DSMCC StreamEvents
Hi @ All out there...
We are a group of students working on an interactive applikation based on mhp. We use a Tekronix MPEG Analyser/Carousel Generator to generate our modified MPEG Streams and modulate them onto Sattelite frequency.
The first step is, that we generate a StreamEventDescriptor list and a NPT Reference Descriptor. For testing the conformity we're using dvbsnoop, and it says fine.. We multiplex them all together with the a/v streams and play them out.
Then we want to filter the Sections via the MHP Middleware SectionFilter with implementing the StreamEventListener. I've already read, that it is possible to view the EventList via DSMCCStreamEvent.getEventList(); But in order to create a DSMCCStreamEvent we must set a Locator in the constructor.
But we don't have a file in the dsmcc carousel to track on, we simply want to receive that event in order to trigger maybe a popup or something like that.
What is missing in this way to get StreamEvents ?
more detailed questions :
1. Do the StreamEventDescriptorList / nptReferenceDescriptor need a special pid ?
2. Does the event userEventReceived(UserEvent event) happen, if we send just these streams ?
3. Do we have to register our stream with the DescriptorList first ?
4. Does anyone knows and simple description or tutorial or maybe a book about the mystic thing streamevents ? (we read now about 1 1/2 month nearly every mpeg / mhp spec, there's so many stuff in it, it does not really help)
We would be really happy for any hint or possible idea to go on with our project !
Thx alot... JavaTVForum is a great one.. We solved a lot of problems with reading in here...
greetz form germany
andy
You need some StreamEvent object in your DSM-CC object carousel if you want to receive stream events: without this, the receiver can not tell what stream events it should monitor. I'm not familiar with the Tektronix carousel generator, but if it claims to be MHP compliant then it should have some way of doing this.
To answer your other questions:
1) None of the DSM-CC descriptors need a special PID, but the stream type must be correct.
2) No. UserEvents are generated by user input only.
3) This question isn't clear to me. What are you referring to by 'DescriptorList'?
4) There's a couple of tutorials on my website that cover DSM-CC, both from a more technical perspective (http://mhp-interactive.org/tutorial/dtv-intro/dsm-cc/index.shtml) and from an MHP API perspective (http://mhp-interactive.org/tutorial/mhp/synchronization.shtml). Alternatively, you could buy my book :) It's called 'Interactive TV Standards'by Steven Morris (me) and Anthony Smith-Chaigneau, and it's available from Amazon.com and other online stores.
Steve.
hi steve...
The first link is a really good one, i never read it before (and we nearly took a look on every tutorial on your page!) Maybe it will help us to understand this cryptographic thing dsmcc.
Your answers do help us a lot because it shows us, that were on the right way.
Now there's only one element, that can cause the problem we have. The "great - but not really great" Tektronix. If you're right (and im sure you are) we 100% need this StreamEvent Object in the Carousel - Generator... And we do not have...
So maybe we phone tekronix in order to get a software update or something else.. (a good user manual were lot more than we have...)
Ok, nevermind thx alot for this answer... and wish you all happy x-mas !
(i thought about buying your book, but i wasnt sure that these things are written down there... so i will do.... :-) )
andy
