/*
 * @(#)BasicMux.java	1.21 02/08/21
 *
 * Copyright (c) 1996-2002 Sun Microsystems, Inc.  All rights reserved.
 */

package com.sun.media.multiplexer;

import javax.media.Clock;
import javax.media.TimeBase;
import javax.media.Time;
import javax.media.Duration;
import javax.media.Buffer;
import javax.media.Multiplexer;
import javax.media.Format;
import javax.media.format.VideoFormat;
import javax.media.PlugIn;
import javax.media.format.AudioFormat;
import javax.media.IncompatibleTimeBaseException;
import javax.media.ClockStoppedException;
import javax.media.control.StreamWriterControl;
import javax.media.Owned;
import javax.media.protocol.Seekable;
import javax.media.protocol.PushDataSource;
import javax.media.protocol.DataSource;
import javax.media.protocol.PushSourceStream;
import javax.media.protocol.SourceStream;
import javax.media.protocol.SourceTransferHandler;
import javax.media.protocol.ContentDescriptor;
import com.sun.media.*;
import com.sun.media.controls.MonitorAdapter;
import javax.media.format.UnsupportedFormatException;
import java.io.IOException;
import javax.media.Control;

public abstract class BasicMux extends com.sun.media.BasicPlugIn
implements javax.media.Multiplexer, Clock {

    /****************************************************************
     * Variables and Constants
     ****************************************************************/
    
    protected Format []              supportedInputs;
    protected ContentDescriptor []   supportedOutputs;
    protected int                    numTracks = 0;
    protected Format []              inputs;
    protected BasicMuxDataSource     source; // push data source
    protected BasicMuxPushStream     stream;
    protected ContentDescriptor      outputCD;
    protected boolean                flushing = false;
    protected Integer                sourceLock = new Integer(0);
    protected boolean                eos = false;
    protected boolean                firstBuffer = true;
    protected int                    fileSize = 0;
    protected int                    filePointer = 0;
    protected long                   fileSizeLimit = -1;
    protected boolean                streamSizeLimitSupported = true;
    protected boolean                fileSizeLimitReached = false;
    protected  SourceTransferHandler   sth = null;
    protected boolean                isLiveData = false;
    
    protected StreamWriterControl    swc = null;
    protected MonitorAdapter         mc[] = null;
    
    // the timebase exported by this clock
    protected BasicMuxTimeBase timeBase = null;

    // synchronisation object on which streams must wait.
    Object startup = new Integer(0);

    // to be used in audio timestamps in case they are -1.
    // to be used to block video till audio is received
    boolean readyToStart = false;

    // Keeps track of the media time per track.
    long mediaTime[];
    boolean ready[];

    protected BasicClock clock = null;
    // index of the master stream incase this mux is a clock and does
    // synchronisation
    int master = 0;

    boolean mClosed = false;

    /****************************************************************
     * Multiplexer methods
     ****************************************************************/

    public BasicMux() {
	timeBase = new BasicMuxTimeBase();
	clock = new BasicClock();
	try{
	    clock.setTimeBase(timeBase);
	} catch (Exception e){ }

	swc = new SWC(this);
	controls = new Control[] { swc };
    }

    public void open() {
	int i;
	firstBuffer = true;
	firstBuffers = new Buffer[inputs.length];
	firstBuffersDone = new boolean[inputs.length];
	nonKeyCount = new int[inputs.length];
	mediaTime = new long[inputs.length];

	for (i = 0; i < inputs.length; i++) {
	    firstBuffers[i] = null;
	    firstBuffersDone[i] = false;
	    nonKeyCount[i] = 0;
	    mediaTime[i] = 0;
	}

	ready = new boolean[inputs.length];
	resetReady();

	int len = 0;
	mc = new MonitorAdapter[inputs.length];

	for (i = 0; i < inputs.length; i++) {
	    if (inputs[i] instanceof VideoFormat ||
		 inputs[i] instanceof AudioFormat) {
		mc[i] = new MonitorAdapter(inputs[i], this);
		if (mc[i] != null)
		    len++;
	    }
	}

	int j = 0;
	controls = new Control[len + 1];
	for (i = 0; i < mc.length; i++) {
	    if (mc[i] != null)
	        controls[j++] = mc[i];
	}
	controls[j] = swc;
    }

    public void close() {
	if (sth != null) {
	    writeFooter();
	    write(null, 0, -1);
	}

