[nas] firefox audio solution?

Paul Fox pgf at foxharp.boston.ma.us
Mon Feb 11 12:44:27 MST 2008


i wrote:
 > jon wrote:
 >  > On Sun, 10 Feb 2008, Paul Fox wrote:
 >  > > > ENVIRONMENT
 >  > > >   FIREFOX_DSP - configures the /dev/dsp wrapper to use.
 >  > > >   Accepted values are "auto", "arts", "esd" or "none" (default).
 >  > > >   Do not use this feature to select "auto" or "esd" as this will
 >  > > >   involve using "esddsp" which is known to be buggy and to make
 >  > > >   Firefox unstable.
 >  > >
 >  > > i'm not sure i understand this.  what _is_ the /dev/dsp wrapper that
 >  > > they're talking about?  is "audio_oss" a dsp wrapper?
 >  > >
 >  > 
 >  >    libaudioss 'wraps' /dev/dsp accesses via open(), write(),
 > 
 > yes, i knoew that's what libaudiooss is -- i was trying to interpret
 > the values of $FIREFOX_DSP.  are they library names?  are they shim
 > names?  is whatever they represent documented?  if libaudiooss a member
 > of that club?  etc.

i did some more research.  i can't find a single occurrence of the
string FIREFOX_DSP anywhere but in /etc/firefox/firefoxrc.  i don't
think the mechanism is implemented anymore.

/etc/firefox/firefoxrc also points at a 2 y.o. launchpad bug:
    $ cat /etc/firefox/firefoxrc 
    # which /dev/dsp wrapper to use
    FIREFOX_DSP="none"
    # Note that "auto" and "esd" involve the use of esddsp, which
    # is known to be buggy and to make Firefox unstable.
    # See https://launchpad.net/bugs/29760.

it seems that the DSP wrapper was only there to support flash, because
flash, unlike the rest of firefox, used /dev/dsp.  the rest of firefox
used libesd.  the bug report talks about all of the problems with the
esddsp wrapper that was being used to make flash work.  (note
that most of these are probably also problems with audiooss.)

later, in the comments on launchpad, it's reported that flash 9 no
longer uses /dev/dsp, but rather uses alsa directly.

i believe firefox may still use esd, but loads an alsa library to get
alsa access.  i'm not sure about this, though.

in any case, there's one more piece to the puzzle:  apparently
adobe has specified a plug-in dll for flash that lets one
redirect the audio. 

these folks:
    http://pulseaudio.revolutionlinux.com/PulseAudio

have developed a flashsupport dll that can support pulse, esound, alsa,
or oss bottom ends.  it may be that a combination of this, plus audiooss
would work.  

of course, it might make more sense to add NAS to their flashsupport library.

and, of course, having NAS support from within alsa would still be best.

paul
=---------------------
 paul fox, pgf at foxharp.boston.ma.us (arlington, ma, where it's 18.7 degrees)



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