[Asterisk-Dev] help needed implementing H324M (UMTS Video)
n-mack at md.neweb.ne.jp
Fri Jun 3 20:37:47 MST 2005
sorry off topic
I found a VW2010 H/W MPEG4 driver for RH73,RH9 linux inside this zip
Did anyone tried it? and Can we drive with IAX on linux and windows?
On Sun, 06 Feb 2005 22:36:34 +0100
Klaus Darilion <klaus.mailinglists at pernau.at> wrote:
> Hi Christian!
> Sorry for my late reply, but I was busy an the video project isn_t top
> comments inline...
> PS: I also cc to the mailing lists - maybe someone is interested in our
> ckruetze at foni.net wrote:
> > Hi,
> > I read your post on the * mailing List regarding your H324 implementation for
> > Asterisk.
> > I'm very interested in that, and I would like to offer you my help.
> > Unfortunately I'm somewhat new to * and therefore I can't answer your questions
> > on how to access the raw bit stream from the channel.
> > Regarding where to implement it, I wouldn't modify the zaptel channel.
> > zaptel cards are not the only way UMTS video could come it. There is also capi
> > channel and maybe it could even come over SIP or IAX, who knows.
> Yes, that's true. I think it would be good to write i as an application.
> The existing channels (zaptel, capi..) have to be modified to
> distinguish normal voice calls from video calls (bearer capability, user
> layer signaling) and handle the information the the dial plan. There I
> have extensions which match only videocalls and handle the call to the
> H324 application.
> Then, the application handles the H324/SIP conversation and uses the
> internal codecs for transcoding (if necessary).
> After digging a littl ebit more into the H.324 specification I realized
> that this gateway is much more complicated then I thought. The H.223
> framing uses the mobile levels which have much more complex frames than
> simple HDLC frames. You will have to code/decode Golay codes and have to
> guess the frames in case of bit errors. IMO this is not trivial.
> After that, H.245 will be used for call control. Mybe its possible to
> reuse things from H.323, nevertheless I will take plenty of time to get
> familiar with the specifications. Another big problem is the asterisk
> architecture - it studied the code for a while and got an idea who
> things will work. Nevertheless, there is to less documentation - there
> are plenty of undocumented data structures and every time I used one I
> was hoping that I will use it in the proper ways.
> Currently, we put the project "on hold" and hope to find some students
> which will implement it as diploma thesis.
> If you are going to work on this project, I can help you with technical
> details about H.324M.
> > I would try to implement H324M as a channel independent codec.
> > First of all there are other ISDN channels other then zaptel, for example the
> > capi channel or the i4l channel (can't remember it's name right now). It will
> > also be more consistent with the current (voice only) codec$BCT(B and more flexible
> > $BK(Bnot everybody wants that in there zaptel channel.
> > After asterisk "speaks" H324M, I would implement the translation into SIP video
> > much like the different audio channels are currently translated from one to
> > another.
> > Of course for that to work, Asterisk would need to understand other codecs such
> > as SIP video.
> > Xten use in there eyebeam products H263 for video, so translation shouldn$BCU(B be
> > too complicated.
> > Feel free to contact me by email, or MSN (same address as my email) or sometimes
> > on the #asterisk chat (user: ckruetze)
> > Looking forward to Video in Asterisk,
> > Christian
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