Bug#775756: -ao pulse stopped producing audio; alsa and oss still work

[Felipe Sateler]

On 19 Jan 2015 22:15, "Josh Triplett" <josh at joshtriplett.org> wrote:
>
> On Mon, Jan 19, 2015 at 08:45:46AM -0800, Josh Triplett wrote:
> > Package: mplayer2
> > Version: 2.0-728-g2c378c7-4+b1
> > Severity: normal
> >
> > A couple of days ago, "mplayer -ao pulse" (the default without -ao
> > specified) stopped producing output.  A running mplayer2 still shows up in
> > pulseaudio's "applications" list, but produces no audio.  Changing
> > volume and toggling mute have no effect.
> >
> > "mplayer -ao alsa" still works, as does "padsp mplayer -ao oss".  paplay
> > works as well, as do other applications using pulseaudio.
> >
> > I tried downgrading libav libraries to before the most recent upgrade a
> > couple of days ago, but that doesn't seem to have made a difference.
>
> After further investigation, it looks like this is tied to HDMI audio.
>
> I hooked up to an external HDMI monitor, and used the GNOME sound
> control panel to switch audio output to HDMI, then played a few movies.
> Afterward, I disconnected from that monitor, but I didn't have any sound
> from the default "pulse" audio output device; "mplayer -ao alsa" worked.
> Just now, I connected to another external monitor, and found that the
> default pulse output worked, without even switching over to it.  I
> manually switched back to speakers, and now the default sound output
> works again, even after disconnecting.  It looks like somehow Pulse got
> into a state where it thought it was sending sound to HDMI.  *However*,
> that state somehow only affected mplayer, not totem, paplay, or the alsa
> output device.
>
> Not sure where the bug was, here, but there's definitely a bug.
>

Hi,

More information would be necessary to be sure (like the output of
pactl info and a verbose pulseaudio log when the problem is exhibiting
itself), but I think this is a feature, not a bug.
Pulseaudio remembers where a stream was playing to last time, and
plugs the stream there. This can lead sometimes to surprising
behavior, but it is the expected behavior from an upstream POV.

You can use pavucontrol to control to which device a given app is
playing to. Pasystray also offers the same functionality and stays on
your tray.

Saludos,