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jssound module

Support wav, aiff, au, voc, sd2, flac, ... sound format using libsndfile and ogg vorbis using libogg and libvorbis.

jssound static members

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_soundObject DecodeOggVorbis( stream )

Decodes a ogg vorbis sample to a sound object.

arguments:

  1. <sub>streamObject</sub> _stream_: any object that has a Read function or that supports the NIStreamRead Native Interface ( file, socket, new Stream(buffer), ... ). For further details about stream objects, see jslang::Stream object and NativeInterface mechanism.

return value:

A sound object in a 16-bit per sample format.

example:

``` LoadModule('jsstd'); LoadModule('jsio'); LoadModule('jssound');

var file = new File('41_30secOgg-q0.ogg'); var buffer = file.content; var stream = new Stream(buffer); var mySoundObject = DecodeOggVorbis(stream); Print('sample length: ', mySoundObject.length, '\n'); ```

<sub>soundObject</sub> DecodeSound( stream )

Decodes a sample from any supported sound format to a sound object.

arguments:

  1. <sub>streamObject</sub> _stream_: any object that has a Read function or that supports the NIStreamRead Native Interface ( file, socket, new Stream(buffer), ... ). For further details about stream objects, see jslang::Stream object and native interface mechanism.

return value:

A sound object in a 16-bit per sample format.

<sub>Array</sub> SplitChannels( sound )

Split channels of the sound into an Array of monaural sound object.

arguments:

  1. <sub>soundObject</sub> _sound_

return value:

An array that contains each individual channel of the sound.

Note

SoundObject concatenation can be achieved using the concat() method. This works becuase a sound object is a Blob with some extra properties.

Examples

example 1:

``` LoadModule('jsstd'); LoadModule('jsio'); LoadModule('jssound');

var file = new File('41_30secOgg-q0.wav'); file.Open('r'); var pcm = DecodeSound(file); file.Close(); Print('sample length: '+pcm.length, '\n'); ```

example 2:

``` LoadModule('jsstd'); LoadModule('jsio'); LoadModule('jssound');

var file = new File('41_30secOgg-q0.wav'); var buffer = file.content; var stream = new Stream(buffer); var pcm = DecodeSound(stream);

Print('sample length: '+pcm.length, '\n'); ```

class jssound::OggVorbisDecoder

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  The OggVorbisDecoder support ogg vorbis data format decoding.

constructor( stream )

Creates a new OggVorbisDecoder object. Seekable and non-seekable streams are supported.

arguments:

  1. <sub>streamObject</sub> _stream_: is the data stream from where encoded data are read from.

example:

LoadModule('jsstd'); LoadModule('jsio'); LoadModule('jssound'); var file = new File('41_30secOgg-q0.ogg'); // file: http://xiph.org/vorbis/listen.html file.Open('r'); var dec = new OggVorbisDecoder( file ); Print( dec.bits, '\n' ); Print( dec.channels, '\n' ); Print( dec.rate, '\n' ); do { var block = dec.Read(10000); Print( 'frames: '+block.frames, '\n' ); } while(block);

Methods

<sub>soundObject</sub> Read( [.mdframes] )

Decodes a piece of audio data. If frames argument is omited, the whole stream is decoded.

arguments:

  1. <sub>integer</sub> _frames_: the number of frames to decode. A frame is a sample of sound.

return value:

A Blob object that has the following properties set: bits, rate, channels, frames

beware:

If all data has been decoded and the Read function is called again, the return expression is evaluated to ALSE.

example:

LoadModule('jsstd'); LoadModule('jsio'); LoadModule('jssound'); var file = new File('41_30secOgg-q0.ogg'); // file: http://xiph.org/vorbis/listen.html file.Open('r'); var dec = new OggVorbisDecoder( file ); var block = dec.Read(10000); Print( 'rezolution: '+block.bits+' per channel', '\n' ); Print( block.channels == 2 ? 'stereo' : 'mono', '\n' ); Print( block.rate+' frames/seconds', '\n' ); Print( 'time: '+(block.frames/block.rate)+' seconds', '\n' );

Properties

object inputStream

Is the stream object where encoded audio data are read from.

<sub>integer</sub> bits

Is the number of bits per frame and per channel.

<sub>integer</sub> rate

Is the number of frames per seconds of the sound.

<sub>integer</sub> channels

Is the number of channels of the sound. 1 is mono, 2 is stereo.

<sub>integer</sub> frames

Is the length (in frames) of the sound. To compute the duration of the sound, use (frames/rate)

class jssound::SoundFileDecoder

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The SoundFileDecoder support various data format decoding. Main supported formats are: wav, aiff, au, voc, sd2, flac, ... For more information about supported formats, see http://www.mega-nerd.com/libsndfile/

constructor( stream )

Creates a new SoundFileDecoder object. Only seekable streams are supported.

arguments:

  1. <sub>streamObject</sub> _stream_: is the data stream from where encoded data are read from.

example:

LoadModule('jsstd'); LoadModule('jsio'); LoadModule('jssound'); var file = new File('41_30secOgg-q0.wav'); // file: http://xiph.org/vorbis/listen.html file.Open('r'); var dec = new SoundFileDecoder( file ); Print( dec.bits, '\n' ); Print( dec.channels, '\n' ); Print( dec.rate, '\n' ); do { var block = dec.Read(10000); Print( 'frames: '+block.frames, '\n' ); } while(block);

Methods

<sub>soundObject</sub> Read( [.mdframes] )

Decodes a piece of audio data. If frames argument is omited, the whole stream is decoded.

arguments:

  1. <sub>integer</sub> _frames_: the number of frames to decode. A frame is a sample of sound.

return value:

A Blob object that has the following properties set: bits, rate, channels, frames

beware:

If all data has been decoded and the Read function is called again, the return expression is evaluated to ALSE.

example:

LoadModule('jsstd'); LoadModule('jsio'); LoadModule('jssound'); var file = new File('41_30secOgg-q0.wav'); // file: http://xiph.org/vorbis/listen.html file.Open('r'); var dec = new SoundFileDecoder( file ); var block = dec.Read(10000); Print( 'rezolution: '+block.bits+' per channel', '\n' ); Print( block.channels == 2 ? 'stereo' : 'mono', '\n' ); Print( block.rate+' frames/seconds', '\n' ); Print( 'time: '+(block.frames/block.rate)+' seconds', '\n' );

Properties

object inputStream

Is the stream object where encoded audio data are read from.

<sub>integer</sub> bits

Is the number of bits per frame and per channel.

<sub>integer</sub> rate

Is the number of frames per seconds of the sound.

<sub>integer</sub> channels

Is the number of channels of the sound. 1 is mono, 2 is stereo.

<sub>integer</sub> frames

Is the length (in frames) of the sound. To compute the duration of the sound, use (frames/rate)

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