Very good on the AVB clocking. I can't get the IEEE pubs legally, since I have not been an IEEE member, or employed by a company large enough to be an IEEE member, since the 1990's.
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.
Ethan...
On Wed, June 19, 2019 3:12 pm, Ethan Funk wrote:
I was under the impression...that the AVB's
precision network time management allows all devices to share a sample
clock.
That is correct for AVB as well as for the other RTP/IP (layer 3) based
transports such as Dante, Livewire, Ravenna, etc.
No asynchronous re-sampling would be required
Correct
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.