- Posted by Simon Byrne
- On June 5, 2017
Streaming of live events has become cost effective and dare I say too easy! Punters are literally firing up the Facebook apps on their phones and streaming live instantly.
Innovative artists and promoters have recognised that streaming all, or at least a taste of their events, drives interest that can be built upon. For corporate events, it increases reach at low cost and Houses of Worship are dramatically increasing their audiences by embracing webcasts.
To do it properly though, it requires planning and expertise.
The first and most critical part of the puzzle is the upload bandwidth for the internet connection that will deliver the stream. Download bandwidth is of no consequence, we want to get the data out. To deliver a decent reliable stream, at least 5Mbps is required with high reliability and low jitter. ADSL2 is not up to the job as it usually capable of 1Mbps at best. VDSL2 is capable of up to 20Mbps and fibre to the node (FTTN) can be as high as 40 Mbps. Plenty.
For temporary jobs, Telstra’s 4GX cellular network has proven to deliver very high speeds with high reliability. Remember how we lost wireless microphone spectrum in the 700Mhz range? Well that is now being used by (mainly) Telstra to deliver higher speeds and reliability so it is worthwhile ensuring that a modem dongle can take advantage of the new 4GX/700Mhz spectrum.
Unfortunately the other providers just don’t play in the same league as Telstra in terms of coverage. In theory though, Optus and Vodafone own some choice spectrum, and the recent announcement by TPG that they are getting into mobiles bodes well as they’ll operate in the prime 700Mhz area too. The key is to test prior the connection to the event, preferably at the same time as the event is planned as this the best way to predict connectivity.
Of critical importance with cellular is to get the RF signal out. This means a good quality external Mimo antenna that is up high. Mimo refers to multiple-input and multiple-output which is a method for multiplying the capacity of a radio link by exploiting multipath propagation. An antenna that supports this is very worthwhile.
So we’ve got a network connection. The next issue is how to encode the content and stream it. There a lot’s of ways to do this but I’m going to concentrate on webcast software. The most popular of which is Wirecast 7 by Telestream.
Wirecast is powerful production switching software (Mac/Windows) that can encode to multiple destinations as well as record simultaneously. If Wirecast is beyond budget, try OBS Studio (Mac/Windows/Linux) which is remarkably powerful, and free!
Both applications take in live video and audio sources as well as pretty much anything else you can think of such as media files, twitter feeds, screen captures, web pages and so on. Once ingested, you can switch live between sources and output the streams. A fairly powerful computer is needed as video encoding requires quite a bit of processing and of course, interfaces are needed to bring the video and audio into the computer.
It’s at this time, decisions need to be made about the audience profile which will determine how the stream is output. There are numerous options ranging in cost and reliability.
It is important to understand that streaming is a one to one relationship in terms of traffic. That is, if you output a single 5Mbps stream to a single destination, that is 5 Meg of bandwidth. To 2 destinations it is 10 Mbps, 4 destinations is 20 Mbps and so on. It quickly becomes apparent that the outgoing connection will be overloaded and buffering or failure will occur. The better solution is to output a single stream to a Content Delivery Network (CDN). CDN’s are privately owned networks that have very high bandwidth and numerous points of presence (POP’s). They take the stream and produce as many copies as needed and deliver them through their POPs. So if you have 1,000 viewers, the CDN has the processing and bandwidth to produce the 1,000 streams needed. For best performance, the CDN need to have POP’s located as close as possible to the originating site, as well as the viewer locations. There is little benefit in using a POP in North America if the audience is mainly in Australia. Sydney or Melbourne would be much more appropriate.
Youtube and Facebook are CDN’s which are free. In the case of Facebook, you can stream to a profile, event, group or page and in Youtube you can set up a live channel.
However, you get what you pay for. Facebook can be flaky but Youtube has proven to be quite robust. But with these free services it is extremely important that copyrighted music is not streamed. Both services are very good at detecting this and will shut the stream down. In many cases they’ll ban the user for a period of time (like months!).
The other downsides are that there is no real support so you are on your own, and the way you set up a connection is not ideal. With Youtube in particular, if the stream is shut down for whatever reason, another key needs to be set up, which in turn means another web address for the audience. Almost impossible to communicate the new address to your audience if you have lost your connection with them!
The alternative is to use a private streaming CDN such as Wowza, Akamai, Limelight, Ustream or Livestream. All CDN’s have slightly different offerings and POP locations so it is important that the right fit for the audience is found. The CDN’s transcode the streams depending on the audience. For example, a lot of enterprises are still on older versions of Internet Explorer so Flash video is best for them. Other viewers might be on Iphones so MP4’s is right for them. Some may only have access to low bandwidth so a smaller size image will meet their need. The ability to transcode and deliver the right streams, called adaptive bitrate delivery is very important.
With all of this data moving around the place, it is not surprising that there is some delay by the time it gets to the viewers. Usually at least 30 seconds. This means 2 way vision and especially audio is not possible. Webcasters often want a method to get questions and feedback from the audience. The easiest way to do this is by SMS. That is, just assign someone’s phone number to receive questions via SMS and publicise the number as the place to send questions. Get someone to write them down and hand them to the moderator. Fancier solutions such as Pidgeonhole and Yammer gives the ability to integrate the question into the webcast. However, they are difficult to implement so there needs to be a reason to go to the extra effort.
If this all a bit too much or it needs to be right, hire a professional. There are lot’s of little gotchas that can be the difference between a successful webcast, or an embarrassing failure. Companies such as Streamgate in Sydney, have built and operate end to end solutions that consistently deliver good results and have the knowledge, experience and relationships with the CDNs to ensure your event is a success.Links:
OBS Studio – Open Broadcaster Software (Free)
I am a contributing writer to CX Magazine. CX Network is the voice of technicians in entertainment and audio visual across Australasia.
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Lot’s of great stuff!