Event-Driven Interactivity in Application-Based TV-Programs
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UPTEC IT 13 001 Examensarbete 30 hp Februari 2013 Event-driven interactivity in application-based TV-programs Per Moberg Abstract Event-driven interactivity in application-based TV-programs Per Moberg Teknisk- naturvetenskaplig fakultet UTH-enheten In recent years TVs and set-top boxes has been featured with built-in internet connectivity which open up doors to new innovations and technologies. This research Besöksadress: has particularly investigated the possibility of adding event-based interactivity into Ångströmlaboratoriet Lägerhyddsvägen 1 application based TV-programs and has focused on the hybrid standard HbbTV. A Hus 4, Plan 0 design suggestion of a framework to make use of eventdriven interactivity has been created and a proof-of-concept prototype has been implemented. Postadress: Box 536 751 21 Uppsala The study has demonstrated that event-driven interactivity can to advantage be used to enhance the user experience of TV-programs, especially in a live Telefon: context with many concurrent viewers. HbbTV has been shown to be a suitable 018 – 471 30 03 standard for connected TV devices and is currently growing in the European Telefax: TV market. 018 – 471 30 00 Hemsida: http://www.teknat.uu.se/student Handledare: Johan Pettersson Ämnesgranskare: Justin Pearson Examinator: Lars-Åke Nordén ISSN: 1401-5749, UPTEC IT13 001 Sponsor: Accedo Broadband Tryckt av: ITC 0.1 Sammanfattning TV-industrin ¨arinne i ett sp¨annandeskede d¨arfler och fler TV-enheter blir uppkopplade mot internet och nya tj¨ansters˚asom applikationsportaler, Video- On-Demand(Vod), IPTV och Pay-per-View utvecklas i snabb takt. Tack vare internet finns nu ¨aven stor m¨ojlighetf¨or¨okad interaktivitet med TV-tj¨anster som inte varit m¨ojligp˚asamma s¨attgenom vanliga digitala TV-n¨atet. Termen interaktiv TV ¨arinte n˚agotnytt. Redan under senare delen av 50- talet s¨andeCBS-television ett barnprogram vid namn "Winky Dink and you" d¨artittarna skulle s¨attap˚aen speciell plastfilm p˚aTV-sk¨armenoch rita teck- ningar f¨oratt hj¨alpaWinky l¨osaproblem. Programmet ¨overlevde dock inte men var en start p˚anya innovationer inom omr˚adet.Exempel p˚ainteraktiva TV-tj¨anstersom har ¨overlevt genom ˚aren¨arbland annat telefonsamtal under direkts¨andingaroch text-tv. Syftet med rapporten ¨aratt unders¨oka m¨ojlighetenf¨oreventbaserad interak- tion under applikationsbaserade TV-program. F¨oratt kunna ge ett proof-of- concept har en prototyp till ramverk implementerats som kan hantera just detta. Beroende p˚avilken typ av program som visas kan event vara av olika typer. De typer som har implementerats i prototypen ¨arfr˚ageevent, statistikevent och reklamevent. F¨oratt kunna testa och implementera ett ramverk har olika plattformer och standarder unders¨okts. MHP, MHEG och HbbTV blev utvalda att granskas noggrannare. Den valda standarden blev HbbTV vilket ¨aren s˚akallad hybrid- plattform som kan ta emot inneh˚allfr˚ankabel-, luftburen- och satellits¨andningar men ¨aven genom internetbaserade l¨osningars˚asom IPTV och WebTV. HbbTV valdes eftersom det ¨aren lovande och v¨aletablerad standard i Europa som har st¨odp˚am˚angaolika plattformar. HbbTV ¨ar¨aven baserad p˚aredan existerande standarder och webbteknologier vilket kan snabba p˚autvecklingsprocessen av applikationer. Baserat p˚alitteraturstudien och den f¨ardigaprototypen ¨arm¨ojligheternaatt l¨aggatill interaktiva event under TV-program mycket goda. Tack vare upp- kopplingen mot internet finns det redan m˚angav¨aletablerade webbteknolo- gier tillg¨angligaoch en stor m¨angdredan existerande data som kan anv¨andas f¨oratt g¨oraTV-program mer dynamiska och interaktiva. Eftersom HbbTV- applikationer mer eller mindre utvecklas som vanliga webbsidor finns redan en stor kompetens vilket kan reducera utvecklingstid och kostnader. Viktiga krav p˚aett system med m˚angasamtidiga anv¨andare¨aratt det ¨arsnabbt och skalbart samt minimerar m¨angdendata som skickas mellan klienter och servern. Som exempel har studien visat att en dokumentdatabas s˚asom mon- goDB ¨armer l¨amplig¨anen relationsdatabas s˚asom MySQL eftersom en doku- mentdatabas ¨armer skalbar och kan h¨amta databasposter snabbare. Nackdelen ¨aratt mer ansvar l¨aggsp˚asystemutvecklaren som m˚astet¨anka p˚aatt de klas- siska ACID villkoren inte uppfylls i en dokumentdatabas. 