Realizing the MPEG-4 multimedia delivery framework

Abstract

MPEG-4 is an emerging international standard based on the encoding of audiovisual data usin object description techniques. This novel a proach to encoding allows MPEGdXased multimedia applications to dynamicaiy com ose complex ried within potentially hundreds of channels. As a result, the underlying transport system must support the rapid creation and release of such channels with QoS uarantees. In addition to defining the format, structure and rules of composition of Xese objects, MPEG-4 also specifies a general application and transport delivery framework called the delivery multimedia integration framework. DMIF's main purpose is to hide the details of the transport network from the user, a s well a s to ensure signaling and transport interoperability between end-systems. W e describe the first reference implementation of the MPEG-4 DMIF standard for ISO, including a full specification of the DMIF application interface. The DAI offers the required functionality for realizing multimedia applications without any concerns regarding the selected communication protocol. The realization of DMIF is greatly facilitated by xbind, a broadband kernel that provides connection management, routing, QoS mapping, and intelligent selection of suitable transport protocol stacks. The resulting system, called XDMIF, supports different QoS requirements, and the rapid creation and release of numerous transport channels, along with efficient management of network resources.scenes from one or more elementary stream obiects. These stream o E jects are car-PEG-4 is an emerging international standard that specifies the coding of audio and video data using object description techniques. This novel approach to coding allows multimedia applications to dynamicaily compose complex scenes from one or more elementary streams or synthetic objects. The scene description information, consisting of the logical structure of the scene, spatial and temporal information of the video/audio objects that make up the scene, object attributes, and graphics primitives, is carried within potentially hundreds of data channels. This calls for a high rate of establishment and release of numerous short-term transport channels with the appropriate quality of service (QoS). Traditional methods of signaling are not adequate to meet this demand because of the high overhead introduced. Figure 1 illustrates a typical scenario for information transport between two hosts, including the channels needed for an MPEG-4 scene transfer and composition.The emergence of MPEG-4-based as well as other distributed multimedia applications exhibiting significantly more stringent QoS requirements than conventional data-oriented applications imply the need for transport protocols with different characteristics to coexist and be integrated within single applications. For the first time, application developers have to contend with the fact that a single protocol stack may perhaps be insufficient to meet all their needs. The same developers are also faced with the need to deliver their a...

Impact of ARQ protocols on QoS in 3GPP systems

“…QoS requirements that have to be fulfilled for delay-sensitive traffic can be expressed for the basic information unit of the RLC layer in terms of average and maximum delay, jitter, and loss probability [20].…”

<title>DMIF over RSVP/IP protocol stack: experimental results for MPEG-4 multimedia streaming</title>

“…The Delivery Layer in MPEG-4 is called Delivery Multimedia Integration Framework (DMIF) and is defined in ISO/IEC 14496-6 14,15 . This layer is media unaware but delivery technology aware [16][17][18] . It provides transparent access to the delivery of content irrespective of the technologies used through the interface between the Sync Layer and DMIF, called DMIF Application Interface (DAI).…”

Implementing multiplexing, streaming, and server interaction for MPEG-4

“…FlexMux) and MuxP. By directly acting on the latter abstractions, the PSB controls the generation, consumption, and processing of streams without being located in the data path [7], [8].…”

“…For the communication between an application and the DMIF C-Plane two abstract C classes are provided [8]. The first class is used for communicating between the application and the DMIF layer and implements the DAI primitives with a _Req and _Rsp extension.…”