LinuxQuestions.org - Java sound: line.write() returns 0

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Java sound: line.write() returns 0

I'm trying to play a sine wave.

I have a SourceDataLine, but when I try to write to it, the write method return 0, meaning that it coulen't write anything to the mixer's output stream, right? I also don't get to hear a thing, by the way.

Here's the code I'm using:

Code:

byte [] sample = new byte[4];

int written = 0;

while (true) {

        int valor = (int) ((2 << 15 -1) * wave.height());

        //System.out.println(valor);

        sample[0] = sample[2] = (byte) (valor & 0xff);

        sample[1] = sample[3] = (byte) (valor >> 8);

        written = line.write(sample, 0, 4);

        if (written != 4) {

                System.err.println("Couldn't write all the bytes!");

                System.exit(1);

        }

        line.drain();

        wave.tic();

}

wave.height() returns the height of the wave (-1 to 1) for that moment in time.

The Audio Format is PCM_SIGNED, at 44.1 KHtz, 16 bits per sample, Stereo, little endian.

Any ideas?

I will refrase the problem:

How can I get a SourceDataLine I could use to hear a wave? Im doing this, but I don't get a single line that works:

Code:

AudioFormat format = new AudioFormat(44100f, 16, 2, true, false);

DataLine.Info info = new DataLine.Info(SourceDataLine.class, format);



SourceDataLine line = null;

Mixer.Info [] mixerInfo = AudioSystem.getMixerInfo();

Mixer mixer;

for (int i = 0; line == null && i < mixerInfo.length; i++) {

        mixer = AudioSystem.getMixer(mixerInfo[i]);

        try {

                line = (SourceDataLine) mixer.getLine(info);

                if (!line.getLineInfo().matches(info)) {

                        line = null;

                }

        } catch (LineUnavailableException e) {

                line = null;

        } catch (IllegalArgumentException e) {

                line = null;

        }

}

                

if (line == null) {

        System.out.println("No line was found");

        System.exit(1);

}

The funny thing is that sometimes mixer.getLine(info) does return a mixer, but then the matches(info) fails. How can I get that done?