Free audio advisor software for linux

Audio::Radio::Sirius is a Perl module to control a Sirius satellite radio tuner.

SYNOPSIS

Sirius satellite radio (http://www.sirius.com) is a US based satellite radio serice. While none of the tuners they make have serial or USB connectors, it has been found that generation 2.5 tuners (Sportster, Starmate, * Replay, Sirius Connect, and others) have a common tuner module.

Furthermore this tuner module generally has a serial interface. Presently only one commercial site is offering a modification for adding a serial port to a Sirius tuner: http://www.rush2112.net. Google should reveal schematics and parts needed for adding ports to other tuners.

Once your tuner is connected to your system and accessible via a serial port like device, you can use this module to access it:

use Audio::Radio::Sirius;
use Win32::SerialPort; # or Device::SerialPort on Linux

my $serial = new Win32::SerialPort(com1);
my $tuner = new Audio::Radio::Sirius;

$tuner->connect($serial);
$tuner->power(1);
$tuner->channel(184); # tune in the preview channel

Audio::Mad is a Perl interface to the mad MPEG decoder library.

SYNOPSIS

use Audio::Mad qw(:all);

my $stream = new Audio::Mad::Stream();
my $frame = new Audio::Mad::Frame();
my $synth = new Audio::Mad::Synth();
my $timer = new Audio::Mad::Timer();
my $resample = new Audio::Mad::Resample(44100, 22050);
my $dither = new Audio::Mad::Dither();

my $buffer = join(, );
$stream->buffer($buffer);

FRAME: {
if ($frame->decode($stream) == -1) {
last FRAME unless ($stream->err_ok());

warn "decoding error: " . $stream->error();
next FRAME;
}

$synth->synth($frame);
my $pcm = $dither->dither($resample->resample($synth->samples()));

print $pcm;
next FRAME;
}

This module is an attempt to provide a perl interface to the MAD (MPEG Audio Decoder) library, written by Robert Leslie. It has been designed to be 100% object oriented, and to follow the MAD interface as closely as possible.

So far, most of the MAD library, plus two companion modules are provided as part of the interface. Seperate documentation is provided in perldoc for all of the modules in the Audio::Mad framework.

Audio::DSP is a Perl interface to *NIX digital audio device.

SYNOPSIS

use Audio::DSP;

($buf, $chan, $fmt, $rate) = (4096, 1, 8, 8192);

$dsp = new Audio::DSP(buffer => $buf,
channels => $chan,
format => $fmt,
rate => $rate);

$seconds = 5;
$length = ($chan * $fmt * $rate * $seconds) / 8;

$dsp->init() || die $dsp->errstr();

# Record 5 seconds of sound
for (my $i = 0; $i < $length; $i += $buf) {
$dsp->read() || die $dsp->errstr();
}

# Play it back
for (;;) {
$dsp->write() || last;
}

$dsp->close();

Audio::DSP is built around the OSS (Open Sound System) API and allows perl to interface with a digital audio device. It provides, among other things, an initialization method which opens and handles ioctl messaging on the audio device file. Audio::DSP also provides some rudimentary methods for the storage and manipulation of audio data in memory.

In order to use Audio::DSP, youll need to have the necessary OSS drivers/libraries installed. OSS is available for many popular Unices, and a GPLed version (with which this extension was initially developed and tested) is distributed with with the Linux kernel.

Audio::LADSPA::Network is a semi automatic connection of Audio::LADSPA::* objects.

SYNOPSIS

use Audio::LADSPA::Network;
use Audio::LADSPA::Plugin::Play;
sub subscriber {
my ($object,$event) = @_;
$object = ref($object);
print "Recieved event $event from $objectn";
}
Audio::LADSPA::Network->add_subscriber(*,⊂scriber);

my $net = Audio::LADSPA::Network->new();
my $sine = $net->add_plugin( label => sine_fcac );
my $delay = $net->add_plugin( label => delay_5s );
my $play = $net->add_plugin(Audio::LADSPA::Plugin::Play);

$net->connect($sine,Output,$delay,Input);
$net->connect($delay,Output,$play,Input);

$sine->set(Frequency (Hz) => 440); # set freq
$sine->set(Amplitude => 1); # set amp

$delay->set(Delay (Seconds) => 1); # 1 sec delay
$delay->set(Dry/Wet Balance => 0.2); # balance - 0.2

for ( 0 .. 100 ) {
$net->run(100);
}
$sine->set(Amplitude => 0); #just delay from now
for ( 0 .. 500 ) {
$net->run(100);
}

This module makes it easier to create connecting Audio::LADSPA::Plugin objects. It automatically keeps the sampling frequencies correct for all plugins, adds control and audio buffers to unconnected plugins and prevents illegal connections.

