Streaming video and live Presentations

Developed by Digidrop

Streaming video over the web is easy but also has its complexities.

Let’s start with the basics. You need a good internet connection. This isn’t always the case in hotels and meeting venues where effectively too many folks pile in at once at a conference on their devices and slow it all down.

BBC iPlayer needs 3.5Mbits for HD video to play. But remember that is the easier bit as that is the download speed the upload is typically about one fifth of the download speed, so to run HD you need about a 25Mbit connection.

There are lots of methods for doing this but I am going to concentrate on YouTube and VMix and bring in Skype, there is also Zoom but you have to pay over a user threshold of 100 with zoom. A typical Ookla test window

There is a single stream and a multiple stream. Multiple stream is what YouTube makes and it has a conversation with your mobile device, laptop or desktop to test the receive capabilities and then auto selects for you the best stream rate without stuttering the video. So it makes a 240, 360, 480, 720, 1920, or 3840 frame range of streams when you upload a video (which is why the 480 one is the only one available at first). Much harder work for the streaming device to provide all at once and YouTube does it all for you with just one HD input.

I recommend a cable connection to the router at home rather than wireless.

If you want to stream to YouTube you need something to convert your camera video to a stream and a connection or interface to the computer. HDMI on laptops and base stations is for output only. Here we need input.

Let’s look at the Mac first. You need the Blackmagic Design mini recorder which connects to your Mac Thunderbolt port and with a camera with HDMI or SDI out it plugs straight in. That will cost about £130.

How far have we now got? All we have done is provided a means of getting a single camera signal into the computer, but we have to do something with it. Fortunately the next step is easy. Download OBS -Open Broadcaster Software https://obsproject.com/download and it is Windows and Apple compatible as well as Linux and it is free. This will make a video data stream for YouTube Live to pick up in your YouTube channel when you click on live event. A box that covers both PC (USB3) and Mac and has analogue inputs is this one Blackmagic Design Intensity it is called and it gives you more connection choices, analogue and digital, if your camera wasn’t HDMI enabled. Around £165. If you want more cameras then it is either an external mixer into one of the above and they can be expensive here is an example

These Datavideo 4 input digital mixers are around £4,500 as on the left. Roland do a VR-4HD which I found for £2,370 from Box Music as on the right.

Blackmagic Design have come in with a cheaper box the Ultrastudio 4K Extreme 3 as below but this goes only with a desktop PC with a PCIe card cable kit or any Mac with a thunderbolt 3 and is mainly aimed at cameras with SDI outputs but can switch between cameras as below at a cheaper £2,400. A computer monitor plugs in and gives a split display of available sources.

So back to a point I was making earlier integrating Skype and video power point and a single camera into a streaming presentation.

I thought I would have a go with VMix presentation software and they give you a free trial full version. It is basically an A/B mixer with multiple sources on a mouse click to load into the preview window you then click fade cut or wipe to bring it into the presentation. It supports video files which as soon as faded to start playing, it embeds power point and Skype. It has a bug in that if the control surface is selected it stays 4 by 3 whatever you set the output to. New sources are selected by adding an “input” and browsing to the file.

I am now going to talk about this on Windows as I haven’t got any Apple kit. Microsoft has made a bit of a hash of the new Skype v12 in that it doesn’t accept any of the traditional cameras and capture devices it used to apart from things like EZ Capture dongles on USB2. Luckily SKYPE classic version 7x is still available and there isn’t the Microsoft influence on there. VMix support told me that Microsoft are just about to include Microsoft Windows NDIS network driver system driver file which is a format VMix supports. For now, we will stick with the classic version.

So our Skype audio settings now look thus (utilising our Virtual Audio cable):

Now SKYPE has a Snag in that you don’t want the audio to howl round. To solve this, you need to download Virtual Audio Cable. Set up 3 inputs in its control panel (3 cables think of these as audio patch leads).

The video setting is simply as below which is showing a Power Point in VMix.

If we look at VMix audio now, Master is what we hear, A is Bus A and you will see that the PC microphone is directed to Bus A not to the main output although we could do that if we were in a hall with a PA system, by clicking the M button on.

Below you will see where the other end of virtual cable 1 is located which is Bus A and anything with A clicked on the right will go to cable one which goes to the SKYPE Audio input.

We next need to set up our external outputs.

The gear wheel for this is on the bottom Line. It needs to show red to send to SKYPE.

Here is our main output and you may wish to limit SKYPE to 1280 by 720 to save stream bandwidth.

If we are lucky enough to have a capture card with an HDMI output then we can set the next screen to address that and see it on a TV or projector.

However VMix allows for those of us without external outputs from Capture cards.

We simply set the displays section of the menu to be on as the external computer monitor, i.e. the socket you would connect to the projector. The projector needs to be connected to set this up.

We now need to set up some inputs.

The first input set up is Desktop capture of the Skype Window the second is a video, the third is the return audio from SKYPE, the fourth is the PC Microphone, and the 5th is a Power Point. The SKYPE window needs to be open and not making a call.

When you click on the Input you want next it will load it to the preview left hand screen and when ready click the transition you want in the middle of the two main video windows, as shown at the bottom of the second page, then that clip is going out. Videos will resume from where they left off unless you click the re-start button.

When we click on the audio button on Audio Line 2 we will hear the other end of the Skype call. You will need to mute your microphone whilst playing video clips.

It includes triggers to turn the mic audio off whilst playing a video and to go to a new input when the last one is finished automatically.

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