[Mp4-tech] MPEG-4 and synchronized interactive applications

[AVARO Olivier FTRD/DIH/REN]

Dear Dominique,
There are different architectures to accomplish what you describe but the issue is not only technical.
Technically, you can do what you describe (and this was demonstrated by AIC in IBC in 1999) by just using existing MPEG-2 Audio, Video and Systems and adding MPEG-4 Systems for the interactive enhancement (without MPEG-J). This is fully specified in MPEG (MPEG-2 and MPEG-4 Systems) and I know a couple of implementations. If you like, you can replace MPEG-2 Video and Audio by more recent MPEG-4 codecs. Code points and format for that have been standardiized by MPEG.
But you may want as well to have the interactive enhancements more tightly integrated with your MHP Systems. MPEG-J comes then into the picture and allows for example the user of an (MHP+MPEG-J) applet application to interact with the MPEG-4 enhancements.
I am not sure DVB is tackling the issue. There were some expectations at some points in time that MHP will be the ultimate answer. It seems now generally accepted that MHP is fine for the application part but that a specific technology is needed for the interactive graphics enhancements. MPEG-4 Systems is to my knowledge the only solution that is fully standardized and allow the frame based synchronization that you request.
Kind regards,
Olivier 
> -----Message d'origine-----
> De : dominique.delcoigne belgacom.be
> [mailto:dominique.delcoigne belgacom.be]
> Envoyé : mardi 12 août 2003 10:02
> À : technotes lists.m4if.org
> Objet : [Mp4-tech] MPEG-4 and synchronized interactive applications
> 
> 
> 
> 
> Dear experts,
> 
> In the traditional digital broadcast world (DVB-MPEG-2), 
> several operators choose for MHP in order to develop 
> interactive applications.
> Several MHP applications do not require a sync with the 
> audiovisual stream (e.g. standalone game, SuperTeletext, 
> ...); however other applications such as a pop-up during a 
> commercial advertising, a locally playable game show,  etc... 
> require a perfect sync with the audiovisual stream.  MHP 
> 
> When operating an MPEG-4 broadband (IP) network, a part of 
> the content will be picked up from DVB sources (satellite, 
> cable, etc...) that include MHP applications.
> 
> How does MPEG-4 tackle this ?
> - Conversion of MPEG-2 audio and video (A/V) into MPEG4 audio 
> and video (OK we could even pass thru baseband SDI with full 
> reencoding) -  This is not the biggest issue I think.
> - What about the MHP applications synchronized with the video 
> content: part of the Java code included in MHP is reused for 
> MPEG-J  'translation' in MPEG-4 ? how is made the sync with 
> A/V ?  Or do we come to the conclusion that there is a need 
> to develop an application code for each system (traditional 
> broadcast DVB MHP) and application code (based on MPEG-J or 
> proprietary middleware software (likly based on Java)) for 
> MPEG-4 IP distribution ?
> - Is the DVB consortium tackling this convergence ?  If yes, 
> how far are we in the roadmap ?
> 
> Any clue how to tackle this issue ?
> 
> 
> 
> Thanks
> 
> Dominique
> 
> 
> 
>