When it comes to streaming video, picking the right protocol can feel like a bit of a head-scratcher. Whether you’re delivering a live sports event to a global audience or offering on-demand movies to viewers on different devices, the choice between HLS (HTTP Live Streaming) and DASH (Dynamic Adaptive Streaming over HTTP) can make a big difference.
For example, imagine broadcasting a major live event where every second counts—HLS might be your go-to for Apple devices, while DASH could be the better choice for low-latency streaming across various platforms. Let’s dive into the details of each protocol and see which one aligns best with your streaming needs.
What is HLS?
HLS (HTTP live streaming), developed by Apple, has changed the way we consume both live and on-demand content, especially within the Apple ecosystem. Its adaptive streaming capabilities enable the delivery of a seamless viewing experience by dynamically adjusting video quality based on varying network conditions. This ensures users receive the best possible video quality without interruptions, making HLS a cornerstone in modern digital media consumption, especially for iOS and mac OS devices.
As of 2023, HLS is used by over 75% of streaming services catering to Apple users due to its strong native support on iOS and macOS devices.
How HLS works?
At its core, HLS divides video content into small, digestible segments delivered via HTTP. The client dynamically adjusts the video quality by switching between different segment streams based on network bandwidth and device capabilities. If the viewer's connection weakens, HLS can seamlessly switch to a lower-resolution segment to ensure smooth playback.
However, this segmented approach traditionally leads to higher latency in live streaming scenarios, as segments can take 10 seconds or more to load. To optimize latency, segment length can be reduced to 2–4 seconds. While this decreases latency, it increases the frequency of HTTP requests, adding overhead. For ultra-low latency streaming, Apple introduced Low-latency HLS (LL-HLS), which allows for near real-time delivery by reducing segment sizes and pre-fetching media parts before they're fully available.
What is DASH?
DASH (Dynamic Adaptive Streaming over HTTP), developed as an open standard by MPEG, is a versatile protocol known for its codec-agnostic nature and wide compatibility across devices. It is a popular choice for streaming platforms and applications targeting a broader audience, such as Android and Windows users.
DASH is used by around 65% of platforms that target non-Apple devices due to its flexibility in codec support and compatibility with a wide range of platforms and devices.
How DASH works?
Like HLS, DASH segments video content into smaller chunks delivered over HTTP. However, DASH is codec-agnostic, supporting various codecs such as H.264, HEVC, VP9, and even the newer AV1 codec. This gives developers the flexibility to choose the best codec for their specific use case, optimizing bandwidth usage and video quality for different audiences and device types.
DASH also supports low-latency streaming by reducing the segment size, but this requires careful management of the manifest (MPD) file and segment delivery to avoid introducing overhead and delays.
Key differences between HLS and DASH
Feature
HLS
DASH
Compatibility
Strong on Apple devices, widely compatible with Android
Excellent on Android, Windows, and other platform
Latency
Generally higher, especially for live streaming
Lower latency with advanced optimization options
Codec support
Historically H.264, now supports HEVC (H.265)
Codec-agnostic, supporting H.264, HEVC, VP9, and AV1
Encryption and DRM
Strong integration with Apple's FairPlay DRM
Supports multiple DRM systems through Common Encryption (CENC)
Segmentation
Traditionally uses MPEG-TS, newer versions support fMP4
Primarily uses fMP4, offering better efficiency and compatibility
HLS vs. DASH: Pros and cons
HLS (HTTP live streaming)
Pros:
Strong integration with Apple devices: Native support on iOS and macOS, ensuring a seamless experience for Apple users.
Ease of implementation: Generally easier to set up and deploy, especially for Apple-centric environments.
Adaptive bitrate streaming: Adjusts video quality based on network conditions to minimize buffering.
Cons:
Higher latency: Typically experiences higher latency compared to DASH, which may be an issue for live streaming scenarios.
Codec limitations: Historically limited to H.264, though newer versions support HEVC (H.265). Limited support for newer codecs like AV1.
Segment format: Traditionally uses MPEG-TS segments, which can be less efficient than newer formats like fMP4.
DASH (Dynamic adaptive streaming over HTTP)
Pros:
Codec flexibility: Supports a wide range of codecs, including H.264, HEVC, VP9, and AV1, allowing for more efficient video compression and delivery.
ower latency: Generally, achieves lower latency compared to HLS, making it more suitable for live streaming applications.
Better efficiency: Uses fMP4 segments, which are more efficient and compatible compared to MPEG-TS.
Cons:
Complex implementation: Can be more complex to set up and deploy, especially for developers unfamiliar with the protocol.
DRM integration: While DASH supports multiple DRM systems, integrating and managing these systems can be more challenging compared to HLS’s FairPlay DRM.
HLS vs. DASH: Choosing the right streaming protocol for your content
When deciding between HLS and DASH, understanding the nature of your content and target audience is crucial. Here’s how they compare in various aspects:
Factors
HLS
DASH
Target audience
Primarily Apple users
Diverse device environments
Content type
Ideal for on-demand content
Better suited for live events and diverse content
Development complexity
Easier to implement, especially for Apple platforms
Requires additional considerations for multi-device compatibility
DRM and security
Strong integration with Apple FairPlay DRM
Supports a wider range of DRM systems
Future-proofing
Limited to H.264 and HEVC
Supports newer codecs like AV1 for efficient, future-proof streaming
Implementing HLS and DASH: A step-by-step guide
HLS implementation
Segmenting video: Divide the video into smaller chunks (segments) for efficient delivery.
