[FFmpeg-devel] [PATCH][RFC] -std=c99

Luca Abeni lucabe72
Tue Aug 19 08:58:20 CEST 2008

Hi Dave,

Dave Dodge wrote:
> The UNIX standard includes IPv6 multicast,

Are you saying that it does not include IVv4 multicast? opengroup.org 
seems to say that "Support for sockets over Internet protocols based on 
IPv4 is mandatory".

> so in theory you could use
> getaddrinfo() to map the IPv4 address to IPv6, and then use the
> standardized IPv6 multicast operations on it.

So, a program is supposed to join an IPv6 multicast group even for 
receiving IPv4 traffic? What about systems that do not support IPv6 (or 
linux based systems with IPv6 support disabled)?

> From a standards viewpoint, note also that the IPv6 code in the same
> function uses the IPV6_ADD_MEMBERSHIP socket option, but UNIX chose to
> call it IPV6_JOIN_GROUP instead (Linux #defines both, with the same
> value).

Yes, opengroup.org seems to confirm this. Fortunately, this is easily 
fixable ;-) I'll test a patch in the next days.


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