Artem Makhutov wrote: > Hello, > > I have an Asrock ALiveSATA2-GLAN mainboard with the onboard ALC888 > soundcard. The soundcard is connected by SPDIF to an external decoder. > > AC3 and PCM playback works fine with xine and mplayer, but after playing > a movie with AC3 sound by using mlpayer it destroys the PCM output. So I > don't get any PCM / stereo sound out of the card any more (by using > xine/mplayer/aplay). AC3 sound still works perfect. > > To get PCM working again, I have to restore my asound.state and reload > the mixer. I can't see any differences in the mixer (by using alsamixer) > before and after playing an AC3 file with mplayer, but there is a > difference in the asound.state file. > > I have attached the both files, and a diff between them. Any > suggestions, how to make mplayer/alsa not destoying my PCM output? > > Thanks, Artem > I haven't a suggestion, but I have attached below a couple of email messages from the alsa-devel list that seem to have a direct relationship to your problem. Takashi's suggestion is to use the iecset utility from alsa-utils. > Dear alsa-devel, > > I recently advised this list of some problems I experienced with the > SPDIF audio / non-audio bit being set inappropriately while using the > ca0106 driver [1]. Seeing as I got no replies, I am trying again. > > When playing AC3 encoded streams (Dolby Digital, DTS), the SPDIF > non-audio bit is set. Otherwise, for PCM streams, the SPDIF is set to > audio. > > Could someone explain to me what part of the software is responsible for > correctly setting the SPDIF audio / non-audio bit? Is it > * alsa-driver > * alsa-lib > * application ? > > It seems to me that currently some applications (MythTV, xine) set it > correctly, but most other applications ignore it. So if it is set to > non-audio (because for example MythTV crashed before re-setting it to > audio), then all applications that are not aware of the setting have > their audio broken. > > Could someone set me straight here so that I can try to produce a > permanent fix for this? > > Thanks, > Ben Stanley. > > [1] http://thread.gmane.org/gmane.linux.alsa.devel/54398/focus=55188 Here is Takashi's response. > At Fri, 15 Aug 2008 00:48:41 +1000, > Ben Stanley wrote: >> > >> > Dear alsa-devel, >> > >> > I recently advised this list of some problems I experienced with the >> > SPDIF audio / non-audio bit being set inappropriately while using the >> > ca0106 driver [1]. Seeing as I got no replies, I am trying again. >> > >> > When playing AC3 encoded streams (Dolby Digital, DTS), the SPDIF >> > non-audio bit is set. Otherwise, for PCM streams, the SPDIF is set to >> > audio. >> > >> > Could someone explain to me what part of the software is responsible for >> > correctly setting the SPDIF audio / non-audio bit? Is it >> > * alsa-driver >> > * alsa-lib >> > * application ? > > It's application, basically. The app can let alsa-lib set the default > values, though. > >> > It seems to me that currently some applications (MythTV, xine) set it >> > correctly, but most other applications ignore it. So if it is set to >> > non-audio (because for example MythTV crashed before re-setting it to >> > audio), then all applications that are not aware of the setting have >> > their audio broken. > > Some drivers have the independent PCM IEC958 status bits while many > have only the default IEC958 status bits. In the former case, the > driver resets automatically the status bits after closing the PCM > stream. Your case is the latter one, which doesn't reset. In this > case, usually alsa-lib takes the old setting back. But when the > program crashes (or aborted unexpectedly), the new setting is kept > even after that, as you described in the above. > >> > Could someone set me straight here so that I can try to produce a >> > permanent fix for this? > > You can change the status easily via iecset program in alsa-utils. > > Maybe it's safer to have an independent PCM iec958 setting on all > drivers. But this requires the change in alsa-lib (system) config, > i.e. it may cause an incompatibility with older alsa-lib configs. > This is an only drawback, I think. > > > Takashi ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