	for (int i = 0; i < mc.length; i++) {
	    if (mc[i] != null)
		mc[i].close();
	}

	synchronized (dataLock) {
	    mClosed = true;
	    dataLock.notifyAll();
	}
    }

    public void reset() {
	//firstBuffer = true;
	for (int i = 0; i < mediaTime.length; i++) {
	    mediaTime[i] = 0;
	    if (mc[i] != null)
		mc[i].reset();
	}
	timeBase.update();
	resetReady();
	synchronized (sourceLock) {
	    flushing = true;
	    sourceLock.notifyAll();
	}
    }

    private void resetReady() {
	for (int i = 0; i < ready.length; i++)
	    ready[i] = false;
	readyToStart = false;
	synchronized (startup) {
	    startup.notifyAll();
	}
    }

    private boolean checkReady() {
	if (readyToStart)
	    return true;
	for (int i = 0; i < ready.length; i++) {
	    if (!ready[i])
		return false;
	}
	readyToStart = true;
	return true;
    }

    public Format [] getSupportedInputFormats() {
	return supportedInputs;
    }

    public ContentDescriptor [] getSupportedOutputContentDescriptors(Format [] inputs) {
	return supportedOutputs;
    }

    public int setNumTracks(int numTracks) {
	this.numTracks = numTracks;

	if (inputs == null)
	    inputs = new Format[numTracks];
	else {
	    Format [] newInputs = new Format[numTracks];
	    for (int i=0; i < inputs.length; i++) {
		newInputs[i] = inputs[i];
	    }
	    inputs = newInputs;
	}
	
	return numTracks;
    }

    /*
     * Override this method to filter out formats unsuitable for the specified
     * content-type
     */
    public Format setInputFormat(Format format, int trackID) {
	inputs[trackID] = format;
	return format;
    }

    public int process(Buffer buffer, int trackID) {
	if (buffer.isDiscard())
	    return BUFFER_PROCESSED_OK;
	if (!isLiveData && (buffer.getFlags() & Buffer.FLAG_LIVE_DATA) > 0) {
	    isLiveData = true;
	}
	// Wait until the datasource is created, connected and started
	while (source == null || !source.isConnected() || !source.isStarted()) {
	    synchronized (sourceLock) {
		try {
		    sourceLock.wait(500);
		} catch (InterruptedException ie) {
		}
		if (flushing) {
		    flushing = false;
		    buffer.setLength(0); // flush the buffer and dont process it
		    return BUFFER_PROCESSED_OK;
		}
	    }
	}

	synchronized (this) {
	    if (firstBuffer) {
		writeHeader();
		firstBuffer = false;
	    }
	}
	
	if (numTracks > 1) {
	    
	    // For buffers with RTP time stamps, we'll skip until
	    // we reach the buffers with non-zero time.  That's
	    // when synchronization is possible.
	    if ((buffer.getFlags() & Buffer.FLAG_RTP_TIME) != 0) {
		if (buffer.getTimeStamp() <= 0)
		    return BUFFER_PROCESSED_OK;
	    }
	    
	    if (!startCompensated) {
		if (!compensateStart(buffer, trackID)) {
		    // Drop the buffer.
		    return BUFFER_PROCESSED_OK;
		}
	    } 
	}
	
	updateClock(buffer, trackID);
	if (mc[trackID] != null && mc[trackID].isEnabled())
	    mc[trackID].process(buffer);
	int processResult = doProcess(buffer, trackID);
	if (fileSizeLimitReached)
	    processResult |= PLUGIN_TERMINATED;
	return processResult;
	
    }

    boolean dataReady = false;
    boolean startCompensated = false;
    Object dataLock = new Object();
    Buffer firstBuffers[];
    boolean firstBuffersDone[];
    int nonKeyCount[];
    long masterTime = -1;

