[LAD] AVB not so dead after all

Fernando Lopez-Lezcano nando at ccrma.Stanford.EDU
Tue Jun 9 02:14:23 UTC 2015


On 06/07/2015 07:15 AM, Len Ovens wrote:
...
> Why is this? Linux is based on lowest common denominator hardware... we
> call it the PC. The Linux world has gotten much better preformance out
> of this box than it was designed for. But, in the case of audio, the HW
> does limit performance at least with AoIP. That limit is the clock. The
> PC does not have a HW PTP clock built in and in this case software is
> not good enough. The way around this is with a custom NIC that does. For
> some reason even though one can buy an ethernet chip that includes a
> stable PTP clock for less than $5, any NICs I have found with a PTP
> clock are closer to $1k.

An Intel I210 Gigabit Ethernet PCI express Card will set you back about 
$70 on Newegg, it does have the hardware support that AVB needs and a 
driver in the OpenAVB project. I have a couple and they seem to work 
just fine. A 24 output AVB Motu box is $995.

I'm actually trying to get this going with one of these AO24 Motu 
"soundcards" (starting with OpenAVB). I have gotten as far as the 
OpenAVB stack talking to the Motu card and slaving its clock to it (and 
the Motu box recognizing it is now the master clock source and AVB is 
active). Audio streaming is next, I'm just not finding the free time to 
do this (anyone gotten further along on this??).

First goal would be a simple jack client that can stream samples, end 
game would be a jack backend so this can be treated as a soundcard. 
We'll see...

-- Fernando



More information about the Linux-audio-dev mailing list