linuxaudio.org

On Tue, 08 Jun 2010 11:37:23 +0200

Nicolas BERCHER  wrote:
> On 08.06.2010 11:21, David Santamauro wrote:

quoted text
> >

> > Hi,

> >

> > On Tue, 08 Jun 2010 10:57:13 +0200

> > Nicolas BERCHER  wrote:

> >

> >

> >> So, I checked what's going on:

> >> $ aseqdump --list

> >>    Port    Client name                      Port name

> >>     0:0    System                           Timer

> >>     0:1    System                           Announce

> >>    14:0    Midi Through                     Midi Through Port-0

> >>    20:0    SB Live! Value [CT4870]          EMU10K1 MPU-401 (UART)

> >>    24:0    USB Keystation 88es              USB Keystation 88es

> >> MIDI 1 $ aseqdump -p 24:0

> >> Waiting for data. Press Ctrl+C to end.

> >> Source_ Event_________________ Ch _Data__

> >>    24:0   Control change          0  64 127

> >>    24:0   Note on                 0  82  82

> >>    24:0   Note on                 0  82   0

> >>    24:0   Control change          0  64   0

> >>

> >> The above sequence dumped by aseqdump shows only one note event

> >> (lines 2+3: press+release) but I heard a delayed note as mentioned

> >> in my first mail.

> >>

> > Actually, there are two note events and both are NOTE ON, one with

> > velocity of 82 and the other 0. The velocity 0 should be

> > interpreted as NOTE OFF.

> >

> > I had a similar problem and solved it by putting kmidimon between my

> > keyboard and sequencer.

> >

> > Could it be that qsynth doesn't handle NOTE ON with

> > velocity of 0 as NOTE OFF? Although I imagine that translation

> > should be happening at a lower level... just a guess.

> >

> Yes it is, you're right, but it happens only for 4 notes among 88 I

> can play!

> If this putting kmidimon between my keyboard and qsynth can solve the

> problem, I'd also like to understand why. Does it mean there exist

> multiple midi standard to describe note on/off events?

> Nicolas.

Sorry, I re-read the initial post -- 4 notes, hrmmm. That points

to a hardware issue but aseqdump doesn't show additional events.
Although I haven't delved into the code, the translation of NOTE ON (0)

to NOTE OFF should be happening at a much lower level than user-space

software. There is one standard for midi note on/off and it is clear

that note on (0) must be interpreted as note off.
Have you tried playing it back through a different sound generator,

possibly external gear attached to your 20:0 port?
Just as a test, what is registered when you route your keyboard into

kmidimon and route kmidimon into qsynth (all defaults, simple piano

patch)

  - does kmidimon show 1 note-on/note-off only

  - does qsynth output correctly?
David
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