Tagged: DASH Toggle Comment Threads | Keyboard Shortcuts

  • joly 1:27 pm on 02/27/2013 Permalink | Reply
    Tags: DASH, MPEG-DASH, ,   

    MPEG-DASH – Video Dynamic Adaptive Streaming over HTTP 

    MPEG-DASHDynamic Adaptive Streaming over HTTP (DASH), is a new standard that enables high quality streaming of media content over the Internet, delivered from conventional HTTP web servers. It works by breaking multi-bitrate encoded content into small segments. A client continuously adjusts its requests according to the local bandwidth condition. It also allows for mixing up variously encoded material in one stream.

    DASH is codec/content agnostic, however its prime implementation will be for video in the MP4 and MPEG-TS containers. This is known as MPEG-DASH, and the common file extension will be mpd. As compatible clients become available it promises to be widely adopted, as it enables playback on a wide range of devices. MPEG-DASH will also allow seamless adoption of the coming improved HEVC video codec aka h.265.

    DASH does have competition, mainly in the form of Apple’s HLS, but it has the support of both Microsoft and Adobe – it’s backwards compatible with their own existing systems – plus Google. A panel of industry experts at Streaming Media East 2012 predicted it would have market dominance by 2015.

    Encryption is part of the standard. A sticking point has been the inability to agree on a common DRM scheme. In January 2013, provisional MPEG DASH-264 guidelines were released that allow DRM to be specified.

    libdash is an open-source C++ library that provides an object orient (OO) interface to the MPEG-DASH standard. The project contains a sample multimedia player based on ffmpeg playback of mpd files. (slides)

    Adobe and Akamai provide an MPEG-DASH Prototype player at http://tinyurl.com/dash4you. More demos are available.

  • joly 4:08 pm on 12/19/2011 Permalink | Reply
    Tags: DASH, http, ISO, MPEG, , ,   

    MPEG DASH video #streaming spec ratified as an ISO standard 

    MPEGThe Motion Pictures Experts Group (MPEG) DASH specification has been approved by 24 national bodies and ratified as an ISO standard (ISO/IEC 23009-1), and is expected to be published in March 2012.

    The specification, a new method of dynamically adaptive streaming over the HTTP protocol, will comprise two types of stream segments – multiplexed streams using MPEG-2 Transport Stream (TS) or elementary streams using fragmented MP4 files (fMP4) – using a Common File Format (CFF) that allows a choice of codecs and digital rights management (DRM) schemes. DASH is expected to eventually supercede all current methods except Apple’s HLS, the differentiating factor being the use of a proprietary manifest file in Apple HLS (known as an .m3u8 file) and a standards-based XML-based manifest file in DASH (known as an MPD or Media Presentation Description file).

    Additional work is to be done on the CFF –  with an emphasis on establishing a common DRM scenario –  at the next MPEG meeting in San Jose, California, in February 2012, after which device vendors and content suppliers will commence interoperability tests.

    [Source: Streaming Media News]


Compose new post
Next post/Next comment
Previous post/Previous comment
Show/Hide comments
Go to top
Go to login
Show/Hide help
shift + esc