Media Source Extensions

Media Source Extensions (MSE) is a W3C specification that allows JavaScript to send byte streams to media codecs within web browsers that support HTML video and audio.^[5] Among other possible uses, this allows the implementation of client-side prefetching and buffering code for streaming media entirely in JavaScript. It is compatible with, but should not be confused with, the Encrypted Media Extensions (EME) specification, and neither requires the use of the other, although many EME implementations are only capable of decrypting media data provided via MSE.^[6]

MSE

Media Source Extensions
Abbreviation	EME, media-source
Native name	Media Source Extensions
Status	Candidate Recommendation[1][2]
Year started	2013 (2013) [3]
First published	January 29, 2013 (2013-01-29)[1]
Latest version	Candidate Recommendation November 17, 2016 (2016-11-17)[1]
Preview version	Editor's draft April 21, 2021 (2021-04-21)[4]
Organization	W3C Google Microsoft Netflix
Committee	HTML Media Extensions Working Group
Editors	Matthew Wolenetz Mark Watson Former editors Jerry Smith (until September 2017 (2017-09)) Aaron Colwell (until April 2015 (2015-04)) Adrian Bateman (until April 2015 (2015-04)) [4][1]
Authors	HTML Media Extensions Working Group
Base standards	HTML, Web IDL
Related standards	Encrypted Media Extensions
Domain	HTML video, HTML audio
Website	Latest version: www.w3.org/TR/media-source/ Editor's draft: w3c.github.io/media-source/

Netflix announced experimental support in June 2014 for the use of MSE playback on the Safari browser on the OS X Yosemite beta release.^[7]

YouTube started using MSE in its HTML5 player in September 2013.

Browser support

Media Source Extensions API is widely supported across all modern web browsers, with the only exception being iPhone-family devices (although it is supported on iPadOS).^[8] Firefox 37 already had a subset of MSE API available for use with only YouTube in Firefox 37 on Windows Vista or later only,^[9] while Mac OS X version had in enabled starting version 38.^[10]

Browser support for Media Source Extensions

Desktop						Mobile devices
Windows, Mac OS, Linux						iOS	Android
Internet Explorer	Edge	Chrome	Firefox	Safari	Opera	All browsers[11]	Edge	Chrome	Firefox	Opera	Samsung Internet
11.0[12]	12+[13]	23–30[14][15]	38–41[14]	8+	30+[16]	iOS 13+[17]	12+	92+	90+	64+	9.2+
		31+	42+[18]

Minor browsers

• Pale Moon from version 27.0, since 22 November 2016.^[19]

Players

• NexPlayer for HTML5 MSE and EME supporting HLS and DASH
• castLabs PRESTOplay video player for HMTL5 MSE and EME supporting DASH and HLS
• Akamai Media Player as a contributor to the Dash Industry Forum and DASH.js (DASH IF reference client). AMP includes Dash.js, HLS.js and advanced QUIC protocol playback from Akamai Edge Servers
• Shaka Player, an open source javascript player library for HTML5 MSE and EME video with DASH and HLS support^[20][21]
• The Video Player by Comcast Technology Solutions
• THEOplayer by OpenTelly: HLS and MPEG-DASH player for cross-platform HTML5 support without the need for Flash fallback^[22]
• Viblast Player: HLS and MPEG-DASH player for HTML5 MSE and EME, with Flash fallback^[23]
• bitmovin's bitdash MPEG-DASH player for HTML5 MSE and EME, with Flash fallback^[24]
• dash-js for HTML5 MSE^[25]
• dash.js for HTML5 MSE and EME^[26]
• rx-player for HTML5 MSE and EME (Live and On Demand)^[27]
• hls.js for HTML5 MSE^[28][29]
• hasplayer.js for HTML5 MSE and EME, supporting DASH, Smooth Streaming and HLS^[30]
• JW Player 7 and later for MPEG-DASH using HTML5 MSE and EME^[31]
• SLDP HTML5 Player supports SLDP via MSE playback^[32]
• Azure Media Player supports MSE, EME, DASH, HLS, Flash, and Silverlight. Streaming URLs are published in an ism/manifest^[33]
• Unreal HTML5 player uses MSE for low latency (sub-second) live playback of streams sent via WebSockets by Unreal Media Server^[34]
• Storm Player uses MSE as one of its delivery modes for ultra-low latency streaming via WebSockets by Storm Streaming Server^[35]

