Quality matters when it comes to broadcasting live video streams. Viewers begin to abandon a video as soon as buffering begins. Around 6 percent of viewers leave per second of buffering. One survey found 62 percent of viewers will view a brand more negatively if they publish a poor quality video. There are many different elements to determine the quality of an online video. This includes proper video streaming software settings. But another key element is multi-bitrate streaming.
This article will focus on the settings you need to get the right to make the experience of the viewer as positive as possible. With that in mind, this article will begin by talking about QoE. Then we’ll go over various elements that play a role in determining the quality of a live stream. We’ll go over the best video streaming software settings.
In the final sections, we’ll discuss how to reach users with slow internet speeds. This includes multi-bitrate streaming. We’ll explore what this is, how it works, and how it compares with other methods. Finally, we’ll finish up by discussing adaptive video players.
Let’s jump right into it.
QoE: why user experience is most important
QoE is a term that’s widely used in the OTT video industry. It stands for Quality of Experience. Quality of Experience is highest when a viewer is delivered the sharpest possible video, continuously, with no interruptions. QoE is a subjective measure, but it’s based on some measurable issues. The main contributors to the low quality of the experience would be:
- Buffering or lagging
- Video tearing and artifacts
- Audio delays or mismatches
- Stream fails to start or fails during the broadcast
- Video or (more importantly) audio quality makes content unwatchable
We already shared in the intro a few statistics on why quality matters to audiences. Few publishers truly consider the importance of these issues. If you’re losing 6 percent of your audience per second of buffering, quality suddenly becomes essential. You want to do every single thing you can to retain those viewers.
So what can you do?
Elements in a quality video stream
What you can do is take steps to maximize the quality of your live stream. There are many elements involved in this. Here are a few important ones:
First, you need to use a quality video camera. This is easier than ever. Today, even many smartphones are capable of producing high-quality HD or even 4K video. However, smartphone quality is not good enough for professionals. Generally, we recommend using a dedicated video camera. It’s best to consider your budget and consult with an expert before selecting a camera compatible with your OVP.
Audio quality is also essential. In fact, as we mentioned above, it’s often more important than video quality. Good audio requires a few things. Like with video, quality equipment matters. Professional-grade recording equipment can greatly improve audio quality. However, there are other issues that can be easily avoided. Mitigate wind noise, for example, by filming indoors or using a wind-sock on microphones.
Another element in high-quality streaming is using a quality video streaming platform / CDN. Video streaming platforms that partner with a high-quality live streaming CDN will provide you with the features you need for successful live streams. Because of this, we recommend choosing a video streaming platform that works with a top CDN. Using a CDN, or Content Delivery Network ensures that your video is delivered via a global network of servers.
Finally, you need to be sure you use quality video streaming software. Make sure the software you choose provides you with the features you need and is compatible with your video streaming platform.
This article will now dive in and provide more detail on three important elements in a quality live stream. We’ll begin by looking at correct video streaming software encoder settings.
Correct video streaming software settings
Let’s review our recommended settings for video streaming software. When used with RTMP compatible streaming software, these settings will ensure a successful RTMP ingest stream over the Akamai network. There is a range of options we will provide here. The first two, resolution and bitrate, are dependent on the amount of bandwidth that is available.
Common video resolution settings
- 426 x 240 (240p)
- 640 x 360 (360p, Low Definition)
- 854 x 480 (480p, Standard Definition, or SD)
- 1280 x 720 (720p HD)
- 1920 x 1080 (1080p, or Full HD)
Video bitrate settings
- 360p video: 400 Kbps – 1000 Kbps
- 480p video: 500 Kbps – 2 Mbps (1 Mbps = 1000 Kbps)
- 720p video: 1.5 – 4 Mbps
- 1080p video: 3 – 6 Mbps
Other video settings
- Video Codec: H.264
- Frame rate: use 30 fps (technically, 29.97 fps) unless you’re shooting sports at 60 fps
- Keyframe interval: 2 seconds
Audio bitrate settings
- 360p video: use 64 Kbps audio bitrate
- 480p video: use 128 Kbps audio bitrate
- 720p video: use 128 Kbps audio bitrate
- 1080p video and above: use 256 Kbps audio bitrate
Other audio settings
- Codec: AAC
- Sample Rate: Use 44100 KHz
- Channels: for 360p video and below, use “mono.” For 480p and up, use “stereo”
Reaching users with slow internet
If you plan to reach a large audience, this likely includes users with slow internet. This may include poor mobile connections, rural DSL lines, or congested urban connections. To reach these users, you need to provide video streams in low bitrates.
Here at Dacast, we recommend always providing a video stream in a bitrate below 1000 Kbps. This ensures that all users should be able to watch your feed, and maximizes the size of your audience as much as possible.
As video quality increases, the necessary bandwidth increases as well. This means that greater video quality may decrease quality in regards to buffering. To achieve the best QoE, broadcasters need to find a balance between these issues.
What is multi-bitrate streaming?
Of course, you don’t want to simply stream a single, low-bitrate video stream. That would provide a bad QoE to users with fast internet. Instead of a high-quality stream as they would expect, they would receive a low-resolution feed. Not good.
The solution is multi-bitrate streaming. Multi-bitrate streaming (MBR) is all about making your video stream available in multiple bitrates. This allows the viewer to select (or automatically be delivered) the best possible video quality at any given time.
How to setup multi-bitrate streaming
Setting up multi-bitrate streaming is relatively easy. It simply involves configuring your encoder to deliver multiple bitrates of your stream simultaneously. This means configuring multiple simultaneous outputs in several different bitrates.
For example, you may wish to stream simultaneously:
- 360p video feed at 800 Kbps
- 720p video feed at 2 Mbps
- 1080p video feed at 4 Mbps
This means viewers will be automatically served as the best possible video quality. We wrote a detailed blog previously that details how to setup multi-bitrate streaming using two video streaming software: vMix and Wirecast. Click that link to view those instructions.
If you’re using a different video streaming software or a hardware encoder, those instructions can still be adapted to your situation.
Adaptive video players
The key feature that goes alongside multi-bitrate streaming is an adaptive video player. Using an adaptive player means that the player will automatically assess a viewer’s internet speed on an ongoing basis.
If their speed decreases, the player will request a lower-bitrate version of the feed. If their speed increases, the quality will increase. This happens automatically, without user input. Using an adaptive video player is essential, and ensures every viewer has the best possible QoE at any given time.
Hopefully, this overview has helped you understand the factors that go into a quality live stream. Harnessing these elements correctly can boost your video quality, and more importantly, increase the QoE for your viewers. That’s a win-win.
All this, of course, requires an online video platform. If you’re interested in testing out a live streaming platform today, sign up for the Dacast free trial. We don’t need your credit card details to sign up. The free trial lasts for 30-days and provides access to nearly every Dacast feature.
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Any questions, comments, or ideas? Let us know in the comments section below! And for regular tips on live streaming and exclusive offers, feel free to join our LinkedIn group. Thanks for reading, and as always, best of luck with your live streams!