Everybody hates buffering. It’s extremely frustrating to watch a video only for it to stall and display some sort of spinning wheel while the next couple of seconds load. This can happen because a video’s bitrate is too low: the amount of data transmitted over a network per second during playback (we typically measure bitrate in Kbps or Mbps). The higher the bitrate, the better the quality — unless you have poor network conditions, which could still result in lags, buffering, grainy visuals, and freezing.
Thankfully, video technology has come a long way over the past few years, so those spinning wheels are much less common thanks to the development of adaptive bitrate (ABR) and multi-bitrate (MBR) streaming. These technologies exist to balance video quality and performance so everyone watching a stream, no matter where they are or what device they’re watching on, can have the best possible viewing experience.
What’s the difference between adaptive bitrate vs. multi-bitrate streaming, though? They both address the same problem but have unique approaches. Let’s explore the key similarities and differences between ABR and MBR and how they impact your content.
Adaptive bitrate vs. multi-bitrate streaming
What is adaptive bitrate (ABR) streaming?
Adaptive bitrate streaming is a technological process that dynamically adjusts a video stream’s quality based on the viewer’s internet connection speed and device capabilities. ABR pre-encodes multiple versions of the video at various bitrates — sometimes called bitrate renditions — so that the video player on the receiving end can automatically select the appropriate version based on real-time conditions such as bandwidth and device performance.
For example, let’s say you start watching a TV show on your phone with your home’s fast Wifi network. You can expect playback to go smoothly with high-resolution visuals because you’re watching the high-bitrate version. However, if your connection slows or if you decide to finish your episode another time somewhere else with less ideal internet, ABR will seamlessly lower the bitrate and resolution to prevent buffering and ensure low latency streaming. The visuals might not be as sharp, but at least you’ll be able to watch the episode smoothly without annoying interruptions.
What is multi-bitrate (MBR) streaming?
Multi-bitrate streaming also offers multiple versions of the video at different bitrates. Unlike ABR, though, MBR does not automatically adjust the stream based on the viewer’s real-time network conditions: instead, the viewer manually selects the bitrate at the beginning of the stream so that a specific version is delivered throughout the entire playback, regardless of whether their network speed improves or degrades. That said, some video players do make it possible to toggle between bitrates mid-stream so viewers can adjust the bitrate as they see fit.
Benefits of ABR vs. MBR
ABR and MBR are highly convenient technologies that optimize the viewer experience. Some benefits of each include:
Benefits of adaptive bitrate streaming
Automatic adjustment: ABR automatically and dynamically adjusts to changing network conditions, whether a singular network experiences those changes or if the viewer moves between different locations.
Smoother viewing experience: By adapting in real-time, ABR minimizes video interruptions, making it ideal for unpredictable networks. Fan engagement software also pairs well with ABR because it reduces the likelihood of frustration and enables more user interaction.
Optimized performance: Adaptive bitrate streaming ensures that viewers can access content on a wide variety of devices, from low-end smartphones to high-definition televisions. The process of creating multiple video renditions can also happen via cloud transcoding, resulting in a higher-quality stream than if you transcoded each version manually.
Benefits of multi-bitrate streaming
Viewer control: With MBR, viewers have control of the quality of the stream they choose based on their network capacity and personal preferences.
Simpler setup: MBR is simpler to implement from a technical perspective because it doesn’t require real-time bandwidth monitoring or dynamic stream switching.
Consistent quality: Once the viewer selects the bitrate, they enjoy consistent quality throughout the stream without fluctuations as long as their network remains stable.
ABR vs. MBR use cases
Now that you know the differences of adaptive bitrate vs. multi-bitrate streaming, how do you, as a video producer or publisher, know when to use which?
ABR use cases
Mobile streaming: ABR is ideal for mobile users who frequently move between network types, such as Wifi and mobile data. Viewers who watch content on their mobile devices are often on the go or use public networks that are less reliable, making ABR’s dynamic nature advantageous.
Live events: Seamless streaming is especially critical during live events like sports and concerts, so ABR minimizes the risk of buffering and ensures continuous playback. You don’t want viewers to complain that they missed the final touchdown!
Broad audience reach: ABR is suitable for platforms serving diverse audiences with varying internet speeds. Your viewers in rural areas with lower-quality internet connections deserve just as optimal of a viewing experience as your audience members in big cities.
MBR use cases
Stable networks: MBR works well in environments where viewers have access to stable, high-bandwidth networks, such as corporate offices or schools.
