On Sun, 11 Jan 2009 08:28:13 -0500 "Theodore J. Allen" <tjallen@xxxxxxx> wrote: > The Soundscape Elite does work, but after a reboot > I noticed that there is an oddness in that there's > a little "pop" before playing sounds with aplay and > a series of short spike pops before the sound plays > with xmms, which uses the old oss interface. > I traced this and the "pop" sound is caused by two things: 1. Codec autocalibration every time a new sound is started (even when sound is muted it produces the "pop" on AD1848). 2. Muting sound on and off every autocalibration. The OSS code from the 2.4 kernel states that autocalibration produced that "pop" so it got disabled. This solves two problems at once as the muting on and off is not required then (and is not done in the code). I am not audiofile so I cannot comment how audible the lack of autocalibration is. Most codecs require it after they are powered up (and most of them except the oldest ones actually force it after powering up). One can autocalibrate the codec only once during a card/codec initialization. I can prepare a patch which disables the autocalibration. This is the only solution as I tested others like slow volume muting but all others still produce some noise. Regards, Krzysztof ----------------------------------------------------------------------- Promocja w Speak Up. Kwartal angielskiego za darmo. 3 miesiace nauki gratis. Sprawdz teraz! >> http://link.interia.pl/f2019 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
