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51 posts

Master Geek

Topic # 4449 20-Jul-2005 16:59
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Hi Guys. I'm working on a mobile portal and I need some expert advice. I want to know a little more about descriptor files - first of all it would be nice to see more examples - I cant find a .dd or .dr file anywhere.

Q.) if we send a user a link to a descriptor file how do we make sure that the image being saved to their phone is the correct screen resolution - I am guessing that when their mobile phone browser hits our server to look at the descriptor file we need to first capture their phone type and then generate the appropriate descriptor.

I'm not sure that this is the way, but it certainly seems logical enough.



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51 posts

Master Geek

  Reply # 16847 21-Jul-2005 17:27
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Still no example nokia .dd files - somebody must have an example???

Anyway, here is what I have come up with, when somebody browsers our portal using their phone I am thinking we should:

  • use the raw data in our apache logs to see if it is a telecom phone that we support
  • check the screen size contained in the logs
  • accordingly create a .gcd or .dd file on the fly
  • let the download commence

Can somebody please tell me if this sounds reasonable.

Also what I really want is a list of phones that Telecom would reccomend using :P

149 posts

Master Geek

  Reply # 16954 22-Jul-2005 18:21
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You can goto nokia's development site and they have all the info on DRM files, they use the OMA spec. GCD is a Sprint spec , and it does not support at this stage Digital rigths.

The method you are using sounds fine, You will need to ID the Handset by there header, then create the file descriptor.
There are example site doing this already. they are using PHP to do this

The big issue if a Telecom phone goes outside the TNZ garden user are geting charge a lot more for there downloads eg 400k = $15 . So you need to have a deal with TNZ

344 posts

Ultimate Geek
+1 received by user: 1


  Reply # 17608 6-Aug-2005 22:43
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hi there,

your in luck! I happen to have done a huge amount of work implementing dd, dr and gcd type drm for TNZL.

Here's the basics... in order to understand what device your dealing with, you can either maintain your own database of device capabilities and using the x-wap user agant for discovery, deliver the correct descriptor, or capture the rdf from the header, and pull the capabilities based on the xml.

Once you know the device your dealing with, you can then point to the descriptor.

heres and example of the contents of a gcd file

Content-Type: audio/vnd.qcelp
Content-Name: Ringtone
Content-Version: 1.0
Content-Vendor: Acme Ringtones
Content-Size: 240768

and a dd file information can be found here,,034-13,00.html

As mentioned, the main issue you will have is off site wap charges.

What is your company trying to do? I may be able to provide some pointers.


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Uber Geek
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  Reply # 18037 11-Aug-2005 10:38
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Figured out how to serv up Ringtones on Nokia 6225's and other phones with DRM or OpenWave 6.2.2.

With most other phones you can do the following, but this doesn't work with the Nokia 6225 / OpenWave 6.2.2 phones as they just play the music, don't let you save it.

Create a mime type (for apache that's the mime.types file) called:

text/vnd.wap.wml wml

That means that all WML files are sent to your phone as a text/vnd.wap.wml mime type.

Then you create a file on your web server called test.wml or whatever so long as it's extension is .wml with the format:

--- Snip ----



--- Snip ----

Then just change the card title and link to whatever midi file you want to download. That works fine for most GSM phones out there, you can also put images up in the same way.

Of course with Openwave 6.2.2 things have got harder since they figured out that people could download ringtones or images or java games without needing to pay for them hence they created DRM or Digital Rights Mgmt.

For this to work you need to add a new mime type called:

application/vnd.oma.dd+xml dd

This then associated the file extension dd with app....

Then you need to create another xml file called "test.dd" or whatever as long as it's a .dd with the following file format:

--- Snip ----


--- Snip ----

Then you need to change the name,size,type,description and objectURI to point to whatever web server you are running.

For midi's you need to use the mime type of "audio/midi" I am sure you can figure out what other mime types you need to use to download images/java apps etc.

Also of course change the objectURI to point to the file sitting on your web server.

Then you should be away!

[Moderator: edited to add code tags]

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Uber Geek
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  Reply # 18039 11-Aug-2005 10:45
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One thing I forgot to add, check out:

They have a central site that has info on pretty much every mobile phone in production. Including features, screen res etc.

Very useful for being able to firstly detect what's on the other end, and then shape the content accordingly.


344 posts

Ultimate Geek
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  Reply # 18061 11-Aug-2005 12:44
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Here's a tip

the dd and gcd files must specify the content type...

audio/midi = midi
audio/sp-midi = Scalable Polyphony MIDI
text/ = Java Application / Game
application/vnd.oma.drm.message = DRM for MMS
application/vnd.oma.dd+xml = reference to a dd file based on an xml doc
application/vnd.oma.drm.rights+xml = reference to a dr binary file as described in an xml doc
application/vnd.wap.mms-message = wap based MMS message
application/vnd.wap.multipart.mixed = multi-part object
application/vnd.wap.sic = Nokia Symbian theme
audio/3gpp = 3gpp ringtone (true tone) gsm standard (can be used for streaming)
audio/3gpp2 = 3gpp2 ringtone (true tone) cdma standard (can be used for streaming)
audio/amr = adaptive multi rate ringtone (true tone)
audio/mid = midi ringtone (poly)
audio/qcelp = PureVoive audio (ringtone) (Qualcomm)
image/gif = static or animated wallpaper
image/jpeg = static wallpaper
image/png = static wallpaper (prefered)
image/vnd.wap.wbmp = black and white wallapaper
text/x-pcs-gcd = Sprint gcd file type (for DRM)
video/3gpp = 3gpp video (gsm standard (can be used for streaming))
video/3gpp2 = 3gpp2 video (gsm standard (can be used for streaming))
video/mp4 = video (and or audio) can be streamed, or downloaded

Pretty sure that's all good. Of course you wouldn't use many of them!



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