G. Blakowski, J. Huebel, and U. Langrehr, "Tools for Specifying and Executing Synchronized Multimedia Presentations," Proc. 2nd Int'l Workshop on Network and Operating System Support for Digital Audio and Video, pp. 271-279, 1991.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....designer are, we need to better understand how a designer actually meets those challenges in practice. The motivation for gaining a better understanding of multimedia design practice is that the multimedia design community has all but ignored design formalisms such as formal design models [5, 19, 21] and methodologies [10, 22] produced from research. At the same time, the multimedia design community still embraces ineffective design methods such as using static screen mockups to simulate complex behavior or using an authoring tool as a rapid prototyping tool. We believe the reason for this ....

Blakowski, G., J. Huebel, and U. Langrehr. Tools for Specifying and Executing Synchronized Multimedia Presentations. Proc. NOSSDAV, 1991.

....ATNs can model text and image media streams using subnetworks. Hence, database queries can access text and image information too. Hirzalla et al. 11] developed a graphical temporal model for interactive multimedia documents to expand the traditional timeline models such as Blakowski et al. [3] to include temporal inequalities between events. The main contribution of this model is to include user actions in their model. A new type of media object called choice is included in the vertical axis of the timeline. This new object is associated with a data structure that contains user ....

G. Blakowski, J. Huebel, and U. Langrehr, "Tools for Specifying and Executing Synchronized Multimedia Presentations," Proc. 2nd Int'l Workshop on Network and Operating System Support for Digital Audio and Video, pp. 271-279, 1991.

....defined three primary approaches for temporal synchronization: 2 Invariably different terminology is used by different models. For example, continuous synchronization is used [1, 2] total synchronization in [3] temporal composition in [4] tightly coupled inter object synchronization in [5], and fine grain synchronization elsewhere. Pazandak, Srivastava A Multimedia Temporal Specification Model and Language Page 4 . hierarchical Using a tree structure, temporal relations are constructed using internals nodes (generally either parallel or serial temporal relation operators) ....

Blakowski, G., J. Huebel, and U. Langrehr. Tools for specifying and executing synchronized Multimedia presentations. in 2nd Int'l Workshop on Network and Operating system support for Digital Audio and Video. 1991. Heidelberg, Germany.

....trigger strategy conditions (59) 62) can be used also in the form of statistical hypothesis tests for the stochastic model (35) 40) 5. Related Work In this section we discuss the relation of the synchronization model with some other previously published models. Hierarchical synchronization [2], 11] or chained synchronization: Data objects are regarded as a tree consisting of nodes that denote serial or parallel presentation of the outgoing subtrees. Hierarchical structures can be synchronized at their beginning or end. Synchronization in [11] 10] is based on a Petri net model and does ....

....of bipartite graphs like Petri nets) Any such hierarchical tree or Petri net based model can be easily mapped into our model, but the contrary does not hold. Note that our model does not prevent simultaneous (parallel) presentation of any number of data units. Synchronization on a time axis [2] or continuous time model or cyclic synchronization: Single media objects are attached to a time axis that represents an abstraction of time. Removing one object does not effect the synchronization of the other objects. This model has difficulties to describe event based synchronization as well as ....

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G. Blakowski, J. Huebel, and U. Langrehr, " Tools for Specifying and Executing Synchronized Multimedia Presentations," In: R. G. Herrtwich (ed.) Network and Operating System Support for Digital Audio and Video, Second International Workshop Heidelberg, Lecture Notes in Computer Science No. 614, pp. 271-282, Springer, Berlin.

....the complexity of the model increases. This complexity can make it very difficult for users to understand the representation of sequences when the model includes many media streams and a great deal of control information. As mentioned in [7] the most prevalent temporal model is the timeline [2], which aligns all events on a single time axis. Although this model provides a simple and graphical representation, it does not model user interaction features because it requires a total specification of all temporal relationships among media objects. In a video game, for example, users need to ....

G. Blakowski, J. Huebel, and U. Langrehr, "Tools for Specifying and Executing Synchronized Multimedia Presentations," Proc. 2nd Int'l Workshop on Network and Operating System Support for Digital Audio and Video, pp. 271-279, 1991.

....as constraints which cause concurrent streams to advance in a closely coupled manner (e.g. 4] These two kinds of constraints are sometimes distinguished as coarse vs. fine grain synchronization [5] Some approaches have a unified model, treating the former as a special case of the latter (e.g. [2], 7] But they are not the same, and should be modeled differently. The two types of constraints have different roles in the multimedia authoring process. Specification of relative ordering constraints, which we might refer to as temporal alignment rather than synchronization, is primarily a ....

