[linux-audio-dev] Basic MIDI question

Dave Robillard drobilla at connect.carleton.ca
Tue Jul 25 16:38:50 UTC 2006


On Tue, 2006-07-25 at 11:03 +0200, Clemens Ladisch wrote:
> Lee Revell wrote:
> > I was confused because I also see these timestamps when snooping
> > the MIDI output stream inside the kernel's MPU401 driver.  I guess I
> > assumed that aplaymidi would deliver the events with correct timing,
> > rather than passing the timestamps through.
> 
> The MIDI data at a raw MIDI port never has timestamps.  What you see are
> the data bytes of the next MIDI command where the command byte itself
> has been omitted because it would be identical to the last one.  (ALSA's
> sequencer event -> rawmidi converter uses running status by default.)
> 
> The running status and the zero note-on velocity (see Nicolas' mail) are
> the only special cases your parser has to look out for.

What about the 1-byte "realtime" events?

(un-normalized MIDI reeally sucks...)

-DR-





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