Sound in videos is full of static

I'm trying to play sound from an FFMpegFrameGrabber by getting the Frame and sending the audio samples to a SourceDataLine. Here's what I have so far:

Creating the SourceDataLine:

int channels = _grabber.getAudioChannels();
int format = _grabber.getSampleFormat();
AudioFormat fmt = new AudioFormat(_grabber.getSampleRate(), format, channels, true, true);
_sourceDataLine=(SourceDataLine)AudioSystem.getLine(new DataLine.Info(SourceDataLine.class, fmt));
_sourceDataLine.open(fmt);
_sourceDataLine.start();

Attempting to play sound (images are handled in the else block):

org.bytedeco.javacv.Frame f = _grabber.grabFrame();

if (f.samples != null && f.samples.length > 0)
{
    byte[] bytes = new byte[4096];
    for (Buffer buffer : f.samples)
    {
        FloatBuffer floatBuffer = (FloatBuffer) buffer;
        ByteBuffer byteBuffer = ByteBuffer.allocate(floatBuffer.capacity() * 4);
        byteBuffer.asFloatBuffer().put(floatBuffer);
        byteBuffer.rewind();
        byteBuffer.get(bytes);
        _sourceDataLine.write(bytes, 0, bytes.length);
    }
}

(Note: I tried a few different versions of this and they all have static. The versions I tried included combining the buffers into one large buffer, only trying to play one sample instead of each channel, and changing the audio format to many different permutations.)

The problem is the sound is full of static, and almost completely unintelligible. This is my first time doing any audio programming, so I'm sure I'm doing something completely ridiculous.

I appreciate any help. Thank you.