CATEGORY

Core, Audio, Structure

SYNOPSIS

use SDL;
use SDL::AudioSpec;

SDL::init(SDL_INIT_AUDIO);

my $audio_spec = SDL::AudioSpec->new();

$audio_spec->freq(22050); # 22050Hz - FM Radio quality
$audio_spec->format(AUDIO_S16SYS); # 16-bit signed audio
$audio_spec->samples(8192); # Large audio buffer reduces risk of dropouts but increases response time
$audio_spec->channels(1); # Mono
$audio_spec->callback('main::callback');

sub callback
{
# do something here
}

DESCRIPTION

The "SDL::AudioSpec" structure is used to describe the format of some audio data. This structure is used by "SDL::Audio::open_audio" and "SDL::Audio::load_wav". While all fields are used by "SDL::Audio::open_audio", only "freq", "format", "samples" and "channels" are used by "SDL::Audio::load_wav". We will detail these common members here.

METHODS

freq

The number of samples sent to the sound device every second. Common values are 11025, 22050 and 44100. The higher the better.

format

Specifies the size and type of each sample element. Values it can take are:

AUDIO_U8

Unsigned 8-bit samples.

AUDIO_S8

Signed 8-bit samples.

AUDIO_U16 or AUDIO_U16LSB

not supported by all hardware (unsigned 16-bit little-endian)

AUDIO_S16 or AUDIO_S16LSB

not supported by all hardware (signed 16-bit little-endian)

AUDIO_U16MSB

not supported by all hardware (unsigned 16-bit big-endian)

AUDIO_S16MSB

not supported by all hardware (signed 16-bit big-endian)

AUDIO_U16SYS

Either AUDIO_U16LSB or AUDIO_U16MSB depending on hardware CPU endianness

AUDIO_S16SYS

Either AUDIO_S16LSB or AUDIO_S16MSB depending on hardware CPU endianness

channels

The number of separate sound channels. 1 is mono (single channel), 2 is stereo (dual channel).

samples

When used with "SDL::Audio::open_audio" this refers to the size of the audio buffer in samples. A sample is a chunk of audio data of the size specified in format multiplied by the number of channels. When the "SDL::AudioSpec" is used with "SDL::Audio::load_wav" samples is set to 4096.

callback

To be documented.

AUTHORS

See ``AUTHORS'' in SDL.