Question on a2j client:port format

[ahlstromcj]

I noticed some puzzling issues with the New Session Manager and jackpatch when a2jmidid is running. After a bunch of hacking, I concluded that jackpatch doesn't parse a2j-created port names properly using sscanf().

Here's 2 sample patch lines from a .jackpatch file:

a2j:Launchpad Mini (capture): Launchpad Mini MIDI 1 |> fluidsynth-midi:midi_00
a2j:Launchpad Mini (capture): Launchpad Mini MIDI 1 |> seq66:a2j:Launchpad Mini (capture): Launchpad Mini MIDI 1

Note the second colon in the a2j client:port name. Not an issue. But after the second colon, just before the port portion, there is a space.

Is that space part of the port name? And is it needed to properly access the port?

Note the more conventional naming of the fluidsynth port.

Any documentation about the format? Or can you point me to where the client:port name in constructed?

Thanks!

[romsom]

Here's the call to snprintf():

a2jmidid/port.c

Lines 114 to 135 in 5b8f5d9

	if (make_unique)
	{
	ret = snprintf(
	port_ptr->name,
	g_max_jack_port_name_size,
	"%s [%d] (%s): [%d] %s",
	snd_seq_client_info_get_name(client_info_ptr),
	snd_seq_client_info_get_client(client_info_ptr),
	type == A2J_PORT_CAPTURE ? "capture": "playback",
	snd_seq_port_info_get_port(port_info_ptr),
	snd_seq_port_info_get_name(port_info_ptr));
	}
	else
	{
	ret = snprintf(
	port_ptr->name,
	g_max_jack_port_name_size,
	"%s (%s): %s",
	snd_seq_client_info_get_name(client_info_ptr),
	type == A2J_PORT_CAPTURE ? "capture": "playback",
	snd_seq_port_info_get_name(port_info_ptr));
	}

I think the inconsistency comes from the fact that both programs (a2jmidid and NSM) use the colon to concatenate client and port names, but differently. As you can see above a2jmidid adds a space after the (ALSA) client name.

[ahlstromcj]

Thanks, just what I needed! My grep fu was failing me.

[romsom]

Please note that depending on the version of a2jmidid there are two distinct variants of the make_unique case.
This is the one I changed in a PR about 5 years ago back when the original author of a2jmidid was inactive. The reason was that long client names get truncated. With the port id being the last element of the name that causes problems with clients (e.g., hardware devices) with multiple ports.
The original author since seems to have come back to maintain the project but rejected the PR because it would break existing pattern matching.
I have an idea how to address this and hopefully will find the time to implement it in the near (less than 5 years :P) future.