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Standards' Perspective - MPEG DASH overview and related efforts

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Presented in the IMTC MPEG DASH webinar, February 16th 2012

Text of Standards' Perspective - MPEG DASH overview and related efforts

  • 1. DASHStandards perspective: MPEG DASHoverview and related effortsThomas Stockhammer Qualcomm Incorporated

2. Agenda Review of what is DASH Latest Status in MPEG DASH Profile Discussion DASH PG and IMTC Summary 2 3. Apple HLSMPEG2008MS SS20102008 OIPFW3C20092011?3GPPDASHothers20092011 Open Standard Delivery Format 3 4. DASH in a Nutshell What: Video streaming solution where small pieces of video streams/files are requestedwith HTTP and spliced together by the client. Client entirely controls delivery. Why: reuse widely deployed standard HTTP servers/caches for scalable delivery, e.g.existing Internet CDNs; traverse NAT/Firewalls; simple rate adaptation; fixed-mobileconvergence; convergence of services, etc. Use case: Accessing OTT video streaming services over any access network to any device HTTP overanyAccess Network (fixed, Media mobile)PreparationMedia HTTP HTTPOrigin ServersCaches 5. Example Deployment ArchitectureOriginal Original content encoded into video streamscontentat different media ratesContent Media player Preparation Segments video streams into HTTP resources MPD file generated for the video files URL generated for MPD fileIngestion component All intelligence is here Accesses MPD file based on URL & makesrequests for appropriate video files Continually monitors and adjusts media ratebased on network conditions, etc. HTTPdeliveryServing Cloud HTTP/IP(HTTP web caching servers)network DASH client Any radio access: any cellular, WiFi,parallel delivery5 6. DASHMPEG DASH 6 7. MPEG DASH Status ISO/IEC 23009-1 DIS ratified in November 2011 to move to IS document is now at ITTF for final processing Final text is made available through liaison to 3GPP and others http://www.3gpp.org/ftp/Inbox/LSs_from_external_bodies/ISO_IEC_J TC1_SG29_WG11/29n12517.zip made available publicly for free after ITTF completes final processing 03/2012. Same publication timeline for extensions to ISO base media FF to support DASH 14496-12/AMD 3 Common Encryption 23001-7 with AES-128 CTR Other documents: Conformance and Reference Software (see WD 23009-2) Technical Report on Implementation Guidelines (see WD 23009-3)7 8. Typical Uses Cases MPEG-DASH supports simple and advanced use cases: On-Demand, Live and time-shift (nPVR) streaming Dynamic ad-insertion Dynamic update of program Delivery of same content on three screens Delivery of any multimedia content (2D, 3D, animation, graphics, multiview, subtitles, text, etc.), not just AV Support of multiple languages and different audio configuration etc. Simple use cases can be gradually extended to more complexand advanced ones 9. What is specified and what is not?Media Presentation on HTTP MediaDASH ClientServerPresentation DescriptionSegment DASH Access EngineResourceson-time httplocated by requests toHTTP-URLs segmentsMedia Engines HTTP HTTP/1.1Access Client9 10. Media Presentation Data Model Media Presentation Description (MPD) describes accessible Segments and corresponding timing Segment InfoInitialization Segmenthttp://www.e.com/dash-5Media PresentationMedia Segment 1Period, start=0sPeriod, start=0sstart=100 Representation 1 http://www.e.com/dahs-5-1baseURL=http://www.e.com/ bandwidth=500kbit/s width 640, height 480 Media Segment 2 Adaptation Set 1start=10shttp://www.e.com/dash-5-2Period, start=100sSegment Info video duration=10sMedia Segment 3start=20s Adaptation Set 2 Template: http://www.e.com/das-5-3 audio./dash-5-$Number$Period, start=295s Representation 2 bandwidth=250kbit/s width 640, height 480 Media Segment 20Splicing ofSelection of start=190s arbitrary contentComponents/TracksSelect/Switch of http://www.e.com/dash-5-20 10 Bandwidth 11. Key feature Common Timeline Representations in one Period share commonpresentation timeline presentation time of access unit within the media streams is mapped to the global common presentation timeline enables synchronization of different media components and seamless switching of different coded versions of the same media components Other timelines segment availability times (mapped to UTC clock) internal media decode time (not exposed on DASH level) 11 12. Client-Side ProcessAdvertisementBack to video SegmentsInsertion250 Kbps500 Kbps1 Mbps Segment30s Period 12s Period 20s Period Process Factors relevant for Representation Client downloads the MPD file selection Client downloads segment by segment based Buffer conditionson playout process Network conditions Bitrate determined by client User change in resolution ex: full screen Device activity and resources 13. Switching Support Features Segment Alignment permits non-overlapping decoding and presentation of segments from different Representations Stream Access Points (SAPs) presentation time and position in segments at which random access