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Re: [Linphone-users] typical delay (latency) time ?
From: |
Marc-Olivier Bernard |
Subject: |
Re: [Linphone-users] typical delay (latency) time ? |
Date: |
Tue, 27 Aug 2002 18:42:58 +0200 (CEST) |
Hi,
Thanks, I will try as linphone-0.9.x as soon as i can find a redhat rpm
package.
By the way, is the download page
(http://www.linphone.org/?lang=fr&rubrique=5) beeing updated ? They are
some null dates (01/01/1970) and some O kb packages.
Of course, i put the jitter time to the lowest, without audible lost.
Marc-Olivier
On 25 Aug 2002, Simon Morlat wrote:
> Hi,
>
> You don't have to choose the alsa mode in linphone. Alsa drivers are
> fully compatible with oss ones. The alsa mode of linphone makes linphone
> using the alsa drivers through their native user level library
> (alsa-lib). However it is deprecated since it only works with
> alsa-lib-0.5.x.
> Try linphone-0.9.0pre4, the sound selection combo box has desapeared (no
> more confusion possible), and some work has been done to improve
> latency.
> Don't forget that you can reduce latency by reducing the jitter
> compensation parameter in the rtp section of the property box.
>
> Simon
>
> Le lun 12/08/2002 à 18:24, Marc-Olivier Bernard a écrit :
> >
> > Thanks for your helpfull comments.
> >
> > We change the drivers to alsa, and the size of the exchanged blocks was
> > shorted from 2048 to 512, and the delay is quite acceptable now.
> >
> > But i still got some errors message, when launching linphone :
> >
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > address@hidden mob]$ linphone &
> > [1] 2241
> > address@hidden mob]$ L3 -1029168427- <osipua.c: 59> info: Starting osip
> > stack
> > and osipua layer.
> > L4 -1029168427- <udp.c: 75> info: Entering osipua thread.
> > You cannot use alsa drivers: recompile linphone with installed alsa
> > drivers and library for that, or use oss.Found 3 interfaces.
> > Found ppp0 interface with ip address 212.11.36.114
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > and when selecting alsa driver in connection > parameter > sound
> > I can read the following message on the terminal :
> >
> >
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ERROR: Linphone was not compiled with alsa support. Recompile it or use
> > OSS.
> > Sound source selection changed to m.
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ps : I'm using linphone-0.8.0-1
> >
> > Marc-Olivier BERNARD
> >
> > On 4 Aug 2002, Simon Morlat wrote:
> >
> > > Hi,
> > >
> > > Usually most part of the delay comes from the sound driver/card. Good
> > > drivers/cards have low latency, this means that blocks of data exchanged
> > > with the application can be short (256 or 512 bytes). Bad drivers/card
> > > can only exchange data with a size of 8192 bytes (0.5 sec) or sometimes
> > > 16384 bytes (1 sec) for some old isa cards.
> > > Alsa drivers usually have a better latency, that 's why I recommend
> > > them.
> > > Here is a formula that should give the delay for one direction:
> > > delay=MAX(local_driver_latency,codec_latency)+jitt_comp+
> > > (ping_delay/2)+MAX(remote_driver_latency,codec_latency)
> > > You can see the driver latency on the terminal when linphone is running:
> > > you should see a message "blocksize=8192" or something like this. The
> > > value is given in number of byte, just divide by 16000 to get it in
> > > seconds.
> > >
> > > So there two things to try for you to improve this delay:
> > > -alsa drivers (but don't change anything in linphone's configuration,
> > > and don't recompile it)
> > > -set jitter compensation to the minimum on both (perhaps you are
> > > already)
> > >
> > > With two PC's connected by ethernet cards (ping=1ms), and alsa drivers
> > > (ens1374, cs41xx), jitt_comp=60ms I have a one way delay of approx 1/4
> > > seconds. This is very acceptable. With adsl connections, the ping time
> > > is about 80ms, however this is still very acceptable (not very different
> > > of a cellular phone call).
> > >
> > > Salutations,
> > > Simon
> > >
> > > Le dim 04/08/2002 à 19:02, Marc-Olivier BERNARD a écrit :
> > > > Hi there,
> > > >
> > > > I encounter important delay by using VoIP/liphone, about 1s and don't
> > > > understand why.
> > > >
> > > > I'm using linphone between 2 computer (see below for system infos) both
> > > >
> > > > connected to internet with (A)DSL, with
> > > >
> > > > * ping average time is 120 ms.
> > > > * sound traitement at both ends are quite quick (I did not try with an
> > > > ALSA
> > > > driver)
> > > > * both machines are directly connected to internet
> > > > * no delay due to firewall (i tried without firewall)
> > > > * codecs G711
> > > > * jitter compensation of 60 ms
> > > > * no proxy
> > > >
> > > > and the delay is around 1s. I don't understand the origin of such a
> > > > delay ?
> > > >
> > > > What kind of delay do you have ? and do you have any idea how to get it
> > > > better
> > > > (install ALSA driver for ex.) ?
> > > >
> > > > system infos :
> > > > ~~~~~~~~~~~~~~
> > > > linphone-0.8.0-1
> > > > redhat 7.3
> > > > OSS driver
> > > > SoundBlaster 5.1 live (full duplex)
> > > >
> > > > --
> > > > Marc-Olivier BERNARD
> > > >
> > > > _______________________________________________
> > > > Linphone-users mailing list
> > > > address@hidden
> > > > http://mail.freesoftware.fsf.org/mailman/listinfo/linphone-users
> > > >
> > >
> > >
> > >
> > >
> >
> > --
> > Marc-Olivier BERNARD
> > address@hidden
> >
> >
> >
> >
> >
> >
> >
>
>
>
--
Marc-Olivier BERNARD
address@hidden