pulseaudio: no sound, Fedora 12, what debugging/diagnostic info is needed to solve this problem?

[Rick Sewill]

On Wed, 2010-03-03 at 22:32 -0600, Rick Sewill wrote: 
> I have found audio, in general, and pulseaudio, in particular, tricky.
> 
> I try to divide audio into parts, alsa is one part, pulseaudio another.
> 
> I believe many software programs use alsa.
> I believe alsa, in turn, uses pulseaudio.
> 
> I must add a caveat.  I believe programs can be configured to use alsa.
> I believe some programs can be configured to use pulseaudio, bypassing
> alsa.  I believe some programs can be configured to bypass pulseaudio,
> and go straight to the hardware device drivers.
> 
> Assuming your configuration uses alsa, which in turn goes to pulseaudio,
> I believe you have to look at both alsa and pulseaudio.
> 
> For alsa, do you have alsa-utils installed?
> For me, it is rpm -q -i alsa-utils:
> rsewill at rsewill:~ <2:18> $ rpm -q -i alsa-utils
> Name        : alsa-utils                   Relocations: (not
> relocatable)
> Version     : 1.0.22                            Vendor: Fedora Project
> Release     : 1.fc12                        Build Date: Sat 02 Jan 2010
> 03:26:02
> ....
> 
> If you this installed, there is a program, amixer, please type
> amixer
> 
> When I type amixer, I get the following:
> rsewill at rsewill:~ <2:16> $ amixer
> Simple mixer control 'Master',0
>   Capabilities: pvolume pswitch pswitch-joined penum
>   Playback channels: Front Left - Front Right
>   Limits: Playback 0 - 65536
>   Mono:
>   Front Left: Playback 15601 [24%] [on]
>   Front Right: Playback 15601 [24%] [on]
> Simple mixer control 'Capture',0
>   Capabilities: cvolume cswitch cswitch-joined penum
>   Capture channels: Front Left - Front Right
>   Limits: Capture 0 - 65536
>   Front Left: Capture 32845 [50%] [on]
>   Front Right: Capture 32845 [50%] [on]
> "Master" seems to control output volume for me.
> "Capture" seems to control input from my microphone.
> 
> For audio output, 
> I want "Front Left" and "Front Right" of "Master"
> to have a certain volume level, in my case 24%, and be on.
> I actually control volume by adjusting the volume of "Master".
> I leave pulseaudio alone once I have it set the way I want it.
> 
> For my microphone, I control the volume using "Capture".
> I leave pulseaudio alone once I have it set the way I want it.
> 
> I believe this is only part of the picture.
> Alsa, in turn goes to pulseaudio.
> 
> There is a pulseaudio volume control applet.
> Do you have pavucontrol installed?
> It is found in the rpm pavucontrol, for me
> rpm -q -i pavucontrol yields
> rsewill at rsewill:~ <2:21> $ rpm -q -i pavucontrol
> Name        : pavucontrol                  Relocations: (not
> relocatable)
> Version     : 0.9.10                            Vendor: Fedora Project
> Release     : 1.fc12                        Build Date: Wed 14 Oct 2009
> 03:11:07 PM CDT
> ....
> 
> When I run this applet, either from the command line, as pavucontrol,
> or from the menu--it is found as
> Applications->Sounds and Video-->Pulse Audio Volume Control
> 
> an applet pops up, with 5 tabs,
> "Playback","Recording","Output Devices","Input Devices","Configuration"
> Please look at the "Output Devices" tab, 
> show "All Output Devices", 
> Please make sure the device is not muted--if the device is muted
> the "Front Left" and "Front Right" lines will be greyed out on a device.
> Please adjust the volume of this device, as appropriate.
> For me, I have the volume of my device adjusted to 24% for both
> "Front Left" and "Front Right".
> 
> I have not found man pages for pavucontrol or amixer.
> I can make educated guesses what the tabs for pavucontrol mean,
> but I would be guessing.
> 
> You will have different hardware.  
> You may get different devices to examine.
> Hope you can adapt what I see on my system to what you have.
> 

I need to make one correction, 
showing that I do not understand audio even yet.

I just learned, when I change the sound, using alsa controls, alsa 
changes the volume on the pulseaudio controls shown by pavucontrol.