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Description and Lookup of Media-Stream Adaptation Services

Description and Lookup of Media-Stream Adaptation Services. Andreas Schorr, Franz Hauck Dept. of Distributed Systems, University of Ulm, Germany andreas.schorr@uni-ulm.de Andreas Kassler Dept. of Computer Science, Karlstad University, Sweden. Multimedia Stream Adaptation Services.

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Description and Lookup of Media-Stream Adaptation Services

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  1. Description and Lookup of Media-Stream Adaptation Services Andreas Schorr, Franz Hauck Dept. of Distributed Systems, University of Ulm, Germany andreas.schorr@uni-ulm.de Andreas Kassler Dept. of Computer Science, Karlstad University, Sweden

  2. Multimedia Stream Adaptation Services Outline of this Talk • Introduction to Multimedia-Stream Adaptation Services (MSAS) • Dynamic Discovery of MSAS • Description of MSAS with RDF • Conclusion / Outlook Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  3. Multimedia Stream Adaptation Services – Introduction to Stream Adaptation Services (MSAS) Motivation • Multimedia-streaming over IP is widely used today (VoIP, Video Conferences, VoD, Audio/Video-Broadcast) • But there still exist compatibility problems because of • Heterogeneous Hardware: screen sizes, CPU power, amount of memory, audio/video capture hardware • Large number of different media formats, e.g., MJPEG, H.263, MPEG-2, MPEG-4, G.711, G.726, proprietary formats • Different network technologies with different bandwidth, bit error rate, delay, and jitter and with variable resource availability • Adaptation of multimedia streams required • Streaming applications require adaptation in real-time Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  4. Multimedia Stream Adaptation Services - Introduction to Stream Adaptation Services (MSAS) Location of Adaptation Services • On the sender/receiver terminal • Provided by a middleware system if applications themselves are not able to perform the conversion • If possible, this is often the most efficient solution, but • Software/hardware modules for adaptation may not available • CPU or memory resources for adaptation process may not be available • On a proxy node on the network • Enables communication between incompatible terminals • No additional load on terminals • Efficient usage of network resources in heterogeneous multicast scenarios Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  5. codec: MPEG-4 Receiver B GPRS-Network Multimedia Stream Adaptation Services - Introduction to Stream Adaptation Services (MSAS) Multimedia-Stream Adaptation Node (MSAN) MSAN codec: H.263 codec: MPEG-2 Receiver A Video Server Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  6. Multimedia Stream Adaptation Services - Introduction to Stream Adaptation Services (MSAS) Heterogeneous Broadcast Services WLAN DVB-T AD HOC MPEG-4 1 Mbps MSAN 2 MPEG-4 1 Mbps Broadcast Server M-JPEG 128 kbps MPEG-4 384 kbps MPEG-2 6 Mbps MSAN 1 MPEG-2 6 Mbps UMTS MSAN 3 H.263 64 kbps H.264 48 kbps GPRS H.263 64 kbps Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  7. Multimedia Stream Adaptation Services - Introduction to Stream Adaptation Services (MSAS) Types of Adaptation Services • Transcoding • Scaling (spatial, temporal, signal-to-noise ratio) • Mixing (e.g., audio streams) • Media translation • Multipoint session • Protocol adaptation • Rate control • Adaptation of (application-layer) error correction mechanisms • Support for MPEG-21 Digital Item Adapation (DIA) tools: • generic Bitstream Syntax Description (gBSD) • usage environment description (UED) Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  8. Multimedia Stream Adaptation Services - Introduction to Stream Adaptation Services (MSAS) Properties of Adaptation Services • Different MSANs may offer operations for different media formats and protocols • Adaptation causes delay, quality reduction, and (optionally) costs • Delay, costs, and quality reduction caused by adaptation may be different for each media format and for each MSAN because transformation from Format A to Format B can be achieved through techniques Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  9. Multimedia Stream Adaptation Services Outline of this Talk • Introduction to Stream Adaptation Services (MSAS) • Dynamic Discovery of MSAS • Description of MSAS with RDF • Conclusion / Outlook Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  10. Multimedia Stream Adaptation Services – Dynamic Discovery of MSAS Dynamic Service Discovery of Multimedia-Stream Adaptation Services • Daidalos: EU Integrated Project (http://www.ist-daidalos.org) • Service discovery protocols and frameworks: SLP, Jini, Salutation, UPnP, ... • Service-specific vocabulary • Integrated into the service discovery protocol • Independent of any protocols • Drawbacks of tradition service discovery protocols • Programming-language specific (Jini) • Limited expressiveness of service description language (SLP) • XML description, but only rooted tree structure (UPnP)  RDF-based vocabulary, independent of the discovery protocol Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  11. Multimedia Stream Adaptation Services – Dynamic Discovery of MSAS Daidalos service discovery architecture Service Invocation Client MSAN MEGACO Service Description RDQL, SPARQL SLP + RDF Service Discovery Server Service Registration Service Query Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  12. Multimedia Stream Adaptation Services Outline of this Talk • Introduction to Stream Adaptation Services (MSAS) • Dynamic Discovery of MSAS • Description of MSAS with RDF • Conclusion / Outlook Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  13. Multimedia Stream Adaptation Services – Description of MSAS with RDF High-level Properties of an MSAN rdf:type true^^xsd:boolean _:1 msas:Contact-List msas:contact-info-set rdf:type msas:gBSD-supported _:2 msas:Media-Adapt-Ops-List msas:media-adapt-ops true^^xsd:boolean rdf:type _:3 msas:Proto-Trans-Ops-List msas:proto-trans-ops msas:ued-supported rdf:type msas:error-cor-ops _:4 msas:Error-Corr-Ops-List http://example.org/MSAN1 rdf:type msas:mix-ops _:5 msas:Mix-Ops-List rdf:type rdf:type msas:rate-control-schemes _:6 msas:Rate-Control-Scheme-List msas:MSAN rdf:type msas:rtp-profiles _:7 msas:RTP-Profile-List rdf:type _:8 msas:Out-Multiplicity-List msas:out-multiplicities rdf:type msas:rtp-payload-formats msas:RTP-Format-List _:0 Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  14. Multimedia Stream Adaptation Services – Description of MSAS with RDF MSAN Contact Information sip:a@b.c contact-address 5060 sig-proto _:9 sip port tcp transp-layer transp-layer-proto _:11 contact-info udp transp-layer-proto session-desc-formats session-desc-format sdp _:1 _:13 session-desc-format sdpng session-desc-formats session-desc-format contact-info sdpng++ 123.45.57.89 contact-address sig-proto _:10 megaco 2944 port transp-layer _:12 tcp transp-layer-proto Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  15. Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  16. Multimedia Stream Adaptation Services – Description of MSAS with RDF Sample Query Find an adaptation service that • supports the MEGACO signalling protocol • can transcode a media stream from format MPEG-2 Simple Profile to MPEG-4 Simple Profile in less than 100 ms Return IP-address and port of at most 4 suitable adaptation services, in ascending order of the delay caused by the adaptation process Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  17. Multimedia Stream Adaptation Services – Description of MSAS with RDF Sample SPARQL Query PREFIX msas: <http://mqos.de/ns/msas-schema-v1.rdf#> SELECT ?address ?port ?delayvalue WHERE { ?msan msas:contact-info-set ?cis . ?cis msas:contact-info ?ci . ?ci msas:sig-proto msas:megaco ; msas:contact-address ?address ; msas:transp-layer ?transp . ?transp msas:port ?port . ?msan msas:media-adapt-ops ?ops . ?ops msas:media-adapt-op ?op . ?op msas:in-format <urn:mpeg:mpeg7:cs:VisualCodingFormatCS:2001:2.1> ; msas:out-format <urn:mpeg:mpeg7:cs:VisualCodingFormatCS:2001:3.1> ; msas:delay ?delay . ?delay msas:content-dependent false ; msas:time-value ?delayvalue . FILTER (?delayvalue < 100) . } ORDER BY ?delayvalue LIMIT 4 Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  18. Multimedia Stream Adaptation Services – Description of MSAS with RDF Result Set • address port delayvalue • 134.60.77.210 2944 50 • 134.60.77.202 2944 75 • 134.60.77.200 2944 85 • 134.60.77.205 2944 99 Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  19. Multimedia Stream Adaptation Services Outline of this Talk • Introduction to Stream Adaptation Services (MSAS) • Dynamic Discovery of MSAS • Description of MSAS with RDF • Conclusion / Outlook Andreas Schorr, Dept. of Distributed Systems, University of Ulm

  20. Multimedia Stream Adaptation Services – Summary Summary • Dynamic discovery of Adaptation Services • RDF Schema for the Description of Media-Stream Adaptation Services (http://mqos.de/ns/msas-schema-v1.rdf#) • Decoupling of Service Discovery Protocol (SLP) and Service Description (RDF) • Integrated into the Daidalos Service Discovery Architecture (http://www.ist-daidalos.org) Andreas Schorr, Dept. of Distributed Systems, University of Ulm

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