Re: synchronization of input and output
Re: synchronization of input and output
- Subject: Re: synchronization of input and output
- From: Peter Thom <email@hidden>
- Date: Sun, 8 Nov 2009 23:02:12 -0800
Is there a way to find out the difference between input and output
timestamps from within an audio unit? I am working on an audio unit
that is recording as well. How can I tell, how far the input and
output buffers are apart?
Peter
On Nov 3, 2009, at 5:39 PM, William Stewart wrote:
Hi Taylor
We don't know of any issues here, so can you file a bug report?
Thanks
Bill
On Oct 31, 2009, at 10:25 AM, Taylor Holliday wrote:
Interesting, upon rebooting the duet was in sync. Putting the
computer
to sleep and waking it back up results in it being out of sync again.
Unplugging the duet and plugging it back in restores the
synchronization. The builtin audio was always out of sync.
Something's buggy!
- Taylor
On Fri, Oct 30, 2009 at 6:14 PM, Taylor Holliday <email@hidden
> wrote:
On Fri, Oct 30, 2009 at 5:30 PM, Brian Willoughby <email@hidden
> wrote:
On Oct 30, 2009, at 17:25, Taylor Holliday wrote:
It's hard to say. There isn't enough context here. You say
everything is
"10
samples or so late", but late as compared to what?. And, is it
10 samples
all the time? If not, what precisely is the variance?
You need to define better what you are measuring and how you
are doing it
before I can provide more information.
I'll try. In order to determine whether newly recorded audio is
properly synchronized with previously recorded audio, I hooked the
output of my duet into its input. Then recorded audio to a
separate
track. The newly recorded audio is 10 samples late relative to the
audio being played back. The 10 samples seems to be a constant.
CoreAudio, and therefore Logic, only has the latency reported by
the audio
driver to go on. If the Apogee Duet provides I/O latency values
which are
off by 10 samples in total, then your test will be off by 10
samples.
Have you tested against other devices? What about the built-in
audio on
your Mac?
Brian Willoughby
Sound Consulting
I just did the same test with builtin audio, the recorded audio is
also out of sync and this time
its about 40 samples too early:
http://wtholliday.org/recording_delay_builtin.jpg
I don't have access to any other devices right now.
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