annotate src/samer/audio/FileSource2.java @ 8:5e3cbbf173aa tip

Reorganise some more

/*
 *	FileSource2.java
 *
 *	Copyright (c) 2000, Samer Abdallah, King's College London.
 *	All rights reserved.
 *
 *	This software is provided AS iS and WITHOUT ANY WARRANTY;
 *	without even the implied warranty of MERCHANTABILITY or
 *	FITNESS FOR A PARTICULAR PURPOSE.
 */

package samer.audio;

import  samer.core.*;
import  samer.core.types.*;
import  samer.core.util.*;
import  samer.tools.*;
import  javax.sound.sampled.*;
import  javax.swing.*;
import  java.io.*;
import  java.util.*;
import  java.nio.ByteBuffer;

/**
	An AudioSource that read from multiple audio files. Can read any
	format for which the appropriate JavaSound plug-in is installed on
	your system, eg WAV, AU, MP3, OGG. The implementation of 
	AudioSource.reader() returns a Task which gets samples from the audio 
	files, going through the play list one by one. 
	An EOFException is thrown if an attempt is made
	to read beyond the end of the last file.
	
	FileSource2 is a Viewable called "playlist", and an Agent with commands
	next, view.
					
*/

public class FileSource2 extends Viewable implements AudioSource, Agent
{
	List<File>				list=null;
	ListIterator<File>	it=null;
	int				channelsToMix;
	File				curFile=null;
	InputStream		in=null;
	AudioFormat		targetFormat=null;
	byte[]  			byte_buf=null;
	int				chunk=0, bytesPerSample=0;

	/**
	 * Construct a FileSource2. 
	 */
	public FileSource2(AudioFormat targetFormat, List<File> files)
	{
		super("playlist");

		setAgent(this);
		Shell.registerViewable(this);
		this.targetFormat=targetFormat;
		this.list=files;
		it=list.listIterator(); 
	}

	// AudioSource interface methods
	public void dispose() {
		close();
		Shell.deregisterViewable(this);
	}

	public int getChannels() { return targetFormat.getChannels(); }
	public float getRate()   { return targetFormat.getFrameRate(); }

	/** Returns current file */
	public File getFile() { return curFile; }

	/** The requested audio format. **/
	public AudioFormat getTargetFormat() { return targetFormat; }

	/** Set playlist to all WAV files in given directory */
	public static List<File> directory(File dir, String ext) {
		return Arrays.asList(dir.listFiles(getFileFilter(ext))); 
	}

	public synchronized List<File> getPlaylist() { return list; }

	/** Move to head of next file in playlist */
	public synchronized void next() throws Exception
	{
		boolean wasOpen=isOpen();

		if (wasOpen) close();
		if (!it.hasNext()) throw new EOFException();
		curFile=it.next();
		if (wasOpen) openCurrent();
	}

	public boolean isOpen() { return in!=null; }

	/** Closes current input stream */
	public synchronized void close() {
		try { 
			if (in!=null) {
				Shell.trace("Closing audio stream...");
				in.close(); in=null; byte_buf=null; 
			}
		}
		catch (IOException ex) {}
	}

	/** Opens the playlist starting with the first file.  */
	public synchronized void open() throws Exception { 
		it=list.listIterator(); next(); 
		if (!isOpen()) openCurrent();
	}

	/** Opens the current file. Next read will returns samples
	 *  from head of given file. If setFormat() was called previously, then
	 *  we will attempt to do format conversion. */
	private synchronized void openCurrent() throws Exception
	{
		File file=curFile;
		Shell.trace("\nFileSource:Opening audio file "+file);

		AudioInputStream ain=AudioSystem.getAudioInputStream(file);

		// convert to target format if required
		if (targetFormat==null) {
			AudioFormat fin=ain.getFormat();
			ain=convertFormat(new AudioFormat( fin.getSampleRate(), 16, fin.getChannels(), true, false), ain);
		} else {
			ain=convertFormat(targetFormat, ain);
		}
		bytesPerSample=ain.getFormat().getSampleSizeInBits()/8;
		if (bytesPerSample!=2) throw new Exception("Must be 16 bits per sample");

		in = new BufferedInputStream(ain,64*1024);

		// If we have a reader task, then update the byte buffer
		if (chunk>0) setByteBuffer();
	}

	/** Returns number of bytes available in current file */
	public int available() throws Exception { return in.available(); }

	private void setBlockSize(int s) { chunk=s; }
	private void setByteBuffer() {
		byte_buf       = new byte[chunk*bytesPerSample];
	}

	public int readInto(ByteBuffer buf, int offset, int len) throws IOException {
		return in.read(buf.array(), offset, len);
	}

