HDS, HLS, HSS -- Adaptive HTTP Streaming Demystified | Verizon Me...
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`HDS, HLS, HSS -- Adaptive HTTP Streaming
`Demystified | Verizon Media Platform
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`As the viewing habits of consumers continues to shift from old media to IP, a number
`of HTTP streaming protocols have been recently introduced to allow for an easier
`and more efficient way to deliver video content. Specifically, the introduction of
`HTTP adaptive bitrate streaming has been an exciting development in terms of
`improving video quality, performance, and accessibility across all devices.
`
`Unfortunately, the streaming industry has adopted the confusing practice of using
`similar three-letter acronyms. Let’s clear up some of this confusion and provide a
`comparison of the available options for HTTP streaming:
`
`Progressive HTTP Streaming
`
`Until recently, video content over HTTP has been delivered progressively — similarly
`to how images load in a web browser, from top to bottom (start to finish). However,
`progressive video streaming has some major drawbacks: viewers can’t skip around in
`a video without fully loading it, stream quality depends on the video file that is being
`downloaded and can’t be changed on the fly, and there are inherent security concerns
`as the video can be easily saved and copied.
`
`Because of these drawbacks, the majority of streaming providers used Adobe’s RTMP
`protocol and their Flash Media Server (FMS), adding significant cost and complexity.
`
`Return of HTTP
`
`Because of the growing use of mobile devices and their lack of support for Adobe’s
`Flash, HTTP streaming has made a comeback. A number of different HTTP
`streaming solutions have been introduced that attempt to fix the drawbacks of
`progressive HTTP streaming and allow for more flexibility than RTMP.
`
`These HTTP streaming solutions all feature adaptive-bitrate delivery, which means
`that they can change video quality on the fly because the actual video and audio files
`are broken up into smaller sized chunks and encoded into different bitrates.
`Depending on bandwidth or CPU conditions, a higher or lower quality stream can be
`automatically requested by a viewer for seamless playback.
`
`An additional benefit to HTTP streaming is the ability to utilize CDNs to cache video
`content closer to end-viewers. Moving content closer to viewers increases
`performance by reducing the amount of hops that need to be made in order to fetch
`the requested video file.
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`HDS
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`HTTP Dynamic Streaming was developed by Adobe as an alternative to their RTMP
`protocol. HDS allows for adaptive streaming over HTTP to any device that’s
`compatible with Adobe Flash or Air. A big benefit to streaming with HDS instead of
`RTMP is not having to rely on a FMS, which significantly decreases the cost of
`operating the stream. Adobe has released a module for Apache, the most popular
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`HDS, HLS, HSS -- Adaptive HTTP Streaming Demystified | Verizon Me...
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`https://www.verizondigitalmedia.com/blog/hds-hls-hss-adaptive-http-str...
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`Open Source HTTP server, that allows it to act as a streaming origin server.
`
`Because of the 97% market penetration that Flash Player has, HDS is a great choice
`for streaming to desktop computers. However, the Flash Player is not supported by
`Android and iOS, which limits practical use for broadcasting to mobile devices.
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`HLS
`
`HLS stands for HTTP Live Streaming and is a protocol developed by Apple for their
`iOS devices and QuickTime player. Support was added to Android 3.0 (Honeycomb)
`which has made HLS the ideal candidate for streaming to the widest range of mobile
`devices. A large number of client video players are available including the default
`HTML5 player and most mobile browsers.
`
`HLS can be deployed using most HTTP servers (including Apache) or a number of
`commercial streaming servers such as Adobe FMS and Wowza. Also, many streaming
`services and CDNs can stream to HLS-compatible players via transmuxing, or
`dynamically repackaging existing video streams into their HLS compatible packages.
`
`Thanks to these handy features, HLS has been adopted as the primary mobile
`streaming protocol for most video content websites.
`
`HSS
`
`HTTP Smooth Streaming is Microsoft’s foray into adaptive HTTP streaming that
`runs on their IIS web server and Silverlight player. The Silverlight player detects local
`bandwidth and CPU conditions and dynamically switches bitrates to offer
`uninterrupted streaming. HSS supports multiple audio and video codecs, and is
`highly customizable. It is often used for very large-scale streams, such as NBC’s
`online stream of the Olympic Games, and is part of Netflix’s streaming stack.
`
`Streaming to Apple devices is possible when using the H.264 video codec. IIS is able
`to transmux HSS fragments into ones compatible with iOS 3.0 and later devices.
`
`TV undeniably is moving to the mobile web. That is why adaptive HTTP streaming
`will be the backbone of any streaming strategy that aims at enabling superior viewing
`experiences on any device. As all HTTP streaming formats add security and DRM
`capabilities, the question which format to choose will ultimately come down to
`supported features and cost of delivery.
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`2 of 2
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`DivX Exhibit 2004
`Netflix & Hulu v. DivX, IPR2020-00648
`Page 2004 - 2
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