Introduction
There are various streaming streaming methods like HTTP Live Streaming HLS, HTTP Dynamic Streaming and MPEG DASH which makes easy delivery of high quality content over HTTP. MSS is also one of them.
So in this article we will cover What Is MSS and Working Of MSS.
What Is MSS
MSS stands for Microsoft Smooth Streaming. Smooth Streaming feature was introduced with Internet Information Services IIS 7.0 by Microsoft. It is HTTP based adaptive streaming extension. Smooth Streaming is one of the first Adaptive Bitrate Streaming introduced by Microsoft.
In Microsoft Smooth Streaming a IIS origin server is installed and this smooth streaming is played in silver light player installed in client’s device. MSS makes easy delivery of Full HD Content 1080p with its lower version 480p and 720p, over HTTP.
There are various factors at client device which are also referenced while smooth streaming. The silver light player installed at client device denotes mainly two things bandwidth of connection as well as CPU usages for smooth delivery of data.
In case if there is good internet bandwidth then content would play in 1080p but if there is high CPU usases then this playing content quality will be reduced to 720p or 480p even more low depending the CPU uses. Smartphone’s batteries are also considered because decoding of high quality video means high CPU uses results high battery consumption. So user can also select manually on which bitrate he needs to play content to maintain good smartphone’s performance like without buffering playing and without hanging of smartphone etc.
Working Of Microsoft Smooth Streaming
As shown above in the figure a IIS smooth streaming origin server is installed at server side. IIS server is connected with HTTP caching server available in the network. This cache server is connected with various high bandwidth and low band width clients.
The IIS server is used to manage the content. A Microsoft Expression Encoder is used provide Adaptive Bitrates. You need to provide a high quality video file to this encoder and its generates its various bitrates of this file as output.
When a request is made from client to play content. Then this request goes to IIS server. Then IIS server provides the highest quality content according to conditions. The content provided by IIS server is in HTTP packets. These HTTP packets are sent to cache server. These HTTP packets are stored on various cache server available in the network for faster delivery of content to the nearest client.
The IIS server provides log how content is consuming and who is consuming content. Microsoft Smooth Streaming makes easy Content Creation , Administration and Management. All the service providers which uses Microsoft Smooth Streaming for protection of premium content they uses PlayReady DRM.
Microsoft Smooth Streaming File System
There are three files used in MSS are,
(1) Server Manifest File = .ism
(2) Client Manifest File = .ismc
(3) Fragmented MP4 Media File (Media Content) = .isma & .ismv
Microsoft Smooth Streaming is done in fragments. Where each fragment contains two box one is Movie Fragment and second one is Media Data. Movie Fragment Box represented by moof and Media Data Box represented by mdat.
All chunks of a file are stored in one file known as MP4. This file start with moov having fragments in middle and mfra in the last. Where moov contains the metadata of file. There are various frames in the middle while mfra is in the last which makes possible to access the different frames.
Conclusion
Microsoft Smooth Streaming is a easy process to deliver high quality video content without much affecting client device performance. In MSS a IIS server needs to install and connect with client device over HTTP. The Client needs to install silver light player in his device for playing of content.
Know More About What Is HLS and HLS Working
reference : microsoft
