Re: AUTimePitch and latency
Re: AUTimePitch and latency
- Subject: Re: AUTimePitch and latency
- From: Chris Rogers <email@hidden>
- Date: Sat, 3 Dec 2005 12:00:15 -0800
Roni,
I recently fixed some bugs relating to the accuracy of the latency
reporting in AUTimePitch.
I'm not sure when the fixes will make it into a release, but the
reporting is much tighter now...
Chris Rogers
Core Audio
Apple Computer
On Dec 3, 2005, at 4:57 AM, Roni Music wrote:
Hi,
I'm doing some tests with the AUTimePitch converter. I'm driving
the Audio Unit rendering process myself as described in the Audio
Unit Rendering docs and everything works fine except the latency
compensation.
I'm calling AudioUnit GetProperty() with the
kAudioUnitProperty_Latency flag after setting up everything (rate,
pitch etc) (actually for this test I'm using a rate setting of 1.0
and pitch setting of 0, i.e. no change and render quality max).
The converter reports it's latency as 75.4 milliseconds or 3325
frames at 44100 Hz sample rate. When I compare the processed file
with the original file (compensating with the reported latency),
the converted audio is around 550 samples frames to early (about 12
milliseconds).
If I switch to using the VariSpeed converter (same settings i.e. no
change), it reports it's latency as 1.09 milliseconds or 48 sample
frames. When I compare the processed file with the original file
(again compensating with the reported latency), the audio is
perfectly alligned.
Also, if I change the kAudioUnitProperty_Quality setting to medium,
it reports the same latency but now the converted audio is 350
samples frames (8 milliseconds) to early.
To me it seems that the AUTimePitch is reporting a wrong/too low
latency value or is there anything I'm missing?
Dual 1 GHz G4, OS X 10.4.3 using XCode 2.2
Thanks for any help
Rolf
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
40apple.com
This email sent to email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden