Subject: Re: [linux-audio-dev] Midi Mapper???
From: Erik de Castro Lopo (erikd-lad_AT_mega-nerd.com)
Date: Thu Jan 03 2002 - 22:37:19 EET
On Thu, 03 Jan 2002 14:34:40 -0500
Paul Davis <pbd_AT_Op.Net> wrote:
> did you bother to ask on alsa-users?
Its an odd project where you have to ask for installation information on a
mailing list while the web page has documentation which is 3 years old.
> AFAIK, almost no USB MIDI device is properly supported under
> Linux.
I think this is actually coming along quite nicely:
http://member.nifty.ne.jp/Breeze/softwares/unix/usbmidi-e.html
On the basis of this I recently picked up a Midiman MidiSport 4x4 (thats
right 4 ins and 4 outs) interface. It uses the same chip as the 1x1/2x2 and
since I have *all* the source code it should be possible to hack it to get
all ports running.
> Its key to remember this - unlike OSS, ALSA includes a user-space
> library to handle issues like this. Under OSS, there is no way to make
> a USB MIDI device appear at /dev/midi without removing /dev/midi and
> using some kind of wierd symlink. OSS doesn't offer any API that isn't
> part of POSIX (open/read/write/close/ioctl) and uses plain file
> descriptors to identify the "target" of all actions. file descriptors
> ultimately point to device drivers in the kernel. since USB MIDI
> devices would be accessed via a USB device driver, not an OSS one, you
> can't use OSS nodes like /dev/midi to access them. Under ALSA, you
> don't use file descriptors like this - you use names, and the ALSA
> library will figure out how to access things for you and provide a
> uniform API for doing so.
I'll have to look into how USBMidi does things.
Erik
-- +-----------------------------------------------------------+ Erik de Castro Lopo nospam_AT_mega-nerd.com (Yes it's valid) +-----------------------------------------------------------+ "I love deadlines. I especially like the whooshing sound they make as they go flying by." -- Douglas Adams
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