> Agreed, that with expensive cards you can get up to frequencies of 40 to > 80KHz. They all have hard falloffs to prevent aliasing however. I do not know > where they put that falloff even for the expensice cards. In may ways it is > silly to put the falloff much above 20KHz since the ear ( which is what sound > cards are all about) cannot hear above that. Well, there are studies which seem to indicate that you can hear sounds above 20KHz subliminally. I think thats why audiophiles have record players and SACDs or DVD-As. I recall reading some specs on some RME product which can sample data at 192KHz but there was no mentioning of the real cutoff though. > Did you use alsa or oss? I did a sound card testing routine using oss, but > since he wants to use alsa I did not suggest that. > Note that there a number of opensource oscilliscope programs out there which > do exactly what he wants I think. He could use the info in those to figure out > how to extract the signal from the sound card. True! I didn't think of these oscilliscope programs. My program uses whatever sound architecture you happen to have since it only executes a recording program and uses the data this program spits out. This way the core of the program could be used in other ways as well and since alsa provides arecord you are ready to go. Just rewrite the analysis part of the program and you're done. But since I do not really know what he is trying to do an oscilliscope program may be better. Or not, because you usually have to deal with a GUI which you might not want. Cheers, Jan ------------------------------------------------------------------------------ Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