Niche applications: Platforms where users have specific quality preferences, including digital live auctions or online learning, may prefer MBR, which is less resource-intensive.
How do ABR and MBR work?
Adaptive bitrate streaming technology encodes multiple versions of the same video at different bitrates and resolutions. The server stores this data in individual “chunks,” which the viewer’s video player can dynamically select based on available bandwidth and the device’s processing power. The video player continuously monitors network conditions and adjusts the stream by switching to the appropriate bitrate that balances the quality of visuals and delivery.
In multi-bitrate streaming, encoding software also creates multiple versions of the video, but the viewer selects which stream they think is best for their bandwidth and expectations. The player then receives that stream in full, without making automatic adjustments according to the user’s network. Essentially, the viewer makes their own experience: if they can tolerate lower quality visuals for faster loading times, they can choose to do so, or they can prioritize resolution if they don’t mind a few pauses here and there.
Some other details you need to know about how ABR and MBR work include:
Adaptive bitrate vs. multi-bitrate streaming: Compatible protocols
If you’re not already familiar, protocols are specific methods that determine how data is packaged and delivered via the Internet. Adaptive bitrate and multi-bitrate streaming are designed to work with many of the most commonly used protocols, especially the following:
MPEG-DASH: Also referred to as simply DASH, this protocol was the first to become a global industry standard and is compatible with almost all device types except Apple (at least natively, there are ways to circumnavigate this).
HLS: Apple developed the highly effective HLS protocol that breaks video data into smaller pieces for streamlined delivery. It used to only work with Apple-made hardware but is now compatible with almost all devices. HLS’s widespread compatibility makes it an effective choice for adaptive and multi-bitrate streaming, though unlike DASH, it requires H.264 or H.265 codecs as particular encoding formats.
WebRTC: ABR and MBR can work with WebRTC through two ways: on the server side, which creates multiple renditions of the video data as we’ve discussed; and on the client-side, where the receiving end transcodes the data into appropriate bitrates instead. This latter process is a version of simulcasting and is Dolby’s method of multi-bitrate streaming when using WebRTC. This process is related to but distinct from re-streaming, which entails delivering multiple versions of a video stream across different platforms.
RTMP: Adaptive bitrate streaming was originally designed to work with HTTP-based protocols, which RTMP is not, but it is still possible to use it for multi-bitrate streaming with Dolby’s WebRTC simulcast feature.
In the world of live streaming, Quality of Experience (QoE) is crucial for maintaining viewer satisfaction, engagement, and retention. A superior QoE ensures that audiences enjoy smooth playback, minimal buffering, and high-quality visuals, all of which are essential for keeping them engaged and coming back for more. For content creators and streaming service providers, prioritizing QoE not only enhances the viewers’ overall streaming experience but also strengthens their brand’s reputation and success in a competitive market.
Adaptive bitrate streaming enhances Quality of Experience (QoE) by providing smoother playback and reducing buffering, leading to greater viewer satisfaction.
Bitrate ladders
A bitrate ladder is a key component of both ABR and MBR. This feature informs your video platform what particular renditions of a video to encode and transcode so they’re available to switch between when it’s time for playback. For example, you could create streams at:
- 1080p (5 Mbps),
- 720p (3 Mbps), or
- 480p (1.5 Mbps).
There are many more variations you can produce. Each version will also have a distinct resolution — if you use a bitrate of 750 Kbps, that would stream with a resolution of 512×382.
Encoding methods
You’ll also need to select between encoding methods, such as:
Constant bitrate (CBR): CBR maintains a fixed bitrate throughout the video, ensuring consistent quality. This is useful for stable environments with predictable bandwidth.
Variable bitrate (VBR): VBR adjusts the bitrate based on the complexity of the video content itself, allowing for better quality during scenes that require more data (e.g., high-motion sequences) while using less bandwidth for simpler scenes.
How to use ABR and MBR with Dolby
Both adaptive bitrate and multi-bitrate streaming are possible with Dolby’s platform. Our Selective Forwarding Unit (SFU) distributes your content and adjusts the bitrate so your viewers’ streaming players select the highest quality stream to enable reliable playback. You can find our documentation on technical specs and implementation here.
Adaptive bitrate and multi-bitrate streaming are essential technologies for optimizing your viewer experience. You strengthen your ability to connect with your audience and make your content more effective if viewers don’t have to deal with frustrating lags and freezes. Make sure your media streams smoothly and get in touch with us to learn more about how Dolby can help you stream to anyone, anywhere.
