Re: Lowest latency I/O
Re: Lowest latency I/O
- Subject: Re: Lowest latency I/O
- From: Christof Faller <email@hidden>
- Date: Mon, 18 Jul 2005 17:17:09 +0200
Dear list,
My questions seem to be not concise enough: :-)
I need lowest possible latency and plan to directly pass the (processed)
sampled getting from the input callback to the output callback.
In order to do this properly I have a question: Is it guaranteed that
while I am in one callback (e.g. input) the other callback (e.g. output)
is not called? Or do I have to be afraid that while I do input callback
processing, the output callback may be called?
Any comments on this topic are appreciated, thanks,
Christof
On Jul 16, 2005, at 7:56 AM, Christof Faller wrote:
Dear list,
For a real-time audio processor with lowest possible latency, I am
using the
input and output callback functions by passing what I had received
from the input
to the output, without any double-buffering. (For example I use
Apple PowerBook
analog-in to MOTU 896 8-channel-out).
The processing I do is in the input callback. The audio processing
needs about
15% of processor load (i.e. to process 100s it needs 15s). Once in
a while my
application runs with a lot of artifacts. Several times stopping
and re-starting
the audio often helps.
Here a question regarding the possible cause of this:
Is it possible that the output callback is called
while the processor is in the input callback (where I do the
processing)?
(This could explain these artifacts, since I use no double-buffering).
Another questions regarding overall latency:
For example if I use a MOTU 896 for input and output
with a 10ms audio buffer, what is the overall latency of the system -
any estimates? (Latency is very cruicial, since the processing I do is
planned for a PA system). Can I get much lower latency than the
MOTU 896
with a PCI card based audio device, or another type of firewire based
audio device?
Any comments are appreciated, thanks,
Christof
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
40volny.cz
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