2 Aug
2008
2 Aug
'08
9:01 a.m.
Florian Faber wrote:
Peter,
My formulation is a bit unfortunate. I mean that ethernet does NOT have
a global absolute time reference. And word clock is not a time
reference. It's a 'rate' reference, which does not contain absolute time
information. What you need to output signals on different devices with
sample accurate phase is an absolute time reference. Which ethernet does
not have.
Greets,
Pieter
I doubt that it is easy over a transport protocol
that doesn't have a
global absolute time reference (like ethernet).
What time reference do you have in mind on ethernet that can be used as
word clock source? 
2 Aug
2 Aug
9:24 a.m.
New subject: embedded high end audio
On Sat, Aug 02, 2008 at 01:01:12PM +0200, Pieter Palmers wrote:
Florian Faber wrote:
The solution I'm using in this case is to distribute
a single audio signal (similar to the one used in jdelay)
to all computers. The signal can be decoded into a sub-
sample accurate time, and all network data are timestamped
using this time scale.
Ciao,
--
FA
Laboratorio di Acustica ed Elettroacustica
Parma, Italia
O tu, che porte, correndo si ?
E guerra e morte !
Peter,
My formulation is a bit unfortunate. I mean that ethernet does NOT have
a global absolute time reference. And word clock is not a time
reference. It's a 'rate' reference, which does not contain absolute time
information. What you need to output signals on different devices with
sample accurate phase is an absolute time reference. Which ethernet does
not have. I doubt that it is easy over a transport protocol
that doesn't have a
global absolute time reference (like ethernet).
What time reference do you have in mind on ethernet that can be used as
word clock source?
9:47 a.m.
New subject: embedded high end audio
Fons Adriaensen wrote:
On Sat, Aug 02, 2008 at 01:01:12PM +0200, Pieter
Palmers wrote:
Now that is a clever solution! Simple and elegant...
Greets,
Pieter
Florian Faber wrote:
The solution I'm using in this case is to distribute
a single audio signal (similar to the one used in jdelay)
to all computers. The signal can be decoded into a sub-
sample accurate time, and all network data are timestamped
using this time scale. Peter,
My formulation is a bit unfortunate. I mean that ethernet does
NOT have
a global absolute time reference. And word clock is not a time
reference. It's a 'rate' reference, which does not contain absolute time
information. What you need to output signals on different devices with
sample accurate phase is an absolute time reference. Which ethernet does
not have. I doubt that it is easy over a transport protocol
that doesn't have a
global absolute time reference (like ethernet).
What time reference do you have in
mind on ethernet that can be used as
word clock source? 
2:45 p.m.
New subject: embedded high end audio
On Sat, 2008-08-02 at 13:47 +0200, Pieter Palmers wrote:
Fons Adriaensen wrote:
and the basis of Steinberg's VSTLink, btw ....
except that they did it by stealing a couple of bits from the sample
bitstream, and distributing the signal.
On Sat, Aug 02, 2008 at 01:01:12PM +0200, Pieter
Palmers wrote:
Now that is a clever solution! Simple and elegant... Florian Faber wrote:
The solution I'm using in this case is to distribute
a single audio signal (similar to the one used in jdelay)
to all computers. The signal can be decoded into a sub-
sample accurate time, and all network data are timestamped
using this time scale. Peter,
> I doubt that it is easy over a transport protocol that doesn't have a
> global absolute time reference (like ethernet).
What time reference do you have in mind on ethernet that can be used as
word clock source?
My formulation is a bit unfortunate. I mean that ethernet does
NOT have
a global absolute time reference. And word clock is not a time
reference. It's a 'rate' reference, which does not contain absolute time
information. What you need to output signals on different devices with
sample accurate phase is an absolute time reference. Which ethernet does
not have. 
7:32 p.m.
New subject: embedded high end audio
On ds, 2008-08-02 at 13:07 +0200, Fons Adriaensen wrote:
On Sat, Aug 02, 2008 at 01:01:12PM +0200, Pieter
Palmers wrote:
Very interesting project indeed.
Up to how many channels the (gigabit) ethernet would be able to scale?
Could the synch audio signal be "linked" from one station to the next,
or should they all receive from a central server? The first would enable
many stations without needing a huge central multichannel device.
Pau
Florian Faber wrote:
The solution I'm using in this case is to distribute
a single audio signal (similar to the one used in jdelay)
to all computers. The signal can be decoded into a sub-
sample accurate time, and all network data are timestamped
using this time scale. Peter,
My formulation is a bit unfortunate. I mean that ethernet does NOT have
a global absolute time reference. And word clock is not a time
reference. It's a 'rate' reference, which does not contain absolute time
information. What you need to output signals on different devices with
sample accurate phase is an absolute time reference. Which ethernet does
not have. I doubt that it is easy over a transport protocol
that doesn't have a
global absolute time reference (like ethernet).
What time reference do you have in mind on ethernet that can be used as
word clock source?
7:36 p.m.
New subject: embedded high end audio
On ds, 2008-08-02 at 23:32 +0200, Pau Arumí wrote:
On ds, 2008-08-02 at 13:07 +0200, Fons Adriaensen
wrote:
Yup, ignore the last question -- the synch signal is the same for all
stations so one output split to many inputs is enough. Easy. :-)
On Sat, Aug 02, 2008 at 01:01:12PM +0200, Pieter
Palmers wrote:
Very interesting project indeed.
Up to how many channels the (gigabit) ethernet would be able to scale?
Could the synch audio signal be "linked" from one station to the next,
or should they all receive from a central server? The first would enable
many stations without needing a huge central multichannel device. Florian Faber wrote:
The solution I'm using in this case is to distribute
a single audio signal (similar to the one used in jdelay)
to all computers. The signal can be decoded into a sub-
sample accurate time, and all network data are timestamped
using this time scale. Peter,
> I doubt that it is easy over a transport protocol that doesn't have a
> global absolute time reference (like ethernet).
What time reference do you have in mind on ethernet that can be used as
word clock source?
My formulation is a bit unfortunate. I mean that ethernet does NOT have
a global absolute time reference. And word clock is not a time
reference. It's a 'rate' reference, which does not contain absolute time
information. What you need to output signals on different devices with
sample accurate phase is an absolute time reference. Which ethernet does
not have.
5752
days inactive
5752
days old
linux-audio-dev@lists.linuxaudio.org
5 comments
4 participants
participants (4)
-
Fons Adriaensen -
Pau Arumí -
Paul Davis -
Pieter Palmers