9 Apr
2018
9 Apr
'18
5:22 p.m.
I've been trying to get DOS midi applications to talk to hardware in
dosemu, and since I normally use native Alsa for everything, I'm not
that familiar with midi through the OSS emulation.
My USB midi interface has three subdevices (in/out pairs) which show up
in Alsa separately, but I have only one /dev/midi3 (the one that maps to
my device), and one /dev/snd/midiC3D0. Is there a way to access
individual subdevices through the OSS emulation?
--
- Brent Busby + ===============================================
+ "The introduction of a new kind of music must
-- Studio -- + be shunned as imperiling the whole state, for
-- Amadeus/ -- + styles of music are never disturbed without
-- Keycorner -- + without affecting the most important political
-- Recording -- + institutions." --Plato, "Republic"
----------------+ ===============================================
9 Apr
9 Apr
7:55 p.m.
And not wanting to reply to my own post...but this whole subject has
brought up the question of what all these midi device nodes are anyway.
For certain ones, there doesn't seem to be a lot of documentation online
that I've been able to find.
On my system, I have:
--8<---------------cut here---------------start------------->8---
brent@village:~/.dosemu/run$ aconnect -o -l
client 14: 'Midi Through' [type=kernel]
0 'Midi Through Port-0'
client 20: 'Hammerfall DSP' [type=kernel,card=1]
0 'HDSP MIDI 1 '
client 28: 'UM-3' [type=kernel,card=3]
0 'UM-3 MIDI 1 '
1 'UM-3 MIDI 2 '
2 'UM-3 MIDI 3 '
client 32: 'Virtual Raw MIDI 4-0' [type=kernel,card=4]
0 'VirMIDI 4-0 '
client 33: 'Virtual Raw MIDI 4-1' [type=kernel,card=4]
0 'VirMIDI 4-1 '
client 34: 'Virtual Raw MIDI 4-2' [type=kernel,card=4]
0 'VirMIDI 4-2 '
client 35: 'Virtual Raw MIDI 4-3' [type=kernel,card=4]
0 'VirMIDI 4-3 '
brent@village:~/.dosemu/run$ find /dev -name "*midi*"
/dev/dmmidi3
/dev/midi3
/dev/admmidi4
/dev/amidi4
/dev/dmmidi4
/dev/midi4
/dev/dmmidi1
/dev/midi1
/dev/snd/midiC3D0
/dev/snd/by-path/platform-snd_virmidi.0
/dev/snd/midiC4D3
/dev/snd/midiC4D2
/dev/snd/midiC4D1
/dev/snd/midiC4D0
/dev/snd/midiC1D0
--8<---------------cut here---------------end--------------->8---
ALSA is putting its prefered devices under /dev/snd/, but only the
virtual devices are showing up there all four times.
But the others...hmm... What is the difference between midi, dmmidi,
amidi, and admmidi?
I think I might be able to route a connection with ALSA MIDI from the
subdevice of the USB interface I want to one of the virtual ports, and
then just use that virtual port's dev node, but even if that solution
works, the curious cat in me still wants to know what all these nodes
are for just to know, and also whether it's possible to directly expose
subdevices of hardware with multiple i/o's to the OSS emulation so the
subdevices show up in /dev.
--
- Brent Busby + ===============================================
+ "The introduction of a new kind of music must
-- Studio -- + be shunned as imperiling the whole state, for
-- Amadeus/ -- + styles of music are never disturbed without
-- Keycorner -- + without affecting the most important political
-- Recording -- + institutions." --Plato, "Republic"
----------------+ ===============================================
8:49 p.m.
Brent Busby wrote:
Is there a way to access individual subdevices through
the OSS emulation?
Short answer: no.
Long answer: opening a device will open the first available subdevice.
What is the difference between midi, dmmidi, amidi,
and admmidi?
/dev/midiX and /dev/dmmidiX are the same.
/dev/amidiX and /dev/admmidiX are the same.
/dev/midiX is MIDI device 0 of card X.
/dev/amidiX is MIDI device 1 of card X.
You can change the OSS device numbers with the midi_map and amidi_map options
of the snd-rawmidi module, with one number per card. E.g., to let /dev/amidi4
point to device 2, use "options snd-rawmidi amidi_map=1,1,1,1,2".
Regards,
Clemens
9:25 p.m.
Clemens Ladisch <clemens(a)ladisch.de> writes:
Brent Busby wrote:
So by virtue of the 'a' prefix device nodes, I actually get the second
subdevice after the one that's mapped (described in your amidi_map
description below) for free? (Or am I interpreting that wrong?)
It looks like I can control the first subdevice that gets exported as a
device node with the amidi_map= option you describe below, plus I also
get the subdevice after that (n+1) on the same device node with the 'a'
prefix added...so I can have two. I may have that wrong.
Just wondering though, what is the purpose of the 'dm' prefix nodes if
they do the same thing?
Is there a way to access individual subdevices
through the OSS emulation?
Short answer: no.
Long answer: opening a device will open the first available subdevice.
What is the difference between midi, dmmidi,
amidi, and admmidi?
/dev/midiX and /dev/dmmidiX are the same.
/dev/amidiX and /dev/admmidiX are the same.
/dev/midiX is MIDI device 0 of card X.
/dev/amidiX is MIDI device 1 of card X. You can change the OSS device numbers with the
midi_map and amidi_map options
of the snd-rawmidi module, with one number per card. E.g., to let /dev/amidi4
point to device 2, use "options snd-rawmidi amidi_map=1,1,1,1,2".
That's very useful to at least be able to choose which subdevice gets
the OSS exposure.
--
- Brent Busby + ===============================================
+ "The introduction of a new kind of music must
-- Studio -- + be shunned as imperiling the whole state, for
-- Amadeus/ -- + styles of music are never disturbed without
-- Keycorner -- + without affecting the most important political
-- Recording -- + institutions." --Plato, "Republic"
----------------+ ===============================================
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Clemens Ladisch