Riding the Media Bits

Last update: 2011/08/21

Riding the media bits

 

 

MPEG's sixth steps

 

MPEG-A: from technology standards to application formats.


In the typical MPEG anticipative fashion, for several years discussions were made about "what else does industry need from MPEG?". Finally at the Munich (March 2004) MPEG came to the conclusion that while MPEG had produced many component standards, the integration of technologies, save for the canonical Aido-Video-System integration, had been left to implementers. The result has been that, e.g. ATSC uses MPEG-2 Systems and Video but a different Audio than specified by MPEG, and DivX uses MPEG-4 Visual, MP3 and AVI. A complete solution, however, required more pieces.

While implementers should be free to make arbitrary decisions in terms of what components technologies they should use for their products and services, this has shortcomings: it may take a long time to go from an MPEG standard to a product, while incompatibilities between different system implementations that trouble end users could be avoided with more careful choices.

So MPEG decided to enter the “system integration” area considering that MPEG has (most of) the technologies needed, the internal expertise to do the integration job and the appropriate industry representation.

Multimedia Application Formats (MAF) is the name of the new standard suite that bears the nice looking ISO number 23000. MAFs specify how to combine metadata with media information typically, but not exclusively, packaged in an MPEG-4 file format to enable media interchange, management, editing, and presentation.

Part 1 is, like MPEG-21 Part 1, an informative document outlining the scope of the ISO/IEC 23000 suite.

Part 2 Music Player Application Format (MPAF) specifies a format to carry MP3 coded audio content in MPEG-4 File Format augmented by and a JPEG image for cover art and simple MPEG-7 metadata commonly expressed in ID3 tags, such as Song title, Album title, Artist, Year, Comment, Track, and Genre.

The MPAF standard also enables album functionality by making reference to MPEG-21. It allows to collect several song files in the above described song file format into one album file.

The second edition of the MPAF has added protection feature by incorporating AES-128 counter mode encryption as default protection tool and MPEG-4 IPMP-X. MPEG-21 IPMP and REL for protection and governance description.

Part 3 Photo-Player Application Format (PPAF) specifies a format to carry JPEG images and their associated MPEG-7 metadata in an MPEG-4 file to enable creation, sharing and viewing digital photo albums.

The supported metadata include image-acquisition parameters (e.g. date, time and camera settings) expressed as EXIF metadata and MPEG-7 visual content descriptions expressed as binary MPEG-7 metadata. The latter allow new, content-enhanced functionality, such as intelligent browsing, content-based search or automatic categorization.

Part 4 Musical Slideshow Application Format (MSSAF) is a superset of the Music Player and the Photo Player AFs in that its combines the features of both AFs. in addition to the technologies already employed by the two AFs, MSSAF employs MPEG-4 Part-17 “Streaming Text Format” for timed text and  MPEG-4 Part-20 “LASeR” Mini Profile.

Part 5 Media Streaming Application Format specifies how to use some MPEG technologies to build a full-fledged media player for streaming governed and ungoverned content. This standard defines by reference to appropriate standards the data formats exchanged between a number of devices used in a media streaming scenario: a Content Provider Device, a Licence Provider Device, an IPMP Tool Provider Device, a Domain Management Device and a Media Streaming Player.

In the most general case a Media Streaming Player obtains streaming content from a Content Provider Device using a Content Access Protocol. In order to use that content, a Media Streaming Player obtains a licence from a Licence Provider Device using a Licence Access Protocol. Further, to actually process the content, a Media Streaming Player may need to obtain the appropriate IPMP Tools from an IPMP Tool Provider Device using an IPMP Tool Access Protocol, as shown in the figure below.

Fig. 1 - Reference diagram of MSAF standard

Part 6 Professional Archival Application Format (PAAF) provides a standardised packaging format for digital files. The format is an implementation of the information package specified by the Reference Model of Open Archival Information System (OAIS), a framework for long-term digital information preservation.

PAAF specifies metadata formats to describe

  • the original structure of digital files archived in a PAAF file
  • context information related to a PAAF file and digital files archived in it
  • necessary information to reverse the pre-processing applied to digital files prior to archiving them in a PA-AF file

and it specifies

  • a file format for carriage of the metadata formats and digital files.

Part 7 Open Access Application Format (OAAF) is a packaging format designed for the release and exchange of content roghts to which is owned by users who have an interest in releasing so that other users can freely access it without making the content "public domain". This was part of a proposal of a DMP use case.

OAAF packages different content types into a single container file and provides a mechanism to attach metadata information, by using a series of technologies, in particular

  • MPEG-7 to describe the resource

  • MPEG-21 REL to model the intentions of the licence

  • MPEG-21 Event Reporting to provide a feedback mechanism, which can notify the author, when a user wants to derive a content or extract an item out of the container file.

Part 8 Portable Video Application Format (PVAF) defines a format for the use of video files on portable devices to give users the possibility to use the resource  interactively.

Part 9 Digital Multimedia Broadcasting Application Format (DMBAF) specifies how to combine the variety of DMB resources and associated information in a well-defined file format to facilitate interchange, management, editing, and presentation of DMB content. Digital Multimedia Broadcasting (DMB) is a mobile TV service enabling users to acquire and consume information anywhere.

Part 10 Surveillance Application Format (SAF) provides a lightweight wrapper to the audio and video content from MPEG technologies, video coding, related metadata and file format, suitable for surveillance.

Part 11 Video Stereoscopic Application Format (VSAF) provides a format for a creator to take and for a service provider to distribute stereoscopic images, enabling users to have more realistic experiences (with or without special glasses) and to store the stereoscopic content for possible redistribution.

Part 12 Interactive Music Application Format (IMAF) defines a format to package interactive music content with audio tracks before mixing, in order to allow users to freely control individual audio tracks. The producer can create several versions (producer mixing 1, producer mixing 2, karaoke, rhythmic, and so on) with just one piece of music, using the metadata structure for mixing information.