Digital storage media command and control (DSM-CC) is a toolkit for developing control channels associated with MPEG-1 and MPEG-2 streams. It is defined in part 6 of the MPEG-2 standard (Extensions for DSM-CC) and uses a client/server model connected via an underlying network (carried via the MPEG-2 multiplex or independently if needed).
DSM-CC may be used for controlling the video reception, providing features normally found on Video Cassette Recorders (VCR) (fast-forward, rewind, pause, etc.). It may also be used for a wide variety of other purposes including packet data transport. It is defined by a series of weighty standards, principally MPEG-2 ISO/IEC 13818-6 (part 6 of the MPEG-2 standard).
DSM-CC may work in conjunction with next generation packet networks, working alongside such internet protocols as RSVP, RTSP, RTP and SCP. Although DSM-CC is usually associated with video delivery (via satellite or terrestrially) and with interactive content, it is also used among audio servers and clients. The architecture describes three main parts of the system: the client, the server, and the session resource manager (SRM). The server provides content and other services to the client, and both are "clients" of the SRM. The SRM allocates and manages network resources (such as channels, bandwidth, and network addresses.) By combining server and client components together onto the same platforms, peer-to-peer content access and delivery systems can be constructed.
These specifications include numerous implementation options. For example, MPEG-2 video can be encoded in different ways, and a DSM-CC system can be constructed to include or exclude certain features and interfaces. Normally, an outside specification will define a profile of specific options, allowing systems built using common profiles to interoperate.
DSM-CC defines or extends five distinct protocols:
User-User
Allows remote access by the client to objects on the server. The User-User specification goes beyond the definition of specific server object classes to define classes local to the client, as well as some of the interaction with other parts of the system. The distributed object model is based on CORBA. Objects are accessed using the internet inter-ORB protocol (IIOP), with some optional extensions. Two subsets, "core" and "extended", are defined. In the model, some clients may also load content onto the server.
User-Network
There are two parts to this protocol: Session and Resource. This protocol is used between the client and SRM, and between the server and SRM. The U-N Session protocol is used to establish sessions with the network, associated with resources which are allocated and released using the U-N Resource protocol.
MPEG transport profiles
The specification provides profiles to the standard MPEG transport protocol (defined by ISO/IEC 13818-1) to allow transmission of event, synchronization, download, and other information in the MPEG transport stream.
Download
Several variations of this protocol allow transfer of content from server to client, either within the MPEG transport stream or on a separate (presumably high-speed) channel. Flow-controlled download allows the download operations to be negotiated and controlled by the client. A variation of download is an autonomous "data carousel" on the server which repeatedly downloads information; the download carousel client waits for the information without initiating the transfer. An extension to the data carousel is the "object carousel", which presents downloaded information as objects compatible with the objects defined by the User-User API. (The choice of download or IIOP protocols is embedded in the object's IOR, so the means of access is transparent to the client application.)
Switched Digital Broadcast-Channel Change Protocol (SDB/CCP)
Enables a client to remotely switch from channel to channel in a broadcast environment. Used to attach a client to a continuous-feed session (CFS) or other broadcast feed. Sometimes used in pay-per-view.
An implementation does not always need all of these protocols. Almost all implementations in the real world use a subset.
Extensionedit
Delivery Multimedia Integration Framework (DMIF) expands upon the MPEG-2 DSM-CC standard (ISO/IEC 13818-6:1998) to enable the convergence of interactive, broadcast and conversational multimedia into one specification which will be applicable to set tops, desktops and mobile stations. The DSM-CC work was extended as part of the ISO/IEC 14496-6 (MPEG-4 Part 6), with the DSM-CC Multimedia Integration Framework (DMIF).[1][2]
Referencesedit
^MPEG (July 1997). . MPEG. Archived from the original on 2010-07-05. Retrieved 2010-08-01.
^Leonardo Chiariglione (2005-03-08). . Archived from the original on 2011-01-22. Retrieved 2010-08-01.
