[vlc-devel] [PATCH 2/2] live555: Use OPTIONS as keep-alive fallback

[Rémi Denis-Courmont]

Le 2015-06-23 14:26, Paul Clark a écrit :
> On 18/06/15 16:33, Julian Scheel wrote:
>> So far no keep-alive messages are sent when GET_PARAMETERS is not 
>> supported by
>> the server. Change this to fall back to sending OPTIONS as 
>> keep-alive message,
>> which is the default keep-alive message in the SAT>IP specification. 
>> As
>> RFC2326 does not enforce a specific command as keep-alive message 
>> this shall
>> be valid for any compliant RTSP server.
>
> I've seen clients (notably Samsung SmartTVs) do this against our
> server, so we support it as well as GET_PARAMETER, but it requires 
> the
> client to send the Session: header with OPTIONS (which is pretty 
> weird
> RTSP, really, but works), and I don't think your patch can be doing
> so:
>
> +            p_sys->rtsp->sendOptionsCommand(NULL, NULL);
>
> Does the SAT>IP spec specify this?

No. SAT>IP requires OPTIONS with a Session header and token, AFAIU:

http://www.satip.info/sites/satip/files/resource/satip_specification_version_1_2_2.pdf

Either way, it makes no sense. The Session header is not allowed in 
OPTIONS request by RFC2326. But without it, there are no ways to specify 
which session is being refreshed. The bottom line is that using OPTIONS 
for refresh is wrong, and should not be attempted unless the server is 
known to expect this.

-- 
Rémi Denis-Courmont
http://www.remlab.net/