Re: xAP-Audio schema questions....

["malcolmcgreen" <groups@xxxxxxxxxxxx>]

I'm now looking at the next stage of xAP implementation in TelCanto.
I need to generate some notifications when the play status changes,
which will include the xAP-Audio.Playlist.Event (Now.Playing).  I also
need an event to indicate change of transport state, but can't find an
event defined in the schema corresponding to the Audio.Transport
command, i.e. an Audio.Transport.Event.  Can anyone enlighten me as to
whether such an event has been defined, perhaps in a later version of
the schema?

Malcolm Green


--- In xAP_developer@xxxxxxx, Kevin Hawkins <lists@u...>
wrote:
> This is a posting of a couple of email exchanges now moved to this
list
> as it is of interest to all I feel.
>
>
> Hi P - yes I can see why you've done that ...
>
> In re-reading the schema I understand how certain .events are sent
but I
> am still unsure of some and I can't see a list of the 'modes' for
> example and what should be sent if say a player is put into pause
or FF
> or whatever. I also see there is a refererence to allowing the
.events
> to be sent 'as needed'
>
> It strikes me we could do with defining some additional time
related
> parameters for inclusion in the event reporting timeline including
>
> Duration  <mandatory>
> StartTime <mandatory>
> EndTime <mandatory>
> CurrentTime  <mandatory>
> ElapsedTime   <optional ?>
> RemainingTime  <optional ?>
>
> .. and that these should be sent periodically at a frequency that
is
> configurable as different users might want tighter feedback. 10
secs
> sounds a useful time for most implementations. Towards the end of
the
> current track it may be desireable to increase the frequency of
events
>
> Just to expand on the above time information I was considering what
> would happen if a player was asked to play a track whose duration
was
> say 5 mins but starting at position 1min22secs and ending at
1min44secs
> which I think our schema should/does support (the actual time being
down
> to 100'ths of a sec perhaps).The current 'Duration' is the length of
the
> whole track and the currentTime the exact current position relative
to
> that. The StartTime and EndTime are the actual markers for what
section
> is to be played. ElapsedTime and RemainingTime can be derived from
the
> other values but could be defined such that they can be inserted as
> optional .
>
> What does anyone think ? I think this is needed and I am keen to
resolve
> it whilst Malcolm is focussed on teh xAP aspects of TelCanto.
Edward
> and Stuart I would particularly value your comments as you are the
two
> who have done this practically already...
>
>     Kevin
>
>
> Patrick Lidstone wrote:
>
> >I do an "elapsed time" event which includes current play
state for
the
> >Rio stuff (sent once every 10s or so, plus whenever a button
causes a
> >change). This is an integral part of the audio spec - I can dig
out the
> >exact message if no-one else chips in.
> >
> >P.
> >
> >
> >
> >>-----Original Message-----
> >>From: Kevin Hawkins
> >>Sent: 09 December 2004 13:44
> >>
> >>
> >>xAP guys...
> >>
> >>    The newer audio schema isnt one I'm familiar with  so I'm
just
> >>coming up to speed on that as I provide feedback to Malcolm.
What
I
> >>can't seem to see is how a player keeps people informed of its
state.
> >>For example when it is paused by a press of the pause button
on
the
> >>player or IR remote or FF'wded perhaps causing the track
position
to
> >>change (not the actual track just the time remaining).  How do
we
> >>indicate a player is in pause/play or whatever ?.    It
strikes
me we
> >>need a whole series of periodic event messages being generated
by
a
> >>player that keep people updated about it current state eg
'time
> >>remaining'.  ... and that such event messages should probably
> >>be issued
> >>quite frequently (configurable), particulalry towards the end
> >>of a track
> >>playing (eg track about to end /finished).  Additionally
> >>anything that
> >>causes the estimated time remaining to change should
> >>immediately send an
> >>update (eg a REW) This way monitoring apps can accurately
> >>become synched
> >>with a players status even if they are only turned on half
> >>way through
> >>a  track eg the xAP Desktop SliMP3 display...    I can see
> >>some specific
> >>SliMP3 bits that would help but not in the general schema and
in
> >>telCanto's case it could be driving lots of different clients.
> >>
> >> Or have I missed something ?
> >>
> >>Kevin
> >>
> >>
> >>