another idea. maybe you cannot measure it dynamically but you can determine the latency exactly with -audiobuf or similar startup-messages. once set the latency stays the same. sme.
----- Original Message ----- From: "Josh Steiner" joschi@eds.org To: "sme" marius.schebella@chello.at Cc: "Pure Data" pd-list@iem.kug.ac.at Sent: Thursday, March 21, 2002 9:20 AM Subject: Re: [PD] dynamically determind real latency?
sorry for the "real audio latency" mixup, i meant "actual audio latency", as you gathered. :)
What I was thinking of was a patch that would be able to auto sense the latency of the soundcard and report that back to my control workstation so i could compensate for the latency (I'm trying to make this system as machine agnostic, and easy to setup as possible). I was wondering if there is some consistant formula that you can apply to determine a cards latency mathematically. Something to do with number of buffers or something? I guess if anyone knows any document describing the flow of data from pd to the psysical dsp and what latencies are in between, I'd love to read it. If its a chapter in that massive "Everything You Ever Wanted to Know about Compuer Music" bible (I forget the actual title), let me know where, since my roommate has a copy that he tries to hide from me. :)
Thanks again.
Josh
On Thu, 21 Mar 2002, sme wrote:
hi to understand you right, are you talking about realtime audio processing
or
Real Audio-playback of a RealPlayer? to test latency of Pd you probably will want to know also the latency of
the
soundcard, which is "before and behind" pd. you can use a stereo signal
(of
a dat-player or minidisc...) from outside the computer and split one
channel
directly to the datŽs inlet and send the other through your computer. the time difference of the two signals gives you the latency. "synchronisation" would be another problem ... sme.
----- Original Message ----- From: "Josh Steiner" joschi@eds.org To: "Pure Data" pd-list@iem.kug.ac.at Sent: Thursday, March 21, 2002 3:57 AM Subject: [PD] dynamically determind real latency?
I've been trying to think of a way to determine real audio latency using
a
pd patch. This is for my brother's and my project to control 5
computers
from 1 workstation using pd. I'm kind of at a loss as to how one might
do
this, or if its even possible. If any of you have any suggestions as to how this might be done, I'd really appriciate it.
thanks again,
Josh
Josh .. Yoshi .. Joschi .. xiphoidprocess.com .. eds.org/~joschi
Josh .. Yoshi .. Joschi .. xiphoidprocess.com .. eds.org/~joschi