RE: Are Quicktime microtones supported?
RE: Are Quicktime microtones supported?
- Subject: RE: Are Quicktime microtones supported?
- From: "Joel May" <email@hidden>
- Date: Tue, 20 Aug 2002 23:25:53 -0500
Chris,
Is there a way to determine the latency of the internal synth?
QTMA has a latency field in one of its data structures. I've found this
to be very useful when synchronizing graphics. (Altough this field
reports the wrong value in QT5 and QT6. I've figured out that it is
always off by about 180 ms.) This field is dynamic -- it varies over
time. Presumably, when the cpu is busier, the latency increases and
this latency is reflected in this field.
I need the same thing in CoreAudio.
Thanks,
Joel May
-----Original Message-----
From: email@hidden
[
mailto:email@hidden] On Behalf Of Chris Rogers
Sent: Tuesday, August 20, 2002 1:06 PM
To: email@hidden
Subject: Re: Are Quicktime microtones supported?
Actually you should use the QuickTime mailing list for this question,
but I can help you out here. The QT APIs are deprecated and we highly
encourage developers to move over to using AudioUnits, the DLS
synth, and the rest of our APIs in CoreMIDI, CoreAudio, and the
AudioToolbox framework. These new APIs provide more features
not accessible from QTMA, as well as being more efficient, etc....
Anyway, a bug fix for the latest release of QuickTime 6 (in Jaguar)
should support the
fractional pitches as they were originally meant to work. The scale
is logarithmic. Fractional pitches are also supported in the
DLS synth AudioUnit, although the fraction in this case is the
fractional part
(from 0.0 -> 1.0) when using MusicDeviceStartNote().
Hope this helps...
Chris Rogers
>
Does anyone know what the story is about microtonal intonation under
>
QuickTime? According to the QuickTime docs, NANotePlay is supposed to
accept
>
fractional pitches, though the meaning of the fraction is poorly
documented
>
(logrithmic, or what?). I'm doing this with OS 10.1.5, and in any
event, it
>
doesn't work: QT clearly understands the format, because it plays the
>
requested midi pitch even though it's shifted - but it ignores the
>
fractional part. I've tried doing this with the pitches all shifted up
what
>
should be about a quartertone: e.g., middle C would be 0x3C7F (3C is
middle
>
C; 7F is halfway though the unsigned fractional range of 0 - ff). What
I get
>
is just the same pitch as if I had supplied 0x003C.
>
>
It would be a very fine thing if this were made to work. I figure
I must
>
have the format right, given that the basic pitch is understood. Can
someone
>
from Apple comment on any plans regarding this?
>
>
Thanks, Jeff Evans
>
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