_daevs blog

A/V: Video chatting, group conferencing and webcasting

( Under construction, being written right now! )

The amazing thing about a dancing bear isn’t how well it dances..
iI’s that the bear dances at all.

Folk proverb

The best way to approach this topic is to first realize how unlikely a proposition this whole teleconferencing thing is.
Real time interactive audio and video streaming over the internet is what our current computer systems are the worst at; the fact that this stuff works at all is a remarkable achievement. And a minor miracle.


First, what do you want to do? As usual, your requirements should be thought through before you start downloading apps and buying expensive hardware.

If you just want to talk to one other person, then almost any of the apps or methods out there will work. I’ll call this Video Chatting, and it’s what Facebook’s video chat and apple’s facetime (and many others based on WebRTC) does acceptably well.

It’s when you want to go beyond that things get more complex.
-Want better video or audio?
You’ll need to go beyond the built in hardware with a better camera, maybe a switcher, and an outboard mixer.
-Want to talk to multiple people or multiple devices eg zoom?
That means somewhere there is a central server that all the devices send data to so it can be processed, mixed, and then sent out again. That server or host needs to have enough horsepower and internet bandwidth for all the devices and service required, which is why group meetings are typically not free.

A group meeting always has a host or organizer that sets up the meeting, starts the session, and moderates it. They also set the type of video and audio sharing that happens.

Next, understand group meetings roughly fall into three scenarios or models.

  1. Distance learning scenario – one to many.
    Lectures and virtual classrooms, moderately interactive.
  2. Group Meeting scenario – many to many.
    Round table discussion may ensue, highly interactive.
  3. Broadcast scenario – one to many, minimal or no interaction.
    Lectures, poetry readings, concerts and plays, other entertainment.

Still with me? OK, then let’s look at these scenarios a little more closely, then we can figure out what stuff we’ll likely need.

(Lots more verbiage to go here.)

Environment & Equipment

The best thing you can do for your video has nothing to do with equipment, it’s all about cleaning up and improving your environment.

First, Camera Location
Put the camera around eye level, just above or below the center of screen you’ll be using for conferencing.
Too low, and we’re looking at your nose hair and ceiling cobwebs.
Too high, and we’ll see you aren’t wearing pants.
Off to one side can make you look disinterested or maniacal, try to avoid this too.

Second, Lighting
Lighting is a whole huge topic by itself, but here are a few tips to get started:
– Do have diffuse, even, lighting on your face.
If you can’t use industry standard soft-boxes, then improvise by bouncing a few lights off your ceiling if it’s pale. Of put up a sheet behind your monitor and bounce a couple of floodlights off of it.
– Don’t have your back to to window and your laptop on a coffee table (like in a typical living room) . You’ll be a black blob (tech name: silhouette) in a white screen, unpleasant for the other people online and impossible to see your facial expressions.

Third, reduce background clutter
A lot of stuff behind you is very distracting. So is your collection of porn and your Freddy Kruger standee, keep them all off camera.

Once you’ve gotten the environmental issues cleaned up, then you can consider video hardware.


Video and cameras

I use a combination of webcams, a Canon DSLR, a HDMI to USB converter, a consumer grade video camcorder, various lighting panels and softboxes, a green screen, and software on either OSX or Windows.
(Sorry Mac folks, most of the best broadcast software is Windows only.)


The problem with typical built-in webcams:
– a fixed lens
– poor low light sensitivity
– automatic settings for video gain, color balance and focus;
Although this makes them easy to use, it means video clarity and quality is often sacrificed.
A step up from the built in cameras is an external USB unit. I like the razor kiyo webcam for this. The built-in ring light really helps in low light conditions (and lets you know it’s active), it has a tripod mount on its built-in folding stand/monitor clip, and it offers a robust 1920×108 60FPS video stream. Lastly, it doesn’t require drivers to be installed on either Windows or OSX.

DSLR as a webcam?

DSLR’s have lots of options for lenses. So wouldn’t it be nice to use your DSLR as a webcam? Sure would! Most current DSLR’s have a USB cable “tethered option” for shooting, but that feature doesn’t usually include the USB class drivers for a streaming camera. IOW, your computer wont “see” it as a video camera source.

Enter SparkoCam, a Windows software package that has the required USB class drivers along with a host of other nifty features (eg, cropping and greenscreen) right in the app. After a quick eval, I decided it was worth the purchase price and bought a license. Next, I put my DSLR on a tripod right under my big screen and plugged in the camera to my PC with the help of an active USB extender cable. Using the SparkoCam app I adjusted the Aperture (depth of field), and ISO settings (video gain) for the size and brightness of the image I wanted. Once that was done, I selected the sparkocam device in xsplits video panel, and viola! A high quality video feed.
Personally, I found the increased latency with this setup too high to use for video conferencing, eg zoom. Also, this really burns through battery charge, be sure to plug in.

Camcorder as a webcam

Some camcorders come with firmware to enable this feature, so enable it, plug in a USB port and go!
Other cameras have a feature called clean HDMI, which will output a video stream without the cameras status displays. You can run that into a HDMI to USB converter box, and then you have a really nice webcam with a zoom lens. Again, this really burns through battery charge, be sure to plug in.

Video switching and stream mgmt

I’m currently using xSplit, which handles video mixing and streaming codec chores nicely. It also enables use of presets and transitions for a professional look, and can package your stream for live streaming, fed to another app for seminar teleconferencing, or recorded for later editing and broadcasting.


