We have received many requests from our audience over the last two months, asking about our Video Cloud and Streaming Cloud service.
First, we really appreciate for your replies and support for our articles and updates, because your feedbacks always matters and help us improve our products and services.
What’s more important, your feedbacks also raise new needs and demands for us to research. If we find them useful through the research and necessary to add to our service, we will do it in no time.
Here we start the new series “Questions from You”, which we pick some typical or valuable questions and requests from you guys, and we will discuss the issue throughout the articles. We hope you enjoy this series, and keep sending us feedbacks.
I want to set up an online education platform for live streaming my course. There will be about 50 to 60 students attending, Q&A should be available and the latency should be within 1 second.
We received quite a lot of requests from the audience as well as the potential users of choosing the right service to set up their e-classroom and give courses through livestream. The question listed above is one of the most typical request we have seen.
We can extract three main demand from this question –
- For online education use (Purpose)
- 50 to 60 students online at the same time (Scale)
- Latency within 1 second (Low latency)
Let’s take a look for the first demand – purpose.
There are a lot of video cloud services available, yet not all of them are dedicated for online education. For big corporations like Baidu, Alibaba and Tencent, even they provide “education solutions”, the video service is not a major part of their cloud computing, which means the functionalities can be limited and the technical support team may not respond in time.
We recommend you consulting online video services which dedicate in education and business fields, such as Qiniu, POLYV, Kaltura and Panopto. They have accumulated online education clients and keep improving their products and services from their feedbacks, and you can directly use their service for building your e-classroom or live streaming courses just like real-life classrooms.
For the scale of students, a capacity of 60 students is not a heavy load for the cloud videos services above at all, thanks to the development of CDN. And if the audience capacity keeps growing, most of the services can still work perfectly, or you can add some more CDN nodes for some sudden high-concurrent scenarios just in case, or balancing the distribution load and make the latency within reasonable range.
The problem for this demand may be the cost of extra CDN nodes. It varies among different video services, so we recommend you asking the customer service team for detailed pricings and plans.
And now the last one – latency.
Almost every video services use HLS or RTMP protocol for pushing or pulling live video streams. The latency of HLS is quite long, which varies from 10 to 35 seconds and is unusable for e-classroom. The latency of RTMP is about 3 to 5 seconds, which is acceptable for most of the live streaming scenarios.
For your latency demand in the question, it is a little too harsh for live streaming services because currently RTMP is not able to reduce latency within 1 second (yes, not even YouTube is able to achieve that so far). If you insist with that, the livestreams have to be transferred through UDP protocol, which is very common in intercom applications where a lot of people can communicate through their microphone at the same time. And of course, these applications are really expensive, and may not be suitable for actual use.
So we have a compromising solution – the course lecturing session can be delivered through ordinary RTMP live streaming, and when student asks or answers questions, you can activate the microphone for the designated student and start conversation with microphone (through UDP protocol) like in an intercom system, while other students remain in RTMP streaming. This is what we known as “Microphone streaming”.
For these features, POLYV, Tencent QCloud, Panopto and a few other live streaming services have integrated Microphone streaming. It is proved useful for e-classroom scenarios, cost less compared to intercom applications, and the actual latency is within fair and acceptable range.
We hope the answer above can satisfy your demands. And if you want to try our service for your live streaming classroom, check out our Streaming Cloud website http://www.polyv.net/live to register your account, and then visit our Download Center http://www.polyv.net/download for our live streaming clients.
And if you want to learn more about our Video Cloud or Streaming Cloud service, check out our blog for our previous articles or visit our official website http://www.polyv.net for more information.
Last but not least, we are looking forward to your next questions, so stay tuned everyone! 🙂