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To: Denis DeLaRoca <CSP1DWD@MVS.OAC.UCLA.EDU>
cc: multimedia@FreeBSD.ORG
Subject: Re: guspnp18 and vat 
In-reply-to: Your message of "Sun, 31 Aug 1997 20:16:00 PDT."
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Date: Sun, 31 Aug 1997 22:13:18 -0700
From: Amancio Hasty <hasty@rah.star-gate.com>
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>From The Desk Of Denis DeLaRoca :
> The other outstanding problem is with passing the audio device among
> multiple active vats. That is completely broken and I think we have
> to wrestle with vat's code to find out how that is supposed to work.

confbus.cc calls the constructor for GroupIPC

class ConfBus : public TclObject, public IPCHandler {
    public:
	ConfBus(int channel);
	~ConfBus();
	void ipc_input(int type, int frompid, u_char* p, int len);
    protected:
	int command(int argc, const char*const* argv);
	GroupIPC* ipc_;
	char* callback_;
};


Group-ipc.cc: opens a socket to receive local ip multicast requests:

GroupIPC::GroupIPC(int channel) : handlers_(0)

----

When vat gets a local ip multicast message it gets processesed here:

in confbus.cc:
void ConfBus::ipc_input(int, int, u_char* msg, int cc)

A call gets issue to ui-audio.tcl to request the audio device which
it first try to do open the audio device via the Obtain method
in audio-voxware.cc

Hope this helps,
	Amancio