....the other streams which are indexed by that point are checked to see if they have yet reached that point. If not, the playback device must take some action to resynchronize the streams. Exactly what action is to be taken is described at the DPL. There are several possible actions to choose from [9, 2], each of which may be useful depending on the playback environment. The DPL also specifies whether a tolerance will associated with a particular synchronization point. Tolerance, in this case, allows two streams to be considered synchronized as long as the trailing stream is within a certain ....

Blakowski, G., Hubel, J., and Langrehr, U. Tools for specifying and executing synchronized multimedia presentations. In The 2nd International Workshop on Network and OS Support for Digital Audio and Video, pages 271--282, 1991.

....a presentation script, different approaches, mostly focusing on the aspect of the temporal relationships between the media streams (intermedia synchronization) have been suggested. Examples are the petri net based OCPN approach [24] Active Objects [15] approaches based on a common time line [3, 8], and multimedia scripting languages such as ScriptX [47] There are already some respective standardization efforts like, e.g. MHEG [30] and PREMO [17] Another important issue within this context deals with quality of service specification for multimedia presentations, e.g. 35] Multimedia as ....

....some delay. For continuous data, the stream management is critical, since playout deadlines for the presentation units (e.g. a frame with respect to a video) have to be considered. t 3 : Synchronization Enforcement. In general, playout management has to enforce the synchronization constraints [36, 8, 14, 24] defined within the presentation specification. Synthetic synchronization constraints define the coarse grained temporal relationships between the different medias of the presentation. For example, such a constraint can define that the presentations of two medias have to be performed sequentially, ....

[Article contains additional citation context not shown here]

Blakowski, G., Hubel, J., Langwehr, U.: "Tools for Specifying and Executing Synchronized Multimedia Presentations", Network and Operating System Support for Digital Audio and Video, 2nd Int. Workshop, Heidelberg, Germany, Springer, November 1991, pp. 271--281

....the presentation script, different approaches, mostly focusing on the aspect of the temporal relationships between the media streams (intermedia synchronization) have been suggested. Examples are the petri net based OCPN approach [18] active objects [11] approaches based on a common time line [2, 5], and multimedia scripting languages such as ScriptXE [34] Multimedia as well as hypermedia documents such as HyTime documents [13] can also be regarded as preorchestrated multimedia presentations. The latter differ from the other approaches by their 6 support of the concept of a link which ....

....critical parameter mismatches in the most appropriate synchronization constraints aware manner. Firstly, we need to assess for our framework the applicability of already proposed approaches such as selective frame drop and duplication [19] intentional delay [17] or alternative presentation form [5]. Furthermore, we are aiming at the development of additional new approaches. Asymmetrical parameter adaptations, i.e. compromising of parameters such as the intentional decrease of a nominal presentation parameter s lower bound in order to gain potential to increase another critical 23 actual ....

[Article contains additional citation context not shown here]

Blakowski, G., Hübel, J., Langwehr, U.: "Tools for Specifying and Executing Synchronized Multimedia Presentations", Network and Operating System Support for Digital Audio and Video, 2nd Int. Workshop, Heidelberg, Germany, Springer, November 1991, pp. 271-281

....forwards through a sequence of slides, the background music should not skip or fast forward along with the slides. The music should play at normal speed and simply stop when all of the slides have been viewed. Many models [CPS96, RH96, Dra93] can not handle variable duration media, and others [LG93, Paz96, BHL91, CO96] allow no or limited user interaction. One method for specifying coarse grain synchronization, FLIPS (FLexible Interactive Presentation Synchronization) SKD96] uses an event based specification model and enforcement policy for handling variable duration media objects and user interactions. The ....

G. Blakowski, J. Huebel, and U. Langrehr. Tools for specifying and executing synchronized multimedia presentations. In 2nd Int'l Workshop on Network and Operating Systems Support for Digital Audio and Video, Heidelberg, Germany, 1991.

....that model. Designing interactive presentations is a difficult task primarily because most synchronization models either do not directly support viewer participation [1, 8, 12, 15, 17, 18, 23] or only support viewer participation or control actions at predefined locations in the presentation [3, 9]. Desirable properties of flexible synchronization models have been outlined in [9] but here we more clearly identify the interactive requirements of a synchronization model useful in building interactive presentations: The ability to specify synchronous interaction. Synchronous interaction is ....

