encoder.java

java处理声音文件

/*
 * Encoder is the base class for all GSM encoding.
 * Copyright (C) 1999  Christopher Edwards
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program 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 for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package	org.tritonus.lowlevel.gsm;

import java.io.*;
import java.lang.*;

public class Encoder
	extends Thread
{
	/* Every Encoder has a state through completion */
	private Gsm_State	g_s = new Gsm_State();
	private Long_term	lg_term_Obj = new Long_term();
	private Lpc		lpc_Obj = new Lpc();
	private Rpe		rpe_Obj = new Rpe();
	private Short_term	sh_term_Obj = new Short_term();

	/* [0..7] LAR coefficients              OUT     */
	private short		LARc[]  = new short[8]; 
	/* [0..3] LTP lag 		            OUT     */
	private short		Nc[] = new short[4]; 	
	/* [0..3] coded LTP gain                OUT     */
	private short		Mc[] = new short[4];
	/* [0..3] RPE grid selection            OUT     */
	private short		bc[]    = new short[4];
	/* [0..3] Coded maximum amplitude       OUT     */
	private short		xmaxc[] = new short[4];
	/* [13*4] normalized RPE samples        OUT     */
	private short		xmc[]   = new short[13*4];

	/* Reads 160 bytes */
	private int[]		input_signal = new int[160];  /* [0..159]  OUT */
	/* Writes 33 bytes */
	private byte[]		frame = new byte[Gsm_Def.FRAME_SIZE];

	/**
	 * Encoder class constructor. 
	 */
	public Encoder()
	{
	}



	/** 
	 * Remove the header info from the stream and verifies the file type. 
	 * As defined by the NeXT/Sun audio file format U-law (.au).
	 * For more info see the README file. <br><br>
	 * Note: Most of this info is not needed to reproduce the sound file
	 * after encoding. All that is needed is the magic number and the sampling rate
	 * to reproduce the sound file during decoding.
	 * 
	 * @param in Strip the header from a Sun/Next formated sound stream.
	 */
	public static void stripAUHeader(InputStream in) 
		throws Exception {
		DataInputStream input = new DataInputStream( (InputStream) in );
	
		/* Just read these bits from the stream and do nothing with them */
		int magic = input.readInt();  	/* magic number SND_MAGIC ((int)0x2e736e64),
						 * which equals ".snd".)
						 */
		input.readInt();			/* offset or pointer to the data */
		input.readInt();			/* number of bytes of data */
		int dataFormat = input.readInt();	/* the data format code */
		int sampleRate = input.readInt();	/* the sampling rate = ~8000 samples/sec. */
		input.readInt();			/* the number of channels */
		input.readChar();			/* optional text information - 4 chars */
		input.readChar();
		input.readChar();
		input.readChar();

	    	if( magic != 0x2E736E64)        // ".snd" in ASCII 
		{
		    	// throw new GsmException("AuFile wrong Magic Number");
		}
	    	else if( dataFormat != 1 )      // 8-Bit mu-Law
		{
			// throw new GsmException("AuFile not 8-bit Mu-Law");
		}
	    	else if( sampleRate != 8000)    // 8kHz
		{
		    	// throw new GsmException("AuFile not 8kHz");
		}
	}

	/**
	 * Encode the specified file.
	 * <br>This method calls the <code>stripAUHeader</code> method for you.<br>
	 * stripAUHeader will verify file type.      
	 *
	 * @param input_file The name of the file to encode.
	 * @param output_file The name of the GSM encoded file.
	 */
	public void encode(String input_file, String output_file) 
		throws Exception {

		File arg1 = new File(input_file);
	    	if(!arg1.exists() || !arg1.isFile() || !arg1.canRead())
		{
			throw new IOException("File : " + 	
					      input_file + "\ndoes not exist or cannot be read.");
		}
	
		FileInputStream from = null;
		FileOutputStream to  = null;
		try
		{
			from = new FileInputStream(input_file);
			to = new FileOutputStream(output_file);

	    		// Remove the header. It gets mangled by the encoding.
	    		stripAUHeader(from);

	    		int check_stream = 0;
	
			// Read bytes till EOF.
			while((check_stream = ulaw_input(from)) > 0)
			{
				//System.out.println("Entering Native method.");
				gsm_encode();

				// Need to do some error check here. Update ulaw_output.
				ulaw_output(to);           // Write bytes.
			}

