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Adaptive Bit Rate video delivery using MPEG-DASH technique is used by Big Brands
The video stored in the server, and it is impressed in some different rates. e.g. rates vary from the 50kbps to 4000kbps, the beautiful thing about this is that each device like Mobile, Laptops, TV’s can select the video rate which is most appropriate for their needs based on the speed the stream size and the resolutions requires. Not only videos upload on the server with different bit rates but also upload audio in different languages. These all stored in a manifest, so before watching the video, each one of these devices is sending GET to the video server. the server is going to send them the manifest, and then the device can select which speed is more appropriate for its needs, for example, the mobile phone chose 200 kbps, PC’s 700 kbps, and the vast screen TV’s 3000kbps.
To watch the video each one of these devices is going to send the get to the server the GET is going to pull back video which is going to be stored in buffer of each one of these devices intern, for example, the buffer with Microsoft server light can vary from one to ten seconds, the default size is mainly 5 seconds but many different manufacturers, of course, will have different buffer sizes. The underlying technology shown here applies to all systems. The adorable thing about this system is It adapts, for example, if the speed and feed coming into the large screen TV pull off because the network is stressed or overloaded the devices can adjust the bitrate according to their needs it does it by monitoring its buffer. As long as the buffer maintains its depths, the device can again adapt back to its original rate.
The MPEG-DASH Toolbox
DASH is an enabler:
- Provides formats to enable high-quality streaming over the Internet
- System definition left to other organizations (SD0s, Companies. etc.)
- Only for HTTP delivery of streaming video/audio with adaptive features
- It standardizes the container description information to ensure interoperability between servers and clients.
- DRM is not explicitly defined but support of DRM metadata is described.
- MPEG-DASH specifies adaptive stream switching using a hierarchical definition of segments, representations, groups and periods
- Captioning, extended data and triggers are not specified but adopted from the underlying formats
- Trick modes are a supported feature of MPEG-DASH
- Promote and catalyze market adoption of MPEG DASH
- Facilitate interoperability tests
- Collaborate with SDOs and industry consortia aligning constant DASH standards development and the use of common profiles
- Publish interoperability and deployment guidelines (DASH264 Base)
DASH IF defines several interoperability points (IOP) regarding:
- MPEG DASH specific features
- Subtitles and closed captioning
- DRM specific aspects
- Transport-layer specific aspects
- Codecs including levels and profiles
DASH264 Base 10Ps Overview
- Restricted version of ISO BMFF Live and On-demand profiles
- No playlist-based addressing
- Video H 264/AVC MP@3.0 for SD.H 264/AVC MP@3.1 for HD
- Audio HE-AC v2
- No muxed audio/video
- No open-GoP switching
- ISO/IEC 23001-7 Common Encryption
- TTML-based Timed Text (SMPTE TT CFF TT, EBU TT)
HEVC main drivers:
- Bandwidth savings at all bitrates (Target is 2:1 over H.264/AVC) Ex: Enables expanding IPTV service delivery footprint for DSL based infrastructure
- Higher resolutions (8K by 4K and 4K by 2K) and frame rates
- Improve performance on mobile devices with -HD- display capabilities More integrated decode functions = less power/battery usage
- Launch 1080p50/60 services to compete against package media (Blu-ray), Current services generally in 720p or 10801
- Expected <10x more computational complexity (encode) and 2x-3x (decode), 720p30 software decode on IPad3 available today (with reference SW decoders)
MPEG DASH – Tomorrow’s Format Today:
DASH intends to be the internet world…what MPEG2-TS and NTSC have been to the broadcast world
What is Dash?
Dynamic Adaptive Streaming over HTTP, MPEG-DASH is an ISO Standard for the adaptive delivery of the content.
ISO 23009: Timeline and Standards in MPEG
The fastest time ever that a standard was developed in MPEG to address the demand of the market.
Live, on-demand and time-shift service area
Efficient and comfort of use of present CDNs, proxies, caches, NATs and firewalls
Independency of demand size and segment magnitude (byte range requirements)
Adaptive Bit Rate Video Delivery Using MPEG-DASH Technique Used By Big Brands like Adobe, Apple and Microsoft.