[alsa-devel] RawMIDI behaviour with MidiFace 4x4

[Ricard Wanderlof]

On Sat, 7 Mar 2015, Kalvas, Taneli wrote:

> I am developing a patch librarian for a synthesizer. Because the 
> communication happens with Midi sysex and timing is not relevant I chose 
> RawMIDI interface and not the alsa sequencer. The problem I have 
> encountered is that writing to the midi port with snd_rawmidi_write() 
> seems to broken. The function accepts any size of data block and claims 
> to have sent everything. In reality only a part of the message is sent. 
> For a large block size I can see the activity light blinking for 
> fraction of a second. This happens both in blocking and non-blocking 
> mode. I would expect the snd_rawmidi_write() to accept only a part of 
> the message.

Can't help with rawmidi, but I can at least report that my experience 
using the sequencer interface has been that it is rather straightforward 
to use, even if just using it to send and transmit sysex data, even when 
the data is longer than 300 bytes. (See for instance 
https://github.com/polluxsynth/xtor/blob/master/midi.c ( midi_send_sysex() 
and midi_input() functions).

/Ricard
-- 
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
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