stanford.cs106.audio

Class StdAudio

java.lang.Object

stanford.cs106.audio.StdAudio

public final class StdAudio
extends 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 Introduction to Programming in Java: An Interdisciplinary Approach by Robert Sedgewick and Kevin Wayne.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	StdAudio.AudioEvent
static interface	StdAudio.AudioEventListener

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	addAudioEventListener(StdAudio.AudioEventListener listener)
static void	clearAudioEventListeners() Removes all audio event listeners from being notified of future audio events, if any were present.
static void	close() Close standard audio.
static boolean	isMuted() Returns whether the audio system is currently muted.
static boolean	isPaused() Returns whether the audio system is currently paused.
static void	loop(String filename) Loop a sound file (in .wav or .au format) in a background thread.
static void	main(String[] args) Test client - play an A major scale to standard audio.
static double[]	note(double hz, double duration, double amplitude) Create a note (sine wave) of the given frequency (Hz), for the given duration (seconds) scaled to the given volume (amplitude).
static void	play(double in) Write one sample (between -1.0 and +1.0) to standard audio.
static void	play(double[] input) Write an array of samples (between -1.0 and +1.0) to standard audio.
static void	play(double[] input, double duration) Write an array of samples (between -1.0 and +1.0) to standard audio.
static void	play(Note note, double[] input, double duration) Write an array of samples (between -1.0 and +1.0) to standard audio.
static void	play(String filename) Play a sound file (in .wav or .au format) in a background thread.
static double[]	read(String filename) Read audio samples from a file (in .wav or .au format) and return them as a double array with values between -1.0 and +1.0.
static void	removeAudioEventListener(StdAudio.AudioEventListener listener) Removes the given audio event listener from being notified of future audio events, if it was present.
static void	save(String filename, double[] input) Save the double array as a sound file (using .wav or .au format).
static void	setMute(boolean mute) Sets whether the audio system is muted.
static void	setPaused(boolean pause) Sets whether the audio system is paused.

Methods inherited from class java.lang.Object

clone, equals, finalize, 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

addAudioEventListener

public static void addAudioEventListener(StdAudio.AudioEventListener listener)

clearAudioEventListeners

public static void clearAudioEventListeners()

Removes all audio event listeners from being notified of future audio events, if any were present. If none were present, has no effect.

close

public static void close()

Close standard audio.

isMuted

public static boolean isMuted()

Returns whether the audio system is currently muted.

isPaused

public static boolean isPaused()

Returns whether the audio system is currently paused.

loop

public static void loop(String filename)

Loop a sound file (in .wav or .au format) in a background thread.

note

public static double[] note(double hz,
                            double duration,
                            double amplitude)

Create a note (sine wave) of the given frequency (Hz), for the given duration (seconds) scaled to the given volume (amplitude).

play

public static void play(double in)

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

play

public static void play(double[] input)

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

play

public static void play(double[] input,
                        double duration)

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

play

public static void play(Note note,
                        double[] input,
                        double duration)

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

play

public static void play(String filename)

Play a sound file (in .wav or .au format) in a background thread.

read

public static double[] read(String filename)

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

removeAudioEventListener

public static void removeAudioEventListener(StdAudio.AudioEventListener listener)

Removes the given audio event listener from being notified of future audio events, if it was present. If not present, has no effect.

save

public static void save(String filename,
                        double[] input)

Save the double array as a sound file (using .wav or .au format).

setMute

public static void setMute(boolean mute)

Sets whether the audio system is muted. If audio is muted, notes do not play and playing methods return immediately.

setPaused

public static void setPaused(boolean pause)

Sets whether the audio system is paused. If audio is paused, playing methods "block" in an infinite while loop.

main

public static void main(String[] args)

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