	/** Returns a Task which copies samples as doubles into the given
	 *  buffer between the given positions. */
	public Task reader(final double [] dbuf, final int off, final int len) {
		setBlockSize(len);
		if (in!=null) setByteBuffer();

		return new AnonymousTask() {
			public void run() throws Exception {
				synchronized (FileSource2.this) {
					// loop until len samples copied into dbuf
					int rem=len, pos=off;
					while (rem>0) {
						int bytesRead = in.read(byte_buf, 0, rem*bytesPerSample);
						if (bytesRead > 0) { // append this chunk to output
							int count=bytesRead/bytesPerSample;
							Util.shortToDouble(byte_buf,dbuf,pos,count);
							pos+=count; rem-=count;
						} else if (it!=null) next(); // next file if there is one
						else throw new EOFException(); // not looping and no more files
					}
				}
			}
		};
	}

	/** Returns a Task which copies samples as floats into the given
	 *  buffer between the given positions. */
	public Task reader(final float [] dbuf, final int off, final int len) {
		setBlockSize(len);
		if (in!=null) setByteBuffer();

		return new AnonymousTask() {
			public synchronized void run() throws Exception {
				synchronized (FileSource2.this) {
					// loop until len samples copied into dbuf
					int rem=len, pos=off;
					while (rem>0) {
						int bytesRead = in.read(byte_buf, 0, rem*bytesPerSample);
						if (bytesRead > 0) {
							int count=bytesRead/bytesPerSample;
							Util.shortToFloat(byte_buf,dbuf,pos,count);
							pos+=count; rem-=count;
						} else if (it!=null) next();
						else throw new EOFException();
					}
				}
			}
		};
	}

	// Agent
	public void getCommands(Agent.Registry r) {
		r.add("next").add("view");
	}

	public void execute(String cmd, Environment env) throws Exception {
		if (cmd.equals("next")) next();
		else if (cmd.equals("view")) {
			if (list!=null) {
				Shell.expose(
					new JScrollPane(new JList(list.toArray())),
					"playlist");
			}
		} 
	}

	// Viewable
	public Viewer getViewer() { return new FileSourceViewer(); }
	class FileSourceViewer extends DefaultViewer implements Agent {
		public FileSourceViewer() {
			super(FileSource2.this);
			//add(curFile);
			add(Shell.createButtonsFor(this));
		}

		public void getCommands(Agent.Registry r) {
			r.add("next").add("view");
		}
		public void execute(String cmd, Environment env) throws Exception {
			FileSource2.this.execute(cmd,env);
		}
	};

	private static java.io.FileFilter getFileFilter(final String ext) { 
		return new java.io.FileFilter() {
			public boolean accept(File file) {
				return file.getName().toLowerCase().endsWith(ext);
			}
		};
	}

	private static AudioInputStream convertVia(AudioFormat fout, AudioInputStream sin, AudioFormat fint) throws Exception
	{
		Shell.trace("  | Trying recursive via "+fint.toString());
		AudioInputStream sint=AudioSystem.getAudioInputStream(fint,sin);
		Shell.trace("  | Obtained  "+sint.getFormat().toString());
		return convertFormat(fout, sint);
	}

	private static AudioInputStream convertFormat(AudioFormat fout, AudioInputStream sin) throws Exception
	{
		AudioFormat fin=sin.getFormat();

		if (fin.equals(fout)) return sin;

		Shell.trace("\nconvertFormat:");
		Shell.trace("  | source: "+fin.toString());
		Shell.trace("  | target: "+fout.toString());

		if (fin.getEncoding()!=AudioFormat.Encoding.PCM_SIGNED) {
			// first get into PCM encoding, then try recursive
			try {
				return convertVia( fout, sin, new AudioFormat( 
					fin.getSampleRate(), fout.getSampleSizeInBits(),
					fin.getChannels(), true, fout.isBigEndian()));
			} catch (IllegalArgumentException ex) { 
				Shell.trace("Direct conversion failed"); 
			}
			return convertVia( fout, sin, new AudioFormat( 
				fin.getSampleRate(), fin.getSampleSizeInBits(),
				fin.getChannels(), true, fout.isBigEndian()));
		} 

		if (fin.getChannels()!=fout.getChannels() || fin.getSampleSizeInBits()!=fout.getSampleSizeInBits()) {
			// convert these before doing any sample rate conversion
			return convertVia(fout, sin, new AudioFormat( 
				fin.getSampleRate(), fout.getSampleSizeInBits(),
				fout.getChannels(), true, fout.isBigEndian()));
		}

		// the only thing left is sample rate
		return AudioSystem.getAudioInputStream(fout,sin);
	}
}