On Tuesday 24 July 2007 12:47:59 Takashi Iwai wrote:
Maybe some apps change the IEC958 status bits and doesn't restore the original value at close. (Or interrupting via ctrl-C may cause it.)
You can see the meaning of these bits via iecset utility included in alsa-utils package.
Thanks. I'll keep that in mind and check things when it happens again.
So, the culprit looks like the analog loopback. Could you try the patch below, and make sure that you set "PCM" as the "IEC958 Playback Source"?
I can confirm this definitely solves the volume problem for me. I can increase the pcm and spdif volume to 100% and no clipping or distortions whatsoever happen on the spdif output. Works like a charm.
So far the other distortions I wrote about are now only hearable when I turn up the volume of my headphone to nearly its maximum. If it stays that way, I can live with it... reminds me, before the problem was fixed, I had my headphone at almost 100% most of the time, so that could be the reason why those distortions where so visible in the first place. I'll have an eye on it...
I am curious, will that patch make it into the offical mercurial repository and what was the problem exactly with the analog loopback?
Thanks for taking the time!
Best regards, Matthias Dahl