In our ongoing series, Tech Talks, we discuss technology solutions to common customer problems with some of the technical experts here at HARMAN Professional Solutions. In today’s edition, we’re speaking with Kaleb Plamondon, Manager, North America Sales Engineering. I reached out to Kaleb to discuss an important and challenging subject: how churches can distribute video across the internet.
In a previous post, I looked at how houses of worship can use networked AV to distribute video throughout a church building. This time, we’re turning our attention to how churches can leverage the internet to distribute video outside church buildings to other facilities and the world at large. We’ll look at this subject in two parts. In today’s post, we’ll look at technology that allows churches to live stream their services online. In a follow-up post, we’ll focus on distributing video to other campuses in a multi-campus or satellite church environment.
[SKD]: What are some of the different situations that you encounter, where churches might need to get video out of the building? How do you go about finding the right solution for these different applications?
[KP]: There are several very common ways in which churches need to get video out of the building. The best way to find the right solution for them is ask the question, “Who is the audience?” If we’re looking to deliver that content out of the building and into the home, that’s one thing. If we want it delivered to other facilities, that’s another thing. And, if we want it recorded, so it can be viewed later on demand, that’s yet another issue, and each of these require different solutions. Sometimes they even require combining several solutions together to meet the needs. Every application is different.
[SKD]: Is there any specific application that you find churches look for most commonly?
[KP]: Often, a facility will make the decision that they want to broadcast to the masses, to anyone who is willing to listen, because that’s part of the mission in houses of worship. They want to get their message out to those that want to hear it. The simplest way to deliver that is through a content delivery network (CDN). If you have ever used a service like YouTube Live, Facebook Live or even watched the news streaming live online, what’s running in the background for these services is a CDN. The CDN is a series of servers that takes the incoming stream and makes it available to whoever you determine, whether that’s public to anyone who views it or password-protected, so only certain people can access it. People can then access that stream from a website, mobile app or a streaming device, such as a Roku or Apple TV (depending on the CDN you use).
[SKD]: Certainly, a CDN is vital. It’s not practical for a church to just provide a public IP address of a video stream and have people access it. You need a service to handle the bandwidth, etc. However, how does the church get the video out of their building to the CDN? What technology, hardware and other tools do I need to get that done?
[KP]: The core of that solution is an H.264 encoder. It takes raw audio and video in through standard AV cables, and then transmits that via a network output to “the internet.” Realistically, it generates a multicast stream of H.264 encoded video and AAC encoded audio. The encoded audio and video is then encapsulated, using one of a number of different streaming protocols sometimes called wrappers (RTP, RTSP, RTMP, HTTP Live, etc.) that allow the data stream to transverse the network.
The encoder puts out a stream to a public URL address. The church IT manager or media director then retrieves the broadcasting URL address and pastes that into the CDN, so it knows where to look for the originating signal. The CDN then replicates that signal out to the various viewers on the far end, but the encoder is really the “magic maker.” It takes the audio and video and converts it into a network stream that can be pushed to a CDN.
[SKD]: Is the ability to stream to a CDN something that is true simply because of the nature of H.264 encoding itself, or are there certain capabilities that are required in order for the encoder to support that?
[KP]: H.264 is a very common video encoding standard, and a number of devices on the market support it. Where you run into issues is with the wrapper protocols (RTP, RTSP, etc., as we mentioned). Different CDNs use different wrappers, and not all encoder manufacturers support the same ones. So, you need to find an encoder that supports a wrapper protocol compatible with the CDN service that you’ve selected. Certain CDNs will only allow RTSP streams, for instance, so if you purchase an H.264 encoder that doesn’t support RTSP, you’re not going to have much luck. The AMX N3000 Series H.264 encoders support a wide range of wrappers, so it will work with most streaming services.
The other consideration isn’t about the encoder itself, but you need to make sure the internet connection to the facility has sufficient bandwidth to support that amount of data being uploaded. Many internet service providers (ISPs) focus on how much download speed you have, but they don’t often talk about how much upload speed you have, and that’s what you’re doing when you’re broadcasting H.264. You’re uploading your content to the CDN for broadcast to the world. You could be looking at needing a constant upload speed of 3–5 Mbps for good, high-quality video. So, you want to make sure you have enough bandwidth from your ISP to do that. The church might have enough bandwidth to support an upload of that size on its own, but depending on the other traffic on the network, the capabilities might need to be bumped up to account for this additional usage.
[SKD]: That’s the age-old issue when you’re dealing with AV on the network: you need to consider the total traffic on the network, not just the bandwidth for your AV stream. It brings up an important question, though. How do you handle the settings on the encoder to get the right balance of video quality vs. bandwidth usage? Depending on your settings, you could have a stream that has great quality but uses too much bandwidth, or conversely, uses very little bandwidth but the quality is poor. How do you ensure you have the right setting for your application?
[KP]: On the N3000 Series encoders, we actually give customers the ability to select their target bitrate. Let’s say the church’s media director goes to the IT manager, who says, “Okay, you can have 2.5 Mbps of data for this stream.” The media director then goes into the N3000 Series encoder and selects that as a maximum stream size, where it will never go more than 2.5 Mbps. Of course, like anything else, you get what you pay for with bandwidth. The more bandwidth you have available, the better picture quality you can get.
To get the most bang for your buck, the N3000 Series actually allows you to go in and not only set your maximum bandwidth, but also manually adjust your frame rate (the number of frames per second). If you have an event like a holiday special, where there is a lot of movement and flashing lights, you want a really good frame rate, so everything looks fluid and smooth. If, instead, I have a sermon where there is little movement, and there is text up on the screen, I might not need the video to be as smooth. In that instance, I could turn down my motion quality slider and increase my image quality slider, so the onscreen text is clear and easy to read. There’s a lot of flexibility with the system, though getting the right balance usually involves some trial and error.
I’d like to extend a big thank you to Kaleb for speaking with us today. Remember to stay tuned for Part Two of the interview, where we’ll talk about distributing video to satellite churches.
Do you have any insights on how to stream live video of church services online? Please share them in the comments.