General sound problems

On Wednesday, May 9th, 2012, at 14:41:48h +0100, Jim Lesurf wrote:

In article , J G Miller

gstreamer is downstream of pulseaudio.


application -- gstreamer -- PulseAudio -- ALSA

Isn't that gstreamer being *upstream* of pulse?

Errrrrrrm, yes.

Sometimes I do not know my up from my down or left from my right.

FWIW I always now use a .asoundrc file in my user directory to define the
default settings and clear or override others.

Okay, so long as you specify the default output device for ALSA in
that, that will indeed override the system settings.

One of the reasons I've hesitated to bug report is that I'm far from clear
what is wrong, or where any bug resides.

In which case an "exploratory" posting on the distribution forum web
site is the best course of action. In this case it looks like the
Ubuntu forum, but the response there can be very limited for more
complex problems such as this, ranging from being totally ignored
to uhelpful suggestions from people who are clueless. But there
is always the chance that somebody might see it and be able to
give some sound advice as to whether or not the problem can be
solved in the user configuration.

Maybe it is in GStreamer.

So the obvious thing is, can you not do a test with an application
which does not use Gstreamer but does send output to PulseAudio?

paplay is surely the program to try with some sounds to see
if PulseAudio is doing what it is being asked to do.

but Audacious, etc, are happy to work as I specify using alsa.

Correct me if I am wrong, but Audacious does not use gstreamer
as far as I can see, so surely if you just use that with the
output selected as PulseAudio, you can test with that as well.

FWIW I've been experimenting with using both the gconf editor and
hand-editing files to fiddle with GStreamer.

Well I know even less about GStreamer than I do about PulseAudio,
but I thought Gstreamer was primarily involved in decoding the
multimedia content (by use of its codecs plugins -- the good,
the bad, and the ugly) and setting up a pipeline through various
filters etc, but only if configured to do such.

The list of well known applications which use Gstreamer at

http://gstreamer.freedesktop.ORG/apps/

does include Parole but not Audacious.

On Wednesday, May 9th, 2012, at 14:31:03h +0100, Jim Lesurf explained:

Bad news is that it still doesn't work. Parole still insists on sending
audio to the headphone socket.

Is that because PulseAudio has decided that the headphone socket is the
default audio output?

I have been searching for a command line invocation to change the
default output device (sink as PulseAudio calls them) and came across
this page today which may be helpful if you did not know about the pacmd
and what it can do.

http://terminalmage.NET/2011/11/17/setting-a-usb-headset-as-the-default-pulseaudio-device/

Perhaps if you follow the example given for a USB headset, and you
battle to create a valid udev rule, you could have a script to
automagically change from your onboard sound card to the USB device
when it is plugged in and change back when you unplug it?

When you have Parole running and it is sending audio to the headphone
socket and not where you want it to go, run pacmd dump and see
what that shews as the default sink.

In article , J G Miller
wrote:
On Wednesday, May 9th, 2012, at 14:31:03h +0100, Jim Lesurf explained:

Bad news is that it still doesn't work. Parole still insists on
sending audio to the headphone socket.

Is that because PulseAudio has decided that the headphone socket is the
default audio output?

I'm presuming that either Pulse or GStreamer is doing this, regardless of
all my attempts to tell them otherwise. My impression is that either they
aren't understanding the defaults I'm giving them, or they are being
over-ruled by some other config file, etc.

e.g. I noticed that the pulse default.pa file does have a comment to the
effect that it only sets the default on a 'per user' basis and implies this
may not work if Pulse is being run on the 'system' level. So I may have a
poke around in the other files in that directory and see if altering them
to specify loading the alsa-sink module, etc, does any good.

The only alternative theory I have is that Pulse (or GStreamer) have a
problem with accepting 'after install' USB DACs that employ the newer
methods for transfer, or require a format like 24bit in 32 bit words.

However the above is really just guesswork based on baffling (and
frustrating) experiences. Maybe the cause of the problem is something else.

I have been searching for a command line invocation to change the
default output device (sink as PulseAudio calls them) and came across
this page today which may be helpful if you did not know about the pacmd
and what it can do.

http://terminalmage.NET/2011/11/17/setting-a-usb-headset-as-the-default-pulseaudio-device/

Thanks. I'll read though that and see if I can try what it suggests.

Perhaps if you follow the example given for a USB headset, and you
battle to create a valid udev rule, you could have a script to
automagically change from your onboard sound card to the USB device when
it is plugged in and change back when you unplug it?

When you have Parole running and it is sending audio to the headphone
socket and not where you want it to go, run pacmd dump and see what that
shews as the default sink.

Ok. thanks. :-)

FWIW Today will be 'busy' with something else as the priority, though. I've
decided that the 'round tuit' has arrived that lets me upgrade the shuttle
in my 'hifi room' system to Xubuntu 11.10 (I have until now left it happy
with Xubuntu 9.04, but 11.10 works nicely on my new box, so that prompts me
to do this.)

Once I've sorted out all the tweaks and additions and got that going, I'll
look at Pulse again.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Thu, 10 May 2012 09:20:25 +0100, Jim Lesurf wrote:

Thanks. I'll read though that and see if I can try what it suggests.

Further investigation reveals that where he wrote pacmd one should use pactl.

I do not know if this is due to a change in the version of PulseAudio
since that article was written.

Currently pacmd is the tool to use to get into a running interactive
pactl shell, so for issuing commands in a shell script, pactl is the
command to use.

man pactl for all the gory details.

In article , J G Miller
wrote:
On Thu, 10 May 2012 09:20:25 +0100, Jim Lesurf wrote:

Thanks. I'll read though that and see if I can try what it suggests.

Further investigation reveals that where he wrote pacmd one should use
pactl.

I do not know if this is due to a change in the version of PulseAudio
since that article was written.

Currently pacmd is the tool to use to get into a running interactive
pactl shell, so for issuing commands in a shell script, pactl is the
command to use.

man pactl for all the gory details.

OK, thanks for the update. I've spent this morning (successfully!)
installing Xubuntu 11.10 onto the shuttle I use in the hifi system. This
went well, and only took me a couple of hours including donwloading all the
updages, adding a lot of installing extra items I want, altering the config
details, etc. I have a few more details to tweak, then I'll have a rest
from getting computers to behave as I want. So I plan to check out the
things you've pointed out tomorrow or over the weekend.

FWIW with the above install I tried having a USB DAC on and connected
thoughout in the hope that *might* let Pulse see it, and that would effect
a success wrt using Pulse. Nope. No sound from Pulse. So as on all previous
occasions I've added my standard .asoundrc file, and then Audacious, VLC,
etc, all work fine with that.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Thursday, May 10th, 2012, at 11:08:46h +0000, J G Miller wrote:

On Thu, 10 May 2012 09:20:25 +0100, Jim Lesurf wrote:

Thanks. I'll read though that and see if I can try what it suggests.

Further investigation reveals that where he wrote pacmd one should use pactl.

Duh! Ignore that comment which is just plain wrong.

I should have read more carefully.

You need pacmd to set the defaults, but pactl can be used to eg fine tune
the parameters of a particular profile.

so for issuing commands in a shell script

What was adding to the confusion is that every time you use pacmd
it spits out the header introduction to the interactive "pa" shell

pacmd set-default-sink alsa_output.0.analog-stereo
Welcome to PulseAudio! Use "help" for usage information.


and the only way to get rid of that is to redirect that to
/dev/null because pacmd has no command line flags.

On Thursday, May 10th, 2012, at 12:22:05h +0100, Jim Lesurf wrote:

FWIW with the above install I tried having a USB DAC on and connected
thoughout in the hope that *might* let Pulse see it

What makes you think that Pulse is not seeing it?

Did you do a pacmd dump to list what sinks have been made
available to PulseAudio?

No sound from Pulse.

PulseAudio has a bad habit of muting ALSA mixer outputs,
and in particular initial installs of ALSA themselves
often mute the master output.

Did you go into alsamixer and adjust the levels accordingly,
both at the PulseAudio level and ALSA level?

Did you fire up Pavucontrol and check which input/outputs
are being used as default and check the levels there as well?

Remember if you have an onboard sound device or audio card
in the machine, that will almost always be set as the default
audio device by an initial installation.

(PS Why did you install Ubuntu which is going its own way on
a cellphone user interface, and not say Linux Mint or [LM]Debian
or openSUSE?)

In article , J G Miller
wrote:
On Thursday, May 10th, 2012, at 12:22:05h +0100, Jim Lesurf wrote:

FWIW with the above install I tried having a USB DAC on and connected
thoughout in the hope that *might* let Pulse see it

What makes you think that Pulse is not seeing it?

Although it seems happy to list a USB DAC as an option, that never actually
works when selected. Which makes me wonder if something in Pulse is broken
between the GUI/config side and what it actually does when given the config
settings, etc. However I really have no idea why Pulse is something that
never works in my experience with USB DACs.

Did you do a pacmd dump to list what sinks have been made available to
PulseAudio?

As explained in my earlier couple of postings I've postponed doing more on
this for a day or two as I've been busy with other things that do work OK.

As I think I said a while ago, I largely gave up on Pulse/GStreamer ages
ago. And can do pretty much the things I want without them. So I am just
revisiting this out of curiosity to see if I can find the problem and fix
it. It has a low priority when there are others things I need for daily
use. I only picked up (again) puzzling over Pulse because although VLC
works well with alsa it seems to get muddled about elapsed timings during
DVD replay. Whereas Parole gets elapsed time right, but lacks other
advantages of VLC.

So I may revert in due course to trying to sort out the timing oddities of
VLC. In the end that may be easier to sort out than Pulse! And I prefer VLC
anyway.

No sound from Pulse.

PulseAudio has a bad habit of muting ALSA mixer outputs, and in
particular initial installs of ALSA themselves often mute the master
output.

Did you go into alsamixer and adjust the levels accordingly, both at the
PulseAudio level and ALSA level?

Yes.

Did you fire up Pavucontrol and check which input/outputs are being used
as default and check the levels there as well?

Not yet for this install. Done that in the past with other distros with
zero success, though.

Remember if you have an onboard sound device or audio card in the
machine, that will almost always be set as the default audio device by
an initial installation.

Yes. I can understand why that makes sense so far as the developers of
distros, etc, are concerned. Not a problem *if* the user can then easily
change it if they choose. That said, if they perhaps understood those with
a serious interest in 'hifi' they might realise that an external or
additional 'soundcard' would be likely to be the desired choice of someone
who has got to the bother and expense of having one! :-)

(PS Why did you install Ubuntu which is going its own way on a cellphone
user interface, and not say Linux Mint or [LM]Debian or openSUSE?)

Slight correction as I prefer and use Xubuntu rather than Ubuntu as such. I
find the Gnome desktop way over the top. Prefer xfce. I'm not attracted by
the GUIs Ubuntu seem determined to provide these days. However the reason
is simple enough. I've used various versions of Xubuntu and overall I find
it works well and gives me a convenient setup in most ways. Become
comfortable with it. Particularly when I've added ROX as my main
filer/panel.

As you can tell from the point that I've only just replaced Xubuntu 9.04
with 11.10 I tend to leave a distro in place in a machine like the hifi one
on the basis that if it works as I want I don't rush to 'upgrade'. Having
done so, I also now will have to re-check that all works as before. e.g.
make some recordings whilst playing files like 96k/24 flac and ensure what
is sent to the USB DAC is sample-by-sample bit-perfect. This can take some
time, so not something I'm keen to do too often! However I use the audio
machines for test and measurement purposes on items like DACs, so need to
ensure things are calibrated and defined OK.

I've not (yet) tried Debian, but IIRC that tends to lean towards avoiding
some of the codecs, etc, I need to use a fair bit. My preference is Flac
or LPCM Wave or BWF, but I do get other file types I need to work with.
e.g. the BBC related work I've done involves AAC+, Flash, etc. Similarly,
using AC3 when examining DVDs. So I can't take an ideal approach to
avoiding closed or owned formats, etc.

I've been tempted by Mint, and may give it a serious go in the near future.
I am also attracted by CrunchBang. May seem an odd mix but...

I installed CrunchBang a while ago on an old laptop, and quite like it.
Seems easy to get it to do what I want. ROX also goes nicely on it. Mint is
interesting since it is clearly well liked by many who use it for purposes
similar to mine, and seem to think it now better than Ubuntu, but as yet
I've not tried it at all.

FWIW I am currently thinking of trying out both CrunchBang and Mint on my
newer laptop since that machine (which currently runs Xubuntu 9.04) is no
longer the main one I use for general purposes. So now useful as a testbed.
Indeed, giving these a tryout soon may make more sense from my POV than
spending much more time on the problems of Pulse on Xubuntu!

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Thursday, May 10th, 2012, at 17:08:27h +0100, Jim Lesurf wrote:

Although it seems happy to list a USB DAC as an option, that never actually
works when selected. Which makes me wonder if something in Pulse is broken
between the GUI/config side and what it actually does when given the config
settings, etc.

In which case use the pacmd and pactl command to change the PulseAudio
settings directly and not use the GUI

However I really have no idea why Pulse is something that
never works in my experience with USB DACs.

Now do not laugh and say that is just a cheap piece of low grade audio junk,
but is this any different in terms of operation that your
highly expensive USB devices

http://us.store.creative.com/Sound-Blaster-XFi-Surround-5.1/M/B0017QQQAE.htm

That said, if they perhaps understood those with
a serious interest in 'hifi' they might realise that an external or
additional 'soundcard' would be likely to be the desired choice of someone
who has got to the bother and expense of having one! :-)

And out of the millions who install Ubuntu on their laptops and
destkop PC, how many might that be?

This is the type of installation feature you are more likely
to find on openSUSE. My memory is a bit hazy but I think that
in the days of SuSE Linux, the audio setup (ALSA only back then)
did allow for the configuration of multiple cards within Yast.

I've not (yet) tried Debian, but IIRC that tends to lean towards avoiding
some of the codecs, etc, I need to use a fair bit.

