MPEG-DASH is one of the biggest and most well-known video-streaming protocols for delivering media through Video on Demand (VOD) or Live streaming to devices like mobile phones and other smart gadgets.
MPEG-DASH is an HTTP-based streaming protocol for providing video to the last user from an HTTP server. A video is divided into segments through this player, and this data is recorded in the MPD.
Castr’s dash player is one of the best MPEG-DASH online players to play your mpd files for free. It comes with a very simple-to-use interface and provides you with a lot of helpful information for your stream
How does MPEG-DASH Works?
Now, we will see how this streaming protocol functions.
Dynamic Adaptive Streaming over HTTP, i.e., DASH, operates according to the Adaptive Bitrate Streaming tenets (ABR). By alternating between high- and low-quality video encodings and bandwidth capacities, the technique enables the material to adapt to the end consumers constantly. MPEG-DASH is a famous real-time video design utilized by a few enormous websites.
While using ABR web-based, a video stage or server is utilized for ingesting a solitary video source and transcoding it into at least twelve distinct renditions. The many renderings come in various sizes for buffer-free listening on multiple devices and connection speeds. This way, viewers with the most sophisticated equipment may view a high-bitrate, high-frame-rate, high-resolution stream.
The renditions are given as a succession of ten-second-long pieces instead of one long stream. Thus, the stream can adjust on its own between a menu of resolution and bitrate options.
The DASH spec provides a stable video-watching experience. However, it also causes delay as it takes time for individual segments to download. However, one way to overcome this problem is to tune latency by reducing the segment size. Another solution is to use the Common Media Application Format, i.e., CMAF.
What is Adaptive Bitrate Streaming?
You may have read the word ‘Adaptive Bitrate Streaming’ or ABR a lot in this blog. So, now let’s understand what exactly Adaptive Bitrate Streaming is.
ABR is the ability to Set the video in the middle of the stream as organizational conditions change. Many streaming conventions, including the MPEG dash player, HLS, and HDS, take into consideration the ABR.
The ABR streaming becomes conceivable as the beginning server encodes the video fragments at different quality levels. It happens at the time of encoding & segmentation processes. The video player can shift from one quality level to the other in the middle of the video without interruption. Thus, it prevents the video from stopping if the network bandwidth gets reduced.
How Does MPEG-DASH Work?
As its name suggests, DASH or Dynamic Adaptive Streaming over HTTP works on the principles of ABR or Adaptive Bitrate Streaming. In a nutshell, this is how MPEG-DASH works –
- A set of encodes (or renditions) of a movie is packaged by a MPEG-DASH packaging service or software. The packager splits each rendition into small pieces or chunks of a specified duration (e.g., 2 seconds or 4 seconds long).
- The packager also records how it split the videos and the order in which they are to be delivered into a text file called an MPD or a manifest.
- The packaged video and the manifest are stored on an origin server waiting to be delivered to a player, usually via a CDN (content delivery network).
- At the other end, there is a MPEG-DASH compliant player with an ABR-streaming engine built into it.
- When the user presses play, the app or video player requests the video’s MPD file. After receiving the MPD, the player parses it to understand how to play the video.
- The player then starts requesting the video’s chunks in the pre-defined order, decodes the chunks, and displays the video to the user.
- The player also continuously monitors the bandwidth conditions. Depending on the available bandwidth, the player chooses one of the bitrates advertised in the MPEG-DASH MPD and requests the CDN to send the next chunk of video from that variant.
This process continues till the end of the video playback session – either the movie comes to an end or the user stops watching it.
Final Thoughts
At last, we would say that the MPEG-DASH player is an amazing video streaming protocol. It splits the video into various segments to record the data in the MPD. It can be a very useful streaming protocol.
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