[M4IF Technotes] Sub-part of a presentation

[Richard Shields]

Chris,
Thanks for clearing this up for me.  To me, it seems that the specification
needs work in the area of sub-presentations.  It doesn't seem very clear
especially when the specification indicates that an item is mandatory, such
as the iods, but really isn't in all cases.
-Richard
> -----Original Message-----
> From: Christopher Wendt [mailto:chris   avipix.com]
> Sent: Friday, July 27, 2023 9:56 AM
> To: Richard Shields; technotes   lists.m4if.org
> Subject: Re: [M4IF Technotes] Sub-part of a presentation
> 
> 
> Hi Richard, all,
> 
> > Where does this root OD exist in the remote file?  In the iods?
> Yes.
> > If so, the
> > iods can contain only one OD and a single OD cannot refer 
> to both a video
> > and an audio stream.
> Right, this is probably not the optimal way to do it (a least 
> just for an
> A/V presentation), it's more useful for inline scenes 
> actually.  You require
> a BIFS and OD streams for the root OD.
> 
> > OK... the specification for the file format states that the iods is
> > mandatory.  Is that not true in this case?  Or can an iods 
> exist but not
> > contain an IOD or OD?
> The iods atom is not required for the case of using data 
> reference.  If you
> don't have an IOD or root OD, then don't create a iods atom.
> 
> -Chris
> 
> -------------------------------------------------------------
> Christopher Wendt,  avipix, llc
> chris   avipix.com
> (732) 682-5549
> http://www.avipix.com
>