mediaframe.mpeg1.audio.player
Class EightBitAudioDevice

java.lang.Object
  |
  +--mediaframe.mpeg1.audio.player.EightBitAudioDevice

All Implemented Interfaces:

AudioDevice, java.lang.Runnable

public class EightBitAudioDevice

extends java.lang.Object

implements java.lang.Runnable, AudioDevice

The EightBitAudioDevice class implements an audio device by using the sun.audio.AudioPlayer class.

Author:

Alan Blount

Field Summary

private short[]	byteBuf The temporary buffer for storing the audio samples.
private mediaframe.mpeg1.audio.decoder.Decoder	decoder The decoder that provides audio data to this audio device.
private boolean	open True if this audio device is opened, false otherwise.
private static int	outputCapacity The size of the circle buffer in the pipe.
private BigPipedInputStream	pis The input stream in the pipe.
private BigPipedOutputStream	pos The output stream in the pipe.

Constructor Summary

EightBitAudioDevice()

Method Summary

void	close() Closes this audio device.
void	endOfFile() Is called if the end of file has been reached.
void	flush() Waits for any buffered audio samples to be played by the audio device.
protected short[]	getShortArray(int length) Gets the temporary buffer that able to store up to length audio samples.
boolean	isEightBitEightKhzMuLaw() Returns true because the EightBitAudioDevice audio device is a crappy eight-bit eight khz ulaw decoder (browser).
void	open(mediaframe.mpeg1.audio.decoder.Decoder decoder) Opens this audio device.
void	pause() Pause the Player.
void	play() Start player playing.
void	run() Starts the sun.audio.AudioPlayer in the "Eight Bit Audio Device" thread.
void	setMute(boolean mute) Sets the mute state of the audio playback.
void	setVolume(float volume) Sets the volume (in the range 0..1) of the audio playback.
void	stop() Stop player playing.
(package private) int	toShortArray(short[] samples, int offset, int len, short[] b, boolean stereoToMono) Copies up to len audio samples from the samples array starting at the offset offset into the b array.
void	write(short[] samples, int offset, int len) Writes audio data to this audio device.

Methods inherited from class java.lang.Object

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

Field Detail

outputCapacity

private static final int outputCapacity

The size of the circle buffer in the pipe.

See Also:

Constant Field Values

byteBuf

private short[] byteBuf

The temporary buffer for storing the audio samples.

pis

private BigPipedInputStream pis

The input stream in the pipe.

pos

private BigPipedOutputStream pos

The output stream in the pipe.

open

private boolean open

True if this audio device is opened, false otherwise.

decoder

private mediaframe.mpeg1.audio.decoder.Decoder decoder

The decoder that provides audio data to this audio device.

Constructor Detail

EightBitAudioDevice

public EightBitAudioDevice()

Method Detail

open

public void open(mediaframe.mpeg1.audio.decoder.Decoder decoder)
          throws mediaframe.mpeg1.audio.decoder.JavaLayerException

Opens this audio device.

Specified by:

open in interface AudioDevice

Parameters:

decoder - the decoder that will provide audio data to this audio device.

Throws:

mediaframe.mpeg1.audio.decoder.JavaLayerException - if the audio device could not be opened.

isEightBitEightKhzMuLaw

public boolean isEightBitEightKhzMuLaw()

Returns true because the EightBitAudioDevice audio device is a crappy eight-bit eight khz ulaw decoder (browser).

Specified by:

isEightBitEightKhzMuLaw in interface AudioDevice

run

public void run()

Starts the sun.audio.AudioPlayer in the "Eight Bit Audio Device" thread. This method is called by the JRE after this audio device is opened and the "Eight Bit Audio Device" thread is started.

Specified by:

run in interface java.lang.Runnable

close

public void close()

Closes this audio device. If the device is currently playing audio, playback is stopped immediately without flushing any buffered audio data.

Specified by:

close in interface AudioDevice

write

public void write(short[] samples,
                  int offset,
                  int len)
           throws mediaframe.mpeg1.audio.decoder.JavaLayerException

Writes audio data to this audio device. Audio data is assumed to be in the output format of the decoder. This method may return before the data has actually been sounded by the device if the device buffers audio samples.

If the audio device is not open, this method does nothing.

Specified by:

write in interface AudioDevice

Parameters:

samples - the samples to write to the audio device.

offset - the offset into the array of the first sample to write.

len - the number of samples from the array to write.

Throws:

mediaframe.mpeg1.audio.decoder.JavaLayerException - if the audio data could not be written to the audio device.

getShortArray

protected short[] getShortArray(int length)

Gets the temporary buffer that able to store up to length audio samples.

Parameters:

length - min size of the temporary buffer.

Returns:

the temporary buffer for storing the audio samples.

toShortArray

int toShortArray(short[] samples,
                 int offset,
                 int len,
                 short[] b,
                 boolean stereoToMono)

Copies up to len audio samples from the samples array starting at the offset offset into the b array. Mix stereo samples into the mono sample if the audio decoder provides stereo data.

Parameters:

samples - the audio data.

offset - the start offset in the data.

len - the number of samples to copy.

b - the destination array of audio data into which the data is copied.

stereoToMono - true if the audio decoder provides stereo data

Returns:

the total number of samples copied into the b array.

flush

public void flush()

Waits for any buffered audio samples to be played by the audio device. This method should only be called prior to closing the device.

Specified by:

flush in interface AudioDevice

play

public void play()

Start player playing.

Specified by:

play in interface AudioDevice

pause

public void pause()

Pause the Player.

Specified by:

pause in interface AudioDevice

stop

public void stop()

Stop player playing.

Specified by:

stop in interface AudioDevice

setVolume

public void setVolume(float volume)

Sets the volume (in the range 0..1) of the audio playback.

Specified by:

setVolume in interface AudioDevice

Parameters:

volume - the volume to set.

setMute

public void setMute(boolean mute)

Sets the mute state of the audio playback.

Specified by:

setMute in interface AudioDevice

Parameters:

mute - the mute state (true if the mute on and the player doesn't play the audio).

endOfFile

public void endOfFile()

Is called if the end of file has been reached.

Specified by:

endOfFile in interface AudioDevice