandale @liminal_andy 

    Thank you all so much for your awesome feedback. I had originally looked into but had a tough time setting it up on my Macbook - I figured it may not be ideal to have the actors go through but based on your advice, I will troubleshoot it more for future projects. 

    I think how I plan to go forward is to 

    A) ensure that all actors are on a wired internet connection in their homes

    B) upgrade the actor with the poor resolution to a Mac Pro in the hopes of giving her a CPU boost

    C) "have a look around in the Skype settings to make sure that nobody has opted to send or receive video on any settings lower than the maximum" 

    @liminal_andy - love your suggestion about simplifying the setup using Syphoner instead, but I can't figure out how to capture a full display using Syphoner - only windows. Does anyone know a solution for this?

    Huge thanks for everyone's support thus far - P2P will be on my horizons in the future. 

  • @andielloyd While I have not used this before I do see this screen capture to syphon utility from a bit of googling, maybe that will help?

    Others have mentioned a wide variety of great alternative CDN ideas. We use BDC at Liminal quite often, but the endpoints are Windows-only and there is quite a fee to manage. We have our own NDI over IP solution that we use, but OBS ninja is another good idea potentially. If you do venture away from Skype, you will be well-supported with other ideas!

  • Tech Staff

    @andielloyd said:

    B) upgrade the actor with the poor resolution to a Mac Pro in the hopes of giving her a CPU boost

     Honestly if you're purchasing a show computer for a performer and looking for high power, low cost, you're probably much better off getting them a Windows 10 machine.

  • @woland @peuclid @liminal_andy @Kathmandale @Fred @Bodo 

    Just want to thank you all again for all your help and insight. We're opening our show tonight, if anyone is interested in viewing the piece you can stream directly on our Twitch! We have two showings, tonight 20:00PST (Vancouver/LA time), and tomorrow (Sunday) same time. 

    Fingers crossed that Skype continues to behave for us! All of your tips and suggestions have been immensely helpful. 

    Grateful always for you all!