[FFmpeg-devel] [PATCH] Make RTP work with IPv6 enabled

Luca Abeni lucabe72
Mon Oct 29 12:18:19 CET 2007

Hi Ronald,

I did not read emails during the weekend, and I am slowly starting
to look at my inbox...

Ronald S. Bultje wrote:
> I read your proposed patch (after noticing +/- 5 stale ffplay processes :-)
> ) in another thread and was able to get ffplay going w/o CONFIG_IPV6 again,
> so that part is solved now.

Ok, good. I'll try to apply that patch soon ;-)

> However, even with the patches in recent
> threads, CONFIG_IPV6 doesn't work with udp. Set up is correct, the bind()
> succeeds but the sendto() in udp_write() fails completely unexpectedly with
> EINVAL, which isn't even documented in its manpage.

The only possibility I can guess is that s->dest_addr or s->dest_addr_len
is not set properly.

Just to be 100% sure that I understand correctly: this happens when you compile
without "--disable-ipv6", even if you try to stream to IPv4 addresses, right?

> If I split the sendto() into a separate connect() in udp_open() followed by
> send() in udp_write(), the whole thing works as expected

This is... Scary :(
I cannot imagine anything that can cause such a behaviour.
In the connect(), you use the same "s->dest_addr" and "s->dest_addr_len" used
in sendto(), right? Can you check with an av_log() that the used values are
the same, just to be 100% sure?

> Best way may be to re-arrange udp.c a bit to first set up the local part in
> udp_open() and then call connect() in set_remote_url() and send() / recv()
> instead of sendto() / recvfrom() in udp_read/write(), or is that a bad idea?

I do not know... But I do not feel confident with bugs going away without reasons...
Before changing the code, I'd like to understand what's going on :)

> (I still don't know what the bug is, but I suppose sendto() is just broken
> on macs (?)...)

That would be a big bug; I think someone should have noticed it before...
Maybe there are some MacOS forums where we can find more information about it?
Any other MacOS users on this list?


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