Hello DSP:ers, I have a delicate problem: two audio devices, not synchronized by any means, are set to the same sampling rate. In reality the sampling rates will differ a little bit, i.e. 44000 and 44001 Hz. Now I need a way of estimating the clock drift between those two devices, preferably in real time: One device is the playback device, and the other one is the recording device (recording the signal that is being played back, after it has been converted to analog and affected by an impulse response). At the recording device I have access to the original signal (before affected by the impulse response) as a reference. What I want is an estimate of the clock drift so that I can resample the streams to the same rate. I've seen posts about PLLs, Costas Loop, sigital servo loops, etc which seem to be in the right direction, but I have no knowledge wbout those things. Where is the best place to start searching for information? Or are there any examples of this procedure to have a look at? Best regards This message was sent using the Comp.DSP web interface on www.DSPRelated.com
Sample rate estimation using a PLL?
Started by ●May 30, 2005
Reply by ●May 30, 20052005-05-30
snappy wrote:> > Hello DSP:ers, > > I have a delicate problem: two audio devices, not synchronized by any > means, are set to the same sampling rate. In reality the sampling rates > will differ a little bit, i.e. 44000 and 44001 Hz.Somebody posted a little program for the jack audio server to support doing exactly this for multiple non sync. soundcards. Have a poke around in the jackit-devel archive and you should find it. I **THINK** it was Torben who wrote it, but I am not sure. Just a pointer to existing code. Regards, Dan.
Reply by ●May 30, 20052005-05-30
Please post the link when you find it. Dan Mills wrote:> snappy wrote: > > >>Hello DSP:ers, >> >>I have a delicate problem: two audio devices, not synchronized by any >>means, are set to the same sampling rate. In reality the sampling rates >>will differ a little bit, i.e. 44000 and 44001 Hz. > > > Somebody posted a little program for the jack audio server to support doing > exactly this for multiple non sync. soundcards. > > Have a poke around in the jackit-devel archive and you should find it. > > I **THINK** it was Torben who wrote it, but I am not sure. > > Just a pointer to existing code. > > Regards, Dan. >
Reply by ●May 31, 20052005-05-31
>Somebody posted a little program for the jack audio server to supportdoing>exactly this for multiple non sync. soundcards. >... >Just a pointer to existing code.Thanks! I guess I'll need some pointer to the underlying theory as well since code in general is quite bad commented. Hm. :) This message was sent using the Comp.DSP web interface on www.DSPRelated.com