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Multimedia Entertainment Applications - Concepts, Enabling Technologies, Enabling Technologies: Formats and Compression, Enabling Technologies: Networks

video music devices virtual

Stefano Cacciaguerra, Marco Roccetti, and Paola Salomoni
Department of Computer Science, University of Bologna, Bologna, Italy

Definition: Multimedia entertainment applications aim at diverting users, engaging them in amazing experiences such as reading a book, listening to music, enjoying videos, and playing a game.

Concepts

To understand modern multimedia entertainment applications a definition of both entertainment and multimedia notions is needed. Entertainment is something diverting or engaging, i.e. a public performance, a usually light comic or an adventure novel. Multimedia means using, involving, or encompassing several media. Classic media are hypertexts, sound, image, video and animation. From these standpoints, multimedia entertainment applications aim at diverting users, engaging them in amazing experiences such as reading a book, listening to music, enjoying videos, and playing a game. While in the past, traditional multimedia entertainment technology offered predominantly passive experiences, such as, video on demand for example, advances in ICT are promoting a greater interactivity as well as allowing more exciting immersive experiences to consumers, such as interactive virtual environments, interactive storytelling and online games. In fact, with the coming of the Internet era, the network communications have been fueled in a way not available on any other medium. This fact improved the chance to interact in real-time with remote applications rather than to sit passively, bringing online the multimedia entertainment.

Further, multimedia entertainment was historically not considered as a topic deserving of serious study. Yet, two main reasons attract, today, an increasing number of researchers and practitioners. The former is the explosive growth of the multimedia entertainment market, from its niche position to a multi-billion dollar industry with an ever-increasing trend. Analysts report the following. In February 2004, 51 million people were using Microsoft’s Windows Media Player, Apple sold over 2,016,000 iPods during the 4 th quarter of 2004 as compared to 336,000 one year ago, Jupiter Research estimates in 1.7 billion $ the 2009 online music market in the US, the gaming industry surpasses even the cinematography industry expecting to increase the sales up to 31.6 billion $ in 2009. The latter reason is represented by the correlation between problems that emerge while developing innovative multimedia entertainment applications and those typical of more serious settings in the Computer Science fields.

The reminder of this article is organized as follows. Section 2 presents surveys for enabling technologies in multimedia entertainment. Further, Section 3 discusses on the main trends of modern multimedia entertainment applications. Finally, Section 4 provides some final considerations about multimedia entertainment applications of the future.

Enabling Technologies

Multimedia technologies provide an important support to entertainment services with a myriad of coding, access and distribution alternatives. Anywhere and anytime communication technologies facilitate entertainment services, while final devices enhance the user experience. Unfortunately, a global end-to-end solution “from the producer to the consumer” involving several media to provide entertainment contents to the final user does not exist. Yet, the main streams for passing from the entertainment producer to the final consumer step through the four following phases shown in Figure 1 and discussed below in isolation.

Enabling Technologies: Formats and Compression

Nowadays, different standard compression formats exist that are at the basis of several multimedia entertainment services (MPEG-1, MPEG-2, MPEG-4, MP3, DivX). MPEG-1, 2 and 4 represent the standard for the efficient bandwidth transmission of digital audio/video. Historically, MPEG-1 targets a bandwidth of 1-1.5 Mbps providing a final user with a VHS quality that works well for VCR activities with a CD-ROM. MPEG-2 improved MPEG-1 supporting higher resolution video, increasing audio capabilities and extending the bit rate at 4-15Mbits/s. Based on these features, MPEG-2 enables for satellite broadcast applications by encoding up to 5 digital channels in the same bandwidth used by a single analog channel. Unfortunately with the Web revolution, MPEG-2 results to be too expensive for Internet infrastructures, as it requires a large amount of bandwidth. MPEG-4, instead, promotes a data rate from 64Kbits/s to higher ones that enable high quality video distributions. MPEG-4 represents units of aural, visual or audiovisual content, as media objects . Media objects can be recorded with a camera, a microphone, or generated with a computer as a synthetic scene.

MP3 is defined as the MPEG Layer III audio compression scheme. MP3 revolutionized the entire music world due to its perfect tradeoff between size and quality. It is possible to transport on a CD support hundreds of MP3 songs, ready to be exchanged at a good sound quality. Finally, few words should be spent on the large diffusion of the DivX format. DivX employs the most advanced video compression technology to creating high-quality video files, up to one tenth the size of MPEG-2: that is small enough to be delivered over the Internet or burned to single CDs.

