24 Jul
2005
24 Jul
'05
8:48 p.m.
Hi,
I just wote a program to configure a m-audio Midisport 8x8.
Currently the program can only write a sysex file.
It would be convenient to send the data to the Midisport
control port instead. UNfortunately, I have no clue how to do
so easily.
I only need to write sysex data which are kept in a character
array. Is there a possibility to easily
* connect to a certain port of a device (the Midisport control
port)
* send the contents of the array to this port
* close the port
I have already seen some documentation (especially the
examples of M- Nagorny), but as I just started to write code
it's still too complicated for me.
Furthermore I was told that I do not need a fully featured
port and that a rawmidi port would be enough for my needs.
So, any pointer to some docs or example code I can understand
would be really cool.
Thanks & best regards
ce
25 Jul
25 Jul
5:11 a.m.
On Mon, 2005-07-25 at 00:50 +0200, Christoph Eckert wrote:
Hi,
I just wote a program to configure a m-audio Midisport 8x8.
Currently the program can only write a sysex file.
It would be convenient to send the data to the Midisport
control port instead. UNfortunately, I have no clue how to do
so easily.
But you know which port is the control port, right?
I only need to write sysex data which are kept in a character
array. Is there a possibility to easily
* connect to a certain port of a device (the Midisport control
port)
#include <sys/soundcard.h> // The oldfashioned way, sorry ;)
char sysexbuf[<somesize>];
int midifd = open("/dev/midi",O_WRONLY); // using the default device?
* send the contents of the array to this port
write(midifd,&sysexbuf,sizeof sysexbuf);
* close the port
close(midifd);
I have already seen some documentation (especially the
examples of M- Nagorny), but as I just started to write code
it's still too complicated for me.
Let's see if not someone will post the alsa version ... soon.
Furthermore I was told that I do not need a fully
featured
port and that a rawmidi port would be enough for my needs.
So, any pointer to some docs or example code I can understand
would be really cool.
Thanks & best regards
ce
--
12:52 p.m.
Hi,
Yes, the Midisport has a dedicated control port.
[...]
It would be
convenient to send the data to the Midisport
control port instead. UNfortunately, I have no clue how
to do so easily.
But you know which port is the control port, right? Let's see if not someone will post the alsa
version ...
soon.
Did I get it right: This is the OSS way of doing MIDI? The
Midisport doesn't work on OSS, so I'd like to avoid using
it ;-) .
Thanks a lot for the info anyway!
Best regards
ce
3:56 p.m.
On Mon, 2005-07-25 at 15:24 +0200, Christoph Eckert wrote:
Did I get it right: This is the OSS way of doing MIDI?
The
Midisport doesn't work on OSS, so I'd like to avoid using
it ;-) .
Ah! Well then perhaps the shortest route would be to just use amidi
combined with one the exec() variants?
But if you do make the effort and boil it down to a few lines of clean
alsa code, please post it back here. The example you are writing is
short, concise and perfect for a mini tutorial.
26 Jul
26 Jul
3:07 p.m.
Ah! Well then perhaps the shortest route would be to
just
use amidi combined with one the exec() variants?
I'll study the code of amidi.
But if you do make the effort and boil it down to a
few
lines of clean alsa code, please post it back here. The
example you are writing is short, concise and perfect for a
mini tutorial.
If I get this far, I'll do so.
Best regards
ce
4:43 p.m.
On Tue, 2005-07-26 at 19:09 +0200, Christoph Eckert wrote:
OK!
What I found so far for a minimum raw_sysex example is:
snd_rawmidi_t *handle_out = 0;
char* device = "hw:0,0"; // This may or may not be the device ...
int err = snd_rawmidi_open(/*in*/NULL,/*out*/&handle_out,
device,0);
if (err)
exit(EXIT_FAILURE);
// some midi data
unsigned char gm_reset[] =
{ 0xf0, 0x7e, 0x7f, 0x09, 0x01, 0xf7 };
snd_rawmidi_write(handle_out,gm_reset,sizeof(gm_reset));
// snd_rawmidi_drain(handle_out);
snd_rawmidi_close(handle_out);
I haven't found an easy shortcut to get a list of possible devices
(except for what is in amidi)
The code above will wait forever if the device is already taken.
Opening the device with SND_RAWMIDI_NONBLOCK as last argument will get
you past that point, but then the write operation may fail (returning
negative) or return less bytes than you asked for to be written. This is
where one should "drain" the device and resend the missing bytes, as I
understand it.
mvh // Jens M Andreasen
Ah! Well then
perhaps the shortest route would be to just
use amidi combined with one the exec() variants?
I'll study the code of amidi.
But if you do make the effort and boil it down to
a few
lines of clean alsa code, please post it back here. The
example you are writing is short, concise and perfect for a
mini tutorial.
If I get this far, I'll do so.
5:17 p.m.
On Tue, 2005-07-26 at 20:43 +0200, Jens M Andreasen wrote:
snd_rawmidi_write(handle_out,gm_reset,sizeof(gm_reset));
// snd_rawmidi_drain(handle_out);
snd_rawmidi_close(handle_out);
On second thought you'd better uncomment:
// snd_rawmidi_drain(handle_out);
... since it is the write that will block, and not the close operation.
/jens
5:47 p.m.
But if you do
make the effort and boil it down to a few
lines of clean alsa code, please post it back here. The
example you are writing is short, concise and perfect for a
mini tutorial.
If I get this far, I'll do so.
6:20 p.m.
I learned this stuff by staring at Matthias
Nagorni's
miniArp.c. It's not labeled as a tutorial, but it's a nice
introduction to ALSA programming. You can find it at
http://www.suse.de/~mana/miniArp.c
THanks for the pointer. Looks interesting.
Best regards
ce
27 Jul
27 Jul
6:04 a.m.
Jens M Andreasen wrote:
int err =
snd_rawmidi_open(/*in*/NULL,/*out*/&handle_out,
device,0);
The code above will wait forever if the device is already taken.
Opening the device with SND_RAWMIDI_NONBLOCK as last argument will get
you past that point, but then the write operation may fail (returning
negative) or return less bytes than you asked for to be written.
You can open the device with SND_RAWMIDI_NONBLOCK and then set it to
blocking mode with "snd_rawmidi_nonblock(handle_out, 0);".
HTH
Clemens
25 Jul
25 Jul
7:44 a.m.
Christoph Eckert wrote:
I only need to write sysex data which are kept in a
character
array. Is there a possibility to easily
* connect to a certain port of a device (the Midisport control
port)
* send the contents of the array to this port
* close the port
This is pretty much exactly what amidi does. The writing itself can
be done trivially with snd_rawmidi_open/snd_rawmidi_write/
snd_rawmidi_close. To get the device name of the control port, you
have to enumerate the MIDI ports; see the device_list function.
HTH
Clemens
11:23 a.m.
This is pretty much exactly what amidi does. The
writing
itself can be done trivially with
snd_rawmidi_open/snd_rawmidi_write/ snd_rawmidi_close. To
get the device name of the control port, you have to
enumerate the MIDI ports; see the device_list function.
Thanks Clemens for the pointer. I'll make usage of the OSS
advantage and study the code of amidi ;-) .
Best regards
ce
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days inactive
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linux-audio-dev@lists.linuxaudio.org
12 comments
4 participants
participants (4)
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Christoph Eckert -
Clemens Ladisch -
Jens M Andreasen -
Peter Brinkmann