    // Check for these special formats since the key frame flag is
    // not reliably set.
    VideoFormat jpegFmt = new VideoFormat(VideoFormat.JPEG);
    VideoFormat mjpgFmt = new VideoFormat(VideoFormat.MJPG);
    VideoFormat rgbFmt = new VideoFormat(VideoFormat.RGB);
    VideoFormat yuvFmt = new VideoFormat(VideoFormat.YUV);

    private boolean compensateStart(Buffer buffer, int trackID) {

      synchronized (dataLock) {

	// This is the case when all the data have arrived, but
	// some buffers should have been dropped.  The following
	// code throw away the buffers that are behind.  For video,
	// key frames are carefully considered.
	if (dataReady) {
	    if (!firstBuffersDone[trackID]) {
		if (buffer.getTimeStamp() < masterTime) {
		    // Drop this frame.
		    return false;
		} else {
		    if (buffer.getFormat() instanceof VideoFormat) {
			Format fmt = buffer.getFormat();
			boolean isKey = (jpegFmt.matches(fmt) ||
					 mjpgFmt.matches(fmt) ||
					 rgbFmt.matches(fmt) ||
					 yuvFmt.matches(fmt));
			if (isKey ||
			    (buffer.getFlags() & Buffer.FLAG_KEY_FRAME) != 0 ||
			    nonKeyCount[trackID]++ > 30) {
			    buffer.setTimeStamp(masterTime);
			    firstBuffersDone[trackID] = true;
			} else
			    return false;
		    } else {
			// For everything else, the media time has exceeded
			// the master time, we reset the timestamps.
			buffer.setTimeStamp(masterTime);
			firstBuffersDone[trackID] = true;
		    }

		    // Check to see if all the first buffers are being
		    // compensated.
		    for (int i = 0; i < firstBuffersDone.length; i++) {
			if (!firstBuffersDone[i])
			    return true;
		    }
		    startCompensated = true;
		    return true;
		}
	    }
	    return true;
	}

	if (buffer.getTimeStamp() < 0) {

	    // At least one of the tracks have undefined timestamps,
	    // synchronization is deem to fail.  We won't attempt any
	    // compensation.
	    startCompensated = true;
	    dataReady = true;
	    dataLock.notifyAll();
	    return true;

	}

	firstBuffers[trackID] = buffer;

	// Check to see if all the buffers have arrived.
	boolean done = true;

	for (int i = 0; i < firstBuffers.length; i++) {
	    if (firstBuffers[i] == null)
		done = false;
	}

	if (!done) {

	    // If not, we'll wait here until all the buffers have arrived.
	    while (!dataReady && !mClosed) {
		try {
		   dataLock.wait();
		} catch (Exception e) {}
	    }

	    if (mClosed || firstBuffers[trackID] == null) {
		// We'll drop this buffer after being compensated for.
		return false;
	    }
	    return true;
	}

	// The first buffers have all arrived.

	// Find the master time.  If audio is there, we
	// use it.  Otherwise, choose the smallest time to
	// be the master time.

	masterTime = firstBuffers[0].getTimeStamp();

	for (int i = 0; i < firstBuffers.length; i++) {
	    if (firstBuffers[i].getFormat() instanceof AudioFormat) {
		masterTime = firstBuffers[i].getTimeStamp();
		break;
	    }
	    if (firstBuffers[i].getTimeStamp() < masterTime)
		masterTime = firstBuffers[i].getTimeStamp();
	}

	// For times bigger than master time, sets it to the
	// master time.  If not, we need to drop the frame.

	startCompensated = true;
	for (int i = 0; i < firstBuffers.length; i++) {

	    if (firstBuffers[i].getTimeStamp() >= masterTime) {
		firstBuffers[i].setTimeStamp(masterTime);
		firstBuffersDone[i] = true;
	    } else {
		firstBuffers[i] = null;
		startCompensated = false;
	    }
	}

	// Release the lock and buffer waiting to be processed since
	// all the initial buffers have arrived.
	synchronized (dataLock) {
	    dataReady = true;
	    dataLock.notifyAll();
	}

	return (firstBuffers[trackID] != null);

      } // dataLock.
    }

    private void updateClock(Buffer buffer, int trackID) {
	// Initially (after reset), block until all the streams 
	// have arrived.
	if (!readyToStart && numTracks > 1) {
	    synchronized (startup) {
		ready[trackID] = true;
		if (checkReady()) {
		    startup.notifyAll();
		} else {
		    try {
			// wait at most for 1 seconds.
			while (!readyToStart)
			    startup.wait(1000);
	    	    } catch (Exception e) { }
		}
	    }
	}