and switching can occur Bitstream Switching concatenation of segments from different Representations results in conforming bitstream Media Stream Structure Similarity permits switching at Open GOP boundaries Alignment and SAPs can also apply for Subsegments13 14. Segments ISO/IEC 23009 focuses on Segment formats based onMPEG container formats. Specifically, in 6.3, Segment formats are described for use with Media Segments based on the ISO Base Media File Format as defined in ISO/IEC 14496-12; In 6.4, Segment formats are described for use with Media Segments based on the MPEG-2 Transport Stream as defined in the ISO/IEC 13818-2; In both cases the Segment formats are defined suchthat the Media Segment formats comply with therespective container formats. Guidelines for adding other Segment formats areprovided in Annex F.14 15. ISO BMFF DASH Segmentsftypmoov moof mdat moof mdatmoof mdat Initialisationstyp sidxmoofmdat moof mdat Segment binary information in ISO box structure on Media Accessible units (one or multiple fragments) Segment Each unit is described by Byte range in the segments Accurate presentation duration (seamless switching) Presence and timing of stream access positions Provides a compact bitrate-over-time profile Can be used for intelligent request scheduling 16. Summary: DASH Selected Feature List Live, On-Demand and Time-shift services Independency of request size and segment size (byte range requests) Segment formats ISO base media FF and MPEG-2 TS guidelines for integrating any other format Are codec independent Support for server and client-side component synchronization(e.g., separate and multiplexed audio and video) Support for efficient trick mode Simple splicing and (targeted) ad insertion Multiple base URLs for the same content Clock drift control for live sessions DASH metrics for reporting the session experience Profile: restriction of DASH and system features (claim & permission) Content Descriptors for Protection, Accessibility, Rating, etc. Enables common encryption, but different DRM (DECE-like)16 17. DASHPROFILES17 18. MPEG Profiles Set of restrictions on the offered Media Presentation (MPD & Segments) can also be understood as permission for DASH clients that only implementthe features required by the profile to process the Media Presentation Profiles defined in ISO/IEC 23009 (as below). More restrictions may be added Full ProfileISO Base media file mainMPEG-2 ISO BaseISO Base MPEG-2TSmedia file media file TSmainformat On format simple Demand Live 18 19. Profile Discussions beyond MPEG Main motivation: broad availability of clients supporting profile enable deployment options in CDNs Client Profile support for one/multiple content profile support for multiple addressing schemes support for efficient, but still simple switching scheme Media Presentation profile Media presentation offering with one content profile, one switching scheme and one addressing scheme19 20. DASHDASH PG AND IMTC20 21. DASH Promoters Group Informal collaboration of companies that have committedor at least significant interest to deploy an open standardfor HTTP-based streaming based on DASH. Effort may include recommending profiles, codecs, DRM Just started to create PR information, white papers,licensing, attend conferences, demos, interoperabilityefforts and so on Current Members: Microsoft, Qualcomm, Netflix, Samsung,Ericsson, Akamai, AEG, Harmonics, Adobe, and many morehave joined recently, please check http://dashpg.org Significant interest from content providers (globally),operators, device manufacturers, etc. Interested companies are invited to listen in and/or join21 22. Profile Considerations @ DASH PG Deployable industry profile Based on combination of ISO BMFF live and On-Demand profile with some restrictions Core Content Profile based on common codecs:H.264/AVC [email protected], HE-AAC, SMPTE TT, andCommon Encryption Extensions into various dimensions (HD, 3D, MCaudio, low latency) Establishment through successfulinteroperability of multiple/many vendors 22 23. IMTC Potential Role Provide framework and credibility for interops Joint work between DASH PG and IMTC Define test cases for deployment profiles organize interop for DASH including differentdevice types (mobile, tablet, STV, iTV) in case of successful interop promotion Problem right now: April is too soon (clashes with NAB and 3GPP SA4) October may be too late23 24. DASHSUMMARY 24 25. Summary MPEG DASH standardization is completed harmonized industry standard for OTT video applicable to TV and mobile world Working towards deployments: Conformance and Reference SW in MPEG Implementation Guidelines (3GPP and MPEG) Integration into 3GPP RANs (3GPP) Integration into browser environment ( Promotion of the technology: events, PR, etc. (DASH PG) Definition of deployable industry profile (DASH PG) Multivendor demonstrations (MWC, NAB, IBC, etc.) Official Interoperability tests (IMTC) Support for all activities welcome and desirable 25 26. DASHTHANK YOU 26

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