[opendtv] Re: OCAP - will it continue to move forward
- From: Bill Sheppard <Bill.Sheppard@xxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Wed, 13 Oct 2004 23:26:42 -0700
Wilms wrote: Bill Sheppard wrote: Like Java's run once, debug everywhere.
Processor and flash-restricted STBs require a very different set of assets
and code finetuning to some bloated STB with a fat CPU and capability to run
VMs and display high-resolution images. Java's "debug everywhere" reputation
is far less accurate in well-defined industry markets, such as MIDP 2.0/JTWI
for mobile phones or MHP/OCAP for DTV. You said the magic phrase
'well-defined'. I translate that to mean 'restricted to'. Hence the
assertionof 'run once debug everywhere' is correct. You might choose that
translation, but it's not relevant. Java spans from 8-bit microcontrollers
to 64-bit CPU's. To expect the same application to run across this breadth
of hardware is neither realistic nor useful.
In terms of these platforms that a Java application is restricted to, will
the same application that runs on a Nokia NGage run on a Siemens C55? Both
use 'Java Technology' Many applications will. And were these phones
compliant with more recent industry-defined specifications, such as MIDP
2.0,a much larger selection of applications would be compatible without
specific debugging effort.
They will, but only if you debug separately on both platforms. To make a
Javaapplication run well on both without modification you have to include
assets for both platforms in the binary (we can't assume that it will be on
the phone), dumb down the VM to the lowest common denominator (maybe pay a
license fee), make sure we only use calls that are available on both
systems,Using calls that are available on both systems means sticking to the
platform specification. Of course if you go beyond the spec you're going to
introduce incompatibilities! OCAP defines a much broader range of
capabilities than MIDP 1.0; going beyond the specification will be much less
likely to be necessary and may not be tolerated by the operators.
and have sections of code devoted to munging and optimizing the user
experience on each platform. Thats a lot of work, and I can see why there
arecompanies out there in the business of providing this service or
providingtheir own VMs. I've had my fun with using Java on PocketPCs - I
think this 'getting started' list proves the sheer horror best (note this
list is outdated, the list is much larger at current crack -- and *only*
partly addresses PocketPC devices):
http://www.comp.lancs.ac.uk/computing/users/fittond/ppcjava.html[1] And
proves my point. The chart indicates VM's implementing more than four
completely different Java specifications targetting completely different
devices, plus VM's which have not passed any proper Java test suite. MHP
andOCAP have extensive test suites which all devices will be required to
pass; no ambiguity about what specification is being implemented. This
makesfor a far more consistent environment for developers. Of course,
memory, CPU, graphics capabilities, and the like will still vary from box to
box, but the vast majority of OCAP applications will run across all boxes
with little-to-no debugging across devices.
-- -------------------------------------------------------------------------
Bill Sheppard Industry Marketing Manager bill.sheppard@xxxxxxx[2] Consumer
and Mobile Systems Group (408) 404-1254 (x68154) Sun Microsystems, Inc.
--- Links ---
1 http://www.comp.lancs.ac.uk/computing/users/fittond/ppcjava.html
2 mailto:bill.sheppard@xxxxxxx
----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at
FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.
Other related posts:
