Re: No sound from Flash, but other methods work well

[Florian Kulzer <florian.kulzer+debian@icfo.es>]

On Sun, Jul 18, 2010 at 12:44:10 -0500, Ron Johnson wrote:
> On 07/18/2010 03:54 AM, Florian Kulzer wrote:
> >On Sat, Jul 17, 2010 at 18:41:35 -0500, Ron Johnson wrote:
> >>On 07/17/2010 05:57 PM, Camaleón wrote:
> >>>On Sat, 17 Jul 2010 17:13:35 -0500, Ron Johnson wrote:
> >>>>On 07/17/2010 04:30 PM, Camaleón wrote:
> >>>
> >>>>>Run "alsamixer" and check the volume for all the channels :-?
> >>>>>
> >>>>>
> >>>>First thing I did.
> >>>>
> >>>>Note, though, that for USB Audio there are only three channels: Bass,
> >>>>Treble, PCM.
> >>>>
> >>>>No "Master".  That may very well be the problem, but I don't know what
> >>>>to do about it.

[...]

> >>>Maybe is not just Flash the only app having no sound in Iceweasel.
> >>>
> >>
> >>MP3s play just fine.
> >
> >Knowing which audio devices are grabbed by which processes might shed
> >some light on the situation; I would be interested to see the output of
> >
> >   lsof +c0 $(find /dev/ -group audio)
> >
> >both when flashplayer tries and fails to play sound and when other
> >plugins of iceweasel do so successfully.
> >
> 
> Attached are 3 files.
> 
> I'm sure it's relevant (and I deeply apologize for forgetting about
> this) that sound only plays *at all* when I've got this ~/.asoundrc
> file:
> 
> $ cat .asoundrc
> pcm.!default {
>     type hw
>     card Device
> }

Strace shows that the plugin does try to access ~/.asoundrc, but I don't
know what it makes of the information in that file. (I don't use
~/.asoundrc at the moment.)

> >Another test would be if killing the pulseaudio daemon makes the sound
> >devices accessible to flashplayer.
> 
> I don't use PA.

OK, I misinterpreted your earlier remark about PA.
 
> >Also, which value of ICEWEASEL_DSP is set in /etc/iceweasel/iceweaselrc?
> 
> "none"

That has been working for me for years.

> $ lsof +c0 $(find /dev/ -group audio)
> COMMAND        PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
> mixer_applet2 2193  ron   21r   CHR  116,9      0t0 3204 /dev/snd/controlC0
> aqualung      3251  ron  mem    CHR  116,8          3201 /dev/snd/pcmC0D0p
> aqualung      3251  ron    4r   CHR  116,8      0t0 3201 /dev/snd/pcmC0D0p

> $ lsof +c0 $(find /dev/ -group audio)
> COMMAND        PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
> mixer_applet2 2193  ron   21r   CHR  116,9      0t0 3204 /dev/snd/controlC0

> $ cat dsp.quiet.txt
>  lsof +c0 $(find /dev/ -group audio)
> COMMAND        PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
> mixer_applet2 2193  ron   21r   CHR  116,9      0t0 3204 /dev/snd/controlC0

Everything is normal with aqualung, but it looks like flashplayer does
not even try to play audio. On my Sid systems it is not bothered at all
by the fact that kmix has /dev/snd/controlC0 open, it simply uses
/dev/snd/pcmC0D0p and /dev/snd/timer as needed.

You could run iceweasel under strace:

  strace -f -efile -o iceweasel-flash.strace iceweasel

Let a flash video play silently for a few seconds and then close the
browser. Afterwards you can check what has been accessed:

  grep -E 'a(lsa|sound)|/dev/(a?dsp|audio|mixer|snd)' iceweasel-flash.strace

Before you break out the big guns, though, you can try to set
ICEWEASEL_DSP to "aoss" (assuming you have "oss-compat" installed), or
maybe installing flashplugin-nonfree-extrasound will help, or switching
from flashplugin-nonfree to flashplayer-mozilla, or vice versa. (I did
not read the entire thread, maybe some of these things were already
suggested.)

-- 
Regards,            |
          Florian   |