Enabling Technologies: Networks

Multimedia entertainments, such as, DivX downloads, digital TV, video on demand, online games require tens of megabits per second to work in a suitable way. The main obstacle, until now, has been the inadequate access to the network infrastructure and the huge cost of the installations. Further, users ask for mobile technologies which permit to enjoy with multimedia entertainment contents from anywhere. Figure 2 shows the most important network technologies and correlate them with both bandwidth and mobility requirements. Emerging network technologies range from the wired copper enhancements (e.g. ADSL, Ethernet to the home, VDSL) to mobile cellular systems (e.g. 3G CDMA) and Wi-Fi (e.g. WLAN). It is reported that more than the 50? of American households (up to the 70? of Korean ones) has a high-speed always-on broadband access to the Internet. In particular, ADSL became the milestone of broadband Internet access speeding up to 40 times faster than the traditional 56Kbps dial-up connection. This technology allows a downstream rate from 1.5 to 9 Mbps and an upstream rate from 16 to 640 Kbps over existing copper telephone lines. Wired post-ADSL network technologies, such as Ethernet to the home or VDSL, has further increased the downstream rate up to 50 Mbps.

On the other side, the invasion of mobile post-ADSL technologies has fueled the demand for multimedia entertainment on portable devices. 3G CDMA cellular systems are able to carry out, simultaneously, voice, video and data at a data rate of: i) 144 Kbps for fast-moving mobile users in vehicles, ii) 384 Kbps for slower moving pedestrian users, and iii) 2 Mbps from fixed locations. Unfortunately, the cost of the 3G spectrum and the build-out of 3G network infrastructures are very high. Alternatively, WLAN solutions are cheaper thanks to their low-cost transceivers and to the use of shared unlicensed spectrum. WLANs offer higher bandwidth (2.4 Ghz 802.11 b offers as many as 11 Mbps) supporting a direct access to the Internet, working only within a short range. As consequence, there exists a trade off. Wireless technologies suffer either from low data rates (3G CDMA) or from a short coverage (WLAN). Instead, wired technologies offer high data rates without any mobility support. From these heterogeneous scenarios emerges the need for networking integration aimed at guaranteeing seamless connectivity, transparent vertical handoff and service continuity.

Enabling Technologies: Distribution Models

Multimedia distribution played a key role in driving digital entertainment. There exist two basic modes: online streaming and P2P file sharing. Online streaming allows consumers to enjoy radio or TV on the desktop. Streaming enables playback of audiovisual content in real time through the use of the Real-Time Streaming Protocol (RTSP). This allows consumers to start, stop, and pause digital audio/video. RTSP relies on the Real-Time Transfer Protocol (RTP) that enables Web casting of live events, supports multiple consumers and uses the bandwidth efficiently. In particular, broadband American users have consumed in 2003 music video (33? of the view share), news (28?) and sports (17?). On the content owners’ side, the audio/video stream is discarded by clients after play, thus preventing unauthorized duplication.

However, it is worth mentioning that many consumers prefer to play MP3s or DivXs on their devices where digital contents had been previously downloaded sharing them with their friends without resorting to an online connection. This preference promoted the planetary success of P2P file sharing. The evolution of multimedia download systems has passed through different P2P generations (Table 1). The success of Napster was based on the high costs of the other traditional distribution systems and on easily downloadable MP3s. Napster implemented a centralized global list for the discovery of files (available on the network at any time) for P2P exchange. To overcome the vulnerability of the centralized global list, 2 nd generation peers act as server or client to perform both searching and downloading activities. Still, servers are used to provide authentication-type activities and general support to other peers. Multiple peers ensure service availability but make the exchange protocol overhead an issue to be solved. The development of 3 rd generation P2P networks are completely server less and peers are responsible for both client and server duties. Each peer should maintain and distribute available-file lists. Unfortunately, performance may be jeopardized by network dimensions: a wide network may be rich of resources, yet difficult to be discovered. The P2P networks have appeared in the music/video community for unauthorized file distribution. Hence, the industry has attacked P2P networks because it thinks of it as a method to circumvent the authority instead of a mean to boost the music/video distribution. Undoubtedly, a way to exploit the P2P distribution without violating the copyright laws is to adopt specific payment models, such as, pay per download, per play, per subscription, or an all-inclusive flat rate.

