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GAINTOOL(6)                      Games Manual                      GAINTOOL(6)



NAME
       gaintool - audio control panel

SYNOPSIS
       gaintool

AVAILABILITY
       This  command  is  only  available  with the Demos installation option.
       Refer to for information on how to install optional software.

DESCRIPTION
       gaintool is a SunView demonstration program that controls various char-
       acteristics  of the SPARCstation 1 audio device, see audio(4S).  Opera-
       tions performed by gaintool affect all audio  programs;  for  instance,
       adjusting the Play Volume instantly changes the output gain, regardless
       of which program is playing.  gaintool also detects audio state changes
       made  by  other  programs, and updates its display accordingly, keeping
       gaintool in sync with the current device configuration.

       gaintool demonstrates an important principle involved in  the  integra-
       tion of audio in the desktop environment: by enabling global control of
       important characteristics, it is not necessary for every application to
       provide  an  interface for these parameters.  For instance, since audio
       output may be paused from the control panel, it is not strictly  neces-
       sary  that  output  applications  display  a Pause button of their own.
       However, such applications  may  detect  that  audio  output  has  been
       paused, and take appropriate action.

   Control Panel
       Play Volume
              This  slider adjusts the output volume.  Volume levels between 0
              and 100 may be selected, where 0 represents infinite attenuation
              and 100 is maximum gain.

       Record Volume
              This  slider  adjusts the recording gain level in the range 0 to
              100.

       Monitor Volume
              This slider adjusts the monitor gain level in  the  range  0  to
              100.   Monitor  gain  controls  the amount of audio input signal
              that is fed through to the output port.   For  instance,  if  an
              audio  source  (such  as  a  radio  or  CD-player)  is connected
              directly to the input port, the input signal  may  be  monitored
              through either the built-in speaker or the headphone jack.

       Output This  selector switches the audio output port between the built-
              in speaker and the external headphone jack.

       Pause Play
              This button may be used to suspend and resume audio output.   If
              audio output is in progress when Pause is clicked, it is stopped
              immediately and subsequent output data remains queued.  The but-
              ton then switches to a Resume button that, when clicked, resumes
              audio output at the point that it was suspended.

              If no process has the device  open  for  output  when  Pause  is
              clicked,  gaintool holds the device open itself, thereby denying
              other processes output access.  Audio programs that simply  open
              and  write  to the audio device will typically be suspended when
              they attempt to open the device.  Programs  that  asynchronously
              poll  the  device  will  discover that it is "busy" and may take
              appropriate action.

   Audio Device Status Panel
              Pressing the PROPS (L3) key brings up a status panel that  shows
              the current state with the its display accordingly, audio appli-
              cations.  Selecting "Done" from the panel menu (or pressing  the
              (L7) key) removes the panel.

              Ordinarily,  the  device  status  is updated only when a SIGPOLL
              signal is delivered to gaintool  (see  audio(4S)).   Because  of
              this, the Active and Samples indicators are not necessarily kept
              up-to-date.  However, when the  mouse  is  positioned  over  the
              panel, status is continually updated.

SEE ALSO
       audio(4S), soundtool(6)

BUGS
       Record  Volume  should be controlled by a separate panel that also pro-
       vides automatic gain level adjustment capabilities.

WARNINGS
       This program is furnished on an as is basis as a demonstration of audio
       applications programming.



                                15 January 1990                    GAINTOOL(6)