22 Sep
2005
22 Sep
'05
3:28 a.m.
On Fri, 2005-09-16 at 17:10 +0200, Clemens Ladisch wrote:
It would be interesting to know what the maximum data rate is.
Well, as said elsewhere; (in this case) it is 16 times higher than you
(by default) allow for in usbmidi.c
While trying to catch up, I noticed that there is a "FIXME" in
---------------------
static void snd_usbmidi_standard_output
(snd_usb_midi_out_endpoint_t* ep)
...
// FIXME: lower-numbered ports can starve higher-numbered ports
------------------------
Uhmm ... I have been meditating on this function all evening. There are
implications surrounding it.
You have decided to go for the worst case scenario where an USB
4byte-frame == a 3byte-midi-msg == 1 milisecond. The obvious anvantage
is that this will not break.
Although, for a physical cable there are best case scenarioes where you
can get 3 messages across/milisecond (ie: channel aftertouch)
I also noticed that the driver envestigates quite a few vendor/product
IDs to get around various "quirks". This route might be a way to go?
mvh // Jens M Andreasen
Regards,
Clemens
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