[vlc-devel] [PATCH]RTSP Trickplay in 0.8.6c

Glen Gray slaine at slaine.org
Thu Nov 22 12:21:08 CET 2007

Remi Denis-Courmont wrote:
>> Is it possible to determine support for scale value from RTSP response
>> on OPTIONS? Or can we assume scale support is always possible?
> In principle, Scale must be understoood, though the server is free to use
> another value or return an error, if it does not like the specified value.
 From my reading of the RFC2326 document, there is no way to know if the 
server supports the Scale feature as it's an optional feature in the RFC 
spec. Ross might be able to comment on if I'm mistaken here.

However, as you said, the server will either be free to use another 
value that it deems sensible or return an error.

If it's possible, the interface layer (in the context of my patch rc.c) 
could query the demux and if it responds to the 
DEMUX_HAS_SCALE_TRICKPLAY control appropriately then we can assume 
trickplay functionality.
I would then suggest removing the --rtsp-scaled-trickplay preference. 
The server will proceed with fastforward or it'll just play at the 
existing scale in the cases I've testing (live555MediaServer and 
Kasenna) or it'll return an error on the Play request. I've tested this 
with live555MediaServer by removing the movies index file and it simple 
keeps playing at Scale 1.0 no matter what I ask.

How does that suit ?

Glen Gray (slaine at slaine.org)

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