....9, 20] One of the wellknown problems with coarse grained models is their inability to express fine grained relationships, thus limiting the overall expressiveness of the model. For example, coarse grained models generally cannot express continuous synchronization, or skew. See Figure 1. The MODE [3] system supports both fine and coarse grained specifications. The system also supports synchronous interaction by explicitly creating interaction objects and synchronizing them with the rest of the presentation. This approach makes it difficult to specify asynchronous interaction and it is also ....

G. Blakowski, J. Huebel, and U. Langrehr, "Tools for Specifying and Executing Synchronized Multimedia Presentations," Network and Operating Systems Support for Digital Audio and Video, Second Int'l Workshop Proceedings. 1991. Heidelberg, Germany.

....The rest of this paper is organized as follows: in section 2 we introduce our temporal model, in section 3 we compare and contrast our model to other related work and in section 4 we draw conclusions. 2. A Temporal Model for Active Multimedia Perhaps the most prevalent model is the timeline [2][3] a simple temporal model that aligns all events (start and end events of media objects) on a single axis which represents time. Since the events are all ordered in the way they should be presented, exactly one of the basic point relations, before ( after ( or simultaneous to ( ....

G.Blakowski, J.Huebel, and U.Langrehr, "Tools for specifying and executing synchronized multimedia presentations," 2nd Int. Workshop on Network and Operating System Support for digital Audio and Video, Nov. 1991

....synchronisable objects with which they are to be synchronised. Synchronisable objects are active objects: when they reach a reference point, synchronisation is performed by exchanging messages with other active objects, waiting for their replies, etc. The reference point model has been inspired by [16]; its details in the MADE environment are specified in [3] Audio, video, and animation objects are obvious examples of synchronisable objects 2 . A MADE programmer may also create new, application specific, 2 To be very precise, certain animation objects, which describe random animation, ....

G. Blakowski, J. H ubel and U. Langrehr (1992). Tools for specifying and executing synchronized multimedia presentations. In Second International Workshop on Network and Operating System Support for Digital Audio and Video (R. G. Herrtwich, ed.), no. 614 in Lecture Notes in Computer Science, (Heidelberg), pp. 271--282, Springer Verlag.

....of optimal schedules with continuous bandwidth and delay tradeoffs in O(N ) time. 5 Bandwidth Constrained Scheduling of Scalable Multimedia Recently, numerous research activities have been reported integrating multimedia objects with varying timing requirements in a multimedia presentation [1, 2, 11]. Their main results were centered around the formal specification and modeling of multimedia composition and the development of synchronization tools such as the automatic scheduling of presentation times. A multimedia presentation may contain text, audio, video, graphics, where the objects are ....

....generation and the latter schedules the transmission of data. In bandwidth constrained environment, the bandwidth limit imposes a constraint on the transmission schedule, which in turn restricts the possible presentation. There have been approaches to treat the two problems separately such as [1, 10]. There are also approaches to concatenate the two stages into a feedback loop such as [3] where presentations are generated until the resulted transmission schedule satisfies the resource constraints. We propose the approach of integrated presentationtransmission scheduling. Based on our ....

G. Blakowski, J. Hubel, and U. Langrehr. Tools for Specifying and Executing Synchronized Multimedia Presentations. Computer Communications, 15(10), 1992.

.... synchronization at the level of presentation scheduling can be classified in terms of different ways for generating events [BDE 93] An approach based on action driven event generation can be found in e.g. LG90b] approaches based on reference point driven event generation are described in [BHL91, AK94] and approaches based on time system driven event generation are proposed in [Gib91, BHL91] HyTime [NKN91] and MHEG [Pri93] also provide synchronization schemes based on time system driven event generation. All of these concepts support the specification of static presentation schemes but ....

.... ways for generating events [BDE 93] An approach based on action driven event generation can be found in e.g. LG90b] approaches based on reference point driven event generation are described in [BHL91, AK94] and approaches based on time system driven event generation are proposed in [Gib91, BHL91] HyTime [NKN91] and MHEG [Pri93] also provide synchronization schemes based on time system driven event generation. All of these concepts support the specification of static presentation schemes but have their deficiencies. Approaches based on time system driven event generation except HyTime ....

G. Blakowski, J. Hubel, and U. Langrehr. Tools for Specifying and Executing Synchronized Multimedia Presentations. In Network and Operating System Support for Digital Audio and Video", Second International Workshop, Proceedings, November 1991.

