[LAU] SPDIF plus NetJack for digital audio transfer between computers.

[Len Ovens]

On Thu, 26 Feb 2015, Brendan Furneaux wrote:

> For starters, NetJack(1|2) does not seem to be designed for the use case where
> the sound cards on two networked computers are actually synced in hardware; thus

The -net backend for jack effectively says that the remote computer is my 
audio device. The known ways around this is with alsa-in or zita-a2j which 
adjust the sample rate as well. There has been talk of making zita-a2j 
able to not resample, but I do not know if that has happened. The zita 
solution has much lower CPU use than alsa-in and better quality too. 
However, if you are using anything that resamples, I would suggest using 
the normal backend on both machines and running zita-j2n/zita-n2j instead 
as it builds easily and runs well on ubuntu.

> netadapter receive MIDI? Is there some other software that would be better?

qmidinet comes with UbuntuStudio and there is windows equivalent 
available.

> I currently have Jack 1.9.10 installed on both computers, and they work fine
> individually.  They are configured with static IPs on the crossover cable, and
> are at least able to ping each other.  However, I have not been able to get
> NetJack2 to connect using either computer as the master.

There are some CLI commands jack_net_master jack_net_slave 
jack_netsource... I have not gotten any of those to work.

Run jackdbus (the default on Studio) either from qjackctl or using 
jack_control from a terminal and then run jack_load netmanager on one 
machine and start the other jackd/jackdbus with the -net backend. Midi 
lines can be set up.

As an aside, why would you not just run audio via spidif? or are there 
more than two channels to deal with?


--
Len Ovens
www.ovenwerks.net