/*
* Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.media.sound;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
/**
* A jitter corrector to be used with SoftAudioPusher.
*
* @author Karl Helgason
*/
public class SoftJitterCorrector extends AudioInputStream {
private static class JitterStream extends InputStream {
static int MAX_BUFFER_SIZE = 1048576;
boolean active = true;
Thread thread;
AudioInputStream stream;
// Cyclic buffer
int writepos = 0;
int readpos = 0;
byte[][] buffers;
Object buffers_mutex = new Object();
// Adapative Drift Statistics
int w_count = 1000;
int w_min_tol = 2;
int w_max_tol = 10;
int w = 0;
int w_min = -1;
// Current read buffer
int bbuffer_pos = 0;
int bbuffer_max = 0;
byte[] bbuffer = null;
public byte[] nextReadBuffer() {
synchronized (buffers_mutex) {
if (writepos > readpos) {
int w_m = writepos - readpos;
if (w_m < w_min)
w_min = w_m;
int buffpos = readpos;
readpos++;
return buffers[buffpos % buffers.length];
}
w_min = -1;
w = w_count - 1;
}
while (true) {
try {
Thread.sleep(1);
} catch (InterruptedException e) {
//e.printStackTrace();
return null;
}
synchronized (buffers_mutex) {
if (writepos > readpos) {
w = 0;
w_min = -1;
w = w_count - 1;
int buffpos = readpos;
readpos++;
return buffers[buffpos % buffers.length];
}
}
}
}
public byte[] nextWriteBuffer() {
synchronized (buffers_mutex) {
return buffers[writepos % buffers.length];
}
}
public void commit() {
synchronized (buffers_mutex) {
writepos++;
if ((writepos - readpos) > buffers.length) {
int newsize = (writepos - readpos) + 10;
newsize = Math.max(buffers.length * 2, newsize);
buffers = new byte[newsize][buffers[0].length];
}
}
}
public JitterStream(AudioInputStream s, int buffersize,
int smallbuffersize) {
this.w_count = 10 * (buffersize / smallbuffersize);
if (w_count < 100)
w_count = 100;
this.buffers
= new byte[(buffersize/smallbuffersize)+10][smallbuffersize];
this.bbuffer_max = MAX_BUFFER_SIZE / smallbuffersize;
this.stream = s;
Runnable runnable = new Runnable() {
public void run() {
AudioFormat format = stream.getFormat();
int bufflen = buffers[0].length;
int frames = bufflen / format.getFrameSize();
long nanos = (long) (frames * 1000000000.0
/ format.getSampleRate());
long now = System.nanoTime();
long next = now + nanos;
int correction = 0;
while (true) {
synchronized (JitterStream.this) {
if (!active)
break;
}
int curbuffsize;
synchronized (buffers) {
curbuffsize = writepos - readpos;
if (correction == 0) {
w++;
if (w_min != Integer.MAX_VALUE) {
if (w == w_count) {
correction = 0;
if (w_min < w_min_tol) {
correction = (w_min_tol + w_max_tol)
/ 2 - w_min;
}
if (w_min > w_max_tol) {
correction = (w_min_tol + w_max_tol)
/ 2 - w_min;
}
w = 0;
w_min = Integer.MAX_VALUE;
}
}
}
}
while (curbuffsize > bbuffer_max) {
synchronized (buffers) {
curbuffsize = writepos - readpos;
}
synchronized (JitterStream.this) {
if (!active)
break;
}
try {
Thread.sleep(1);
} catch (InterruptedException e) {
//e.printStackTrace();
}
}
if (correction < 0)
correction++;
else {
byte[] buff = nextWriteBuffer();
try {
int n = 0;
while (n != buff.length) {
int s = stream.read(buff, n, buff.length
- n);
if (s < 0)
throw new EOFException();
if (s == 0)
Thread.yield();
n += s;
}
} catch (IOException e1) {
//e1.printStackTrace();
}
commit();
}
if (correction > 0) {
correction--;
next = System.nanoTime() + nanos;
continue;
}
long wait = next - System.nanoTime();
if (wait > 0) {
try {
Thread.sleep(wait / 1000000L);
} catch (InterruptedException e) {
//e.printStackTrace();
}
}
next += nanos;
}
}
};
thread = new Thread(runnable);
thread.setDaemon(true);
thread.setPriority(Thread.MAX_PRIORITY);
thread.start();
}
public void close() throws IOException {
synchronized (this) {
active = false;
}
try {
thread.join();
} catch (InterruptedException e) {
//e.printStackTrace();
}
stream.close();
}
public int read() throws IOException {
byte[] b = new byte[1];
if (read(b) == -1)
return -1;
return b[0] & 0xFF;
}
public void fillBuffer() {
bbuffer = nextReadBuffer();
bbuffer_pos = 0;
}
public int read(byte[] b, int off, int len) {
if (bbuffer == null)
fillBuffer();
int bbuffer_len = bbuffer.length;
int offlen = off + len;
while (off < offlen) {
if (available() == 0)
fillBuffer();
else {
byte[] bbuffer = this.bbuffer;
int bbuffer_pos = this.bbuffer_pos;
while (off < offlen && bbuffer_pos < bbuffer_len)
b[off++] = bbuffer[bbuffer_pos++];
this.bbuffer_pos = bbuffer_pos;
}
}
return len;
}
public int available() {
return bbuffer.length - bbuffer_pos;
}
}
public SoftJitterCorrector(AudioInputStream stream, int buffersize,
int smallbuffersize) {
super(new JitterStream(stream, buffersize, smallbuffersize),
stream.getFormat(), stream.getFrameLength());
}
}