Sound(3) User Contributed Perl Documentation Sound(3)NAME
Win32::Sound - An extension to play with Windows sounds
SYNOPSIS
use Win32::Sound;
Win32::Sound::Volume('100%');
Win32::Sound::Play("file.wav");
Win32::Sound::Stop();
# ...and read on for more fun ;-)
FUNCTIONS
Win32::Sound::Play(SOUND, [FLAGS])
Plays the specified sound: SOUND can the be name of a WAV file or
one of the following predefined sound names:
SystemDefault
SystemAsterisk
SystemExclamation
SystemExit
SystemHand
SystemQuestion
SystemStart
Additionally, if the named sound could not be found, the function
plays the system default sound (unless you specify the
"SND_NODEFAULT" flag). If no parameters are given, this function
stops the sound actually playing (see also Win32::Sound::Stop).
FLAGS can be a combination of the following constants:
"SND_ASYNC"
The sound is played asynchronously and the function returns
immediately after beginning the sound (if this flag is not
specified, the sound is played synchronously and the function
returns when the sound ends).
"SND_LOOP"
The sound plays repeatedly until it is stopped. You must also
specify "SND_ASYNC" flag.
"SND_NODEFAULT"
No default sound is used. If the specified sound cannot be
found, the function returns without playing anything.
"SND_NOSTOP"
If a sound is already playing, the function fails. By default,
any new call to the function will stop previously playing
sounds.
Win32::Sound::Stop()
Stops the sound currently playing.
Win32::Sound::Volume()
Returns the wave device volume; if called in an array context,
returns left and right values. Otherwise, returns a single 32 bit
value (left in the low word, right in the high word). In case of
error, returns "undef" and sets $!.
Examples:
($L, $R) = Win32::Sound::Volume();
if( not defined Win32::Sound::Volume() ) {
die "Can't get volume: $!";
}
Win32::Sound::Volume(LEFT, [RIGHT])
Sets the wave device volume; if two arguments are given, sets left
and right channels independently, otherwise sets them both to LEFT
(eg. RIGHT=LEFT). Values range from 0 to 65535 (0xFFFF), but they
can also be given as percentage (use a string containing a number
followed by a percent sign).
Returns "undef" and sets $! in case of error, a true value if
successful.
Examples:
Win32::Sound::Volume('50%');
Win32::Sound::Volume(0xFFFF, 0x7FFF);
Win32::Sound::Volume('100%', '50%');
Win32::Sound::Volume(0);
Win32::Sound::Format(filename)
Returns information about the specified WAV file format; the array
contains:
· sample rate (in Hz)
· bits per sample (8 or 16)
· channels (1 for mono, 2 for stereo)
Example:
($hz, $bits, $channels)
= Win32::Sound::Format("file.wav");
Win32::Sound::Devices()
Returns all the available sound devices; their names contain the
type of the device (WAVEOUT, WAVEIN, MIDIOUT, MIDIIN, AUX or MIXER)
and a zero-based ID number: valid devices names are for example:
WAVEOUT0
WAVEOUT1
WAVEIN0
MIDIOUT0
MIDIIN0
AUX0
AUX1
AUX2
There are also two special device names, "WAVE_MAPPER" and
"MIDI_MAPPER" (the default devices for wave output and midi
output).
Example:
@devices = Win32::Sound::Devices();
Win32::Sound::DeviceInfo(DEVICE)
Returns an associative array of information about the sound device
named DEVICE (the same format of Win32::Sound::Devices).
The content of the array depends on the device type queried. Each
device type returns at least the following information:
manufacturer_id
product_id
name
driver_version
For additional data refer to the following table:
WAVEIN..... formats
channels
WAVEOUT.... formats
channels
support
MIDIOUT.... technology
voices
notes
channels
support
AUX........ technology
support
MIXER...... destinations
support
The meaning of the fields, where not obvious, can be evinced from
the Microsoft SDK documentation (too long to report here, maybe one
day... :-).
Example:
%info = Win32::Sound::DeviceInfo('WAVE_MAPPER');
print "$info{name} version $info{driver_version}\n";
THE WaveOut PACKAGE
Win32::Sound also provides a different, more powerful approach to wave
audio data with its "WaveOut" package. It has methods to load and then
play WAV files, with the additional feature of specifying the start and
end range, so you can play only a portion of an audio file.
