Alsamixertest
=============
In lack of a manpage...here's at least a small introduction.

alsamixertest plays back sound at different volumes and records them at the same time, to find out whether the alsamixer is correct or buggy. It also tests mixer control names to see if they meet up with PulseAudio's expectations.

Installation:
=============

If you have a Debian/Ubuntu system, just install the Debian package. Otherwise, do this:

* Unpack the source.tar.gz and cd into that directory.
* Make sure you have libfftw3 development headers installed (as well as gcc, make, pkg-config, and python)
* Run "make"
* Optionally, do "make install" as root. You can also run the program from the current directory.

Setup:
======

You'll need an audio output, an audio input, and some way to connect them. Some ways do to this are to:
 * Connect a loopback cable between line-in and line-out
 * Connect a loopback cable between headphone-out and mic-in
 * Do nothing and test internal mic and internal speakers
 * I've also tested a headset once by holding the headset mic towards the headset's speaker :-)

Second, you'll need to fix the capture settings. This is easiest done in alsamixer. To find out the name of your card, "cat /proc/asound/cards". Then run "alsamixer -c 0", where 0 is the index of the card you want to capture from. Make sure you have set the mixer to a reasonable input level and selected the right input (e g mic, line-in etc). 

Options:
========

  -p path, --path=path  PulseAudio mixer path to test, available options:
                        analog-output, analog-output-headphones, analog-
                        output-speaker-center, analog-output-speaker-front,
                        analog-output-speaker-lfe, analog-output-speaker-rear,
                        analog-output-speaker-side


This path should match what output you're testing. So if you are testing internal (front) speakers, set this to analog-output-speaker-front. 
If you're testing headphones, analog-output-headphones. If you're testing rear surround output, analog-output-speaker-rear (and also make sure the loopback cable is connected to the rear outputs).

  -c card, --sound-card=card
                        Sets up a loopback through the specified sound card.
                        Available options: 0, SB, 1, Juli, 2, HDMI

This one controls the output sound card. If this isn't obvious from the names (and sometimes it isn't), "cat /proc/asound/cards" to see if that helps.

Those two options is what you need to set properly to make a proper test. In addition, if you're playing back and recording from *different* sound cards, you also want to set this switch:

  -i device, --input-device=device
                        ALSA device name for input device (overrides the -c
                        switch)

E g, if you're playing back through the "SB" soundcard and recording through the "Juli" sound card, you should set "-c SB -i plughw:Juli". 

License:
========
The short version: GPLv3

The slightly longer version:

Written by David Henningsson <david.henningsson@canonical.com>
Copyright 2010 Canonical Ltd.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License version 3, as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranties of MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program.  If not, see <http://www.gnu.org/licenses/>.



