Adaptive bitrate streaming: Difference between revisions

Revision as of 21:01, 3 January 2023

Revision as of 04:17, 9 January 2023

Line 41:

{{Main article|HTTP Live Streaming}}

HTTP Live Streaming (HLS) is an HTTP-based media streaming communications protocol implemented by [[Apple Inc.]] as part of [[QuickTime X|QuickTime&nbsp;X]] and [[iOS]]. HLS supports both live and [[Video on demand]] content. It works by breaking down media streams or files into short pieces (media segments) which are stored as [[MPEG transport stream|MPEG-TS]] or [[MP4_file_format|fragmented MP4]] files. This is typically done at multiple bitrates using a stream or file segmenter application, also known as a packager. One such segmenter implementation is provided by Apple.<ref>{{citation |title=Mac Developer Library |publisher=Apple |url=https://developer.apple.com/library/mac/documentation/networkinginternet/conceptual/streamingmediaguide/UsingHTTPLiveStreaming/UsingHTTPLiveStreaming.html |access-date=2 June 2014}}</ref> Additional packagers are available, including free / open source offerings like Google's Shaka Packager <ref>{{citation |title=Shaka Packager Github Repository |publisher=Google |url=https://github.com/shaka-project/shaka-packager |access-date=3 January 2023}}</ref> and various commercial tools as well - such as Unified Streaming .<ref>{{citation |title=Unified Streaming |publisher=Unified Streaming |url=https://www.unified-streaming.com/ |access-date=3 January 2023}}</ref>. The segmenter is also responsible for producing a set of playlist files in the M3U8 format which describe the media chunks. Each playlist is specific to a given bitrate, and contains the relative or absolute URLs to the chunks for that bitrate. The client is then responsible for requesting the appropriate playlist depending on available bandwidth.

HTTP Live Streaming is a standard feature in the iPhone 3.0 and newer versions.<ref>{{cite web |url=http://www.appleinsider.com/articles/09/07/08/apple_launches_http_live_streaming_standard_in_iphone_3_0.html |publisher=AppleInsider |title=Apple launches HTTP Live Streaming standard in iPhone 3.0 |author=Prince McLean |date=9 July 2009 |accessdate=15 October 2011}}</ref>