1 Studien har ¨aven p˚avisatatt WebSockets ¨aratt f¨oredrasom push-teknologi j¨amf¨ortmed long-polling och polling. Alla HbbTV-enheter st¨odjerdock inte WebSockets s˚aen elegant l¨osningp˚adet problemet ¨aratt prim¨artanv¨anda WebSockets och nedgradera till long-polling d˚ast¨odetsaknas. I framtiden ligger sv˚arigheteni att ¨overtyga inneh˚allsleverant¨oreratt l¨aggatill mer interaktivt inneh˚alli sina s¨andningar. Det ¨arett krav eftersom de ¨ager alla r¨attighetertill det som visas p˚as¨andningen inklusive eventuella interaktiva events. Den andra sv˚arauppgiften ¨aratt ¨overtyga anv¨andareatt faktiskt vilja anv¨andaoch svara p˚agenererade events. Den f¨ardigaprototypen har testats p˚aen HbbTV-kompatibel set-top box. Det implementerade ramverket har integrerats med en simpel HbbTV applikation som visar statiska mp4-str¨ommaroch en live HLS-str¨om.Prototypen fungerar som v¨antat och illustrerar hur eventbaserad interaktion kan se ut. 2 Contents 0.1 Sammanfattning . .1 0.2 Abbreviations . .5 1 Introduction 7 1.1 Background . .7 1.2 Problem formulation . .9 1.3 Purpose . 10 1.4 Constraints . 11 1.5 Previous research . 11 1.5.1 Event-driven interactivity in IPTV . 12 1.5.2 Hybrid Broadcast Broadband TV (HbbTV) . 12 2 Method 13 2.1 Pre-study . 13 2.2 Performance Tests . 14 2.2.1 MongoDB vs MySQL . 14 2.2.2 WebSockets vs Long-polling . 14 2.3 Development method . 15 2.4 Use cases . 15 2.4.1 Use case 1 - live entertainment show . 15 2.4.2 Use case 2 - non-live movie . 16 2.4.3 Use case 3 - live debate . 16 2.5 Chapter summary . 17 3 Theory 18 3.1 Internet technologies . 18 3.1.1 JavaScript . 18 3.1.2 AJAX . 18 3.1.3 JSON . 19 3.1.4 Push technologies . 19 3.2 DVB technologies . 20 3.2.1 DVB . 20 3.2.2 DSM-CC . 21 3.2.3 Stream-events . 21 3 3.3 Considered Hybrid Standards . 22 3.3.1 HbbTV . 22 3.3.2 MHEG-5 . 23 3.3.3 MHP . 24 3.4 Considered databases . 24 3.4.1 SQL . 24 3.4.2 NoSQL . 25 4 Resulting prototype and discussion 26 4.1 Chosen standard . 26 4.2 Final Design . 27 4.3 Management Portal . 28 4.4 Server . 30 4.5 Database . 30 4.6 Push Server . 32 4.7 Client . 35 4.7.1 Client framework . 37 4.8 Event delivery . 38 4.8.1 Event format . 38 4.8.2 Events in a non-live context . 39 4.8.3 Events in a live context . 39 5 Conclusions, Future work and Improvements 40 5.1 Conclusions . 40 5.2 Improvements . 41 5.2.1 Graphical improvements . 41 5.2.2 Optimizations . 41 5.3 Future work . 42 5.3.1 Receive real video content . 42 5.3.2 Customized push server . 42 5.3.3 Events through broadcast stream . 42 5.3.4 Events on secondary screen . 42 Appendix A Software and Hardware 46 A.1 Software . 46 A.2 Hardware . 46 4 0.2 Abbreviations ACID Atomicity, Consistency, Isolation, Durability AJAX Asynchronous JavaScript and XML CEA Consumer Electronics Association CE Consumer Electronics CSS Cascading Style Sheets DOM Document Object Model DRM Digital Rights Management DVB Digital Video Broadcasting ETSI European Telecommunications Standards Institute HbbTV Hybrid Broadcast Broadband Television HTML HyperText Markup Language HTTP HyperText Transfer Protocol IPTV Internet Protocol Television ISO International Organization for Standardization JSON JavaScript Object Notation MHEG Multimedia and Hypermedia Expert Group MHP Multimedia Home Platform MPEG Moving Picture Experts Group OIPF Open IPTV Forum PPV Pay-per-view PVR Personal Video Recorder RDBMS Relational Database Management System SMS Short Message Service STB Set-Top Box SQL Structured Query Language TSP Transport Service Provider TV Television VHS Video Home System VoD Video on Demand 5 W3C World Wide Web Consortium 6 Chapter 1 Introduction In this chapter the context, in which this thesis is carried out, is explained. The main problem, and why this problem is of interest is also addressed. The last part of this chapter is explaining constraints of this paper and gives a short summary of previous research which is of relevance for this thesis. 1.1 Background The television industry is in an exciting phase where new technologies and inno- vations are developed rapidly. The linear television is on its way to become a full interactive entertainment machine and will in similarity with smartphones be customizable with applications from various kinds of application-stores. These kind of features are now possible due to the fact that almost all new television devices have built-in internet connectivity. Informa1, which is one of the leading providers of business information and services, predicts that connected TV devices will be one of the most fast-selling type of consumer electronics production in history. According to Informa there will be more than 1.8 billion TV devices with in-built internet connectivity in use in over 570 million homes by the end of 2016[1]. A more detailed graph of Informa's forecast can be seen in figure 1.1. A huge benefit with internet is that it has a two-way-communication by definition which can be used to enhance user interaction with the television set. The term interactive TV is not something new. In the late 1950s CBS televi- sion network broadcasted a children program named \Winky Dink And You" where viewers were suppose to attach a special plastic film on the television screen and do drawings to help Winky Dink solve problems. The series did not 1www.informatandm.com 7 Figure 1.1: Predicted amount of connected-TV devices globally during the period 2011- 2016[1] survive but it was an eye opener for new innovations[9].