Adaptive Playback of MPEG-DASH supports both live streaming and VOD. MPEG-DASH is the latest trend in online video space. DASH is standard for adaptive streaming over HTTP. It can replace the proprietary technologies such as Microsoft Smooth Streaming, Apple HTTP Live Streaming, etc.
HTTP Live Streaming
HTTP Live Streaming or HLS is the technology available for adaptive streaming to iOS and Apple TV devices. Live and on-demand files can be distributed with this communication protocol that is created by Apple.
HLS protocol is supported by several vendors like Wowza, RealNetworks, Microsoft, and Abode. The popularity of iOS devices is increasing due to the distribution related technology is the reason for increased support on the player side as well.
Any publisher producing an app in the Apple App Store and if the video length is longer than ten minutes, HTTP live streaming needs to be used. And they should also provide one stream at 64Kbps or lower bandwidth. The basic knowledge of HLS is important for the publishers who are targeting the iOS devices with their streaming.
Multiple files for distribution to the player are created and the streams are changed to optimize the playback experience. HLS works like any other adaptive streaming technologies. The switching logic resides on the player and thus the streaming server is required for the HTTP-based technology.
HLS does not support digital rights management. It is, however, possible to encrypt the data and provide key access with HTTPS authentication. Third party DRM solutions are available and these include AuthenTec, SecureMedia and WideVine.
Let us now know about the deliver advantages of delivering via HTTP. There is no need of any streaming server. The content via HTTP should pass through many firewalls. There are two components with HLS experience. These are set of .ts format and manifest fest that are required.
Pros and Con of HLS
HLS or HTTP was introduced in the year 2009 by Apple. It is a format that breaks streams into file-based segments that can be downloaded over HTTP. This format is mostly used for viewing streaming in real time. Let see some of the advantages and disadvantages of HLS.
There are many reasons why HLS is used for live streams. HLS is supported widely. It was first meant to support Apple, iOS and Safari browsers but now this format is implemented on most of the browsers.
Most of the leading browsers now support MPEG-DASH also. But this is not supported by iOS and Apple Safari. Clients can choose from a variety of streams based on the bandwidth available. HTTP Live Streaming was designed for multiple quality streams.
But not for delivering the video fast. It is a great choice for distribution streams on a variety of browsers, operating systems, and mobile phones. But this is a slow protocol.
HLS and WebRTC are contenders for in-browser video solutions. HTTP live streaming is client-server protocol to deliver streaming video. The streaming video is represented as series of regular file downloads.
HLS is HTTP based, the video is securely transmitted to the end clients over HTTPS. The individual stream can be sent to multiple clients without any difficulty.
HLS is a TCP-based protocol. It uses H.264 as the video codec and MP3 or AAC as the audio codec and delivers high-quality audio and video with less battery and CPU impact.
HLS works best when video needs to be transmitted securely, and an individual stream is required to be transmitted to multiple clients. However, it is not suitable for real-time communications as there are latency issues.