Re: Display JPEGs on your Tivo from ANYWHERE

[Kevin Hawkins <lists@xxxxxxxxxxxxxxxxx>]

Sullivan, Glenn wrote:
> I guess it makes sense to do that, and then an app can send out a
> display message to either the whole set of TiVo's (by addressing to
> BushSoft.xAPTiVoJPEGWriter.GMSServer), or to an individual TiVo (by
> addressing to BushSoft.xAPTiVoJPEGWriter.GMSServer:LivingRoom)
>
>
Just a comment here on some rethinks I/we've been having over targeting
after some practical experience using sub addressing.

Firstly addressing the 'whole' application with
Target=BushSoft.xAPTiVoJPEGWriter.GMSServer
is intended for things that the whole/main application would
action/respond to, rather than the endpoints eg perhaps a general status
query like 'uptime' or how many attached devices there are or what
machine the SlimServer is running on. . If actually you are wanting all
the endpoints to do something (eg display a  message) then you should
construct the target= line to address all the endpoints rather than the
main application ie something like
Target=BushSoft.xAPTiVoJPEGWriter.GMSServer:>
Obviously various constructs can be used to select a sub group of
players or just one specific one as appropriate.

The concept of sub addresses was originally purposed for one
application/device with several embedded hardware endpoints - with one
hardware device and lots of I/O its ideal and in something like
SlimServer with one server application and several display/player
devices this works quite well -  With several Tivo's all sort of made
into one collection it's stretching the model somewhat but actually as
one 'application' is providing all the segmenting to multiple devices
I'm thinking it's appropriate too as sub addresses provide a useful way
of addressing each player within the target= line.

Secondly ( and people have a slightly divided opinion here ) as to
whether there is a difference between an untargeted message and a
message containing target=>:>  (which addresses everything) or even
target=> or say target=*.*.> which only addresses whole applications
and
not any endpoints.      My view is that as xAP is essentially
'informational' (as it is a broadcast protocol) then informational
packets that aren't necessarily required to be acted upon should be sent
without a target, - thing like time, weather , statistics, status
information etc. If a receiver is interested in such information it can
choose to receive it and can be configured if necessary to act upon it
(eg display it) . Hence interested parties choose to process the
information.  However if the same message is sent targeted (even if it
is to everyone) then  a receiver should act upon it if it can. The
target line is effectively saying 'please action this if you can and
your address matches'.      If we look at this in the context of a
display or OSD message then I feel a message without a target line
serves the purpose of providing information that a receiver can (or may
not) choose to display depending on how the particular receiver is
configured.   An LCD display might always do this but your TV for
example might not (as it is intrusive) even though it has an ability to
action OSD messages .   The fact the message is using a 'display' or
'osd' schema gives it the construct to know how to display it should it
want to . However if the same message was sent with a target
'everything' line then it should display it if it can.   All this means
really is that if you want to send a display or OSD message with the
intent that it is displayed on every possible device then it should have
a target=>:> line in it.   < NB this is my take on the issue and
not a
xAP official one>.

A similar sort of functionality can also be achieved by a priority field
in a message - and again perhaps you might have a TV set to only display
messages above priority 3 or something...

Kevin

PS ... can be summarised as... ;-)

"the whole set of TiVo's by addressing to
BushSoft.xAPTiVoJPEGWriter.GMSServer"

should actually be addressed to  BushSoft.xAPTiVoJPEGWriter.GMSServer:>