Furthermore, it is possible to load arbitrary binary data to the
soundcard to let it play and save them back into WAV files; in a few
words, you can do some sound synthesis work.
FUNCTIONS
new Win32::Sound::WaveOut(FILENAME)
new Win32::Sound::WaveOut(SAMPLERATE, BITS, CHANNELS)
new Win32::Sound::WaveOut()
This function creates a "WaveOut" object; the first form opens the
specified wave file (see also "Open()" ), so you can directly
"Play()" it.
The second (and third) form opens the wave output device with the
format given (or if none given, defaults to 44.1kHz, 16 bits,
stereo); to produce something audible you can either "Open()" a
wave file or "Load()" binary data to the soundcard and then
"Write()" it.
Close()
Closes the wave file currently opened.
CloseDevice()
Closes the wave output device; you can change format and reopen it
with "OpenDevice()".
GetErrorText(ERROR)
Returns the error text associated with the specified ERROR number;
note it only works for wave-output-specific errors.
Load(DATA)
Loads the DATA buffer in the soundcard. The format of the data
buffer depends on the format used; for example, with 8 bit mono
each sample is one character, while with 16 bit stereo each sample
is four characters long (two 16 bit values for left and right
channels). The sample rate defines how much samples are in one
second of sound. For example, to fit one second at 44.1kHz 16 bit
stereo your buffer must contain 176400 bytes (44100 * 4).
Open(FILE)
Opens the specified wave FILE.
OpenDevice()
Opens the wave output device with the current sound format (not
needed unless you used "CloseDevice()").
Pause()
Pauses the sound currently playing; use "Restart()" to continue
playing.
Play( [FROM, TO] )
Plays the opened wave file. You can optionally specify a FROM - TO
range, where FROM and TO are expressed in samples (or use FROM=0
for the first sample and TO=-1 for the last sample). Playback
happens always asynchronously, eg. in the background.
Position()
Returns the sample number currently playing; note that the play
position is not zeroed when the sound ends, so you have to call a
"Reset()" between plays to receive the correct position in the
current sound.
Reset()
Stops playing and resets the play position (see "Position()").
Restart()
Continues playing the sound paused by "Pause()".
Save(FILE, [DATA])
Writes the DATA buffer (if not given, uses the buffer currently
loaded in the soundcard) to the specified wave FILE.
Status()
Returns 0 if the soundcard is currently playing, 1 if it's free, or
"undef" on errors.
Unload()
Frees the soundcard from the loaded data.
Volume( [LEFT, RIGHT] )
Gets or sets the volume for the wave output device. It works the
same way as Win32::Sound::Volume.
Write()
Plays the data currently loaded in the soundcard; playback happens
always asynchronously, eg. in the background.
THE SOUND FORMAT
The sound format is stored in three properties of the "WaveOut" object:
"samplerate", "bits" and "channels". If you need to change them
without creating a new object, you should close before and reopen
afterwards the device.
$WAV->CloseDevice();
$WAV->{samplerate} = 44100; # 44.1kHz
$WAV->{bits} = 8; # 8 bit
$WAV->{channels} = 1; # mono
$WAV->OpenDevice();
You can also use the properties to query the sound format currently
used.
EXAMPLE
This small example produces a 1 second sinusoidal wave at 440Hz and
saves it in sinus.wav:
use Win32::Sound;
# Create the object
$WAV = new Win32::Sound::WaveOut(44100, 8, 2);
$data = "";
$counter = 0;
$increment = 440/44100;
# Generate 44100 samples ( = 1 second)
for $i (1..44100) {
# Calculate the pitch
# (range 0..255 for 8 bits)
$v = sin($counter/2*3.14) * 128 + 128;
# "pack" it twice for left and right
$data .= pack("cc", $v, $v);
$counter += $increment;
}
$WAV->Load($data); # get it
$WAV->Write(); # hear it
1 until $WAV->Status(); # wait for completion
$WAV->Save("sinus.wav"); # write to disk
$WAV->Unload(); # drop it
VERSION
Win32::Sound version 0.46, 25 Sep 1999.
AUTHOR
Aldo Calpini, "dada@divinf.it"
Parts of the code provided and/or suggested by Dave Roth.
perl v5.14.2 2005-09-17 Sound(3)