External linksedit
ISO/IEC 13818-6:1998 - Information technology -- Generic coding of moving pictures and associated audio information - Part 6: Extensions for DSM-CC
- DSM-CC from the perspective of IDTV
January 01, 1970
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Digital storage media command and control DSM CC is a toolkit for developing control channels associated with MPEG 1 and MPEG 2 streams It is defined in part 6 of the MPEG 2 standard Extensions for DSM CC and uses a client server model connected via an underlying network carried via the MPEG 2 multiplex or independently if needed DSM CC may be used for controlling the video reception providing features normally found on Video Cassette Recorders VCR fast forward rewind pause etc It may also be used for a wide variety of other purposes including packet data transport It is defined by a series of weighty standards principally MPEG 2 ISO IEC 13818 6 part 6 of the MPEG 2 standard DSM CC may work in conjunction with next generation packet networks working alongside such internet protocols as RSVP RTSP RTP and SCP Although DSM CC is usually associated with video delivery via satellite or terrestrially and with interactive content it is also used among audio servers and clients The architecture describes three main parts of the system the client the server and the session resource manager SRM The server provides content and other services to the client and both are clients of the SRM The SRM allocates and manages network resources such as channels bandwidth and network addresses By combining server and client components together onto the same platforms peer to peer content access and delivery systems can be constructed These specifications include numerous implementation options For example MPEG 2 video can be encoded in different ways and a DSM CC system can be constructed to include or exclude certain features and interfaces Normally an outside specification will define a profile of specific options allowing systems built using common profiles to interoperate DSM CC defines or extends five distinct protocols User User Allows remote access by the client to objects on the server The User User specification goes beyond the definition of specific server object classes to define classes local to the client as well as some of the interaction with other parts of the system The distributed object model is based on CORBA Objects are accessed using the internet inter ORB protocol IIOP with some optional extensions Two subsets core and extended are defined In the model some clients may also load content onto the server User Network There are two parts to this protocol Session and Resource This protocol is used between the client and SRM and between the server and SRM The U N Session protocol is used to establish sessions with the network associated with resources which are allocated and released using the U N Resource protocol MPEG transport profiles The specification provides profiles to the standard MPEG transport protocol defined by ISO IEC 13818 1 to allow transmission of event synchronization download and other information in the MPEG transport stream Download Several variations of this protocol allow transfer of content from server to client either within the MPEG transport stream or on a separate presumably high speed channel Flow controlled download allows the download operations to be negotiated and controlled by the client A variation of download is an autonomous data carousel on the server which repeatedly downloads information the download carousel client waits for the information without initiating the transfer An extension to the data carousel is the object carousel which presents downloaded information as objects compatible with the objects defined by the User User API The choice of download or IIOP protocols is embedded in the object s IOR so the means of access is transparent to the client application Switched Digital Broadcast Channel Change Protocol SDB CCP Enables a client to remotely switch from channel to channel in a broadcast environment Used to attach a client to a continuous feed session CFS or other broadcast feed Sometimes used in pay per view An implementation does not always need all of these protocols Almost all implementations in the real world use a subset Extension editDelivery Multimedia Integration Framework DMIF expands upon the MPEG 2 DSM CC standard ISO IEC 13818 6 1998 to enable the convergence of interactive broadcast and conversational multimedia into one specification which will be applicable to set tops desktops and mobile stations The DSM CC work was extended as part of the ISO IEC 14496 6 MPEG 4 Part 6 with the DSM CC Multimedia Integration Framework DMIF 1 2 References edit MPEG July 1997 mpeg Press amp Public Release Stockholm MPEG Archived from the original on 2010 07 05 Retrieved 2010 08 01 Leonardo Chiariglione 2005 03 08 Riding the Media Bits MPEG s third steps Archived from the original on 2011 01 22 Retrieved 2010 08 01 External links editISO IEC 13818 6 1998 Information technology Generic coding of moving pictures and associated audio information Part 6 Extensions for DSM CC How To Become An Expert In DSM CC DSM CC from the perspective of IDTV OpenCaster free GPL licensed software for transport stream broadcasting supporting DSM CC Retrieved from https en wikipedia org w index php title DSM CC amp oldid 997365914, wikipedia, wiki, book, books, library,