Core Debian yes, but one just adds the independent "Debian" multi media
repository so wonderfully maintained by Monsieur Frédéric Brière.

It seems to me that you have got trapped in the "distribution branding"
frame of mind.

In article , J G Miller
wrote:
On Thursday, May 10th, 2012, at 17:08:27h +0100, Jim Lesurf wrote:

Although it seems happy to list a USB DAC as an option, that never
actually works when selected. Which makes me wonder if something in
Pulse is broken between the GUI/config side and what it actually does
when given the config settings, etc.

In which case use the pacmd and pactl command to change the PulseAudio
settings directly and not use the GUI

However I really have no idea why Pulse is something that never works
in my experience with USB DACs.

Now do not laugh and say that is just a cheap piece of low grade audio
junk, but is this any different in terms of operation that your highly
expensive USB devices

http://us.store.creative.com/Sound-Blaster-XFi-Surround-5.1/M/B0017QQQAE.htm

Afraid I can't really tell from what the page shows. From the comments it
seems more like something that 'processes' the sound data for output as 5.1
than a straightforward USB transfer DAC. So not clear, for example, if it
uses asynch/isochronous transfers with adequate bufferring and a good
clock. Not clear what the details of the DAC conversion may be. I'd need to
test one to tell more, and see a technical spec. Not encouraging that one
'reviewer' indicates it requires a lot of CPU. That really shouldn't be
needed for playing even 96k/24bit Flac stereo. And *accepting* 24 bit data
is no guarantee that the DAC actually used the full 24 bits. There are
various ways for such a system to not do all that it seems.

That said, if they perhaps understood those with a serious interest in
'hifi' they might realise that an external or additional 'soundcard'
would be likely to be the desired choice of someone who has got to the
bother and expense of having one! :-)

And out of the millions who install Ubuntu on their laptops and destkop
PC, how many might that be?

I can't tell. I assume it is a minority, but depends on what we'd decide
was meant by 'serious interest'. I'd take it to be people who are prepared
to put some cash and effort into getting good results, and have some idea
of how good a stereo system can sound, and why many commercial systems
people use are quite poor.

However I can say that - judging by things like hifi magazine sales, we'd
talking of around a few percent of the general population. How many are in
that small class overlap with the class of (aware) Linux users I can't
tell. What I *can* say is that is people know more about the topics they
might actually be drawn to useing a combination of Linux and 'serious'
hardware if they enjoy music.

This is the type of installation feature you are more likely to find on
openSUSE. My memory is a bit hazy but I think that in the days of SuSE
Linux, the audio setup (ALSA only back then) did allow for the
configuration of multiple cards within Yast.

If you know the card you point to about works with the USB modules, etc in
the current kernels, I'd be happy to see if I can blag one to check out
sometime. On of the points of the measurements I've been making is to
generate at least a partial list of what devices work OK with Linux
distros. In theory, all those that say they follow the defined class spec
should. But I've found at least one that didn't!

I've not (yet) tried Debian, but IIRC that tends to lean towards
avoiding some of the codecs, etc, I need to use a fair bit.

Core Debian yes, but one just adds the independent "Debian" multi media
repository so wonderfully maintained by Monsieur Frédéric Brière.

Ah. Thanks for that. I didn't realise. I'll put Debian higher on my list of
distros to try sometime.

It seems to me that you have got trapped in the "distribution branding"
frame of mind.

That may not explain why I add ROX and alter so many details of the setup
to suit me. :-) I think it is more a case of only making changes slowly
once I find a given setup does as I wish. Plus one advantage of staying
with a given distro is familiarity with where it tends to 'hide away'
various config files, etc.[1]

Having found how to generally get Xubuntu to behave as I choose I am happy
enough to use it as a basis for the systems. I have also been cautious as
until recently I've only had two 'modern' machines. One being in daily use
in the hifi system, the other as a workhorse. Now I have an additional new
machine it will be easier to use a 'freed' laptop to simply experiment with
distros, etc. (The only other machine I have is a very old laptop with
256 MB of ram. So somewhat limited as a system for trying distros, etc.
This works nicely with CrunchBang, but isn't really up to many curret
distros 'out of the box'. But the freed laptop has 1GB of ram and a dual
core CPU, so rather more able.)

I have tried other distros in the past, and plan to do so again. But I am
not as interested as some may be in trying many new releases of many
distros. My interest is in use rather than computer science as such. :-)

However as indicated above, I now have in mind using my freed laptop to try
out a series of distros as I get time to do so. I did plan Mint and the
current CrunchBang as starters, but I've now added Debian to that
shortlist. :-)

Slainte,

Jim

[1] That said, I can't find the pseudo-files for CPU temperature when
running Xubuntu 11.10. Any idea where they have gone?

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html