HLS, DASH, CMAF: Choosing the Best Streaming Protocol for Your OTT Platform

As OTT platforms continue to scale globally, choosing the right streaming protocol is critical for delivering high-quality, low-latency video experiences. Among the most widely adopted protocols, HLS (HTTP Live Streaming), DASH (Dynamic Adaptive Streaming over HTTP), and CMAF (Common Media Application Format) each offer distinct advantages and challenges.

In this article, we’ll break down these three protocols from an OTT operator’s perspective, focusing on their strengths, weaknesses, and practical considerations for a modern streaming OTT platform.

HLS: The Apple-Backed Standard

HTTP Live Streaming (HLS) was developed by Apple and has become the default streaming protocol for iOS devices, Safari browsers, and Apple TV. Originally using MPEG-TS as its transport format, HLS has since evolved to support fMP4 (fragmented MP4), improving efficiency and reducing latency.

Why OTT Operators Use HLS? 

There are a few parameters of HLS OTT operators appreciate: 

• Broad device compatibility: HLS is supported across most devices, including iPhones, iPads, Apple TVs, and modern browsers.
• Strong adaptive bitrate support: ensures smooth playback by dynamically adjusting video quality based on network conditions.
• Robust content protection: supports AES-128 encryption and DRM integration for secure content delivery.

HLS traditionally uses segment durations of around 6 seconds, which can contribute to higher latency in live streaming. However, with the introduction of Low-Latency HLS (LL-HLS), segment durations have been reduced to 2–4 seconds to decrease latency.

HLS may also require additional setup for optimal performance on Android and other platforms.

DASH: The Open-Standard Alternative

Dynamic Adaptive Streaming over HTTP (DASH), commonly referred to as MPEG-DASH, is an adaptive bitrate streaming method that allows high-quality media streaming over the internet using standard HTTP web servers. DASH is an open-source alternative to HLS, designed to provide flexible, codec-agnostic streaming across multiple platforms. Unlike HLS, which was initially tied to Apple’s ecosystem, DASH is supported by Android, Smart TVs, gaming consoles, and web browsers.

Why OTT Operators Use DASH:

DASH provides the following capabilities for OTT providers:

• Codec flexibility: works with H.264, H.265 (HEVC), AV1, and VP9, allowing operators to optimize for efficiency.
• Lower latency: DASH supports shorter segment durations, typically around 2–4 seconds.
• Widespread adoption: used by major platforms like Netflix, YouTube, and Hulu due to its scalability and quality. DASH supports multiple DRM systems, including Google Widevine and Microsoft PlayReady.
• CMAF: A Unifying Format for HLS and DASH

CMAF was developed as a solution to reduce format fragmentation between HLS and DASH. Instead of maintaining two separate encoding workflows, CMAF enables the use of a single fragmented MP4 (fMP4) format that works across both protocols. CMAF also integrates MPEG Common Encryption (CENC), allowing content protection across multiple DRM systems while ensuring broad device compatibility.

CMAF is gaining traction as a solution to unify streaming workflows by reducing the need for multiple encoding processes, thereby optimizing storage and delivery costs.

Why OTT Operators Use CMAF:

• One encoding, two outputs: reduces storage and encoding costs by supporting both HLS and DASH with a single format.
• Lower latency: supports chunked transfer encoding, which helps minimize buffering and improves real-time playback.
• More efficient CDN caching: since HLS and DASH can share the same CMAF-encoded media segments, operators can optimize bandwidth usage and reduce load on CDNs.

CMAF is a format, not a delivery protocol, meaning it still requires either HLS or DASH for streaming. Older Apple and Android devices may still require traditional HLS or DASH. OTT operators should assess their audience's device capabilities before fully transitioning to CMAF.

To Wrap Up

Selecting the right streaming protocol is a strategic decision for OTT operators looking to optimize reach, performance, and scalability.

The choice between HLS, DASH, and CMAF ultimately depends on several factors, including:

• Device ecosystem: If your primary audience is on Apple devices, HLS is essential. For Android, Smart TVs, and a wider range of devices, DASH offers better cross-platform support.
• Live vs. on-demand streaming: DASH is ideal for livestreaming due to its lower latency configurations, while LL-HLS ensures iOS compatibility. On-demand streaming platforms may benefit from CMAF, which reduces encoding and storage overhead.
• Scalability: OTT platforms with a global audience require protocols that support CDNs, caching, and multi-CDN strategies to maintain consistent quality. CMAF helps reduce redundancy by allowing a single encoder to serve both HLS and DASH.
• Security & content protection: DRM integration is essential for premium content. HLS supports FairPlay DRM, DASH is compatible with Widevine and PlayReady, and CMAF enables a single encryption method across multiple protocols.

For OTT operators, the best approach is often not choosing a single protocol, but rather a combination of them. By carefully evaluating audience behavior, device compatibility, and performance needs, OTT providers can build a future-proof streaming strategy that ensures scalability, security, and a superior user experience.