		}
		catch (Exception e)
		{ 	
			throw new Exception("Encoder: " + e.getMessage());
		}
		finally
		{
			if (from != null)
			{
				try
				{
					from.close();
				}
				catch (IOException e)
				{
					throw new IOException("Encoder: " + e.getMessage());
				}
			}
			if (to != null)
			{
				try
				{
					to.close();
				}
				catch (IOException e)
				{
					throw new IOException("Encoder: " + e.getMessage());
				}
			}
		}
	}



	/**
	 * Encode the specified InputStream.     
	 *
	 * @param input The stream to encode.
	 * @param output_file The name of the GSM encoded file.
	 */
	public void encode(InputStream input, String output_file) 
		throws IOException
	{
		FileOutputStream to  = null;
		try
		{
			to = new FileOutputStream(output_file);

			int check_stream = 0;
	
			// Read bytes till EOF.
			while((check_stream = ulaw_input(input)) > 0)
			{
				gsm_encode();

				// Need to do some error check here. Update ulaw_output.
				ulaw_output(to);           // Write bytes.
			}

		}
		catch (IOException e)
		{
			throw new IOException( "Encoder: " + e.getMessage());
		}
		finally
		{
			if (to != null)
			{
				try
				{
					to.close();
				}
				catch (IOException e)
				{
					throw new IOException("Encoder: " + e.getMessage());
				}
			}
		}
	}


	/**	Encodes a block of data.
	 *
	 *	@param asBuffer	an 160-element array with the data to encode
	 *			int PCM 16 bit format.
	 *
	 *	@param abFrame	the encoded GSM frame (33 bytes).
	 */
	public void encode(short[] asBuffer, byte[] abFrame)
	{
		for (int i = 0; i < 160; i++)
		{
			input_signal[i] = asBuffer[i];
		}
		gsm_encode();
		System.arraycopy(frame, 0, abFrame, 0, frame.length);
	}



	/**
	 * Read 160 bytes from a U-law stream and set up the input_signal array. 
	 */
	private int ulaw_input(InputStream in) 
		throws IOException
	{
		int c = 0;
		int i = 0;

		for (i = 0; i < input_signal.length && ((c = in.read()) != -1); i++)
		{
			if (c < 0)
			{
				throw new IOException("Encoder ulaw_input: Corrupt InputStream.");
			}
			else
			{
				input_signal[i] = u2s[c];
			}
		}
		return (i);
	}



	private void gsm_encode()
	{ 
		int index = 0;
	
		Gsm_Coder_java();

		frame[index++]  = (byte) (((0xD) << 4)			/* 1 */
					  | ((LARc[0] >> 2) & 0xF));
		frame[index++]  = (byte) (((LARc[0] & 0x3) << 6)	/* 2 */
					  | (LARc[1] & 0x3F));
		frame[index++]  = (byte) (((LARc[2] & 0x1F) << 3)	/* 3 */
					  | ((LARc[3] >> 2) & 0x7));
		frame[index++]  = (byte) (((LARc[3] & 0x3) << 6)	/* 4 */
					  | ((LARc[4] & 0xF) << 2)
					  | ((LARc[5] >> 2) & 0x3));
		frame[index++]  = (byte) (((LARc[5] & 0x3) << 6)	/* 5 */
					  | ((LARc[6] & 0x7) << 3)
					  | (LARc[7] & 0x7));
		frame[index++]  = (byte) (((Nc[0] & 0x7F) << 1)		/* 6 */
					  | ((bc[0] >> 1) & 0x1));
		frame[index++]  = (byte) (((bc[0] & 0x1) << 7)		/* 7 */
					  | ((Mc[0] & 0x3) << 5)
					  | ((xmaxc[0] >> 1) & 0x1F));
		frame[index++]  = (byte) (((xmaxc[0] & 0x1) << 7)	/* 8 */
					  | ((xmc[0] & 0x7) << 4)
					  | ((xmc[1] & 0x7) << 1)
					  | ((xmc[2] >> 2) & 0x1));
		frame[index++]  = (byte) (((xmc[2] & 0x3) << 6)		/* 9 */
					  | ((xmc[3] & 0x7) << 3)
					  | (xmc[4] & 0x7));
		frame[index++]  = (byte) (((xmc[5] & 0x7) << 5)		/* 10 */