/* * SimpleAudioPlayer.java * * This file is part of the Java Sound Examples. */
/* * Copyright (c) 1999 - 2001 by Matthias Pfisterer <Matthias.Pfisterer@web.de> * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Library General Public License as published * by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */
public class SimpleAudioPlayer { private static final int EXTERNAL_BUFFER_SIZE = 128000;
public static void main(String[] args) { /* We check that there is exactely one command-line argument. If not, we display the usage message and exit. */
/* Now, that we're shure there is an argument, we take it as the filename of the soundfile we want to play. */ String strFilename = "c:\\joke.wav"; //String strFilename = args[0]; File soundFile = new File(strFilename);
/* We have to read in the sound file. */ AudioInputStream audioInputStream = null; try { audioInputStream = AudioSystem.getAudioInputStream(soundFile); } catch (Exception e) { /* In case of an exception, we dump the exception including the stack trace to the console output. Then, we exit the program. */ e.printStackTrace(); System.exit(1); }
/* From the AudioInputStream, i.e. from the sound file, we fetch information about the format of the audio data. These information include the sampling frequency, the number of channels and the size of the samples. These information are needed to ask Java Sound for a suitable output line for this audio file. */ AudioFormat audioFormat = audioInputStream.getFormat();
/* Asking for a line is a rather tricky thing. We have to construct an Info object that specifies the desired properties for the line. First, we have to say which kind of line we want. The possibilities are: SourceDataLine (for playback), Clip (for repeated playback) and TargetDataLine (for recording). Here, we want to do normal playback, so we ask for a SourceDataLine. Then, we have to pass an AudioFormat object, so that the Line knows which format the data passed to it will have. Furthermore, we can give Java Sound a hint about how big the internal buffer for the line should be. This isn't used here, signaling that we don't care about the exact size. Java Sound will use some default value for the buffer size. */ SourceDataLine line = null; DataLine.Info info = new DataLine.Info(SourceDataLine.class, audioFormat); try { line = (SourceDataLine) AudioSystem.getLine(info);
/* The line is there, but it is not yet ready to receive audio data. We have to open the line. */ line.open(audioFormat); } catch (LineUnavailableException e) { e.printStackTrace(); System.exit(1); } catch (Exception e) { e.printStackTrace(); System.exit(1); }
/* Still not enough. The line now can receive data, but will not pass them on to the audio output device (which means to your sound card). This has to be activated. */ line.start();
/* Ok, finally the line is prepared. Now comes the real job: we have to write data to the line. We do this in a loop. First, we read data from the AudioInputStream to a buffer. Then, we write from this buffer to the Line. This is done until the end of the file is reached, which is detected by a return value of -1 from the read method of the AudioInputStream. */ int nBytesRead = 0; byte[] abData = new byte[EXTERNAL_BUFFER_SIZE]; while (nBytesRead != -1) { try { nBytesRead = audioInputStream.read(abData, 0, abData.length); } catch (IOException e) { e.printStackTrace(); } if (nBytesRead >= 0) { int nBytesWritten = line.write(abData, 0, nBytesRead); } }
/* Wait until all data are played. This is only necessary because of the bug noted below. (If we do not wait, we would interrupt the playback by prematurely closing the line and exiting the VM.)
Thanks to Margie Fitch for bringing me on the right path to this solution. */ line.drain();
/* All data are played. We can close the shop. */ line.close();
/* There is a bug in the jdk1.3. It prevents correct termination of the VM. So we have to exit ourselves. */ System.exit(0); } }
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