The Dynamic Adaptive streaming over the HTTP is known as the DASH. It is also called as the MPEG-DASH. MPEG DASH is a technique related to the adaptive bitrates streaming technology that allows high-quality streaming of content across the internet using the HTTP web servers.
It is an international standard of streaming over HTTP. It is different from Apple, Adobe, or Microsoft. It is an agnostic code where the HTTP can pass different types of data, which is the best factor.
The codec agnostic is significant as the vendors like Apple, Adobe; Google has the proprietary codecs which don’t play up to the mark on the competitor’s devices. You generally can’t avoid these providers as their devices are popular. The thing is, you need to please everyone without troubling the consumer, and hence DASH comes into play regarding this.
Table of Contents
There are two essential components in the media presentation, and the basic things are the video and the metadata, and it is called as a media presentation in DASH language. The media presentations include multimedia, webcasts, podcasts, etc.
The media presentation is the entire presentation that might be a movie or deals with the messages or trailers. DASH understands the need for what producer wants to go with. Every video and audio is called an adaptation. The adaptations are called a period and every period holds some open or more adaptations. The period will allow the audio, video, and other data which separates from the rest.
MPEG DASH Specification
MPEG is known as the Moving Picture Expert Group. With challenges involved in consumer electronics and the multiple platforms, reach has challenged the content creators with costs and complications.
The MPEG was developed using various standards of multimedia, which are included with the MPEG-2, MPEG-4, and MPEG -7 and 21. The Dynamic Adaptive streaming over the HTTP is the latest standard for solving the complexities of the media delivery to multiple devices.
The adaptive bitrates video is superior in delivering the static video form into the single bitrates as the video stream is switched mid-stream basing on the network speed that is available for the client to watch the content. It used three different protocols for the delivery, such as the HTTP Live Streaming, HTTP Dynamic, and Microsoft Smooth Streaming.
Every protocol used various formats and methods. So the device needs to support the content must be received from each server by supporting the protocol. By using the standards for the HTTP streaming of the multimedia content, it will allow the various standards-based clients for the content stream across the standards-based server, which in turn unified the servers and as well as the clients related to the different vendors.
MPEG DASH MPD
MPD means Media Presentation Description. It can be written in XML format that provides the valuable metadata which identifies the various parts or components of the stream, establishing the place and sequence.
A DASH player needs an important manifestation to keep things in an orderly manner. It was going with a client’s device that segment the play. It is operated with some precision.
The process of structuring the Data is known as Media Presentation Description. It is opened up in DASH in a different type of applications as well as the DASH is a strict standard of H.264.
MPEG DASH vs. HLS
The HLS and DASH are the two different rival formats that deliver the video over the web. HLS is an old version that is supported widely, but there is no such likelihood to make it as an official standard. DASH is a new and most efficient one which has no native support for the HTML5.
The HLS is developed by Apple, and it can deliver the file in one go. Every segment needs 10 seconds duration to use as a video codec. DASH is an alternative format for video streaming.
DASH and HLS are considered as international standards. Both of them are differentiated from one another, mainly in supporting the DRM.
Many other formats are available for smooth streaming, HDS, etc. however, the DASH and HLS are the most dominant among all these things. Both DASH and HLS are based on the HTTP protocols using the Standard HTTP traffic, proxy servers as well as the ports.
The main benefit is with UDP-based protocols that have a tunnel through the ports. Both are ideal for the content delivery networks as they can be cached at the edge and makes them simple like protocols RTMP.
MPEG DASH PLAYER
You can build the MPEG –DASH player by using the media source Extensions API towards an HTML5 video element and can find the sample codes for constructing your MPEG-DASH player.
Go to the media source object that is filled with the media data from the files that are segmented. They consist of a series of single files that are indexed in the sections that can be downloaded.
MPEG DASH FFMPEG
If you are trying to get on with the adaptive streaming setup, then you might already solve some problems. Just ingest the source code for the video and transcode it to 5 resolutions with every three bitrates.
Later split them into 5-second chunks that allow the best possible viewing, create or generate the MPD manifest file and use MP4Box.
MPEG DASH SERVER
The Dynamic adaptive streaming over the HTTP is the best way to stream your video using the internet. DASH utilizes the multiple video files, and MPEG-DASH server can be set up using simple steps on your own.
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Guide to Adaptive Playback of MPEG-DASH and HLS
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 a client-server protocol to deliver streaming video. The streaming video is represented as a 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 a 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.