[FFADO-devel] Port naming

[Arnold K. <ar...@ar...>]

Hi all,

I tried to discuss this with pieter today, but time was short on my side.

I am unsatisfied with the way the ports visible in jack are named(*).
I have the following setup: A firepod as the main device that is also connected 
to the speakers and a saffire for development of the dice things. Sometimes both 
devices are used, sometimes only the firepod.

The problem is that the firepod alone is of course device 0, when the saffire is 
connected and used too, the firepod becomes device 1.
As I don't want to redo all the connections every time, jconvolver (used for 
the digital room correction) is told to connect to system:playback[12], could 
also be "firewire_pcm:P[01]_dev0_Output [12][LR]", that is the first two outputs 
when only the firepod is there.
But as the port names aren't device dependant, when I use both devices, the 
auto-connection from above connects to the wrong device.

I think there are two possible solutions for that:

1) Provide a way to specify the order ffado should use for the devices. This 
most probably means dealing with GUID on the command-line without a simple way 
(apart from the debug-output which should be deactivated by distributions) to 
get this number. And as far as my tests go, the -dgui:0x... option of the 
firewire backend allows which device to use, the syntax to specify multiple 
devices and their order seems to be not existing or _very_ obscure.

2) Include the GUID in the port name. This makes port names rather long. But 
it is a very good way of making them unique. People using graphical tools will 
not care about the length of the name, people using text-only know ways of 
copy'n'paste on the commandline. And in jack1 there is still the alias of 
system:playback_*...

In case you haven't guessed it, I prefer #2.
The order in which the devices are found on the bus should not matter at all, 
which makes any manual ordering superfluous.
The nickname could also be used for this, but nickname-changing doesn't work 
that well with all the devices. My firepod doesn't allow a change and the saffire 
forgets these changes when powered down. And by default both include part of 
the GUID to make them unique. So using the GUID is easier...

What do you think?

Have fun,

Arnold

(*) Doesn't matter whether its jack1 or jack2, the names in jack2 are 
available as aliases in jack1 too.

BTW: Why are the system:-aliases not available in jack2 anymore? They are so 
much easier when it comes to running an ardour session on different 
soundcards...