Week Five Notes

Import java.io.*;
Import javax.sound.sampled.*;

/**
* Class Soundengine provides functionality to process sound files.
* The Soundengine class provides the ability to handle sound files.
* Sounds can be loaded, played, paused, resumed, and stopped.
* Sound can be loaded, played, paused, resumed, and stopped.
*
* The sound engine can play multiple sounds simultaniously
* The last sound loaded can controlled (pased, resumed, etc).
* Music player sounds can play a variety of sound simultaniously, but only the last sound load can be controlled (obsolete, recovery, etc.).
*
* The sound engine accepts files in WAV, AIFF, and AU formats (although
* Not all WAV files-it depends on the encoding in the file).
* Music player accepts WAV files, Aiff,au format (although not all WAV files, depending on the encoded file).
*
* @author Michael kolling and David J Barnes
* @version 1.0
*/
public class Soundengine
{
The following three fields hold information about the sound clip
The following three fields hold information about the sound clip
Currently loaded in this engine
Private Clip currentsoundclip = null;
private int currentsoundduration = 0;
private int currentsoundframelength = 0;

/**
* Create a soundengine that can play sound files.
*/
Public Soundengine ()
{
}

/**
* Load and play a specified sound file. If the file is not in a
* Recognised file format, False is returned. Otherwise The Sound
* is started and true is returned. The method returns immediately
* After the sound starts (not after the sound finishes).
* Load and play the specified sound file. If the file is not in the Confirm file format, the error is returned. Otherwise the sound starts and returns correctly.
* Method immediately returns after the sound has started (after the sound has ended).
* @param soundfile the file to be loaded.
* @return True If the sound file could is loaded, false otherwise.
*/
public boolean play (File soundfile)
{
if (Loadsound (soundfile)) {
Currentsoundclip.start ();
return true;
}
else {
return false;
}
}

/**
* Stop the currently playing sound (if there is one playing). If No
* Sound was playing, this method has no effect.
*/
public void Stop ()
{
if (currentsoundclip! = null) {
Currentsoundclip.stop ();
Currentsoundclip = null;
}
}

/**
* Pause the currently playing sound. If no sound is currently playing,
* Calling this method has no effect.
*/
public void Pause ()
{
if (currentsoundclip! = null) {
Currentsoundclip.stop ();
}
}

/**
* Resume the currently paused sound. If no sound is currently paused,
* This method has no effect.
*/
public void Resume ()
{
if (currentsoundclip! = null) {
Currentsoundclip.start ();
}
}

/**
* Set the current playing position in the currently playing sound to ' value '.
* ' Value ' is a percentage value (0 to 100). If There is no sound currently
* Playing, this method has no effect.
*
* @param value the target position in the sound file, as a percentage.
*/
public void Seek (int value)
{
if (currentsoundclip! = null) {
int seekposition = currentsoundframelength/100 * value;
Currentsoundclip.setframeposition (seekposition);
}
}

/**
* Set the playback volume of the current sound. If no sound is currently
* Loaded, this method has no effect.
*
* @param vol Volume level as a percentage (0..100).
*/
public void SetVolume (int vol)
{
if (Currentsoundclip = = null) {
Return
}
if (Vol < 0 | | Vol > 100) {
vol = 100;
}

Double val = vol/100.0;

try {
Floatcontrol Volcontrol =
(Floatcontrol) Currentsoundclip.getcontrol (FloatControl.Type.MASTER_GAIN);
float DB = (float) (Math.log (val = = 0.0 0.0001:val)/Math.log (10.0) * 20.0);
Volcontrol.setvalue (DB);
} catch (Exception ex) {
System.out.println ("Could not set volume");
}
}

/**
* Return the duration of the currently loaded sound clip.
*
* @return The duration of the current sound, or 0 if no sound has been loaded.
*/
public int getduration ()
{
return currentsoundduration;
}

/**
* Load the sound file supplied by the parameter to this sound engine.
*
* @return True If successful, False if the file could not is decoded.
*/
Private Boolean loadsound (file file)
{
currentsoundduration = 0;

try {
Audioinputstream stream = audiosystem.getaudioinputstream (file);
Audioformat format = Stream.getformat ();

//We cannot play alaw/ulaw, so we convert them to PCM
//
if ((format.getencoding () = = AudioFormat.Encoding.UL AW) | |
(format.getencoding () = = AudioFormat.Encoding.ALAW))
{
Audioformat tmp = new Audioformat (
AudioFormat.Encoding.PCM_SIGNED,
Format.getsamplerate (),
Format.getsamplesizeinbits () * 2,
Format.getchannels (),
Format.getframesize () * 2,
Format.getframerate (),
true);
Stream = Audiosystem.getaudioinputstream (tmp, stream);
format = tmp;
}
Dataline.info Info = new Dataline.info (Clip.class,
Stream.getformat (),
(int) stream.getframelength ( ) *
Format.getframesize ()));

Currentsoundclip = (Clip) audiosystem.getline (info);
Currentsoundclip.open (stream);
Currentsoundframelength = (int) stream.getframelength ();
currentsoundduration = (int) (Currentsoundclip.getbuffersize ()/
(Currentsoundclip.getformat (). Getframesize () *
Currentsoundclip.getformat (). Getframerate ());
return true;
} catch (Exception ex) {
Currentsoundclip = null;
return false;
}
}
}

Week Five Notes