The current server side channel handling of AUDIO_INPUT is currently
very constrained:
- Server implementations cannot measure the clients uplink, since the
Incoming Data PDU is currently unhandled and FreeRDPs DSP handling
delays the callback call of ReceiveSamples
- Servers currently cannot prefer a different protocol version
- Servers currently cannot change the used format
To solve these issues without running into the risk that some
simplifications constraint certain API usage, rework the current channel
handling to be very close to the documentation.
This means, that all documented API calls can be made by server
implementations and all documented PDUs, that the server side is
expected to receive are just parsed inside FreeRDP and then forwarded to
the API implementation.