Re: [LAD] AVB not so dead after all

Oh and of course you have the Open-AVB project first started by Intel.

Looks like folks are talking about getting it running on a BeagleBone or
iMX6 based board:
http://sourceforge.net/p/open-avb/mailman/message/33026258/

On Sun, Jun 7, 2015 at 12:08 PM, Jesse Cobra <jessecobra@email-addr-hidden> wrote:

> Just a few notes, not sure if this is of any use:
>
> Motu and Presonus are now shipping some semi-affordable AVB audio devices
> and switches. The Motu switch is $295.
>
> All shipping Apple hardware supports AVB, via the BroadCom NIC they are
> using. You could of course install Linux on said hardware.
>
> Any computer using the same BroadCom chipset can also support AVB. For
> Windows Echo Audio was making an AVB to ASIO application for this. Again
> you could install Linux on any of these computers.
>
> The NIC that the FreeScale iMX6 and Texas Instruments AM335x (of which the
> BeagleBone is based) can support AVB. Some audio companies are shipping
> closed AVB products based on the AM335x and iMX6 that use Linux.
>
> I know of one developer who was thinking of making his AVB stack for Linux
> on AM335x BeagleBone open source but currently it remains a closed solution.
>
> Then of course you have the XMOS reference design but that has nothing to
> do with Linux.
>
> I think the cost to do this is becoming a non-issue, with a $200 switch
> and a BeagleBone based audio interface it should be possible to make a
> cheap AVB solution on Linux.
>
> Just my 2 cents...
>
>
> On Sun, Jun 7, 2015 at 7:15 AM, Len Ovens <len@email-addr-hidden> wrote:
>
>> On Sat, 6 Jun 2015, Reuben Martin wrote:
>>
>> I thought I would post this since there was a big conversation here a
>>> while back about AES67 and the slow death of AVB due to lack of support.
>>>
>>> Well I was talking with a guy from Meyer Sound who told me that AVB has
>>> been resurrected from the dead. Apparently Cisco and other large network
>>> hardware vendors were willing to back it as long as it was made more
>>> generic to accommodate industrial uses that are also time-sensitive.
>>>
>>> So apparently it has been re-branded as “Time-Sensitive Networking” and
>>> has a lot more momentum behind it.
>>>
>>> http://en.wikipedia.org/wiki/Time-Sensitive_Networking
>>>
>>> http://www.commercialintegrator.com/article/rebranding_avb_4_key_takeaways_from_time_sensitive_networks_conference
>>>
>>
>> Interesting.
>>
>> Some notes on AoIP and Linux. There are some well funded people/companies
>> that use Linux for many things, but much of the development in the audio
>> world is with people who have hardware that they can't afford to replace
>> and so write drivers for. I think this is part of the reason we are not
>> seeing much in the way of Linux drivers for AoIP (AVB, AES67, Ravena,
>> whatever). Right now, AoIP on Linux costs about twice as much as a normal
>> audio card because the Linux box requires both an interface card in the
>> computer as well as the Audio IF on the other end of the network cable (not
>> to mention a switch in the middle).
>>
>> 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.
>>
>> I was "listening in" on a IRC conversation about the differences between
>> ALSA and Core audio and why Core audio "does it right". The difference ends
>> up being this HW clock. That is ALSA is build the way it is because the PC
>> requires it to be.
>>
>> Whats the point of all this? TSN sounds good to me. It widens the scope
>> of low latency networking and the requirement of distributed clocking into
>> areas where cost matters. I am hopeful that this means the cost of a NIC
>> with good HW clock will go down or even become standard. All kinds of AoIP
>> would see the benefit from this. I also think the cost of AoIP audio
>> interfaces would come down to similar cost as USB or firewire.
>>
>> There is no reason we could not make an ALSA AES67 driver that would work
>> with any GB-NIC out there but the closed drivers now available show that on
>> a PC latency is double that of Core audio and handles fewer channels.
>> (Core audio at 192K = 64 channels in and out min latency 32 samples, Win
>> at 192k = 16 channels in and out min 64 samples) So any ALSA driver would
>> suffer from similar lower performance. This is why almost all AoIP setups
>> suggest their PCI(e) card in place of your stock NIC.
>>
>> * numbers from:
>> http://www.merging.com/products/networked-audio/for-3rd-party-daw
>> I have seen similar numbers (or worse) elsewhere.
>>
>> * I am not in any way suggesting anyone use 192k sample rate for audio
>> recording or streams. It's use here is only to show the difference in HW
>> capabilities. 48k is what I use and suggest others use.
>>
>> --
>> Len Ovens
>> www.ovenwerks.net
>>
>> _______________________________________________
>> Linux-audio-dev mailing list
>> Linux-audio-dev@email-addr-hidden
>> http://lists.linuxaudio.org/listinfo/linux-audio-dev
>>
>>
>

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Received on Mon Jun 8 00:15:01 2015