org.jsresources

Class TimedAudioRecorder

java.lang.Object

java.lang.Thread

org.jsresources.TimedAudioRecorder

All Implemented Interfaces:

Runnable

public class TimedAudioRecorder
extends Thread

TimedAudioRecorder: Recording to an audio file (timed version)

Purpose: Records audio data and stores it in a file. The data is recorded in CD quality (44.1 kHz, 16 bit linear, stereo) and stored in a .wav file.

Usage: java TimedAudioRecorder choice="plain" -h java TimedAudioRecorder choice="plain" audiofile

Parameters: -h print usage information, then exit audiofile the file name of the audio file that should be produced from the recorded data

Bugs, limitations: You cannot select audio formats and the audio file type on the command line. See AudioRecorder for a version that has more advanced options. Due to a bug in the Sun jdk1.3/1.4, this program does not work with it.

Source code: TimedAudioRecorder.java

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
TimedAudioRecorder(TargetDataLine line, AudioFileFormat.Type targetType, File file, long timeout)

Method Summary

Methods

Modifier and Type	Method and Description
static void	main(String[] args)
void	run() Main working method.
void	start() Starts the recording.
void	stopRecording() Stops the recording.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

TimedAudioRecorder

public TimedAudioRecorder(TargetDataLine line,
                  AudioFileFormat.Type targetType,
                  File file,
                  long timeout)

Method Detail

start

public void start()

Starts the recording. To accomplish this, (i) the line is started and (ii) the thread is started.

Overrides:

start in class Thread

stopRecording

public void stopRecording()

Stops the recording. Note that stopping the thread explicitely is not necessary. Once no more data can be read from the TargetDataLine, no more data be read from our AudioInputStream. And if there is no more data from the AudioInputStream, the method 'AudioSystem.write()' (called in 'run()' returns. Returning from 'AudioSystem.write()' is followed by returning from 'run()', and thus, the thread is terminated automatically. It's not a good idea to call this method just 'stop()' because stop() is a (deprecated) method of the class 'Thread'. And we don't want to override this method.

run

public void run()

Main working method. You may be surprised that here, just 'AudioSystem.write()' is called. But internally, it works like this: AudioSystem.write() contains a loop that is trying to read from the passed AudioInputStream. Since we have a special AudioInputStream that gets its data from a TargetDataLine, reading from the AudioInputStream leads to reading from the TargetDataLine. The data read this way is then written to the passed File. Before writing of audio data starts, a header is written according to the desired audio file type. Reading continues untill no more data can be read from the AudioInputStream. In our case, this happens if no more data can be read from the TargetDataLine. This, in turn, happens if the TargetDataLine is stopped or closed (which implies stopping). (Also see the comment above.) Then, the file is closed and 'AudioSystem.write()' returns.

Specified by:

run in interface Runnable

Overrides:

run in class Thread

main

public static void main(String[] args)