Pulseaudio and alsa and accessibility

[Sam Hartman <hartmans@debian.org>]

>>>>> "Mario" == Mario Lang <mlang@delysid.org> writes:


    Mario> That is what I was thinking as well, but just recently I had
    Mario> to killall pulseaudio to be able to access my ALSA device
    Mario> again.

Pulseaudio explicitly bypasses the dmix plugin and opens the alsa
hardware directly.

There's kind of a mess in accessibility land:

* speech-dispatcher holds the audio stream open even when it's not using
  it.  This prevents pulseaudio from suspending.  That sucks both for
  battery and because you'll never be able to use a non-pulse interface
  to your alsa devices.

* The pulse alsa plugin interacts differently than raw alsa especially
  with short audio as produced by a single character from a speech
  synthesizer.  Raw espeak kind of gives depressing results depending on
  what application is driving it and depending on whether you're going
  through pulse+alsa or just alsa.

* speech-dispatcher never recovers from a pulse failure.

* Sadly, pulse fails.  Sometimes it gives you completely garbled audio,
  sometimes it just fails.

* speech-dispatcher and gdm and pulse interact amazingly badly;
generally you get speech for the first login session but the gdm login
window doesn't talk after that.

I've mostly gotten to be happier with pulse than without it.
I've filed some of these as bugs.
I'd definitely be happier if there were an easy way to convince pulse to
go through dmix even if it introduces latency or decreases audio
quality.