Adaptive Streaming for Apple on Http

Adobe Dynamic Streaming for Flash

"Dynamic streaming is the process of efficiently delivering streaming video to users by dynamically switching among different streams of varying quality and size during playback. This provides users with the best possible viewing experience their bandwidth and local computer hardware (CPU) can support. Another major goal of dynamic streaming is to make this process smooth and seamless to users, so that if up-scaling or down-scaling the quality of the stream is necessary, it is a smooth and nearly unnoticeable switch without disrupting the continuous playback." ^[4]

The latest versions of Flash Player and Flash Media Server support adaptive bit-rate streaming over the traditional RTMP protocol, as well as HTTP, similar to the HTTP-based solutions from Apple and Microsoft.^[5] HTTP-based streaming has the advantage of not requiring any firewall ports being opened outside of the normal ports used by web browsers. HTTP-based streaming also allows video fragments to be cached by browsers, proxies, and CDNs, drastically reducing the load on the source server.

[edit] Apple HTTP Adaptive Streaming for iPhone/iPad

Main article: HTTP Live Streaming

"HTTP Live Streaming is an HTTP-based media streaming communications protocol implemented by Apple Inc. as part of their QuickTime X, and iPhone software systems." Apple's newly released iPad also provides HTTP Live Streaming capabilities. It works by breaking down streams into several small HTTP-based file downloads that load simultaneously at variable adaptive rates.

HTTP Live Streaming is a standard feature in the iPhone 3.0 and newer versions.^[6]

HTTP adaptive bit rate streaming is based on HTTP progressive download, but contrary to the previous approach, here the files are very small, so that they can be compared to the streaming of packets, much like the case of using RTSP and RTP.^[7]

While all adaptive bit-rate streaming solutions are proprietary offerings as of October 2010, Apple has submitted its solution to the IETF for consideration as an Internet standard.^[8]

[edit] Microsoft Smooth Streaming for Silverlight and Windows Phone 7

Smooth Streaming is an IIS Media Services extension that enables adaptive streaming of media to clients over HTTP. ^[9] The format specification is based on the ISO Base Media File Format and standardized by Microsoft as the Protected Interoperable File Format. ^[10] Microsoft is actively involved with 3GPP, MPEG and DECE organizations' efforts to standardize adaptive bit-rate HTTP streaming. Microsoft provides Smooth Streaming Client software development kits for Silverlight and Windows Phone 7. IIS Media Services 4.0, released in November 2010, introduced a feature which enables Smooth Streaming H.264/AAC videos, both live and on-demand, to be dynamically repackaged into the Apple HTTP Adaptive Streaming format and delivered to iOS devices without the need for re-encoding. Microsoft has successfully demonstrated delivery of both live and on-demand 1080p HD video with Smooth Streaming to Silverlight clients. In 2010 Microsoft also partnered with NVIDIA to demonstrate live streaming of 1080p stereoscopic 3D video to PCs equipped with NVIDIA 3D Vision technology. ^[11].