Initial Props value are parsed from device settings, further changes are triggered by 'set_param' on a2dp node.
Codec can then use props to tweak its transcoder.
We would like to have BT device codec capability checks beyond what's
possible based on A2DP caps.
Split SBC-XQ to a separate codec, and enable it in the device-dependent
check (although currently it just uses the config option).
Some codecs need the MTU as a parameter so wait until we acquire
with creating the codec context.
Make some method to enumerate the parameters from the transport
config and use that for the EnumFormat param.
Make the list of supported codecs available.
Register all supported codecs endpoints
Find the codec from the endpoint name
Put the codec on the transport for the sink to find.
Actually compile the codec config and declare the config as extern
or else it's just all 0.
Only acquire the transport when ACTIVE.
Implement transport state_change signal and acquire the transport
when going to pending/active.
Try to acquire the transport before we expose the device if we
can.
Force device expose when we get the device ServicesResolved=1 property
update.
Free transport when the rfcomm is closed.
Implement various DBus signals to detect dynamic property updates.