See also

• HTML video
• Dynamic Adaptive Streaming over HTTP (DASH)
• WebRTC

References

1. Wolenetz, Matthew; Smith, Jerry; Watson, Mark; Colwell, Aaron; Bateman, Adrian (eds.). Media Source Extensions™. W3C (Technical report) – via W3C.
2. "Media Source Extensions™ Publication History - W3C". W3C. 21 September 2022.
3. Colwell, Aaron; Bateman, Adrian; Watson, Mark, eds. (2013-01-29). Media Source Extensions. W3C (Technical report). Retrieved 2021-03-19 – via W3C.
4. Media Working Group (2021-04-21). Wolenetz, Matthew; Watson, Mark; Smith, Jerry; Colwell, Aaron; Bateman, Adrian (eds.). "Media Source Extensions™". w3c.github.io. Editor's draft. Media Working Group. Retrieved 2021-04-21.
5. "Media Source Extensions W3C Recommendation". 17 November 2016. Retrieved 5 January 2021.
6. "Encrypted Media Extensions". 18 September 2017. Retrieved 29 January 2020.
7. Anthony Park and Mark Watson (3 June 2013). "HTML5 Video in Safari on OS X Yosemite". Netflix.
8. "Media Source Extensions". Can I use... Retrieved 2021-07-30. Fully supported only in iPadOS 13 and later
9. Mozilla (2015-03-31). "Firefox 37.0, See All New Features, Updates and Fixes". Mozilla. 37.0. Retrieved 2021-04-24.
10. Mozilla (2015-05-12). "Firefox 38.0, See All New Features, Updates and Fixes". Mozilla. 38.0. Retrieved 2021-04-24.
11. All browsers on iOS platform must use WebKit engine
12. Stefan; et al. (bitmovin Team) (2015-02-02). "The Status of MPEG-DASH today, and why YouTube & Netflix use it in HTML5 & beyond". dash-player.com. Archived from the original on 2015-02-21. Retrieved 2021-04-24.
13. McCormick, Libby (2015-11-05). "Media Source Extensions (MSE) (Windows)". docs.microsoft.com. Retrieved 2021-04-24.
14. Not supported by default, but could be enabled via browser settings
15. "Media Source Extensions - Chrome Platform Status". www.chromestatus.com. Retrieved 2021-07-30.
16. Bynens, Mathias (2015-06-09). "Dev.Opera — Opera 30 released". dev.opera.com. Retrieved 2021-04-24.
17. Media Source Extensions is only available on iPadOS
18. Mozilla (2015-11-03). "Firefox 42.0, See All New Features, Updates and Fixes". Mozilla. 42.0. Retrieved 2021-04-24.
19. "Pale Moon - Release Notes for Archived Versions § 27.0.0 (2016-11-22)". www.palemoon.org. 27.0.0. 2016-11-22. Retrieved 2021-04-24.
20. "JavaScript player library / DASH & HLS client / MSE-EME player: google/shaka-player". March 24, 2019 – via GitHub.
21. "Shaka Player Demo". shaka-player-demo.appspot.com.
22. NV, THEO Technologies. "THEOplayer – Universal Video Player". www.theoplayer.com.
23. "Viblast Player". viblast.com.
24. "HTML5 Player for Adaptive Streaming from Bitmovin". Bitmovin. January 22, 2016.
25. "DASH-JS | ITEC – Dynamic Adaptive Streaming over HTTP".
26. "A reference client implementation for the playback of MPEG DASH via Javascript and compliant browsers.: Dash-Industry-Forum/dash.js". March 23, 2019 – via GitHub.
27. "GitHub - canalplus/rx-player: Smooth/DASH HTML5 Video Player". March 21, 2019 – via GitHub.
28. "dailymotion – Medium". Medium.
29. "hls.js demo page". Archived from the original on 2015-11-20. Retrieved 2017-12-03.
30. "Http Adaptive Streaming javascript player based on HTML5 premium extensions (MSE/EME): Orange-OpenSource/hasplayer.js". February 20, 2019 – via GitHub.
31. "JW Player Support". JW Player Support.
32. "HTML5 player for SLDP". Softvelum.
33. "Azure Media Player". Microsoft. 2015. Retrieved 2016-06-14.
34. "Unreal Media Server". www.umediaserver.net.
35. "Storm Streaming Server". Storm Streaming. Retrieved 2021-07-30.