Dynamic Adaptive Streaming over HTTP

MPEG-DASH technology was developed under MPEG. Work on DASH started in 2010; it became a Draft International Standard in January 2011, and an International Standard in November 2011. The MPEG-DASH standard was published in April, 2012 but has been revised in 2019 and then once more in 2022 as . DASH is a technology related to Adobe Systems HTTP Dynamic Streaming, Apple Inc. HTTP Live Streaming (HLS) and Microsoft Smooth Streaming. DASH is based on Adaptive HTTP streaming (AHS) in 3GPP Release 9 and on HTTP Adaptive Streaming (HAS) in Open IPTV Forum Release 2. As part of their collaboration with MPEG, 3GPP Release 10 has adopted DASH (with specific codecs and operating modes) for use over wireless networks. further promotes and catalyzes the adoption of MPEG-DASH and helps transition it from a specification into a real business. It consists of major streaming and media companies, including Microsoft, Netflix, Google, Ericsson, Samsung, Adobe, etc. and creates guidelines on the usage of DASH for different use cases in practice. MPEG-DASH is integrated in other standards, e.g. MPEG-DASH is supported in HbbTV (as of Version 1.5). == Overview ==

DASH is an adaptive bitrate streaming technology where a multimedia file is partitioned into one or more segments and delivered to a client using HTTP. A media presentation description (MPD) describes segment information (timing, URL, media characteristics like video resolution and bit rates), and can be organized in different ways such as SegmentList, SegmentTemplate, SegmentBase and SegmentTimeline, depending on the use case. Segments can contain any media data, however the specification provides specific guidance and formats for use with two types of containers: ISO base media file format (e.g. MP4 file format) or MPEG-2 Transport Stream. An early predecessor of DASH was an HTTP web server based streaming system called SProxy, developed and deployed in the Hewlett Packard Laboratories in 2006. It showed how to use HTTP range requests to break the content into small segments. SProxy showed the effectiveness of segment based streaming, gaining Internet penetration in the presence of the wide deployment of firewalls (which are prone to blocking novel protocols), and reducing the unnecessary traffic transmission if a user chooses to terminate the streaming session earlier before reaching the end. DASH is audio/video codec agnostic. One or more representations (i.e., versions at different resolutions or bit rates) of multimedia files are typically available, and selection can be made based on network conditions, device capabilities and user preferences, enabling adaptive bitrate streaming and QoE (Quality of Experience) fairness. DASH standard does not specify the adaptive bitrate streaming (ABR) logic. The current MPEG-DASH reference client dash.js offers both buffer-based (BOLA) and hybrid (DYNAMIC On July 27, 2015, MPEG LA announced a call for MPEG-DASH-related patents in order to create a single patent pool for this technology. MPEG LA announced its MPEG-DASH patent portfolio licence. MPEG-LA claims that the included patents are essential to the MPEG Dynamic Adaptive Streaming over HTTP standard. == Implementations ==

MPEG-DASH is available natively on Android through the ExoPlayer, on Samsung Smart TVs 2012+, LG Smart TV 2012+, Sony TV 2012+, Philips NetTV 4.1+, Panasonic Viera 2013+ and Chromecast. YouTube as well as Netflix already support MPEG-DASH, and different MPEG-DASH players are available. While MPEG-DASH isn't directly supported in HTML5, there are JavaScript implementations of MPEG-DASH which allow using MPEG-DASH in web browsers using the HTML5 Media Source Extensions (MSE). There are also JavaScript implementations such as the bitdash player which support DRM for MPEG-DASH using the HTML5 Encrypted Media Extensions. In combination with WebGL, the HTML5-based adaptive bitrate streaming of MPEG-DASH enables also the efficient streaming of 360° video for live and on-demand use cases. Clients and libraries • Shaka Player, is the open source DASH HTML5 video player from Google for Low Bandwidth Connections. • VLC media player 3.0 shipped a new client plugin for MP4/MPEG and Live streams. • The cross-platform FOSS multimedia framework GStreamer has supported MPEG-DASH and WebM DASH since at least v1.4. • The open-source library libdash is platform independent and runs on mobile platforms such as Android, iOS, Windows Phone. • bitmovin provides the bitdash MPEG-DASH player for HTML5 and Flash. • VideoJS is an open-source HTML5 video player, supports HLS, DASH, WebM, and progressive MP4 for Live and VOD streaming. • Brightcove Zencoder has support for MPEG-DASH transmuxing/transcoding. • Elemental Technologies video processing solutions support DASH. • Helix Universal Server has support for DASH in various modes. • Nimble Streamer has live and VOD MPEG-DASH support. For VOD it supports both H.265 and H.264 codecs • Unified Origin supports MPEG-DASH. Services • Akamai CDN supports DASH. • Amazon CloudFront CDN supports DASH. • Amazon Web Services Elastic Transcoder has support for MPEG-DASH. • Azure Media Services platform has support for MPEG-DASH. • Bitmovin provides the cloud-based transcoding service bitcodin.com which supports MPEG-DASH. • CloudFlare Stream supports transcoding into DASH in VP9 before serving to the end user. • Cloudinary provides automatic transcoding with support for MPEG-DASH. • Lumen CDN supports DASH. • Limelight Networks CDN supports DASH. • Project Shield CDN supports DASH. • Tata Communications CDN supports DASH. • DogalZeka MS2 Alarm Monitoring, Transcoding and Recording DASH input/output support. • Resi Live Stream Platform supports ingest, transcoding and CDN delivery of MPEG-DASH. Content generators • ITEC's DASHEncoder. • MP4Box and its multimedia framework from GPAC at Télécom Paris • dashcast from Télécom Paris supports MPEG-DASH live streaming • MediaGoom MPEG-DASH Packager • Bento4 opensource tools and SDK Other • ITEC offers a validation service for MPEG-DASH Media Presentation Description (MPD) files are offered by the Institute of Information Technology (ITEC) at Alpen-Adria University Klagenfurt, the GPAC group at Telecom ParisTech • The BBC has DASH test streams, including DASH over HTTP/2. • Widevine DRM supports DASH and Encrypted Media Extensions. • Mividi provides software tool for analyzing and monitoring live MPEG-DASH streams. == Supported players and servers ==

Clients Windows 10 used to have native support for DASH streaming in EdgeHTML, a proprietary browser engine that was used in Microsoft Edge (now referred to as Edge Legacy) before the transition to the Chromium-based Blink browser engine. Edge Legacy was included in Windows 10 up till version 2004. It was replaced by Edge Chromium in version 20H2. DASH support on other browsers & operating systems is available via Media Source Extensions. == Patent holders ==