	// get the timestamp on the incoming buffer
	long timestamp = buffer.getTimeStamp();

	if (timestamp <= 0 && buffer.getFormat() instanceof AudioFormat) {
	    // If it's audio data and the time stamp is undefined,
	    // we'll compute from the audio duration.
	    timestamp = mediaTime[trackID];
	    mediaTime[trackID] += getDuration(buffer);
	} else if (timestamp <= 0) {
	    // This is video with TIME_UNKNOWN.
	    mediaTime[trackID] = System.currentTimeMillis() * 1000000 -
				systemStartTime;
	} else
	    mediaTime[trackID] = timestamp;

	timeBase.update();
    }
    
    public ContentDescriptor setContentDescriptor(ContentDescriptor outputCD) {
	if (matches(outputCD, supportedOutputs) == null)
	    return null;

	// create the datasource and set its output
	// contentdescriptor
	this.outputCD = outputCD;
	return outputCD;
    }

    public DataSource getDataOutput() {
	if (source == null) {
	    source = new BasicMuxDataSource(this, outputCD);
	    synchronized (sourceLock) {
		sourceLock.notifyAll();
	    }
	}
	return source;
    }

    /****************************************************************
     * Local methods
     ****************************************************************/

    protected int doProcess(Buffer buffer, int trackID) {
	// Simple mux - just write the contents of the buffer
	byte [] data = (byte[]) buffer.getData();
	int dataLen = buffer.getLength();
	if (!buffer.isEOM())
	    write(data, buffer.getOffset(), dataLen);
	return BUFFER_PROCESSED_OK;
    }

    protected int write(byte [] data, int offset, int length) {
	if (source == null || !source.isConnected())
	    return length;
	if (length > 0) {
	    filePointer += length;
	    if (filePointer > fileSize)
		fileSize = filePointer;
	    if (fileSizeLimit > 0 && fileSize >= fileSizeLimit)
		fileSizeLimitReached = true;
	}
	return stream.write(data, offset, length);
    }

    void setStream(BasicMuxPushStream ps) {
	stream = ps;
    }

    long getStreamSize() {
	return fileSize;
    }
    
    /* Should return true if it requires a seekable transfer handler */
    boolean needsSeekable() {
	return false;
    }

    protected int seek(int location) {
	if (source == null || !source.isConnected())
	    return location;
	filePointer = stream.seek(location);
	return filePointer;
    }

    boolean isEOS() {
	return eos;
    }

    protected void writeHeader() {
    }

    protected void writeFooter() {
    }

    protected int maxBufSize = 32768; // Don't reduce this value below 2048
    protected byte [] buf = new byte[maxBufSize];
    protected int     bufOffset;
    protected int     bufLength;
    
    protected void bufClear() {
	bufOffset = 0;
	bufLength = 0;
    }

    protected void bufSkip(int size) {
	bufOffset += size;
	bufLength += size;
	filePointer += size;
    }
    
    protected void bufWriteBytes(String s) {
	byte [] bytes = s.getBytes();
	bufWriteBytes(bytes);
    }

    protected void bufWriteBytes(byte [] bytes) {
	System.arraycopy(bytes, 0,
			 buf, bufOffset, bytes.length);
	bufOffset += bytes.length;
	bufLength += bytes.length;
	filePointer += bytes.length;
    }

    protected void bufWriteInt(int value) {
	buf[bufOffset + 0] = (byte)((value >> 24) & 0xFF);
	buf[bufOffset + 1] = (byte)((value >> 16) & 0xFF);
	buf[bufOffset + 2] = (byte)((value >>  8) & 0xFF);
	buf[bufOffset + 3] = (byte)((value >>  0) & 0xFF);
	bufOffset += 4;
	bufLength += 4;
	filePointer += 4;
    }

    protected void bufWriteIntLittleEndian(int value) {
	buf[bufOffset + 3] = (byte)((value >>> 24) & 0xFF);
	buf[bufOffset + 2] = (byte)((value >>> 16) & 0xFF);
	buf[bufOffset + 1] = (byte)((value >>>  8) & 0xFF);
	buf[bufOffset + 0] = (byte)((value >>>  0) & 0xFF);
	bufOffset += 4;
	bufLength += 4;
	filePointer += 4;
    }

    protected void bufWriteShort(short value) {
	buf[bufOffset + 0] = (byte)((value >> 8) & 0xFF);
	buf[bufOffset + 1] = (byte)((value >> 0) & 0xFF);
	bufOffset += 2;
	bufLength += 2;
	filePointer += 2;
    }

    protected void bufWriteShortLittleEndian(short value) {
	buf[bufOffset + 1] = (byte)((value >> 8) & 0xFF);
	buf[bufOffset + 0] = (byte)((value >> 0) & 0xFF);
	bufOffset += 2;
	bufLength += 2;
	filePointer += 2;
    }

