osstest(1)							 OSS User Commands							osstest(1)

NAME

       osstest - Open Sound System audio self test applet.

DESCRIPTION

       The osstest applet is a simple test application that can be used to test functionality of the sound hardware installed in the system.

       osstest performs a playback test for each installed audio device. If there are any "machine detectable" problems they will be reported. You
       will first hear an audio sample played on the left speaker, then the right speaker and finally in stereo on both speakers.

       It's user's responsibility to listen if the test sound is audible. If no sound output can be heard the possible reason is one of  the  fol-
       lowing:

       1.  An  error  was reported by osstest. In this case there will usually not be any sound output. The error needs to be fixed before running
	   osstest again.

       2.  There is no headphones or speakers connected. Or the connection is not made correctly.

       3.  The mixer volume level is set to a too low value. By default it should be OK. The mixer level can be adjusted using the  mixer,  ossmix
	   and ossxmix utilities distributed with OSS.

       4.  Some  notebooks  have  nonstandard volume control and/or speaker selection hardware that is not supported by OSS. It's very likely that
	   OSS doesn't support such vendor specific additions.

       If no errors were reported and the test sound was audible it means that OSS and your sound hardware is functioning correctly. If you  still
       encounter  problems  with some sound applications the reason is almost certainly in the application. Check it's configuration or try to use
       another equivivalent application.

       If you are having problems with JDS, KDE and/or Gnome system sounds, you need to make sure that OSS gets started before	the  GUI  environ-
       ment. Refer to your operating system's startup procedures.

   SAMPLE RATE DRIFT
       The  osstest  utility  measures	a sample rate drift value after playing back the test sound. Ideally it should be 0% but in practice there
       will be an error of few percents. 0% means that the 48000 Hz test file was played exactly at 48000 Hz sampling rate.

       The sample rate measurement is based on the system timer which has limited precision. It's likely that less than 1% differenc  between  the
       nominal	and the measured sampling rates are actually caused by an error in the measurement.  For this reason the drift reported by osstest
       should not be used as any kind of quality measurement. However if the drift is very large it means that there is  something  wrong  in  the
       system. The oscillator chip used with the sound chip is broken or the system clock is running at a wrong speed.

   USING OSSTEST MANUALLY
       The osstest utility is located in the /usr/bin directory. It can be run manually to test functionality of OSS and your sound hardware. When
       invoked without any command line parameters osstest performs the default test on all devices. However it will skip some of the devices base
       on the following rules.

       o  It  is  possible  to	test just one of the available audio devices by giving its number on command line (for example osstest 1). Use the
	  device index numbers reported by "ossinfo -a".

       o  Use the -l command line option to loop the test infinitely.

       o  Virtual mixer devices will not be tested. Use the -V command line option to force test of virtual devices.

       o  The actual (physical) audio devices will be tested directly (bypassing virtual mixer). If you want to test playback  through	vmix  then
	  use the -V option.

       o  Multiple  device files related with the same physical device will not be tested. Only the first one gets tested while the remaining ones
	  will be skipped. At this moment there is no way to force osstest to test this kind of devices.

       o  Only stereo devices will be tested. Future versions of osstest will be able to test mono and multi channel  devices  too.  Also  osstest
	  requires that the device supports the 16 bit signed format and 48kHz sampling rate.

       o  Send a SIGQUIT (Ctrl- on most terminals) to make osstest skip a device.

FILES

       /usr/bin/osstest

SEE ALSO

       savemixer(1)

AUTHOR

       4Front Technologies

								 16 December 2012							osstest(1)