Audio::Mixer - Perl extension for Sound Mixer control

Audio-Mixer documentation Contained in the Audio-Mixer distribution.

Index

Code Index:

NAME

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Audio::Mixer - Perl extension for Sound Mixer control

SYNOPSIS

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  use Audio::Mixer;
  $volume = Audio::Mixer::get_cval('vol');
  if (Audio::Mixer::set_cval('vol', 50, 40)) {
    die("Can't set volume...");
  }

DESCRIPTION

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Library to query / set various sound mixer parameters.

This is just a very simple Perl interface which allows to set various sound mixer parameters. The most important probably 'vol' (volume). The list of all mixer parameters can be obtained using get_mixer_params() function.

All values (lcval, rcval) are numbers in 0-100 range.

FUNCTIONS

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get_cval(cntrl) - Get parameter value Parameters: cntrl - name of parameter Returns: in array context: (lcval, rcval), where: lcval - left channel value rcval - right channel value in scalar context returns value of get_param_val() (see below)

set_cval(cntrl, lcval, rcval) - Set parameter value Parameters: cntrl - name of parameter lcval - left channel value rcval - right channel value (optional, if not supplied will be equal to lcval) Returns: 0 if Ok, -1 if failed

set_source(cntrl) - set record source Parameters: cntrl - name of channel to record from Returns: 0 if Ok, -1 if failed

get_source(cntrl) - get record source Returns: name of channel to record from

set_mixer_dev(fname) - Set mixer device name (optional), /dev/mixer is used by default fname - device name Returns: 0 if Ok

init_mixer() - Initialize mixer (open it) set_cval() / get_cval() opens / closes the mixer each time they called unless init_mixer() called before. In case if init_mixer() called before all other functions will use already opened device instead of opening it each time.

close_mixer() - Close device. Should be called only if init_mixer() was used.

get_mixer_params() - Get list of mixer parameters Returns: list of parameters names.

LOW LEVEL FUNCTIONS:

get_param_val(cntrl) - Get parameter value Parameter: cntrl - name of parameter Returns: integer value, which will be constructed as follows: lower byte (x & 0xff) - value of the left channel (or whole value) next byte (x & 0xff00) - value of the right channel third byte (x & 0xff0000) - flags (if x & 0x10000 then 2 channels exist) or -1 in case of failure.

set_param_val(cntrl, lcval, rcval) - Set parameter value. Here all parameters are mandatory (in contrast to set_cval()). Parameters: cntrl - name of parameter lcval - left channel value rcval - right channel value Returns: 0 if Ok, -1 if failed

AUTHOR

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Sergey Gribov, sergey@sergey.com

LICENSE

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Copyright (c) 2001 Sergey Gribov. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

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perl(1).

Audio-Mixer documentation Contained in the Audio-Mixer distribution. 
package Audio::Mixer;

#
# Library to query / set various sound mixer parameters.
# See POD documentation below for more info.
#
# Copyright (c) 2000 Sergey Gribov <sergey@sergey.com>
# This is free software with ABSOLUTELY NO WARRANTY.
# You can redistribute and modify it freely, but please leave
# this message attached to this file.
#
# Subject to terms of GNU General Public License (www.gnu.org)
#
# Last update: $Date: 2002/04/30 00:48:21 $ by $Author: sergey $
# Revision: $Revision: 1.4 $

use strict;
use Carp;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK $AUTOLOAD);

require Exporter;
require DynaLoader;
require AutoLoader;

@ISA = qw(Exporter DynaLoader);
# Items to export into callers namespace by default. Note: do not export
# names by default without a very good reason. Use EXPORT_OK instead.
# Do not simply export all your public functions/methods/constants.
@EXPORT = qw();
@EXPORT_OK = qw(
	MIXER
);
$VERSION = '0.7';

sub AUTOLOAD {
    # This AUTOLOAD is used to 'autoload' constants from the constant()
    # XS function.  If a constant is not found then control is passed
    # to the AUTOLOAD in AutoLoader.

    my $constname;
    ($constname = $AUTOLOAD) =~ s/.*:://;
    croak "& not defined" if $constname eq 'constant';
    my $val = constant($constname, @_ ? $_[0] : 0);
    if ($! != 0) {
	if ($! =~ /Invalid/) {
	    $AutoLoader::AUTOLOAD = $AUTOLOAD;
	    goto &AutoLoader::AUTOLOAD;
	}
	else {
		croak "Your vendor has not defined Audio::Mixer macro $constname";
	}
    }
    no strict 'refs';
    *$AUTOLOAD = sub () { $val };
    goto &$AUTOLOAD;
}

bootstrap Audio::Mixer $VERSION;

# Preloaded methods go here.

# Autoload methods go after =cut, and are processed by the autosplit program.


sub get_cval {
  my $channel = shift;
  my ($val, $lcval, $rcval);
  $val = get_param_val($channel);
  $lcval = $val & 0xff;
  $rcval = $val & 0x10000 ? ($val & 0xff00) >> 8 : $lcval;
  return wantarray ? ($lcval, $rcval) : $val;
}

sub set_cval {
  my ($channel, $lcval, $rcval) = @_;
  $lcval = 0 unless $lcval;
  $rcval = $lcval unless $rcval;
  return set_param_val($channel, $lcval, $rcval);
}

sub get_mixer_params {
  return(split(/ /, get_params_list()));
}

1;
__END__
# Below is the stub of documentation for your module. You better edit it!