Re: [orca-list] [pulseaudio-discuss] Has anyone ever gotten Orca and Pulse Audio to work together well?

[Jacob Schmude <j schmude gmail com>]

Hi
Alsa-plugins only applies when espeak is using its own output methods as it is, for example, when using 
gnome-speech. You can, of course, recompile espeak to use Pulseaudio as it does have native Pulseaudio 
support. However, if using speech dispatcher this does not apply as speech dispatcher handles audio output 
itself. If speech dispatcher is set to output via Pulse, then the sound is output via pulse regardless of how 
espeak is configured. The latest version of Ubuntu and all subsequent versions are using speech dispatcher by 
default, and it seems only a matter of time before everyone else follows this lead as gnome-speech will not 
be around much longer.
On Dec 12, 2009, at 14:32, Daniel Chen wrote:

> On Sat, Dec 12, 2009 at 2:43 PM, Bill Cox <waywardgeek gmail com> wrote:
> > I'm trying to narrow down where the problem is that causes the 1/2
> > second delay when Orca tries to read text using pulseaudio.  Is it in
> > pulseaudio's main code trunk, or in Ubuntu's version of pulseaudio?
>
> alsa-plugins, actually.
>
> The issue seems to be that espeak, in Ubuntu, uses an old version of
> PortAudio known not to support PulseAudio adequately.  Further, it is
> configured not to use PulseAudio by default but instead routes through
> the pulse pcm & ctl ALSA plugin, which introduces latency.  Based on a
> bug report[0], I'm going to configure it to use the PulseAudio backend
> instead.
>
> > I have googled, but was unable to find a single instance where a blind
> > user was able to get Orca working well with Pulse Audio, without the
> > 1/2 second delay.  I've also been able to convince myself that most of
> > the issues listed on
> >
> >    http://pulseaudio.org/wiki/UbuntuBugs
> >
> > are not causing the problem.  In particular, I was able to run
> > pulseaudio with nice -11 and rtprio 9, and the delay is still there.
> > I haven't yet dealt with the out of date libcanberra.
>
> That wiki page lists some blatantly false information, like MMX/SSE
> acceleration being disabled by default.  Also, it is unclear what
> "additional modules have been removed" means.  I have raised these
> questions in the appropriate PulseAudio venues.  (As one of the de
> facto audio maintainers in Ubuntu, this is some pretty serious muck
> I'd like to see corrected -- both in documentation and in source
> code.)
>
> > Do any of you know of any case where pulseaudio has been configured to
> > deliver speech from Orca without the delay?  Is this simply a problem
> > now because Ubuntu was the version most blind users preferred before
> > Ubuntu switched to pulseaudio?  Has this problem been there forever?
>
> This problem has become exacerbated with the advent of PulseAudio
> exposing broken bits in the audio stack: alsa-lib, linux, hardware
> itself.  (Note: just because things appeared to work without
> PulseAudio does *not* preclude the brokenness of the other parts in
> the stack!)
>
> -Dan
>
> [0] https://launchpad.net/bugs/377060
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