Covering almost every group audio scenario is this little gem from Allen&Heath, the ZED i8. (Shown here next to Mac and Win PC Laptops.)

If you’re not into Pro audio, you may not have hear of Allen&Heath. They’re a UK based, well-regarded, Pro audio company with rugged, reliable products that sound great.

The ZED i8 is basically a compact, high quality analog audio mixer… with a very good USB audio interface integrated into it. Nothing fancy, no special FX, no extra mix busses, no complex send paths… just a good clean analog audio mixer and a USB class 2 interface. It makes a great small gig/coffee house type mixer when you’re not using it as a USB interface, and this little guy is a definite cut above the Behringer/Nady units at this under $200 price point.

Features include two good quality mic inputs (with phantom power and high pass), two stereo line inputs, basic eq, and simple but adequate send, monitoring and metering.
Finishing off the list is a nice 24/bit/96K stereo USB class 2 audio interface interface that has worked flawlessly on all the OS’s I’ve tried it with: Windows 10, Mac OSX, iPad/iOS, and Android.

Tech note: After years and years of waiting, Windows (starting with version 10 release 1703) finally has a USB class 2 audio driver. Finally!
Finally you can get 24bit/96khz high def audio without a passel of flaky drivers!
See https://docs.microsoft.com/en-us/windows-hardware/drivers/audio/usb-2-0-audio-drivers

In other words, this mixer has got just the right feature set for almost any personal teleconferencing application: Podcasting & live interviews, conferencing, webcast and concert streaming, lecturing, dance classes, etc.

I’ll be putting it on my lab bench for some measurements with my ancient but trusty audio precision analyzer shortly, but I expect it to meet or exceed the companies published specs.


After some tinkering, I’ve settled on Zoom for teleconferencing and XSplit as my webcast/presentation video switcher app. Both feature decent overall usability & reliability, and they can be coaxed into supporting high quality stereo audio. And XSplit can “feed” into Zoom, letting you use it’s nifty switching and whiteboard features.

Common problems with video conference calls

The first and best thing you can do to improve your streaming experience is to plug in. Plug into AC power for highest performance, as most laptops reduce performance on batteries.
Plug into your network connection, as wifi is prone to interference in a tightly packed highly contested radio spectrum, whereas a direct ethernet cable is interference free.
Do it.

No audio or it’s very faint / distorted

This is almost always caused by using the wrong device or the levels set wrong. To figure this out, you need to open up the audio device control panels. In fact, I have these open all the time.

Windows PC: open “Volume Mixer” and “Sound” control panels. They look like this:

Volume Mixer Panel
Sound Panel

Mac OSX, open the Audio and MIDI setup app.

Mac OSX Audio and midi panel

Android and iOS OS’s don’t have control panels, they use the platforms internal default devices unless you plug in an external one.

First, make sure the devices you think you’re using are actually selected.
Next, if the levels are too quiet or too loud, change the volumes or gains to about 75%, fine tune as needed.

Stuttering and robot noises

While in your conference call, set the speaker volume to the lowest sound level you can. This will help the echo canceler prevent echos, noise bursts, and that weird robot voice when it gets really confused.

Latency and lip synch issues

Latency is a chronic issue with these systems, it’s unavoidable. And there’s two concepts to consider; overall latency(lag) and the differing latencies for the video and audio paths (lip synch).

Bandwidth constraints – video breaking up

Acoustic Feedback

‘casting notes:


Removing audio processing
Under advanced audio settings, enable the ” Allow users to select original sound in their client settings ” option. Original sound means to disables the echo canceler and some background noise processing. No comments on whether limiting or other eq/processing is still on.

To enable broadcasting in stereo, go to the web portal:
You also need to turn it on in your local app, Note caveat that it’s in the desktop app only. A quick test shows this to work, but the lack of audio metering make this a bit of a guessing game.

Zoom uses the Opus audio codec, an open source codec capable of stereo and high quality, scaling smoothly to minimal bit rates as needed. http://opus-codec.org/


Stereo feature only available in paid version.

Here’s my handy and slightly sarcastic etiquette guide – Teleconferencing notes

(author topic storage area)

A burning question?

Today’s odd shower thought. (Follow along at home.)
According to most christian religions, humans are “made in gods image”.
So that means the converse is true too: god looks like us.

OK, so then how often does god poop?

And… To continue with this, if god is assumed to be perfect, then gods poop must likewise be perfect.
What does perfect poop look and smell like?

For that matter, what does a heavenly bathroom look like? TP or a bidet? Who cleans them? How does a celestial waste disposal plant work?

This is a whole Pandora’s box of poop.

Demon musings

Much is made about accidentally summoning a demon, but just think about how that must make a demon feel?
I mean, he/she/it/they respond to your call, ready to do some damage, and its all like hand fluttering and “oh dear” and nary a request for limitless power or destruction of the universe or whatever.

I suspect this is really why demons are always in a bad mood, constant interruptions by people with poor planning skills.
So, always have some nice hot tea ready when attempting to read Latin, fix a buttonhole, calculate your taxes, and other such activities prone to accidental demon summoning.
Then if a demon is invoked, simply act nonchalant and offer a spot of tea. Viola! New BFF, and a happy demon.

Your PSA for today.

Photoshoot with Chey

Chey is a traveling model I’ve worked with several times. She was briefly available on her way to Canada, so of course I had to shoot with her. Her exotic looks and sunny personality are perfect for a beach shoot.
She even brought her own prop. 🙂 That’s Leo, her travel buddy.

Chey and Leo