Re: [GnomeMeeting-list] whats happening inside jitter buffer?

[Damien Sandras <damien sandras it-optics com>]

Le mar 18/11/2003 à 19:06, nauman ahmed a écrit :
> hi Damien,
> sorry for bothering u again n again . 

No problem :)

> i just wanted to know two thing  u said that in gnomemeetign
> the jitter buffer  is adaptive , then wat is the purpose of
> setting the size of  jitter buffer (in msec) in the preferences tab.

If you are not using a too old gnomemeeting version, you should be able
to set the maximum jitter buffer size. It will be adapted following some
network conditions (packets loss, packets out of order, too late) but
will never be larger than the maximum specified size.

> We are actually trying to assess the speech quality by changing the
> delay in the networ and trying to study the effect of changing the
> jitter buffer size at the receiving side .....
>  
> Seconldly wat i want to know in my previous mail was wat  happens when
> the jitter buffer empties, ie there are no more packets in the jitter
> buffer to process , does it wait for the amount of time specified in
> the jitter buffer setting ...

No, it waits the amount of time displayed in the statistics panel (as it
is adaptative), the prefs present the max. size, ie the current size is
maximum the max. size, but that could be less too.

> i now hope u understand my point ....in my university no one has ever
> done such projects ...i will be very grateful to u if u can help me
> out ....i hva only two day left for my final presentation .....thanks
> inadvance
> nauman 
> 
> Damien Sandras <damien sandras it-optics com> wrote:
>         Le dim 16/11/2003 18:04, nauman ahmed a crit :
>         > i am doing some serious project which includes gnomemeeting
>         as a
>         > tool.i am a
>         > bit confused about the
>         > working of jitter buffer.i have two alternative concepts
>         about jitter
>         > buffer
>         > here i refer to jitter buffer which is" not adaptive" i.e it
>         size can
>         > be changed 
>         > manually. ihave the following two concepts
>         > 
>         
>         The one in gnomemeeting is adaptative.
>         
>         > 1-jitter buffer size(in bytes)is " fixed".Suppose it is 3
>         times the
>         > payload size .suppose it is set to 100ms at the start
>         > the codec waits for 100ms and then start processing the
>         packets during
>         > that any packet
>         > whose sequence no lies within first 3 sequnce nos arrives
>         then
>         > 
>         > 1-it is admitted if it arrives before playout time is
>         admitted to the
>         > buffer.after finishing
>         > the buffer the codec again waits for 100ms and the above
>         process is
>         > repeated
>         > again
>         > 
>         > 2- it is not admitted to the buffer and simply
>         discarded..after
>         > finishing 
>         > the buffer the codec again waits for 100ms and the above
>         process is
>         > repeated
>         > again
>         > in both cases any packet whose sequence no
>         > doesnot lie
>         > in the jitter buffer(the packet has arrived much earlier
>         tahn its
>         > playout time)
>         > is buffered in a seperate memory space
>         > 
>         > which of the two is correct? or
>         > both are wrong .please
>         > help me.
>         
>         I'm not sure I understand you correctly. However, 1) seems
>         correct from
>         what I understand. If you need more information, you can look
>         at the
>         jitter.cxx file in openh323. It has recently been improved.
>         
>         
>         > 
>         > 
>         > nauman
>         > 
>         > 
>         > 
>         >
>         ______________________________________________________________________
>         > Do you Yahoo!?
>         > Protect your identity with Yahoo! Mail AddressGuard
>         -- 
>         _ Damien Sandras
>         (o- 
>         //\ It-Optics s.a.
>         v_/_ GnomeMeeting: http://www.gnomemeeting.org/
>         FOSDEM 2004: http://www.fosdem.org
>         H.323 phone: callto:ils.seconix.com/dsandras seconix com
>         
>         _______________________________________________
>         GnomeMeeting-list mailing list
>         GnomeMeeting-list gnome org
>         http://mail.gnome.org/mailman/listinfo/gnomemeeting-list
> 
> 
> ______________________________________________________________________
> Do you Yahoo!?
> Protect your identity with Yahoo! Mail AddressGuard
-- 
 _      Damien Sandras
(o-     
//\     It-Optics s.a.
v_/_    GnomeMeeting: http://www.gnomemeeting.org/
        FOSDEM 2004:  http://www.fosdem.org
        H.323 phone:  callto:ils.seconix.com/dsandras seconix com