Subject: RE: RTSP: relative time

From: Eric Fleischman <[email-masked]>
Date: Thu, 6 Mar 1997 13:56:13 -0800

>Does "TimeOffset=seconds:microseconds" in the Range header seem
>appropriate ? I think it is granular enough and (can't help thinking
>this way :-) it maps easily to struct timeval.
>An example would be:
>PLAY foo/bar RTSP/1.0
>Range: TimeOffset=3:3452-5:8765

Does this example mean to play beginning at 3.3452 on the session timeline 
and going to 5.8765 on the session timeline? If so, then I believe that we 
are "in synch" and "in agreement" as to how to indicate time.

Naturally, I think that our state machine would be simpler if we would not 
support a range value but rather specify "play" at an offset and range and 
then let the user "pause" whenever (s)he feels like it.

A "tough call" for this WG to make is regarding how complex we are willing 
to make the state machine in order to support so many header field 
alternatives within a method. As you can tell, my own preference is to make 
the state machine be as simple as possible. I believe that this is not so 
much a matter of permitting server x to support something that server y can 
not but rather has to do with the very integrity of the underlying protocol 
itself. The more complex the state machine becomes, the greater the danger 
of getting into an undefined state. I view an "undefined state" as the true 
enemy of any protocol maker.

---

From: Anup Rao <[email-masked]>
Date: Thu, 06 Mar 1997 14:33:01 -0800

> are "in synch" and "in agreement" as to how to indicate time.

Yes. The session timeline is associated with the media itself or in
DSM-CC terms is the Normal Play Time(NPT). (i.e in FF mode, it would
increment faster)

Regards
-- 
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  Anup Rao                                                      
  Netscape Communications Corp.                   
  email : [email-masked]         Phone : (415) 937 3129       
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