    protected void bufWriteByte(byte value) {
	buf[bufOffset] = value;
	bufOffset++;
	bufLength++;
	filePointer++;
    }

    protected void bufFlush() {
	filePointer -= bufLength;  // It is going to be incremented in write()
	write(buf, 0, bufLength);
    }

    private long getDuration(Buffer buffer){
	javax.media.format.AudioFormat format =
	  (javax.media.format.AudioFormat)buffer.getFormat();

	long duration = format.computeDuration(buffer.getLength());

	if (duration < 0)
	   return 0;

	return duration;
    }

    /****************************************************************
     * Clock methods
     ****************************************************************/

    Object timeSetSync = new Object();
    boolean started = false;
    long systemStartTime = System.currentTimeMillis() * 1000000;
    
    public void setTimeBase(TimeBase master) throws IncompatibleTimeBaseException {
	if (master != timeBase)
	    throw new IncompatibleTimeBaseException();
    }
    
    public void syncStart(Time at) {
	synchronized (timeSetSync){
	    if (started) return;
	    started = true;
	    clock.syncStart(at);
	    timeBase.mediaStarted();
	    systemStartTime = System.currentTimeMillis() * 1000000;
	}
    }

    public void stop() {
	synchronized (timeSetSync){
	    if (!started) return;
	    started = false;
	    clock.stop();
	    timeBase.mediaStopped();
	}
    }

    public void setStopTime(Time stopTime) {
	clock.setStopTime(stopTime);
    }

    public Time getStopTime() {
	return clock.getStopTime();
    }

    public void setMediaTime(Time now) {
	synchronized (timeSetSync) {
	    clock.setMediaTime(now);
	    for (int i = 0; i < mediaTime.length; i++)
		mediaTime[i] = now.getNanoseconds();
	    timeBase.update();
	}
    }

    public Time getMediaTime() {
	return clock.getMediaTime();
	
    }

    public long getMediaNanoseconds() {
	return clock.getMediaNanoseconds();
    }

    public Time getSyncTime() {
	return clock.getSyncTime();
	
    }

    public TimeBase getTimeBase() {
	return clock.getTimeBase();
    }

    public Time mapToTimeBase(Time t) throws ClockStoppedException {
	return clock.mapToTimeBase(t);
    }

    public float getRate() {
	return clock.getRate();
    }

    public float setRate(float factor) {
	if (factor == clock.getRate())
	    return factor;
	return clock.setRate(1.0f);
    }

    /**
     * sub classes should override this method and return true if
     * two passes are required to create the media file.
     * Two passes may be required for example to rearrange the media
     * file so that the resultant file is Streamable
     */
    public boolean requireTwoPass() {
	return false;
    }

    /****************************************************************
     * INNER CLASSES
     ****************************************************************/

    class SWC implements StreamWriterControl, Owned {

	private BasicMux bmx;
	
	public SWC(BasicMux bmx) {
	    this.bmx = bmx;
	}
	
	public boolean setStreamSizeLimit(long limit) {
	    bmx.fileSizeLimit = limit;
	    return streamSizeLimitSupported;
	}

	public long getStreamSize() {
	    return bmx.getStreamSize();
	}

	public Object getOwner() {
	    return bmx;
	}

	public java.awt.Component getControlComponent() {
	    return null;
	}
    }
    
    class BasicMuxTimeBase extends MediaTimeBase {

	long ticks = 0;
	boolean updated = false;

        public long getMediaTime() {
	    if (!updated)
		return ticks;

	    if (mediaTime.length == 1) {
		ticks = mediaTime[0];
	    } else { 
		ticks = mediaTime[0];
		for (int i = 1; i < mediaTime.length; i++) {
		    if (mediaTime[i] < ticks)
			ticks = mediaTime[i];
		}
	    }
	    updated = false;
	    return ticks;
        }

	public void update() {
	    updated = true;
	}

    }// end of BasicMuxTimeBase

    
    class BasicMuxDataSource extends PushDataSource {

	private BasicMux            mux;
	private ContentDescriptor   cd;
	private BasicMuxPushStream [] streams;
	private BasicMuxPushStream    stream;
	private boolean             connected = false;
	private boolean             started = false;
	
	public BasicMuxDataSource(BasicMux mux, ContentDescriptor cd) {
	    this.cd = cd;
	    this.mux = mux;	    
	}