Enabling Technologies: Final Devices

Consuming multimedia entertainment applications is possible through a multitude of portable devices (e.g. iPod, DVD-player), mobile devices (e.g. smart phone, PDA) and pervasive devices (e.g. head-mounted displays, datagloves). These devices are quickly evolving to simplify user activities and to enhance its experience. Portable devices offer a simple way to play multimedia data, collected by means of an Internet distribution service or bought in a shop, from anywhere. New generations of DVD/CD player devices support also DivX and MP3 formats. In line with this, iPod represents the archetypical music player device (portable). An iPod can carry personal music collections anywhere, can play up to 12 hours straight, and can even store up to 5000 songs. FireWire and USB 2.0 technologies support the transfer of music from an entire CD to an iPod in a few of seconds.

Mobile devices, such as smart phone, combine computing, phone, Internet and networking features. Smart phones improve the capabilities of typical mobile phones, by running a complete operating system that provides a standardized interface and platform for application developers. Compared to standard phones, they have larger displays and more powerful processors. Typically, they mount software for media exchanging, simple multiplayer games and chats.

Pervasive devices serve as portals into virtual reality to augment the sensorial experience of the user. Head-mounted displays adopted to obtain a stereoscopic vision and a stereo sound effect of a Virtual Environment (VE) build up a physical connection between the user and the computer promoting an immersive audio/visual experience. Further, data gloves enable immersive haptic experience allowing users to interact in the VE by touching objects inside it.

Entertainment Applications

It is possible to identify different ways with which people have fun: i) listening to music, ii) watching videos, iii) playing games, iv) participating in an interactive story, v) meeting people in virtual environments. Nowadays, innovation in entertainment applications emerges as a response to different requirements to be met: high interactivity, mobility, context awareness. Older computer-mediated digital technologies offer predominantly passive experiences (e.g., audio/video on demand). Modern entertainment, instead, is taking advantage from high interactivity and offers new applications that consumers can control. Interesting examples are represented by applications that involve participating in virtual environments, interactive story telling and online gaming. Along this line, consumers can enjoy the accuracy of an environment, the immediateness of an interface, the interactivity of their avatars and the fascination in a given story. Radical innovations (in both user devices and network technologies) have fueled the development of mobile forms of entertainment. Further, new entertainment applications use context information (e.g. location, time, temperature, and other people nearby) in interactions thus adapting to specific situations. In the reminder of this article, we will discuss first on same examples of applications aimed at offering passive experiences. Then, we will report on more interactive ways of enjoying computer based entertainment experiences.

Digital Music/Video

Listening to music and Watching videos have existed in known digital versions for tens of years as a much appreciated way of entertaining. As of today, modern forms of multimedia entertainment allow users to consume a digital song or a video comfortably seated in their armchair exploiting online connections or wandering about a city with a portable device. Today’s market for music/video players is currently dominated by Microsoft’s Windows Media Player (WMP) and RealNetworks’ RealOne Player (ROP). Microsoft has benefited from its dominant position of desktop software integrating WMP in all versions of Windows OS. The WMP 10 series shows interesting features such as surround sound, variable speed playback, cross-fading, auto-volume leveling and sophisticated video smoothing technology for content encoding along low-bandwidth connections. Rather, the latest version of RealOne lets users rewind and fast-forward live video during play, and adjust brightness, contrast, and sharpness. Microsoft and Real are competing for streaming music/video data, moving from the Web to the mobile devices. Earlier in the 2004, Microsoft bought the exclusive Web casting right for Major League Baseball and it is trying to enter in the smart phone market, where Real leads Microsoft. The mobile version of Real’s player is preinstalled on Symbian OS mounted by Nokia, Siemens, Sony-Ericsson, and other smart phones. Further, Real and Microsoft are competing with US-based PacketVideo, also if the mobile streaming is at the beginning of it era, and consumers would be disappointed by low quality streams showing grainy choppy video in small windows. Today’s music market on portable device is currently dominated by Apples’ iPod + iTunes. iPod + iTunes is offering a complete pipeline of multimedia entertainment allowing users to buy more than one million of different songs and to play them anywhere. iTunes has been one of the first successful initiatives that legally offer pay-per-download music in massively distributed contexts. The perfect marriage between iPod and iTunes provides users the opportunities for managing a digital music collection. iTunes Music Store offers to users the possibility to browse through more than 9,000 audio books. iTunes application makes also easier to quickly transfer songs, just popping a CD into a PC and clicking a button.

