[Libav-user] Stream RTP to a specific network interface OR accessing underlying UDP socket

[LP C]

Hi everybody,

Currently coding a C application that is sending video over the network 
using MULTICAST, I am looking for a way to set on which network 
interface the RTP stream should be sent.

I tried to use 'rtp://237.0.0.1:1234?localaddr=192.168.1.1' but it does 
not work. After digging in the source code of the RTP protocol, it seems 
that this option is not supported right now.

Thus I would like to know if I can access to the underlying socket in 
order to apply IP_MULTICAST_IF using setsockopt (6.3: 
https://www.tldp.org/HOWTO/Multicast-HOWTO-6.html)

Any clues of how to solve this issue programmatically?

Thanks,