	public PushSourceStream [] getStreams() {
	    if (streams == null) {
		streams = new BasicMuxPushStream[1];
		stream = new BasicMuxPushStream(cd);
		streams[0] = stream;
		setStream(stream);
	    }
	    return streams;
	}

	public String getContentType() {
	    return cd.getContentType();
	}
	
	public void connect() throws IOException {
	    if (streams == null)
		getStreams();
	    connected = true;
	    synchronized (sourceLock) {
		sourceLock.notifyAll();
	    }
	}

	boolean isConnected() {
	    return connected;
	}

	boolean isStarted() {
	    return started;
	}

	public void disconnect() {
	    connected = false;
	}

	public void start() throws IOException {
	    if (streams == null || !connected)
		throw new IOException("Source not connected yet!");
	    started = true;
	    synchronized (sourceLock) {
		sourceLock.notifyAll();
	    }
	}

	public void stop() {
	    started = false;
	}

	public Object [] getControls() {
	    return new Control[0];
	}

	public Object getControl(String s) {
	    return null;
	}

	public Time getDuration() {
	    return Duration.DURATION_UNKNOWN;
	}
    }

    /****************************************************************
     * BasicMuxPushStream
     ****************************************************************/
    
    class BasicMuxPushStream implements PushSourceStream {

	private ContentDescriptor cd;
	private byte [] data;
	private int     dataLen;
	private int     dataOff;
	private Integer writeLock = new Integer(0);
	
	public BasicMuxPushStream(ContentDescriptor cd) {
	    this.cd = cd;
	}
	
	public ContentDescriptor getContentDescriptor() {
	    return cd;
	}

	public long getContentLength() {
	    return LENGTH_UNKNOWN;
	}

	public boolean endOfStream() {
	    return isEOS();
	}

	synchronized int write(byte [] data, int offset, int length) {
	    
	    if (sth == null)
		return 0;

	    if (isLiveData && sth instanceof Syncable)
		((Syncable)sth).setSyncEnabled();
	    
	    synchronized (writeLock) {
		this.data = data;
		dataOff = offset;
		dataLen = length;
		// tell the source transfer handler that data is available
		//  (even if its an eos)
		sth.transferData(this);
		while (dataLen > 0) {
		    if (dataLen == length) {
			try {
			    writeLock.wait();
			} catch (InterruptedException ie) {
			}
		    }
		    if (sth == null)
			break;
		    // If its not fully consumed but atleast partially consumed
		    if (dataLen > 0 && dataLen != length) {
			length = dataLen;
			sth.transferData(this);
		    }
		}
	    }
	    return length; // what is this value for?
	}

	synchronized int seek(int location) {
	    if (sth != null) {
	        ((Seekable)sth).seek(location);
	        int seekVal = (int) (((Seekable)sth).tell());
	        return seekVal;
	    }
	    return -1;
	}

	public int read(byte[] buffer, int offset, int length) throws IOException {
	    int transferred = 0;
	    
	    synchronized (writeLock) {
		if (dataLen == -1)
		    transferred = -1;
		else {
		    if (length >= dataLen) {
			transferred = dataLen;
		    } else {
			transferred = length;
		    }
		    System.arraycopy(data, dataOff, buffer, offset,
				     transferred);
		    dataLen -= transferred;
		    dataOff += transferred;
		}
		writeLock.notifyAll();
		return transferred;
	    }
	}

	public int getMinimumTransferSize() {
	    return dataLen;
	}

	public void setTransferHandler(SourceTransferHandler sth) {
	    synchronized (writeLock) {
	        BasicMux.this.sth = sth;
	        if (sth != null && needsSeekable() && !(sth instanceof Seekable)) {
		    throw new java.lang.Error("SourceTransferHandler needs to be seekable");
	        }
		boolean requireTwoPass = BasicMux.this.requireTwoPass();

		if (requireTwoPass) {
		    if ( (sth != null) &&
			 (sth instanceof com.sun.media.datasink.RandomAccess) ) {
			com.sun.media.datasink.RandomAccess st = (com.sun.media.datasink.RandomAccess) sth;
			st.setEnabled(true);
		    }
		}
		writeLock.notifyAll();
	    }
	}
	
	public Object [] getControls() {
	    return new Control[0];
	}

	public Object getControl(String s) {
	    return null;
	}

    }
}