As a consequence of this success, modern radio stations offer to consumer an eclectic selection of music in iPod-style. Traditional way to schedule programs picks from a library of 300-400 titles with the same 30-40 songs, repeating them several time in a day. Modern radio stations, such as U.S. “Jack”, for example, offer broadband diffusion of serendipitous playlists obtained by more than 1200 songs get played only once every few days. The Jack format claims that users want to hear a large selection and a variety of familiar music. Hence, Jack implements this idea in line with iPodders podcatching the last podcast. Finally, advances in the video technologies are also fueling the emergence of digital cinema.

Virtual Environment, Interactive Storytelling, Online Games

A more recent phenomenon in the Internet is to create VEs into which humans are embedded. This approach implements realistic and entertaining environments where humans can participate by controlling the behavior of software agents within a synthetic world. Take a virtual cafe, where each user can be represented by an avatar playing the role of a costumer or of a barman engaged in the typical activities of a bar, such as ordering/serving a cup of tea or speaking about the last football match. One of the main goals of virtual reality is to achieve an immersive sensorial representation of the imagined system, realistic enough to be perceived by the participants. To implement such virtual reality it is necessary to build VEs that allows embedded humans to develop skills applicable in similar real cases. One of the prominent examples is represented by Second Life: a new online virtual society, shaped entirely by its residents. Participants join a world full of people, activities, and fun. Second Life is an evolutional shared reality where people can explore, build on virtual land, socialize, or vie for status. In particular, if people play specific roles according to a fantasy scenario, it is possible to compose a dynamic story whose final plot is obtained by interactions of all participants. Hence, the integration of interactive virtual environments with fascinating story drives the development of dynamic narrative structure called Interactive Story Telling (IST). An interesting example is Supafly: a virtual soap opera where the goal is to become a virtual celebrity. To reach this goal, a user should create as much gossip around him/her-self as possible, while maintaining relations and status in him/her group. In particular, the participation in Supafly can take place, anytime and anywhere, in the real world through SMS commands, voice services and Web interfaces.

Indeed, it is not important that VE reproduces exactly a real system, but rather that the sensorial perception should be acceptable. Hence, if two independent events occur close enough in time that the human being is not able to perceive which has been generated first, VE can process them in its preferred order. On the other side, VE should correctly reproduce the ordering of the events if there is a causal relationship among them. These considerations are at the basis of several interactive games Real Tournament and the NeverWinter Nights (NWN). In the former, each player uses a customized handset integrating GPS, sensors, Wi-Fi, GPRS, and a PDA to competitively capture monsters in a virtual arena mapped onto a park in Lancaster. The latter is a role-playing game based on Dungeons and Dragons, where a player chooses the skills of a character and develops it during a synthetic life in a fantasy world. NWN allows to create virtual worlds giving to each player the tools needed to construct lands of adventure for a cooperative group of friends.

Conclusions

Multimedia entertainment is at the same time a great technological challenge and a wide still-increasing market. New scenarios arise considering multimedia entertainment applications lining in anytime, anywhere, any device dimensions, further fueled by the advent of mobile terminals. These applications start new technological challenges, offer new services and open new markets. Participations in virtual environment, interactive storytelling and online games are near to offer users “virtual life” experiences. In spite of this phenomenon, multimedia distribution is not ready to leave the role of killer application and new services are still under development to better fit users needs, including mobility. New forms of entertainment based on network availability and new amazing devices are arising. In the near future, pervasion of multimedia entertainment will still increase and humans will be soon immersed in online devices that follow us: during all day, in many different places, inside a wide part of our daily activities. While we hail the arrival of the digital revolution and the information era, the average citizen continues to wait for the realities of these promises to materialize in their daily lives. To maintain this promise, technology experts should provide the consumers with simplicity of use (plug and play devices, simple commands, no need of manuals), simplicity of integration (interoperability of devices), seamless mobility of users and applications.

Multimedia File Sharing - Background, Early, Private file sharing, Public file sharing, The legal issues [next] [back] Multimedia Encryption - Streaming Video Encryption, Preserve real time playback and decrease cost via partial encryption

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