DASH

DASH (MPEG-DASH, ISO/IEC 23009-1) is the codec-agnostic, open-standard adaptive-streaming format used widely on everything except Apple devices: Android, Chrome, Windows, smart TVs, and set-top boxes. Like HLS it segments the stream and delivers over HTTP, but its manifest is an XML Media Presentation Description (MPD) that describes renditions, timelines, and tracks.

DASH's design goals were vendor and codec neutrality: it does not mandate a codec or DRM, which makes it flexible but means interoperability is defined by profiles (such as DASH-IF) rather than the spec alone. It supports rich features — multiple periods (useful for ad insertion), flexible audio/subtitle signaling, and low-latency operation (LL-DASH).

In practice platforms serve both HLS and DASH to cover all devices, and CMAF lets them do so from one set of segments. DASH commonly pairs with Widevine and PlayReady via Common Encryption (cenc or, increasingly, cbcs).

The handbook · 7 volumes

Fora Soft Video Engineering Handbook

DASH is the adaptive streaming format for Android, Chrome, smart TVs, and set-top boxes, and its XML manifest is where most interop bugs live. We wrote seven volumes covering the video stack; for DASH start with Volume 2 on segment protocols, MPEG-DASH, HLS, and CMAF, then Volume 1 on encoding, with ABR and players in Volume 3. Written by Nikolay Sapunov, CEO at Fora Soft.

Browse the handbook on Amazon →7 volumes · 9,000+ pages · Kindle & paperback