Creating manifest: Generate a manifest file (m3u8) that lists the segments and their attributes.
Using a player: Choose a compatible player such as FastPix Player, JW Player, or the native HTML5 video player.
Loading manifest: Load the m3u8 manifest file into the player.
Playback: The player reads the manifest, downloads the segments, and plays the video.
Optimizing latency: For live streaming, reduce the segment duration to 2–4 seconds to minimize latency. Consider implementing Low-Latency HLS (LL-HLS) to achieve near real-time delivery for live events.
DASH implementation
Segmenting video: Divide the video into smaller chunks (segments), similar to HLS.
Creating manifest: Generate a MPD manifest file that contains information about available representations and segments.
Using a player: Choose a compatible player such as Shaka Player or DASH.js.
Loading manifest: Load the MPD file into the player.
Playback: The player analyzes the MPD, selects the appropriate representation based on network conditions, and streams the video.
Unique challenges and considerations
Cost analysis: HLS may incur lower initial costs due to simpler implementation, especially for Apple-centric content. However, DASH's broader codec support, such as AV1, enables more efficient video delivery, potentially reducing bandwidth costs in the long term.
Security and DRM: Both protocols provide strong content protection options:
HLS integrates seamlessly with Apple's FairPlay DRM, making it ideal for platforms focusing on Apple devices.
DASH supports multiple DRM systems via CENC, offering flexibility for multi-device streaming. Studies have shown DASH’s support for multiple DRMs can help reduce piracy.
Developer experience: HLS has a large developer community and extensive documentation, allowing for faster time-to-market, especially in Apple environments. Conversely, DASH offers more flexibility in terms of codec support and cross-device compatibility, but at the cost of increased implementation complexity.
How to choose: Protocols for different use cases
On-demand vs. Live streaming
HLS: Best suited for on-demand content such as movies, TV shows, and educational videos. Its simplicity in implementation and strong support on Apple devices make it ideal for services targeting iOS and macOS users.
DASH: Particularly effective for live streaming applications where low latency is crucial, such as sports events, live news, and interactive live broadcasts. Its adaptive bitrate streaming helps maintain performance even under varying network conditions.
Device compatibility considerations
Targeting Apple devices: HLS is natively supported on iOS and macOS, making it the go-to choose for platforms focused on Apple devices. It ensures seamless integration and optimal performance on iPhones, iPads, and Macs.
Diverse device ecosystems: DASH excels in environments with a variety of devices and platforms, including Android, Windows, and smart TVs. It’s ideal for services aiming to reach a global audience with diverse device preferences.
High-definition and 4K streaming
HLS: Supports high-definition and 4K content on Apple devices with its recent updates, making it suitable for premium video services and high-resolution streaming within the Apple ecosystem.
DASH: Provides robust support for multiple codecs like HEVC and AV1, making it a strong choice for platforms offering high-definition and 4K content to a wide range of devices.
Interactive and real-time applications
HLS: Although traditionally not optimized for low-latency scenarios, newer versions of HLS have improved real-time streaming capabilities. It is now viable for interactive applications such as live webinars and Q&A sessions.
DASH: Known for its lower latency, DASH is ideal for real-time interactions like live sports streaming, interactive gaming, and virtual events where minimizing delay is critical.
Interactive and real-time applications
HLS: Although traditionally not optimized for low-latency scenarios, newer versions of HLS have improved real-time streaming capabilities. It is now viable for interactive applications such as live webinars and Q&A sessions.
DASH: Known for its lower latency, DASH is ideal for real-time interactions like live sports streaming, interactive gaming, and virtual events where minimizing delay is critical.
Content protection and DRM
HLS: Integrates seamlessly with Apple’s FairPlay DRM, making it a preferred choice for secure content delivery in Apple-centric environments. Ideal for premium video services and subscription platforms within the Apple ecosystem.
DASH: Offers flexibility with various DRM systems through CENC, providing a versatile solution for diverse content protection needs. Suitable for multi-device streaming services and international content distribution.
Global reach and multi-language support
HLS: Effective for platforms targeting specific regions with a strong presence of Apple devices. Supports multiple audio tracks and subtitles but may have limitations in global codec support.
DASH: Provides extensive global compatibility and supports a wide range of audio tracks and languages. Ideal for international platforms requiring diverse content options and global reach.
Adaptive streaming for low-bandwidth conditions
HLS: Handles varying bandwidth scenarios well with its adaptive streaming capabilities, making it effective in regions with unreliable internet connections.
DASH: Also excels in adaptive streaming, with codec flexibility allowing it to perform well in low-bandwidth situations. Suitable for applications where maintaining quality across variable network conditions is important.
Enterprise and internal use
HLS: Commonly used in enterprise settings for internal video streaming, training, and corporate communications, especially where Apple devices are prevalent, and ease of deployment is crucial.
DASH: Suitable for enterprise environments with diverse devices, including internal training platforms and corporate video distribution, offering flexibility in supporting multiple device types.
Final thoughts
Choosing between HLS and DASH for your streaming project depends on various factors, including your target audience, content type, and desired latency. HLS excels in delivering a seamless experience for Apple device users with its strong integration and adaptive bitrate streaming, making it a solid choice for on-demand content. On the other hand, DASH offers greater codec flexibility and lower latency, which is advantageous for live streaming and a diverse range of devices.
At FastPix, we streamline the implementation of both HLS and DASH, ensuring efficient video delivery and optimized streaming performance. Our multi-CDN technology helps maintain fast, reliable streaming across different protocols, keeping your audience engaged and satisfied.