AVB_MRP_SEND_NEW was defined as 0, making it indistinguishable from
"no pending send" in the MSRP and MVRP event handlers which check
`if (!pending_send)`. This meant that when an attribute was first
declared (applicant state VN or AN), the NEW message was silently
dropped instead of being transmitted on the network.
Fix by shifting all AVB_MRP_SEND_* values to start at 1, so that 0
unambiguously means "no send pending". Update the MSRP and MVRP
encoders to subtract 1 when encoding to the IEEE 802.1Q wire format
(which uses 0-based event values).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add in input/output stream, setup the talker/listeners.
Implement IEC61883 audio packets, send and receive data.
Implement talker encoding.
With this, audio can be sent and received from MOTU M64.
