Transmitting AufioFormat Class and sampled bytes

Question

Hello everyone,
I am building an audio server of sorts. The objective is something like this: the client makes a request which comprises of the filename that it wants served, and the maximum network bandwidth it wants to use for this music. upon receipt of this request, the server reads the audio in uncompressed form and decides on choice of algorithm it employs to compress the audio (along with sampling rate, sample resolution), then it tells the client about the encoding scheme it's employing to compress the subsequent audio then sends the audio packet by packet in same encoding scheme, until the client decides to change it's bandwidth specification (thus quality). when this happen, the server re-decides on encoding scheme and process repeats until the whole audio is played out.
I have decided to run the server such that it creates a new thread for each client, and this thread handles the receipt of 'quality' packet and subsequent reading and compression. As of now i have already developed the classes that handle the various compression schemes, i have also written the codes for mutli-threaded server and client. (note: compression classes take raw bytes and compress them) and that's about it, rest of the job is yet to be done.
What is the best way to handle this type of applications? Is EJB required for this? how to go about doing this? what are the best ways to extract only the audio bytes from a file ( and not the data about it's encoding scheme) what classes store it? how to make client aware of decoding schemes?
PS: i'll provide any further relevant data and codes
{here's the snippets from my implementation for some important aspects:
my server which spawns new threads to serve.
{code} try {
ServerSocket serverSocket = new ServerSocket(902);
while (true)
new AudioServerThread(serverSocket.accept()).run();
} catch .. { }
the run method of the server thread: out = socket.getOutputStream();
in = socket.getInputStream(); //both these within try catch.
two methods in server thread ( write and read) handle the reading and writing to these streams and their error handling)
Sorry for the long winded post like this one.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

Answer 1

thanks yet again, captfoss. i implemented many things u mentioned, it's working alright, but here, i'm hitting a roadblock that look like it'll be a big one ;-(.
let me explain all that i have done:
I have implemented the ServerServer class, which sits listening to requests to spawn new threads to services the client,
the run method in ServerThread looks like this: (all the risky statements are in appropriate try catch blocks and
SerializableAudioFormat is the class i taked about in prev post, it sends enough info over to the cleint for the client to re construct the audio format class )
          out = socket.getOutputStream();
        in = socket.getInputStream();soundFile = new File("C:\\welcome.wav");
        audioInputStream = AudioSystem.getAudioInputStream(soundFile);
        audioFormat = audioInputStream.getFormat();
        SerializableAudioFormat sf = new SerializableAudioFormat(audioFormat.getEncoding(), audioFormat.getSampleRate(), audioFormat.getSampleSizeInBits(), audioFormat.getChannels(), audioFormat.getFrameSize(), audioFormat.getFrameRate(), audioFormat.isBigEndian());
        Write(getBytes(sf));
        audioInputStream = AudioSystem.getAudioInputStream(soundFile);
        int nBytesRead = 0;
        byte[] abData = new byte[Main.BUFFER]; // BUFFER is declared in Main class
                         //as a final integer 10*1024*1024 which is 10 mega bytes.
        while (nBytesRead != -1) {
                nBytesRead = audioInputStream.read(abData, 0, abData.length);
            if (nBytesRead >= 0) {
                this.Write(abData);
            }and Write(byte[] b) wroks like with out.write(b) bmethod (out is o/p stream returned by the socket's getOutputStream() fn.)
the byte[] getBytes(Object obj) method works like this:
bos = new ByteArrayOutputStream();
            oos = new ObjectOutputStream(bos);
            oos.writeObject(obj);
            oos.flush();
            oos.close();
            bos.close();
return bos.bos.toByteArray();////////////////////////////////
All the try catch statements are eliminatd for readability.
Client side a function playFromStream() works like this:
byte[] buf = new byte[Main.BUFFER];   // BUFFER is declared in Main class
                    //as a final integer 10*1024*1024 which is 10 mega bytes.
Encoding e = null;
        if(this.Read(buf) ==0)
            return;
        SerializableAudioFormat sf = (SerializableAudioFormat) toObject(buf);
        if (sf.int_encoding == 1)
            e=Encoding.ALAW;
         else if (sf.int_encoding == 2)
            e=Encoding.PCM_SIGNED;
         else if (sf.int_encoding == 3)
            e=Encoding.PCM_UNSIGNED;
         else if (sf.int_encoding == 4)
            e= Encoding.ULAW;
        audioFormat = new AudioFormat(e,
                sf.sampleRate, sf.sampleSizeInBits,
                sf.channels, sf.frameSize,
                sf.frameRate, sf.bigEndian);
        SourceDataLine line = null;
        DataLine.Info info = new DataLine.Info(SourceDataLine.class, audioFormat);
        line = (SourceDataLine) AudioSystem.getLine(info);
        line.open(audioFormat);
        line.start();
        int nBytesRead = 0;
        while (nBytesRead != -1) {
            nBytesRead = Read(buf );
            System.out.println(nBytesRead);
            if (buf.length == 0) {
                System.out.println("done");
                break;
            } else {
                line.write(buf, 0, nBytesRead);
        line.drain();
        line.close();Read function just reads from inputstream obtained from socket's getInpotStream() fn.
and toObject function works like this:
object = new java.io.ObjectInputStream(new java.io.ByteArrayInputStream(bytes)).readObject();and this object is returned
the problem seems a little too big (pun unintended) when i run this program i get
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at audiostream.Client.<init>(Client.java:23)
at audiostream.Client.main(Client.java:35)
Java Result: 1
and when i decrease that buffer space to 1 MB the audio plays, but like a dog: I can hear a spasmodic fit that says "welcome to java multimedia programming", the audio plays in fits tht last about 500 milliseconds then halts for about a second and next 500ms plays and so on. The welcome.wav file is just 473KB and the whole audio lasts less than 3 seconds.
god save me, what do i do?