Java example source code file (AlawEncoderSync.java)

This example Java source code file (AlawEncoderSync.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

alawencodersync, audioformat, audioinputstream, bytearrayinputstream, bytearrayoutputstream, conversionthread, failed, interruptedexception, main, not, override, passed, runtimeexception, thread_count, util

The AlawEncoderSync.java Java example source code

/*
 * Copyright (c) 2010, 2013, 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.
 *
 * 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/**
 * @test
 * @bug 6938426
 * @bug 7058852
 * @summary Tests that Alaw encoder works properly in multithreaded environment
 * @author Alex Menkov
 */

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.Arrays;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;

public class AlawEncoderSync {

    static final int THREAD_COUNT   = 20;

    static final AudioFormat pcmFormat = new AudioFormat(8000f, 16, 2, true, false);
    static final int STREAM_LENGTH = 10;    // in seconds
    static byte[] pcmBuffer;
    static final AudioFormat alawFormat
            = new AudioFormat(AudioFormat.Encoding.ALAW, 8000f, 8, 2, 2, 8000f, false);

    static final ConversionThread[] threads = new ConversionThread[THREAD_COUNT];

    public static void main(String[] args) {
        preparePCMBuffer();
        log("pcmStream size: " + pcmBuffer.length);

        for (int i=0; i<THREAD_COUNT; i++) {
            threads[i] = new ConversionThread(i);
            threads[i].start();
        }

        for (int i=0; i<THREAD_COUNT; i++) {
            try {
                threads[i].join();
            } catch (InterruptedException ex) {
                log("Main thread was interrupted, exiting.");
                return;
            }
        }

        int failed = 0;
        log("comparing result arrays...");
        for (int i=1; i<THREAD_COUNT; i++) {
            if (!Arrays.equals(threads[0].resultArray, threads[i].resultArray)) {
                failed++;
                log("NOT equals: 0 and " + i);
            }
        }
        if (failed > 0) {
            throw new RuntimeException("test FAILED");
        }
        log("test PASSED.");
    }


    static void preparePCMBuffer() {
        pcmBuffer = new byte[STREAM_LENGTH * (int)pcmFormat.getSampleRate()
                * (pcmFormat.getSampleSizeInBits() / 8) * pcmFormat.getChannels()];
        for (int i=0; i<pcmBuffer.length; i++) {
            pcmBuffer[i] = (byte)(Math.random() * 256.0 - 128.0);
        }
    }

    static AudioInputStream createPCMStream() {
        InputStream byteStream = new ByteArrayInputStream(pcmBuffer);
        return new AudioInputStream(byteStream, pcmFormat, AudioSystem.NOT_SPECIFIED);
    }

    static class ConversionThread extends Thread {
        public final int num;
        public byte[] resultArray = null;
        public ConversionThread(int num) {
            this.num = num;
        }
        @Override
        public void run() {
            log("ConversionThread[" + num + "] started.");
            try {
                InputStream inStream = new ByteArrayInputStream(pcmBuffer);

                AudioInputStream pcmStream = new AudioInputStream(
                        inStream, pcmFormat, AudioSystem.NOT_SPECIFIED);
                AudioInputStream alawStream = AudioSystem.getAudioInputStream(alawFormat, pcmStream);

                ByteArrayOutputStream outStream = new ByteArrayOutputStream();
                int read = 0;
                byte[] data = new byte[4096];
                while((read = alawStream.read(data)) != -1) {
                    outStream.write(data, 0, read);
               }
               alawStream.close();
               resultArray = outStream.toByteArray();
            } catch (Exception ex) {
                log("ConversionThread[" + num + "] exception:");
                log(ex);
            }
            log("ConversionThread[" + num + "] completed.");
        }
    }

    static void log(String s) {
        System.out.println(s);
    }

    static void log(Exception ex) {
        ex.printStackTrace(System.out);
    }
}