| luisator 2005-06-09, 11:33 am |
| Hi every one...I am modifying an application that make the Pc speaker have acces to the rtp stream comming from a telephone. The problem is, the rtp stream could be one of G.711U or G.711A or G.729 or G.729A depending on which codec was setup and the Speaker supports PCM_UNSIGNED. i need to do the conversion. The app works but I get horrible noise and I think is because the lack of conversion. The code is:
import java.io.IOException;
import java.nio.ByteBuffer;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.SourceDataLine;
import javax.sound.sampled.DataLine;
import com.avaya.api.media.channels.MediaSink;
public class TutorialSpeaker implements MediaSink{
// Constants for Audio Format
private static final AudioFormat.Encoding ENCODING =
AudioFormat.Encoding.PCM_UNSIGNED;
private static final int SAMPLE_SIZE_IN_BITS = 8; // 8bits per PCM sample
private static final float SAMPLE_RATE = 8000; // 8Khz sampling rate
private static final int CHANNELS = 1; // monoaural system
// sampleSizeInBytes * channels
private static final int FRAME_SIZE = CHANNELS * SAMPLE_SIZE_IN_BITS / 8;
//sampleRate/frameSize; frames per sec
private static final float FRAME_RATE = SAMPLE_RATE;
// true for network byte order
private static final boolean BIG_ENDIAN = true;
private SourceDataLine sourcedataline;
private AudioFormat audioFormat = null;
private DataLine.Info targetInfo = null;
private String codec;
private int packetSize;
public TutorialSpeaker(){
audioFormat = new AudioFormat(AudioFormat.Encoding.PCM_UNSIGNED,
SAMPLE_RATE,SAMPLE_SIZE_IN_BITS,
CHANNELS,FRAME_SIZE,
FRAME_RATE,BIG_ENDIAN);
targetInfo = new DataLine.Info(SourceDataLine.class,audioFormat);
if (!AudioSystem.isLineSupported(targetInfo)) {
System.out.println("WARNING: Unsupported Source Data Line Format");
}
}
/**
* The Client Media Stack (i.e. The Audio RTP Receiver)
* uses the write method to deliver a ByteBuffer to the Speaker (MediaSink)
*/
public int write(ByteBuffer src) throws IOException {
// Start the Speaker if not already open
if((sourcedataline == null) || (!sourcedataline.isOpen())){
try {
sourcedataline =
(SourceDataLine)AudioSystem.getLine(targetInfo);
sourcedataline.open(audioFormat);
sourcedataline.start();
} catch (LineUnavailableException e) {
throw new IOException(e.getMessage());
}
}
int bytesWritten = 0;
if(sourcedataline.available() >= src.remaining()){
I NEED TO DO THE CONVERSION IN HERE!!!
bytesWritten = sourcedataline.write(src.array(),src.arrayOffset(),
src.remaining());
// System.out.println("bytes Written= " +bytesWritten);
}
return bytesWritten;
}
/**
* Closes the Speaker (and hence this MediaSink)
*/
public void close() throws IOException {
if(sourcedataline != null)
sourcedataline.close();
}
/**
* Return the status of the Speaker
*/
public boolean isOpen() {
return true;
}
/**
* Sets the Codec type and packet Size of the source.
* This is the codec and packetSize of the incoming Audio RTP
* Stream.
*/
public void setCodec(String codec, int packetSize) {
this.codec = codec;
this.packetSize = packetSize;
}
/**
* Gets the codec of the Audio RTP Stream being used
* by the Speaker.
*/
public String getCodec() {
return codec;
}
/**
* Gets the packetSize of the Audio RTP Stream being used by
* the Speaker.
*/
public int getPacketSize() {
return packetSize;
}
}
THANKS FOR YOUR HELP! |