How to send multicast audio in Pure Data?

romulovieira-me

Dear community,

I am trying to send multicast audio from one computer to another as follows:
[connect 224.0.0.0 8080]
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[ggee/streamout~]

Pure data log returns the message: "connecting to a multicast address", but the audio is still not received.

Can you help me?

Thanks

whale-av

@romulovieira-me You might find it will work straight away with 224.0.0.1
If not there should be more help for the receiving computer here....... https://low-orbit.net/linux-how-to-join-multicast-group
David.

romulovieira-me

@whale-av Thanks for the answer. I tried address 224.0.0.1 and got multicast access to OSC information. But the audio still doesn't work.
Should I join a multicast group?

whale-av

@romulovieira-me Sorry.... I don't know.
[streamin~] has no method to specify an address. It seems to just listen for the port on it's local host.
I cannot get [streamout~] to declare that it is connected to a multicast address in Windows..... 239.0.0.1 just gives me a socket error...... so I cannot test.

[udpsend~] and [udpreceive~] will do multicast for me...... but the dropouts are significant even with a [buffer 15( set.
Basic Wi-Fi though. Ethernet or 5GHz Wi-Fi should help with that.
Davd.

whale-av

@romulovieira-me After further reading...... yes... you probably need to tell the interface on the receiving computer to join the group.
This is useful reading........ https://tldp.org/HOWTO/Multicast-HOWTO-2.html ....

But if you ping 239.0.0.1 from your sending computer you will probably find that r-inspiron3442.local is already a group member (as osc is working).
If that is the case then [streamin~] is the problem as it never makes a request to the os to receive a multicast address.

If the ping is not returned then do a google search for "Linux '(whichever) IGMP" to find out how to join the group.
David.

romulovieira-me

@whale-av Solved

I had to put the two computers that were going to exchange messages on the same multicast address. This link was helpful https://low-orbit.net/linux-how-to-join-multicast-group
[ggee/streamout~] didn't really work. I used [mrpeach/net/udpsend ~].

Thus, my code was as follows:

[connect 239.255.255.250 8080]
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[dac~]
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[mrpeach/net/udpsend~ 8080 2]

So, I sent the audio from the microphone connected to one computer to another, via the network and using multicast