Audio format conversion problems

[Robert J. Walker]

Before getting into details, let me first explain what it is I'm trying to do. The application I'm working on is supposed to be able to record a voice message from a person over the telephone in WAV format (via a VoiceXML client), store it in a database in MP3 format, and later play it back again over the phone in WAV format. Tritonus expects a stream for the encoding conversion, but the database expects a byte array. Everything works EXCEPT when I need to convert the audio data back to WAV format from the MP3 stored in the database. To perform the conversion, I'm using the Java Sound API with Tritonus. Here is the utility class I've developed to perform the conversions:

package mshare;
 
import java.io.*;
 
import javax.sound.sampled.*;
 
import org.tritonus.share.sampled.AudioFileTypes;
import org.tritonus.share.sampled.Encodings;
 
/**
 * Sound format conversion utility class
 */
public class SoundUtil {
    // Audio type contants
    public static final AudioType MP3 = new AudioType("MPEG1L3", "MP3", "mp3");
    public static final AudioType WAV = new AudioType("ULAW", "WAVE", "wav");
 
private SoundUtil(){
    }
 
/**
 * Converts a byte array of sound data to the given audio type, also returned as a byte array.
 * @param byte[] source
 * @param SoundUtil.AudioType targetType
 * @return byte[]
 */
public static byte[] convertAsByteArray(byte[] source, AudioType targetType) {
    try {
        System.out.print("Converting byte array to AudioInputStream...");
        AudioInputStream ais = toStream(source, targetType);
        System.out.println("done.");
        System.out.print("Converting stream to new audio format...");
        ais = convertAsStream(ais, targetType);
        System.out.println("done.");
        System.out.print("Converting new stream to byte array...");
        byte[] target = toByteArray(ais, targetType);
        System.out.println("done.");
        return target;
        } catch (IOException ex) {
            throw new RuntimeException("Exception during audio conversion", ex);
        } catch (UnsupportedAudioFileException ex) {
            throw new RuntimeException("Exception during audio conversion", ex);
        }
}
 
/**
 * Converts an InputStream of sound data to the given audio type, returned as a byte array.
 * @param InputStream source
 * @param AudioType targetType
 * @return byte[]
 */
public static byte[] convertAsByteArray(InputStream is, AudioType targetType) {
    try {
    AudioInputStream ais = AudioSystem.getAudioInputStream(is);
    ais = convertAsStream(ais, targetType);
    byte[] bytes = toByteArray(ais, targetType);
    return bytes;
    } catch (IOException ex) {
        throw new RuntimeException("Exception during audio conversion", ex);
    } catch (UnsupportedAudioFileException ex) {
        throw new RuntimeException("Exception during audio conversion", ex);
    }
}
 
/**
 * Converts an AudioInputStream to the indicated audio type, also returned as an AudioInputStream.
 * @param AudioInputStream sourceStream
 * @param SoundUtil.Type targetType
 * @return AudioInputStream
 */
public static AudioInputStream convertAsStream(AudioInputStream sourceStream, AudioType targetType) {
    AudioFormat.Encoding targetEncoding = targetType.getEncoding();
AudioFormat sourceFormat = sourceStream.getFormat();
AudioInputStream targetStream = null;
 
if (!AudioSystem.isConversionSupported(targetEncoding, sourceFormat)) {
    // Direct conversion not possible, trying with intermediate PCM format
AudioFormat intermediateFormat = new AudioFormat(
                                     AudioFormat.Encoding.PCM_SIGNED,
                                     sourceFormat.getSampleRate(),
                                     16,
                                     sourceFormat.getChannels(),
                                     2 * sourceFormat.getChannels(), // frameSize
                                     sourceFormat.getSampleRate(),
                                     false);
 
if (AudioSystem.isConversionSupported(intermediateFormat, sourceFormat)) {
// Intermediate conversion is supported
sourceStream = AudioSystem.getAudioInputStream(intermediateFormat, sourceStream);
}
}
 
targetStream = AudioSystem.getAudioInputStream(targetEncoding, sourceStream);
 
if(targetStream == null) {
throw new RuntimeException("Audio conversion not supported");
}
 
return targetStream;
}
 
/**
 * Converts a byte array to an AudioInputStream with the same audio format.
 * @param byte[] source
 * @return AudioInputStream
 * @throws IOException
 * @throws UnsupportedAudioFileException
 */
private static AudioInputStream toStream(byte[] bytes, AudioType targetType)
throws IOException, UnsupportedAudioFileException {
    ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
    AudioInputStream ais = AudioSystem.getAudioInputStream(bais);
    return ais;
}
 
/**
 * Converts an AudioInputStream to a byte array with the same audio format.
 * @param AudioInputStream ais
 * @param AudioType targetType
 * @return byte[]
 * @throws IOException
 */
private static byte[] toByteArray(AudioInputStream ais, AudioType targetType) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        AudioSystem.write(ais, targetType.getFileFormat(), baos);
        return baos.toByteArray();
}
 
/**
     * Class representing an audio type, encapsulating an encoding and a file format.
     */
    public static class AudioType {
        private String encodingName;
        private String typeName;
        private String extension;
 
        public AudioType(String encodingName, String typeName, String extension) {
            this.encodingName = encodingName;
            this.typeName = typeName;
            this.extension = extension;
        }
 
        public AudioFormat.Encoding getEncoding() {
            return Encodings.getEncoding(encodingName);
        }
        
        public AudioFileFormat.Type getFileFormat() {
            return AudioFileTypes.getType(typeName, extension);
        }
    }
}

So say I have a byte[] called wav containing WAV data from the voice browser, and before I save it to the database, I want to convert it to MP3. I would do this:

byte[] mp3 = SoundUtil.convertAsByteArray(wav, SoundUtil.MP3);

This works perfectly. But now if I want play that audio clip back, I need to convert the MP3 data provided by the database back to WAV. So, naturally, I would write this:

byte[] wav = SoundUtil.convertAsByteArray(mp3, SoundUtil.WAV);

But executing that code produces the following error:

java.io.IOException: stream length not specified
at com.sun.media.sound.WaveFileWriter.write(WaveFileWriter.java:114)
at javax.sound.sampled.AudioSystem.write(AudioSystem.java:935)
at mshare.SoundUtil.toByteArray(SoundUtil.java:125)
at mshare.SoundUtil.convertAsByteArray(SoundUtil.java:36)
... 2 more

Maybe I'm just too close to the problem (or too overworked...), but I just can't seem to figure out how to appease the AudioSystem's demand that I provide a stream length. Even after scouring the Javadoc and the Internet in general for two days, I remain unenlightened. So I turn to you, oh great JavaRanchers. Have you any idea why this is happening, and more importantly, what I can do to make it work!

Most humbly yours, with thanks in advance,

Robert J. Walker
[ January 06, 2005: Message edited by: Robert J. Walker ]

[Ashwini alvekod]

Hi,

I am recording a voice message through mobile and sending to server in by array format through JSON, i want to convert byte array format voice message into appropriate audio format and store it in database. how implement this feature?? need help.....