[FFmpeg-devel] [PATCH] always enable reuse for reading multicast udp

[Martin Storsjö]

On Thu, 7 Oct 2010, aviad rozenhek wrote:

> On Tue, Oct 5, 2010 at 00:01, aviad rozenhek <aviadr1 at gmail.com> wrote:
> 
> > On Thu, Sep 16, 2010 at 13:50, aviad rozenhek <aviadr1 at gmail.com> wrote:
> >
> >> On Thu, Sep 16, 2010 at 04:51, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> >>
> >>> aviad rozenhek <aviadr1 <at> gmail.com> writes:
> >>>
> >>> > -    int len;
> >>> > +    int len, has_reuse_arg = 0;
> >>>
> >>> Being read-only, the new variable does not look useful.
> >>>
> >>>
> >> fixed by using it properly
> >>
> >> +        if (find_info_tag(buf, sizeof(buf), "reuse", p)) {
> >> +            s->reuse_socket = strtol(buf, NULL, 10);
> >> +            has_reuse_arg = 1;
> >> +        }
> >>
> >
> > attached is the correct patch which IMHO addresses the comments made
> > earlier.
> > again the idea here is that reuse should be enabled by default for
> > read-only multicast udp, but it can be overriden by user.
> >
> 
> 
> ping

> From b9b796d79368dceaaec9995ffed7ce181a21b244 Mon Sep 17 00:00:00 2001
> From: aviad <aviad at aviad-ubuntu.(none)>
> Date: Mon, 4 Oct 2010 23:43:02 -0400
> Subject: [PATCH] enable mutlicast udp reuse, for read-only multicast udp
> 
> ---
>  libavformat/udp.c |    9 +++++++--
>  1 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/libavformat/udp.c b/libavformat/udp.c
> index 83e8b37..5197053 100644
> --- a/libavformat/udp.c
> +++ b/libavformat/udp.c
> @@ -314,7 +314,7 @@ static int udp_open(URLContext *h, const char *uri, int flags)
>      const char *p;
>      char buf[256];
>      struct sockaddr_storage my_addr;
> -    int len;
> +    int len, has_reuse_arg = 0;
>  
>      h->is_streamed = 1;
>      h->max_packet_size = 1472;
> @@ -331,7 +331,10 @@ static int udp_open(URLContext *h, const char *uri, int flags)
>  
>      p = strchr(uri, '?');
>      if (p) {
> -        s->reuse_socket = find_info_tag(buf, sizeof(buf), "reuse", p);
> +        if (find_info_tag(buf, sizeof(buf), "reuse", p)) {
> +            s->reuse_socket = strtol(buf, NULL, 10);
> +            has_reuse_arg = 1;
> +        }
>          if (find_info_tag(buf, sizeof(buf), "ttl", p)) {
>              s->ttl = strtol(buf, NULL, 10);
>          }
> @@ -361,6 +364,8 @@ static int udp_open(URLContext *h, const char *uri, int flags)
>  
>      if (s->is_multicast && !(h->flags & URL_WRONLY))
>          s->local_port = port;
> +    if(s->is_multicast && !has_reuse_arg && !(h->flags & (URL_WRONLY | URL_RDWR)))
> +        s->reuse_socket = 1;

Couldn't you do just && h->flags & URL_RDONLY at the end?

>      udp_fd = udp_socket_create(s, &my_addr, &len);
>      if (udp_fd < 0)
>          goto fail;
> -- 
> 1.6.0.4
> 

I don't think this would do much harm if enabled for all read-only 
sockets, not only multicast. Then the code could be quite much simplified, 
into something like this: