DSM CC

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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).

MPEG-1 is a standard for lossy compression of video and audio. It is designed to compress VHS-quality raw digital video and CD audio down to 1.5 Mbit/s without excessive quality loss, making video CDs, digital cable/satellite TV and digital audio broadcasting (DAB) possible.

MPEG-2 standard for the generic coding of moving pictures

MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods, which permit storage and transmission of movies using currently available storage media and transmission bandwidth. While MPEG-2 is not as efficient as newer standards such as H.264/AVC and H.265/HEVC, backwards compatibility with existing hardware and software means it is still widely used, for example in over-the-air digital television broadcasting and in the DVD-Video standard.

Multiplexing method by which multiple analog or digital signals are combined into one signal over a shared medium

In telecommunications and computer networks, multiplexing is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource. For example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in telegraphy in the 1870s, and is now widely applied in communications. In telephony, George Owen Squier is credited with the development of telephone carrier multiplexing in 1910.

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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).

International Organization for Standardization An international standard-setting body composed of representatives from national standards organizations

The International Organization for Standardization is an international standard-setting body composed of representatives from various national standards organizations.

International Electrotechnical Commission organization

The International Electrotechnical Commission is an international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology". IEC standards cover a vast range of technologies from power generation, transmission and distribution to home appliances and office equipment, semiconductors, fibre optics, batteries, solar energy, nanotechnology and marine energy as well as many others. The IEC also manages three global conformity assessment systems that certify whether equipment, system or components conform to its International Standards.

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.

The Real-time Transport Protocol (RTP) is a network protocol for delivering audio and video over IP networks. RTP is used in communication and entertainment systems that involve streaming media, such as telephony, video teleconference applications including WebRTC, television services and web-based push-to-talk features.

Secure copy protocol (SCP) is a means of securely transferring computer files between a local host and a remote host or between two remote hosts. It is based on the Secure Shell (SSH) protocol. "SCP" commonly refers to both the Secure Copy Protocol and the program itself.

Satellite Human-made object put into an orbit

In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as Earth's Moon.

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

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]

DMIF, or Delivery Multimedia Integration Framework, is a uniform interface between the application and the transport, that allows the MPEG-4 application developer to stop worrying about that transport. DMIF was defined in MPEG-4 Part 6 in 1999. DMIF defines two interfaces: the DAI and the DNI. A single application can run on different transport layers when supported by the right DMIF instantiation. MPEG-4 DMIF supports the following functionalities:

MPEG-4 is a method of defining compression of audio and visual (AV) digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG) under the formal standard ISO/IEC 14496 – Coding of audio-visual objects. Uses of MPEG-4 include compression of AV data for web and CD distribution, voice and broadcast television applications.

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Moving Picture Experts Group working group to set standards for audio and video compression

The Moving Picture Experts Group (MPEG) is a working group of authorities that was formed by ISO and IEC to set standards for audio and video compression and transmission. It was established in 1988 by the initiative of Hiroshi Yasuda and Leonardo Chiariglione, group Chair since its inception. The first MPEG meeting was in May 1988 in Ottawa, Canada. As of late 2005, MPEG has grown to include approximately 350 members per meeting from various industries, universities, and research institutions. MPEG's official designation is ISO/IEC JTC 1/SC 29/WG 11 – Coding of moving pictures and audio.

The Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, and terminating real-time sessions that include voice, video and messaging applications. SIP is used for signaling and controlling multimedia communication sessions in applications of Internet telephony for voice and video calls, in private IP telephone systems, in instant messaging over Internet Protocol (IP) networks as well as mobile phone calling over LTE (VoLTE).

MPEG-7 is a multimedia content description standard. It was standardized in ISO/IEC 15938. This description will be associated with the content itself, to allow fast and efficient searching for material that is of interest to the user. MPEG-7 is formally called Multimedia Content Description Interface. Thus, it is not a standard which deals with the actual encoding of moving pictures and audio, like MPEG-1, MPEG-2 and MPEG-4. It uses XML to store metadata, and can be attached to timecode in order to tag particular events, or synchronise lyrics to a song, for example.

The MPEG-21 standard, from the Moving Picture Experts Group, aims at defining an open framework for multimedia applications. MPEG-21 is ratified in the standards ISO/IEC 21000 - Multimedia framework (MPEG-21).

Advanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at the same bit rate. The confusingly named AAC+ (HE-AAC) does so only at low bit rates and less so at high ones.

MPEG-4 Part 3 or MPEG-4 Audio is the third part of the ISO/IEC MPEG-4 international standard developed by Moving Picture Experts Group. It specifies audio coding methods. The first version of ISO/IEC 14496-3 was published in 1999.

3GP is a multimedia container format defined by the Third Generation Partnership Project (3GPP) for 3G UMTS multimedia services. It is used on 3G mobile phones but can also be played on some 2G and 4G phones.

Manufacturing Message Specification (MMS) is an international standard dealing with messaging systems for transferring real time process data and supervisory control information between networked devices or computer applications. The standard is developed and maintained by the ISO Technical Committee 184 (TC184). MMS defines the following

Program-specific information (PSI) is metadata about a program (channel) and part of an MPEG transport stream.

Digital Item is the basic unit of transaction in the MPEG-21 framework. It is a structured digital object, including a standard representation, identification and metadata.

MPEG Multichannel is an extension to the MPEG-1 Layer II audio compression specification, as defined in the MPEG-2 Audio standard which allows it provide up to 5.1-channels of audio. To maintain backwards compatibility with the older 2-channel (stereo) audio specification, it uses a channel matrixing scheme, where the additional channels are mixed into the two backwards compatible channels. Extra information in the data stream contains signals to process extra channels from the matrix.

In digital video broadcasting (DVB), a data and object carousel is used for repeatedly delivering data in a continuous cycle. Carousels allow data to be pushed from a broadcaster to multiple receivers by transmitting a data set repeatedly in a standard format. A set-top box receiver may tune to the data stream at any time and is able to reconstitute the data into a virtual file system. The carousel may therefore be considered as a transport file system or file broadcasting system that allows data files to be transmitted from the broadcaster to multiple receivers or clients simultaneously.

MPEG-4 Part 14 MP4 digital format for storing video and audio

MPEG-4 Part 14 or MP4 is a digital multimedia container format most commonly used to store video and audio, but it can also be used to store other data such as subtitles and still images. Like most modern container formats, it allows streaming over the Internet. The only official filename extension for MPEG-4 Part 14 files is .mp4. MPEG-4 Part 14 is a standard specified as a part of MPEG-4.

MPEG-4 Part 20, or MPEG-4 Lightweight Application Scene Representation (LASeR) is a rich media standard dedicated to the mobile, embedded and consumer electronics industries specified by the MPEG standardization group. LASeR is based on SVG Tiny and adds methods for sending dynamic updates and a binary compression format.

ISO base media file format defines a general structure for time-based multimedia files such as video and audio. The identical text is published as ISO/IEC 15444-12.

Dynamic Adaptive Streaming over HTTP (DASH), also known as MPEG-DASH, is an adaptive bitrate streaming technique that enables high quality streaming of media content over the Internet delivered from conventional HTTP web servers. Similar to Apple's HTTP Live Streaming (HLS) solution, MPEG-DASH works by breaking the content into a sequence of small HTTP-based file segments, each segment containing a short interval of playback time of content that is potentially many hours in duration, such as a movie or the live broadcast of a sports event. The content is made available at a variety of different bit rates, i.e., alternative segments encoded at different bit rates covering aligned short intervals of playback time. While the content is being played back by an MPEG-DASH client, the client automatically selects from the alternatives the next segment to download and play based on current network conditions. The client automatically selects the segment with the highest bit rate possible that can be downloaded in time for playback without causing stalls or re-buffering events in the playback. Thus, an MPEG-DASH client can seamlessly adapt to changing network conditions and provide high quality playback with fewer stalls or re-buffering events.

MPEG media transport (MMT), specified as ISO/IEC 23008-1, is a digital container standard developed by Moving Picture Experts Group (MPEG) that supports High Efficiency Video Coding (HEVC) video. MMT was designed to transfer data using the all-Internet Protocol (All-IP) network.

References

  1. ↑ MPEG (July 1997). "mpeg Press & Public Release - Stockholm". MPEG. Archived from the original on 2010-07-05. Retrieved 2010-08-01.
  2. ↑ 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.
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