Re: [pygame] Re: Determining note duration from midi input

[Neilen Marais <nmarais@xxxxxxxxx>]

Hi Luke

On Fri, Apr 2, 2010 at 7:00 PM, Luke Paireepinart
<rabidpoobear@xxxxxxxxx> wrote:
> No problem.
> I just changed 'casio_i' until it started reading midi data from my
> keyboard.  my ID was 1.  how did you figure out your ID's? trial and error?

There is pygame.midi.get_count() and pygame.midi.get_device_info()
that  can help. There is a pretty nice example in
pygame/examples/midi.py that comes with the source distribution.

> I'm not sure if your keyboard has aftertouch, but you basically had the
> right idea.   I'm not sure why you think timestamp is wrong.  Do you get
> keyup's when you release the key?  your keyboard may force sending keyups
> before the key is actually released.
> Here's some event data from my keyboard (playing 2 notes of different
> lengths):
> <Event(34-Unknown {'status': 144, 'vice_id': 1, 'timestamp': 2105, 'data1':
> 72, 'data3': 0, 'data2': 66})>
> <Event(34-Unknown {'status': 128, 'vice_id': 1, 'timestamp': 2390, 'data1':
> 72, 'data3': 0, 'data2': 64})>
> <Event(34-Unknown {'status': 144, 'vice_id': 1, 'timestamp': 4633, 'data1':
> 69, 'data3': 0, 'data2': 66})>
> <Event(34-Unknown {'status': 128, 'vice_id': 1, 'timestamp': 9216, 'data1':
> 69, 'data3': 0, 'data2': 64})>

Hmm, there definitely seems to be something wrong here. No after
touch, simple "digital piano" (Casio Privia PX-200). The numbers I get
don't make sense. Using code that I modified from yours
(http://pastebin.com/kMTt0kQH ), I generated the following output by
playing a stacato note (i.e. very short duration), followed by a short
note followed by a long note. As you can see the timestamps make no
sense! However, looking at the midi event stream in real time, the
events are created at the right time. i.e. I press a key - key down
event. Hold - nothing. Release - key up event.

<Event(29-UserEvent {'status': 144, 'vice_id': 3, 'timestamp': -1,
'data1': 60, 'data3': 0, 'data2': 95})>
Key 60 was pressed.
<Event(29-UserEvent {'status': 128, 'vice_id': 3, 'timestamp': 0,
'data1': 60, 'data3': 0, 'data2': 64})>
Key 60 was held down for 1.
<Event(29-UserEvent {'status': 144, 'vice_id': 3, 'timestamp': 0,
'data1': 60, 'data3': 0, 'data2': 63})>
Key 60 was pressed.
<Event(29-UserEvent {'status': 128, 'vice_id': 3, 'timestamp': 2,
'data1': 60, 'data3': 0, 'data2': 64})>
Key 60 was held down for 2.
<Event(29-UserEvent {'status': 144, 'vice_id': 3, 'timestamp': 0,
'data1': 60, 'data3': 0, 'data2': 67})>
Key 60 was pressed.
<Event(29-UserEvent {'status': 128, 'vice_id': 3, 'timestamp': 0,
'data1': 60, 'data3': 0, 'data2': 64})>
Key 60 was held down for 0.
<Event(29-UserEvent {'status': 144, 'vice_id': 3, 'timestamp': 0,
'data1': 60, 'data3': 0, 'data2': 92})>
Key 60 was pressed.
<Event(29-UserEvent {'status': 128, 'vice_id': 3, 'timestamp': -1,
'data1': 60, 'data3': 0, 'data2': 64})>
Key 60 was held down for -1.

> Also I dont' think you're registering the events properly because I'm unable
> to actually use the event like a normal event.
> ....
> Yeah, could you specify which version of pygame you're using?
> I'm not sure what 'fastevent' is, I can't find it in the docs.

As far as I can tell it's a work-alike that is supposed to be faster
(http://www.pygame.org/wiki/todo#fastevent%20as%20default%20event%20module
). I simply used it because that is what the included pygame example
code used. More info
(http://dev.laptop.org/~mcfletch/OLPCGames/pydoc/pygame.fastevent.html
)

> I'm
> suspecting it's broken in my pygame version because the events you were
> registering I wasn't able to access their data meembers.

I'm using pygame 1.9.1. Conversely, I found that your code that used
the  normal event did not work. Digging deeper it seems that the
pygame.midi is buggy in the sense that it uses an event number that is
bigger than pygame.NUMEVENTS, causing them to be ignored. By changing
the pygame/midi.py source to use a lower event number, both
pygame.event and pygame.fastevent works for me.

> What do you think?

Would have been great it it worked for me! Well, it seems like there
is some problem with my hardware or some other software component
between pygame and the hardware.  Would you agree? I'm pretty sure the
basic hardware and drivers work though, since I tested recording with
rosegarden and it seemed to work quite well!

Thanks
Neilen