Exploring HLS vs. DASH: A Comprehensive Guide for Video Streaming Technology
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Back in the old days, you had to download an entire video file if you wanted to watch it. Thanks to the dynamic adaptive streaming capabilities of protocols like HTTP Live Streaming (HLS) and Dynamic Adaptive Streaming over HTTP (DASH), those troubles are finally over. The adaptive bitrate streaming technique allows you to break up your media into smaller chunks.
However, there are still differences between those video streaming protocols, making each one preferable for certain scenarios.
Let’s discuss the technicalities behind an HLS and a DASH stream and walk through scenarios that might make one a better choice over the other.
What are HLS and DASH?
If you’ve ever watched live video content — chances are you’ve either relied on HLS or DASH streaming. Both are adaptive protocols used for encoding audio and video content. The idea behind that is to have different video quality levels available and divide the file into smaller parts. That way, the viewer doesn’t need to download the entire media content before they can play it. It also guarantees a smooth user experience while adapting to each device’s limitations and connection strength.
While the basic principles of both standards are the same, there are some differences between the two.
First, HLS is a closed standard developed by Apple in 2009. However, it’s not just available on iPhones and iPads. So far, Google has added support for the protocol to Android. It’s also supported by HP’s webOS, Microsoft Edge, and Twitch.
DASH, on the other hand, has been an international open standard since 2011, and it was developed by the Moving Picture Experts Group (MPEG), which is why you’ll sometimes see it referred to as MPEG-DASH. That means it’s natively supported on other operating systems, smart TV platforms being one example. By its design, it’s the more vendor-neutral solution for adaptive streaming, which is why it’s often chosen for services targeting multiple interfaces.
What Are the Advantages and Disadvantages of HLS vs. DASH?
Due to their historical background and guiding principles, each streaming protocol serves slightly different audiences, even though they cover almost identical feature sets.
For one, the support of HLS is strongly tied to Apple’s ecosystem and branding, which has already led to other companies like Google to back it. With two of the large software companies supporting it, it’s likely HLS streaming is available on your mobile device. While that can make it a good choice for some scenarios, DASH still remains the open and standardized streaming protocol catering to a broader range of platforms. That often makes HLS the de-facto video player standard for organizations planning to benefit from a consistent user experience and easy setup procedures across an Apple ecosystem.
In theory, both protocols support live streaming as well as on-demand stream applications. However, HLS has proven more reliable in offering smooth streaming during live stream events, partly due to its multi-bitrate support. Both protocols may provide comparable options for adaptive streaming, but DASH gives users direct control over the quality level, whereas HLS automates its adaptive bitrate streaming in the background.
Under the HLS protocol, the player handles the adaptation logic, making it the perfect solution for live streaming events with quickly changing latency, network conditions, and device requirements.
Equally, the segment length is used to affect how differently the two perform during live streams, but these days, the default length is adjustable for both protocols.
As an open standard, DASH is codec-agnostic, whereas HLS only has limited support for codecs such as H.265, H.264, AAC-LC, FLAC, or Apple Lossless. The gap between those two will shrink as HLS goes more mainstream. But for the time being, DASH will make for a better solution for those requiring codec flexibility.
You’ll end up paying for that flexibility, though, during implementation, as DASH’s extensibility requires a solid understanding of the protocol’s intricacies.
Example Use Cases for HLS and DASH
Because many technical factors are involved, most of which overlap between the two protocols, let’s walk through scenarios where one might make for a better solution than the other.
Many universities already partake in Apple’s educational program, which makes the hardware you can expect in a lecture hall at least somewhat predictable. If you’re an educational content provider catering to an iOS-centric audience, HLS would likely be the better choice for playback.
It would ensure a seamless viewing experience across various Apple devices and minimize buffering or interruptions, especially during peak usage hours. By choosing HLS, the provider could take advantage of its reliability for streaming video content, which you’ll need when consuming it by a specific date relevant to an exam. That scenario could change quickly when we transfer it to a different country because iOS share varies immensely from one region to another.
For an online video streaming service, reaching a broad audience is the top priority. That means they need to consider a vast variety of devices and browsers, from various smartphones using Google Chrome and closed systems like Apple TV to smart TV setups. Some users might want to manually control the video quality, either to customize their video stream experience or to prevent the consumption of their limited data volume. Others might choose to wait for the video to buffer, just to have the full cinematic experience, even if they’re watching on a smaller screen.
In those cases, DASH would be a more suitable option because it provides advanced manual control over different bitrates and, ultimately, content quality. Relying on open platforms with HLS support also future-proofs your content delivery because you’re catering to the widest range of devices and formats possible.
Ultimately, the choice between the two protocols comes down to personal preference or philosophy. If you know your users prefer a more interactive experience or advanced controls, HLS might make them feel less comfortable despite offering a seamless experience. When choosing one over the other, it’s best to consider the devices that need to be supported as well as user preferences and long-term strategies.
How Vbrick’s eCDN Solutions Address the Challenges of HLS and DASH
Depending on your technical setup and preferences, you may either dive deep into your custom settings or never hear about HLS or DASH again. With our Universal eCDN solution, you can leverage each one and adjust additional features to get the most out of video streaming. If you use our Peer-to-Peer eCDN, you can focus on messaging or the next network meeting and not worry about technicalities.
If you’d like to learn more about our different eCDN solutions, get in touch with our team and schedule a demo today.
