[MPlayer-dev-eng] [PATCH] use playback_switch with alsa for muting

[Reimar Döffinger]

Hi,
On Fri, Nov 18, 2005 at 02:09:17PM +0100, Matthias Lederhofer wrote:
> I wrote a patch to libao2/ao_alsa.c which uses
> snd_mixer_selem_set_playback_switch when the volume is set to 0.0.
> This is the function intended for muting by alsa and I can still hear
> a bit of the sound without it when I set master and my speakers to
> full volume.

Overcomplicated, try the attached patch. Anyway, I am a bit unsure about
this, but what about any other channels? Since it is called FRONT_LEFT,
I guess there also is REAR_LEFT or so?

Greetings,
Reimar Döffinger
-------------- next part --------------
Index: libao2/ao_alsa.c
===================================================================
RCS file: /cvsroot/mplayer/main/libao2/ao_alsa.c,v
retrieving revision 1.20
diff -u -r1.20 ao_alsa.c
--- libao2/ao_alsa.c	25 Aug 2005 21:46:32 -0000	1.20
+++ libao2/ao_alsa.c	18 Nov 2005 15:35:07 -0000
@@ -197,6 +197,15 @@
 	}
 	mp_msg(MSGT_AO,MSGL_DBG2,"right=%li, pmin=%li, pmax=%li, mult=%f\n", 
 	       set_vol, pmin, pmax, f_multi);
+
+	if (snd_mixer_selem_has_playback_switch(elem)) {
+	  int lmute = (vol->left == 0.0);
+	  int rmute = (vol->right == 0.0);
+	  if (snd_mixer_selem_has_playback_switch_joined(elem))
+	    lmute = rmute = lmute & rmute;
+	  snd_mixer_selem_set_playback_switch(elem, SND_MIXER_SCHN_FRONT_LEFT, lmute);
+	  snd_mixer_selem_set_playback_switch(elem, SND_MIXER_SCHN_FRONT_RIGHT, rmute);
+	}
       }
       else {
 	snd_mixer_selem_get_playback_volume(elem, 0, &get_vol);