edu.princeton.cs.algs4

Class StdAudio

java.lang.Object

edu.princeton.cs.algs4.StdAudio

public final class StdAudio
extends java.lang.Object

Standard audio. This class provides a basic capability for creating, reading, and saving audio.

The audio format uses a sampling rate of 44,100 (CD quality audio), 16-bit, monaural.

For additional documentation, see Section 1.5 of Computer Science: An Interdisciplinary Approach by Robert Sedgewick and Kevin Wayne.

Field Summary

Fields

Modifier and Type	Field and Description
static int	SAMPLE_RATE The sample rate - 44,100 Hz for CD quality audio.

Method Summary

Modifier and Type	Method and Description
static void	close() Closes standard audio.
static void	loop(java.lang.String filename) Loops an audio file (in .wav, .mid, or .au format) in a background thread.
static void	main(java.lang.String[] args) Test client - play an A major scale to standard audio.
static void	play(double sample) Writes one sample (between -1.0 and +1.0) to standard audio.
static void	play(double[] samples) Writes the array of samples (between -1.0 and +1.0) to standard audio.
static void	play(java.lang.String filename) Plays an audio file (in .wav, .mid, or .au format) in a background thread.
static double[]	read(java.lang.String filename) Reads audio samples from a file (in .wav or .au format) and returns them as a double array with values between -1.0 and +1.0.
static void	save(java.lang.String filename, double[] samples) Saves the double array as an audio file (using .wav or .au format).

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SAMPLE_RATE

public static final int SAMPLE_RATE

The sample rate - 44,100 Hz for CD quality audio.

See Also:

Constant Field Values

Method Detail

close

public static void close()

Closes standard audio.

play

public static void play(double sample)

Writes one sample (between -1.0 and +1.0) to standard audio. If the sample is outside the range, it will be clipped.

Parameters:

sample - the sample to play

Throws:

java.lang.IllegalArgumentException - if the sample is Double.NaN

play

public static void play(double[] samples)

Writes the array of samples (between -1.0 and +1.0) to standard audio. If a sample is outside the range, it will be clipped.

Parameters:

samples - the array of samples to play

Throws:

java.lang.IllegalArgumentException - if any sample is Double.NaN

java.lang.IllegalArgumentException - if samples is null

read

public static double[] read(java.lang.String filename)

Reads audio samples from a file (in .wav or .au format) and returns them as a double array with values between -1.0 and +1.0.

Parameters:

filename - the name of the audio file

Returns:

the array of samples

save

public static void save(java.lang.String filename,
                        double[] samples)

Saves the double array as an audio file (using .wav or .au format).

Parameters:

filename - the name of the audio file

samples - the array of samples

Throws:

java.lang.IllegalArgumentException - if unable to save filename

java.lang.IllegalArgumentException - if samples is null

play

public static void play(java.lang.String filename)

Plays an audio file (in .wav, .mid, or .au format) in a background thread.

Parameters:

filename - the name of the audio file

Throws:

java.lang.IllegalArgumentException - if unable to play filename

java.lang.IllegalArgumentException - if filename is null

loop

public static void loop(java.lang.String filename)

Loops an audio file (in .wav, .mid, or .au format) in a background thread.

Parameters:

filename - the name of the audio file

Throws:

java.lang.IllegalArgumentException - if filename is null

main

public static void main(java.lang.String[] args)

Test client - play an A major scale to standard audio.

Parameters:

args - the command-line arguments