It also implements an observable-type API via Class::Publisher that can be used to recieve notifications of events in the network. Amongst other things, this makes writing loosely coupled GUIs fairly straightforward.

Audio::Ecasound is a Perl binding to the ecasound sampler, recorder, fx-processor.

SYNOPSIS
One function interface:
use Audio::Ecasound qw(:simple);

eci("cs-add play_chainsetup");
eci("c-add 1st_chain");
eci("-i:some_file.wav");
eci("-o:/dev/dsp");
# multiple n separated commands
eci("cop-add -efl:100
# with comments
cop-select 1
copp-select 1
cs-connect");
eci("start");
my $cutoff_inc = 500.0;
while (1) {
sleep(1);
last if eci("engine-status") ne "running";

my $curpos = eci("get-position");
last if $curpos > 15;

my $next_cutoff = $cutoff_inc + eci("copp-get");
# Optional float argument
eci("copp-set", $next_cutoff);
}
eci("stop");
eci("cs-disconnect");
print "Chain operator status: ", eci("cop-status");

Object Interface

use Audio::Ecasound;

my $e = new Audio::Ecasound;
$e->on_error();
$e->eci("cs-add play_chainsetup");
# etc.
Vanilla Ecasound Control Interface (See Ecasounds Programmer Guide):
use Audio::Ecasound qw(:std);

command("copp-get");
$precise_float = last_float() / 2;
command_float_arg("copp-set", $precise_float);
warn last_error() if error();
IAM Interface, pretend interactive mode commands are functions.
use Audio::Ecasound qw(:iam :simple);

# iam commands as functions with s/-/_/g
my $val = copp_get;
copp_set $val+0.1; # floats are stringified so beware
eci("-i /dev/dsp"); # not all commands are exported

Audio::Ecasound provides perl bindings to the ecasound control interface of the ecasound program. You can use perl to automate or interact with ecasound so you dont have to turn you back on the adoring masses packed into Wembly Stadium.
Ecasound is a software package designed for multitrack audio processing. It can be used for audio playback, recording, format conversions, effects processing, mixing, as a LADSPA plugin host and JACK node. Version >= 2.2.X must be installed to use this package. "SEE ALSO" for more info.

Linux Audio Backstop project is a system for automated scheduling of audio recording and playback in a broadcast environment.
It includes features for controlling external audio switcher devices by means of serial and TCP/IP commands, as well as the ability to record and playback relay closures by means of the line of digital GPIO cards manufactured by MeasurementComputing.
The Linux Audio Backstop runs on the popular GNU/Linux operating system. It is freely available under the GNU General Public License.
Main features:
- Record and Playback up to four feeds simultaneously.
- Programmable from any web browser.
- Supports capture and playout of up to twenty-four discrete relay closures.
- Very lightweight and efficient - a Pentium 1 system is capable of hosting a complete system
- Runs on the rock-solid GNU/Linux operating system.
- Totally free and open -- No dongles, unlock codes, software keys or other arbitrary limitations.

Audio::LADSPA::Buffer is a Perl module for LADSPA buffer.

SYNOPSIS

use Audio::LADSPA;

my $buffer = Audio::LADSPA::Buffer->new($size);

$plugin->connect(Port name => $buffer);

$buffer->set( @values );

# or get a buffer from a plugin..

$buffer2 = $plugin->get_buffer(Other port);

# make audio buffer louder

$buffer *= 2;

Audio::LADSPA::Buffer objects implement the connections between Audio::LADSA::Plugin objects. You can set up the buffer, and let some plugin write to it, while others read from it, or read from or write to it yourself.

There is no real difference between audio and control buffers, except that control buffers have a size of 1 sample *) and audio buffers are usually bigger.
*) Samples in LADSPA are implemented as native floats.