| Mms pdu - HELP!!!!! |  Search
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NowSMS Support Forums ⬆ NowSMS Support - SMS Issues ⬆ Archive through December 09, 2003 ⬆ |
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| Author | Message | |||
| Darek Chorazewicz |
Hi. I want to send wallpaper but I have some problems. In document "How to create MMS service" I have found many good advices. There is something like that "84h is Content-Type, 1Bh the length of the value, B3h is application/vnd.wap.multipart.related". This is of course method how to encode mms message. But I want to use "application/vnd.wap.multipart.mixed" so what is the code in hex dump ? And what the "1Bh" means? How explain this? And one more question. How to encode actual data in mms body part? DARO admin@statsms.net | |||
| Bryce Norwood - NowSMS Support |
Where to start ... where to start? I'd suggest that you use the "Search" function on this discussion board. Search for MMS PDU, and you want messages that contain both keywords. That will give you links to several messages that will have some information that you might find useful. Most of the discussion is about the m_notification_ind message, which is sent out over SMS as the notification ... but I also found some good discussions that focus on the actual MMS content (m_send_req if you are submitting to an MMSC, m_retrieve_conf if the message is to be retrieved after a notification is generated). You're going to want to look at the relevant specifications, published by the Open Mobile Alliance (http://www.openmobilealliance.org). A binary MMS message file starts with an MMS header, which is documented in the MMS Encapsulation Specification. The MMS header encodes most header values using encoding defined in the WSP (Wireless Session Protocol) specification. For example, 0x84 is the binary encoding for the content-type in an MMS header, but the value of the content type is encoded according to WSP rules (for example, with multipart/related content, you will typically have content type parameters like type= and start=, which is why the length value is present). After the MMS header, you have content that is encoded as either "application/vnd.wap.multipart.related" or "application/vnd.wap.multipart.mixed". Those MIME types are documented in the WSP specification referenced above. If your needs are simple, you might just want to look at the MMSCOMP utility that is included in the Now SMS/MMS Gateway, a trial of which you can download from this web site. MMSCOMP takes a text version of the MMS header and a list of content files as input, and generates the binary MMS file as output. -bn | |||
| tim |
Hi Bryce According to http://www.wapforum.org/wina/wsp-content-type.htm application/vnd.wap.multipart.related is encoded as 0x33, why 0xB3 ??? Many thanks Tim | |||
| Bryce Norwood - NowSMS Support |
Tim, This is because the format of the content type field in the WSP header is defined in Section 8.4.2.24 of the WSP specification. Here, it is defined as having the format "Constrained-media" or "content-general-form". The latter is a more complicated format. In this case, the "Constrained-media" encoding is used. Section 8.4.2.7 defined "Constrained-media" as being equivalent to "Constrained-encoding". "Constrained-encoding" is defined in Section 8.4.2.1 as either a text string or a "short-integer". A "Short-integer" is defined in this same section as "Integers in range 0-127 shall be encoded as a one octet value with the most significant bit set to one (1xxx xxxx) and with the value in the remaining least significant bits." That's where the definition that the high bit gets set comes from ... which turns 0x33 to 0xB3. Yes ... these specifications are a tad confusing. -bn | |||
| tim |
Hi Bryce, Many thanks for your explaination!, that's clear now. Tim | |||