.... layer include the following: Interstream (i.e. parallel streams) and intrastream (including integrated streams and single stream order) synchronization [Yavatkar 1992] Whereby the synchronization timing can be specified using hierarchical relationships, a time line, and reference points [Blakowski, Hubel, and Langrehr 1991]. Integration of synchronized multimedia data, such as blending two video signals, mapping a video signal onto a graphics surface, and mixing multiple audio streams . Presentation specific processing of a stream, such as chroma keying or warping a video signal. 3.2. Media Presentation ....

Blakowski, G., J. Hubel, and U. Langrehr, 1991. "Tools for Specifying and Executing Synchronized Multimedia Presentations," Second International Workshop on Networking and Operating System Support for Digital Audio and Video, Heidelberg, Germany (November).

....bandwidth that will be required during the next few seconds was available so the feedback algorithm could begin reducing the frame rate in anticipation of a change in the required bandwidth. 4. Related Work Many groups are working on multimedia applications that include playing continuous media [1, 2, 3, 6, 7, 8, 14, 15, 19]. None of these systems report an application Figure 7. Frames played versus time with adaptive control Frame rate (fps) 25 20 15 10 5 0 time 20 40 60 80 100 Figure 6. Frames played versus time without adaptive control. time Frame rate (fps) 20 40 60 80 100 25 20 15 10 5 0 24 fps 16 fps 12 ....

Blakowski, G., et.al., Tools for specifying and executing synchronized multimedia presentations, Proc. 2nd Int. Wkshp on Network and OS Support for Digital Audio and Video, Heidelberg (November 1991).

....system, while using a highly visual metaphor, is really a script based timeline editing system. It is also weak in its higher level composition facilities. Other systems using composition and or sync arcs to create synchronized multimedia presentations (without hyperlinks) are described in [2] and [8] Commercial systems addressing synchronization are generally of the timeline or scripting variety, e.g. 12] Even though some of these systems have been ported between common platforms (e.g. Apple s QuickTime [1] is now also available under Microsoft Windows) they were never designed ....

Gerold Blakowski, Jens Hübel and Ulrike Langrehr, "Tools for Specifying and Executing Synchronized Multimedia Presentations", 2nd International Workshop on Network and OS Support for Digital Audio/Video, Heidelberg, Germany, Nov. 18-19, 1991.

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G. Blakowski, J. Huebel, and U. Langrehr, "Tools for Specifying and Executing Synchronized Multimedia Presentations," Proc. 2nd Int'l Workshop on Network and Operating System Support for Digital Audio and Video, pp. 271-279, 1991.

No context found.

G. Blakowski, J. Huebel, and U. Langrehr. Tools for specifying and executing synchronized multimedia presentations. In Proc. 2nd Int'l Workshop on Network and Operating System Support for Digital Audio and Video, pages 271--279, 1991.

No context found.

Blakowski, G., J. Huebel, and U. Langrehr. "Tools for specifying and executing synchronized Multimedia presentations," in 2nd Int'l Workshop on Network and Operating system support for Digital Audio and Video. 1991. Heidelberg, Germany.

No context found.

Blakowski, G., J. Huebel, and U. Langrehr. "Tools for specifying and executing synchronized Multimedia presentations," in 2nd Int'l Workshop on Network and Operating system support for Digital Audio and Video. 1991. Heidelberg, Germany.

No context found.

Blakowski, G., J. Huebel, and U. Langrehr. "Tools for Specifying and Executing Synchronized Multimedia Presentation," 2nd Int'l Workshop on Network and Operating System Support for Digital Audio and Video. 1991. Heidelberg, Germany.

No context found.

Gerold Blakowski, Jens Hubel, and Ulrike Langrehr. "Tools for Specifying and Executing Synchronized Multimedia Presentation," Network and Operating System Support for Digital Audio and Video, Lecture Notes in Computer Science No. 614, Springer-Verlag, November 1991.

No context found.

G.Blakowski, J.Hubel, and U.Langrehr, Tools for specifying and executing synchronized multimedia presentations, 2nd Intl. Workshop on Network and Oper. Sys. Support for Digital Audio and Video, Heidelberg, Germany, Nov. 18-19, 1991.

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Blakowski, G., Hubel, J., and Langrehr, U., "Tools for Specifying and Executing Synchronized Multimedia Presentations," Second International Workshop on Networking and Operating System Support for Digital Audio and Video, Heidelberg, Germany, November 1991.

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