Michael, This feedback occurs in Win7 if the soundcard/adapter is set to monitor the input (mic) which outputs the audio after it is processed back to the headphone/speaker. A real big annoyance. I would look for a similar setting in your sound card. But perhaps, those running Ubuntu will have a direct answer to this issue as I am only speculating it is a similar problem.
Mel, K0PFX ----- Original Message ----- From: "Michael Hartje" <[email protected]> To: <[email protected]> Sent: Thursday, June 26, 2014 10:58 AM Subject: [Freetel-codec2] problems with usb-soundcard? > dear list, > > when i use freedv 0.96.6.beta (ubuntu saucy on a laptop) in a > configuration, where I give the TX-out-signal back to the RX-Input, I > can hear analog or digital feed through-signals. The Ubuntu saucy uses > kernel 3.11. the internal soundcard is use to head the TRX, an > USB-Soundcard is used for headphone and mic. The soundcard is a USB-SC > with CM108 (cmedia). > > There is a smal time delay between direct speach to microphone and feed > back audio from the speaker. This is for analog and for digital nearly > the same delaytime. -- ok I think this is not dramatic and is the > principle of digital signal processing. > > But after some ten seconds or after some time with loud microphone > signals (Amplitude up to .8) i observe (in digtial and in analog feed > through) a drastic increase of cpu usage from 30 to 35 % up to 65 and > sometimes 77 %. On the audio output-signal at the same time there begins > a stuttering signal > > If I use the USB-SC for TRX, in digital mode I get some errors -- the > signal "frm radio" shows interruptions > with the configuration USB-SC for headphone and mic, there are no > errors, but the audio is stuttering as well. > > It seems to be no a freeDV-problem but an USB-Soundcard-problem. > > Are there any hints out there where to put screwdriver on the os or > anywhere else? > > thanks > > Michael > DK5HH > > > ------------------------------------------------------------------------------ > Open source business process management suite built on Java and Eclipse > Turn processes into business applications with Bonita BPM Community > Edition > Quickly connect people, data, and systems into organized workflows > Winner of BOSSIE, CODIE, OW2 and Gartner awards > http://p.sf.net/sfu/Bonitasoft > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
