24 Jun
2019
24 Jun
'19
6:46 a.m.
Actually,
As a side question regarding Jack2 and midi: I would
like to use jack's
midi mechanism to pass control information between components in my
automation system. So far I have been able to twist existing midi
packets suck as time-code, and such to control player components and
keep my mixer appraised as to source play positions and such. However, I
have no easy way to pass meta data, such as song tags, through midi,
with out the complexity of using sysex messages and base64 encoding the
8 bit meta-data fto be passed as midi data. Can I ignore midi's
underlying byte format and just pass 8 bit buffers to jack and expect
jack to deliver the buffers with out jack inspecting the buffers for
validity according to midi? I only intend to use the midi ports within
my applications various player and encoder components. I do not expect
any of this data to actually be send to a device or program that is
expecting real midi data.
in the AVB realm, you would use AVDECC AEM for such a purpose instead
of abusing MIDI for it. ;-)
I did not look at JACKs meta data API, but I suppose it could be
integrated with AEM very nicely...
>
>> I am not clear how one goes about setting up which
>> device on the network is the clock master
>
> If you have access to IEEE specs see IEEE 1588-2008 and IEEE 802.1AS.
> 802.1AS is a profile of 1588-2008, there is what is known as "best master
> clock algorithm" to select the best clock. If multiple devices are
> advertising equivalent quality ranking there is a tie breaker, I think
> based on MAC address, but don't quote that, I am going from memory and
> have not looked at the details in quite a while.
As mentioned BMCA takescare of it. It is a nice feature to be able to
choose the GM, but it practically makes no sense.
What is the need for a specific GM if you AVB switch is down?
Thus, one of the AVB switches involved should be the GM. The "core-most"
switch in particular.
Or can someone think of a scenario, where this does not make sense?
Best,
Ck