man3/AFSetInputGain.3

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    AFQueryInputGain(3)					  AFQueryInputGain(3)

    NAME
      AFQueryInputGain, AFQueryOutputGain, AFSetInputGain, AFSetOutputGain -
      query	or set input or	output gain

    SYNTAX
      #include <AF/AFlib.h>

      int AFQueryInputGain ( AC ac,	int *min_input_gain, int *max_input_gain)

      int AFQueryOutputGain	( AC ac, int *min_output_gain, int *max_output_gain)

      void AFSetInputGain (	AC ac, int gain)

      void AFSetOutputGain ( AC ac,	int gain)

    ARGUMENTS

      ac	    An audio context for some audio device.

      gain	    Specifies the gain in dB. Should be	in min/max range as returned
    	    by AFQueryInputGain	or AFQueryOutputGain as	appropriate.

      min_input_gain
    	    Returns the	minimum	gain supported by the audio device (could be
    	    negative if	it is attenuation.)

      min_output_gain
    	    Returns the	minimum	gain supported by the audio device (could be
    	    negative if	it is attenuation.)

      max_input_gain
    	    Returns the	maximum	gain supported by the audio device (could be
    	    negative if	it is attenuation.)

      max_output_gain
    	    Returns the	maximum	gain supported by the audio device (could be
    	    negative if	it is attenuation.)

    DESCRIPTION
      The AFQueryInputGain function	returns	the current input gain setting.	 The
      minimum and maximum allowable	gain settings for the audio device specified
      in the audio context are written to min_input_gain and max_input_gain.

      The AFQueryOutputGain	function returns the current output gain setting.
      The minimum and maximum allowable gain settings for the audio	device speci-
      fied in the audio context are	written	to min_output_gain and
      max_output_gain.

      The AFSetInputGain function sets the input gain of the audio device con-
      tained in the	audio context to the value specified by	gain.

      The AFSetOutputGain function sets the	gain of	the audio device specified by
      the audio context to gain.

    SEE ALSO
      AAudioDeviceDescriptor(3)
      AF(1)

    BUGS
      If you encounter a reproducible bug, please submit a problem report to
      (af-bugs@crl.dec.com).

    COPYRIGHT
      Copyright 1990-1994, Digital Equipment Corporation.
      See AF(1) for	a full statement of rights and permissions.

    AUTHORS
      Digital Cambridge Research Lab