Re: [AVT] Q for 3984bis-06

[Ye-Kui Wang <yekuiwang at huawei.com>]

I shortened the text. 

> If the offerer is legacy, then they don't include 
> level-upgrade-allowed,
> and as stated the answerer is not allowed to upgrade the 
> level.  If the
> answerer is legacy, then they will ignore 
> level-upgrade-allowed, and won't
> upgrade the level.  So those 3 cases are all handled.

OK. But it is possible that the answerer is new but does not want to upgrade
the level in an offer/answer process. It would be certainly useful that the
answerer lets the other side know whether it is new or legacy. Therefore,
I'd prefer to include level-upgrade-allowed equal to 1 if the device is new
(does understand the parameter and allows level upgrade). Note that
something is allowed does not mean it is in use. 

> >The conflict is at the offerer's side. It includes a lower 
> level, but you
> >are proposing requires that the offerer can receive a higher 
> level. To do
> >this, you must change the current semantics of profile-level-id.
> 
> No, unless we decide to take the option mentioned in my table 
> (change it to
> "level-asymmetry-allowed").  Then (and only then) could the 
> offerer could
> receive a level above what they offered.  
> 

Sorry, I mis-read your table. But that just makes a difference on receiving
or sending capability, not the conclusion. In the righ case in the table
(i.e. offer includes B, and answer includes C). The current semantics say
that the offerer would only be able to send B and lower. But you want the
offerer to be able to send C which is higher than B.

> >> Perhaps this table will help:
> >> 
> >> Offer is level "B".  I'll use level "A" to indicate a 
> lower level, and
> >> "C" for a higher one (A < B < C).  I'm assuming the offer includes
> >> level-upgrade-allowed=1.
> >> 
> >> 
> >>  Answer level:     lower (A)       same (B)       higher (C)
> >> 
> >> Offerer can send:     A              B               C
> >> Answerer can send:    A*             B               B
> >> 
> >
> >In the right case (the answer includes level C), what if the 
> offerer's
> >receiveing capability is actually lower than C?
> 
> Then they shouldn't answer with "C".  They should answer with whatever
> level they do support.  The point of this is to allow the answerer to
> offer to receive a higher level; they get to choose what that 
> level is.

Now with the correct reading of the table. Again, that just makes a
difference on receiving or sending capability, not the conclusion. You are
basically assuming that the offerer's sending (i.e. encoding) capability is
not limited, i.e. it can send whatever high level the answer may include.
How can that assumption be correct?

BR, YK