[PD] Writing a MIDI file...or at least a qlist...to disc

Richard Bowers richard.bowers at ntlworld.com
Wed Oct 11 23:31:01 CEST 2006

Many, many thanks, Frank (and Kyle). I'll get on the case when I'm more
alert. Tiredness can kill when driving PD ... So I'll pick up the thread


-----Original Message-----
From: pd-list-bounces at iem.at [mailto:pd-list-bounces at iem.at] On Behalf
Of Frank Barknecht
Sent: 11 October 2006 22:14
To: pd-list at iem.at
Subject: Re: [PD] Writing a MIDI file...or at least a qlist...to disc

Richard Bowers hat gesagt: // Richard Bowers wrote:

> Basically, I'm running a PD patch on a Mac which is sending 
> (internally, not through hardware) MIDI note on/off pairs to another 
> program (Arkaos). I would like to be able to capture the MIDI stream 
> within PD (or the numeric values on which the MIDI notes are based) 
> into a file for later retrieval. So
> 1) is there a purpose-built object which will handle this? or
> 2) can a file be written to disc as a qlist? If so, could someone 
> describe how to write such a file?

You can write a qlist's content using "write FILENAME", but I guess, you
know this already. The important thing to remember with qlist is that it
stores lists conisting of at least three elements: First the "Inter
Onset Interval" or IOI, which is the time between successive events,
then the name of a receiver, which receives the qlist data, if the qlist
is playing back, and after that the actual data to record: 

qlist: IOI receiver data ...

"data" can be a list itself, in your case it is a note events consisting
of note number and velocities. Then you need to build the other two
elements: Just decide on a receiver name (attached patch uses "NOTEIN")
and calculate the IOI. IOI-calculation is very simply done by
double-banging a [timer]: 

 "events, events, ..."
 [t b b]
 |     |

At the start of a recording, you should reset the [timer] to 0 through
its left(!) inlet, and you should "clear" the qlist.

Attached is a working example, but maybe you want to try to build a
qlist-recorder on your own first. It shouldn't be too hard if you follow
the hints above.

 Frank Barknecht                 _ ______footils.org_ __goto10.org__

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