[Live-devel] RTSP-over-HTTP and inconsistent SETUP requests.

[Ross Finlayson]

>(As there's no RFC on RTSP over HTTP, as far as I know, I use this 
>document as a reference: 
><http://developer.apple.com/quicktime/icefloe/dispatch028.html>http://developer.apple.com/quicktime/icefloe/dispatch028.html

FYI, another document - with a little more detail - is here: 
http://images.apple.com/br/quicktime/pdf/QTSS_Modules.pdf (starting 
on page 107)


>1) Milestone doesn't send us "Accept:" or "Content-Type:" string of 
>"application/x-rtsp-tunnelled" in the HTTP GET. I deactivated the 
>check in the RTSPServer.cpp code and everything works. Will you 
>incorporate this in the future code?

Note that the document that I referred to above explicitly states 
that the "application/x-rtsp-tunnelled" header must be present. 
However - in the spirit of "Be liberal in what you accept" - I will 
deactivate this check in the next release of the code.  (Note, 
though, that the "x-sessioncookie:" header absolutely has to be 
present in the request, both to distinguish RTSP-tunneling requests 
from regular HTTP "GET" commands (which should be rejected because 
we're not a real HTTP server), and to enable us to tie together the 
"GET" and "POST" requests.  I presume, though, that the 'Milestone' 
client is including this header OK, otherwise the code wouldn't be 
working.)


>2) Milestone sends us a base64 encoded POST that contains this SETUP:
>
>SETUP 
><rtsp://192.168.1.83:8554/video/track1>rtsp://192.168.1.83:8554/video/track1 
>RTSP/1.0
>CSeq: 2
>Transport: RTP/AVP;unicast;client_port=12154-12155
>
>This makes RtspServer send its packets in UDP, while Milestone seems 
>to want them tunneled in the TCP connection (openRTSP gets it right, 
>sending a more reasonable Transport: 
>RTP/AVP/TCP;unicast;interleaved=0-1).
>
>My question is: does not the GET imply that the stream data must be 
>tunneled, regardless the (incorrect) Transport:RTP/AVT request from 
>the Milestone? What could be the point on requesting UDP/RTP data 
>over an RTSP/HTTP negotiation?

I can imagine that this *might* be useful for tunneling across a 
firewall that passes UDP packets, but blocks TCP connections to 
anything other than port 80.  I agree, though, that this is unlikely 
to be what you want to do.

So, with some reluctance, I will modify the server code (in the next 
release) so that - when HTTP tunneling is being done - it assumes 
that it will stream over the TCP (HTTP) connection, regardless of 
what the "SETUP" command says.  I say "with some reluctance", though, 
because I'm getting tired of the assumption that - just because we're 
Open Source - we should inevitably modify our code in order to be 
compatible with other people's broken, non-standard software (or 
hardware).  I'm willing to bet that the installed base of our 
software is larger than that of 'Milestone'.  So, even though I'll 
modify our server code to work around these two bugs, I'd like you to 
also please contact 'Milestone', informing them of these bugs, and 
asking them to fix them in their software.
-- 

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/
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