wavheader.java

编辑视频文件

/*
 * File:     WAVHeader.java
 * Project:  MPI Linguistic Application
 * Date:     02 May 2007
 *
 * Copyright (C) 2001-2007  Max Planck Institute for Psycholinguistics
 *
 * 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
 */

/*
 * $Id: WAVHeader.java,v 1.5 2007/04/05 15:29:37 klasal Exp $
 */
package mpi.eudico.client.util;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;


/**
 * Reads the Header of a wav-file. If used standalone, it takes the name of the
 * wav-file as first argument.
 *
 * @author Alexander Klassmann
 * @version april 2003
 */
public class WAVHeader {
    /** Holds value of property DOCUMENT ME! */
    public static final short WAVE_FORMAT_UNCOMPRESSED = 0;

    /** Holds value of property DOCUMENT ME! */
    public static final short WAVE_FORMAT_PCM = 1;

    /** Holds value of property DOCUMENT ME! */
    public static final short WAVE_FORMAT_IEEE_FLOAT = 3;

    /** Holds value of property DOCUMENT ME! */
    public static final short WAVE_FORMAT_ALAW = 6;

    /** Holds value of property DOCUMENT ME! */
    public static final short WAVE_FORMAT_MULAW = 7;

    /** Holds value of property DOCUMENT ME! */
    public static final String[] formatDescriptions = {
        "Unknown", "PCM (uncompressed)", "MS ADPCM", "IEEE float", "",
        "IBM CVSD", "8-bit ITU-T G.711 A-law", "8-bit ITU-T G.711 \u00B5-law"
    };
    private HashMap infos = new HashMap();
    private WAVCuePoint[] cuePoints = new WAVCuePoint[0];
    private WAVCueSection[] cueSections = new WAVCueSection[0];
    private char[] dID = new char[4];
    private char[] fID = new char[4];
    private short[] formatSpecific;
    private char[] riff = new char[4];
    private char[] wID = new char[4];
    private int dLen;
    private int fLen;
    private int headerSize;
    private int nAvgBytesPerSec;
    private int nSamplesPerSec;
    private int rLen;
    private long fileSize;
    private short nBlockAlign;
    private short nChannels;
    private short wFormatTag;

    /**
     * Creates a new WAVHeader object.
     *
     * @param fileName Location of the wav file.
     */
    public WAVHeader(String fileName) {
        try {
            read(new RandomAccessFile(fileName, "r"));
        } catch (FileNotFoundException fne) {
            System.out.println("File " + fileName + " not found.");

            return;
        }
    }

    /**
     * Creates a new WAVHeader object.
     *
     * @param soundFile The wav file.
     */
    public WAVHeader(RandomAccessFile soundFile) {
        read(soundFile);
    }

    /**
     * Returns the compression code, one of the following:
     *
     * <ul>
     * <li>
     * 0 - Unknown
     * </li>
     * <li>
     * 1 - PCM/uncompressed
     * </li>
     * <li>
     * 2 - Microsoft ADPCM
     * </li>
     * <li>
     * 6 - ITU G.711 a-law
     * </li>
     * <li>
     * 7 - ITU G.711 mu-law
     * </li>
     * <li>
     * 17 - IMA ADPCM
     * </li>
     * <li>
     * 20 - ITU G.723 ADPCM
     * </li>
     * <li>
     * 49 - GSM 6.10
     * </li>
     * <li>
     * 64 - ITU G.721 ADPCM
     * </li>
     * <li>
     * 80 - MPEG
     * </li>
     * </ul>
     *
     *
     * @return The compression code.
     */
    public short getCompressionCode() {
        return wFormatTag;
    }

    /**
     * returns cue points which may be present in the tail of the file
     *
     * @return WAVCuePoint[]
     */
    public WAVCuePoint[] getCuePoints() {
        return cuePoints;
    }

    /**
     * returns cue section which may be present in the tail of the file
     *
     * @return WAVCueSection[]
     */
    public WAVCueSection[] getCueSections() {
        return cueSections;
    }

    /**
     * Returns the size of the data (in bytes)
     *
     * @return int
     */
    public int getDataLength() {
        return dLen;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public long getFileSize() {
        return fileSize;
    }

    /**
     * Returns the sample frequency (e.g. 44100 for CD)
     *
     * @return int
     */
    public int getFrequency() {
        return nSamplesPerSec;
    }

    /**
     * Returns the size of the header (in bytes)
     *
     * @return int
     */
    public int getHeaderSize() {
        return headerSize;
    }

    /**
     * returns summary of info in wav trail
     *
     * @return String
     */
    public String getInfo() {
        StringBuffer info = new StringBuffer();

        for (Iterator iter = infos.keySet().iterator(); iter.hasNext();) {
            Object key = iter.next();
            info.append("\n" + key + " : " + infos.get(key));
        }

        return info.toString();
    }

    /**
     * Returns the number of channels (1 = mono; 2 = stereo)
     *
     * @return short
     */
    public short getNumberOfChannels() {
        return nChannels;
    }

    /**
     * Returns the size (in bytes) of a single sample
     *
     * @return short
     */
    public short getSampleSize() {
        return nBlockAlign;
    }

    /**
     * For standalone use. First parameter has to be the filename of the
     * wav-file
     *
     * @param args
     */
    public static void main(String[] args) {
        try {
            if (args.length > 0) {
                WAVHeader wavHeader = new WAVHeader(args[0]);
                System.out.println(wavHeader);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Reads the header of the specified wav-file and sets the attributes of
     * this WAVHeader instance.
     *
     * @param soundFile DOCUMENT ME!
     */
    public void read(RandomAccessFile soundFile) {
        try {
            fileSize = soundFile.length();

            byte[] b;

            //read first 12 bytes (3 groups of 4 bytes: RIFF identifier, size, RIFF type ("WAVE"))
            b = new byte[12];
            soundFile.read(b);

            for (int i = 0; i < 4; i++) {
                riff[i] = (char) b[i];
            }

            rLen = getInt(b[4], b[5], b[6], b[7]);

            for (int i = 0; i < 4; i++) {
                wID[i] = (char) b[8 + i];
            }

            headerSize = 12;

            //read header chunks until reaching "data" identifier
            String chunkID;
            int chunkDataSize;

            while (true) {
                //read chunk header consisting of identifier (4 bytes) and specification of chunk data length (4 bytes)
                b = new byte[8];
                soundFile.read(b);
                headerSize += 8;

                chunkID = getString(b, 4);
                chunkDataSize = getInt(b[4], b[5], b[6], b[7]);

                if ("data".equalsIgnoreCase(chunkID)) { //end of header reached, so break from loop
                    dID = chunkID.toCharArray();
                    dLen = chunkDataSize;

                    break;
                }

                //read contents of chunk
                b = new byte[chunkDataSize];
                soundFile.read(b);

                if ("fmt ".equals(chunkID)) {
                    fID = chunkID.toCharArray();
                    fLen = chunkDataSize;

                    //assign instance attributes
                    //1. parse common fmt bytes
                    wFormatTag = getShort(b[0], b[1]);
                    nChannels = getShort(b[2], b[3]);
                    nSamplesPerSec = getInt(b[4], b[5], b[6], b[7]);
                    nAvgBytesPerSec = getInt(b[8], b[9], b[10], b[11]);
                    nBlockAlign = getShort(b[12], b[13]);

                    //2. parse format-specific bytes
                    int fslength = fLen - 14;
                    formatSpecific = new short[fslength / 2];

                    for (int i = 0; i < fslength; i += 2) {
                        formatSpecific[i / 2] = getShort(b[14 + i], b[15 + i]);
                    }
                } else {
                    System.out.println(chunkID +
                        " header found - ignoring contents...");
                }

                headerSize += chunkDataSize;
            }

            if (fileSize > (28 + fLen + dLen)) {
                readCues(soundFile);
            }
        } catch (IOException ioe) {
            System.out.println(ioe.getMessage());
        }
    }

    /**
     * Returns the whole header information in table form
     *
     * @see java.lang.Object#toString()
     */
    public String toString() {
        StringBuffer output = new StringBuffer("File size: " + fileSize +
                " Bytes");

        //NOTE: byte numbers shown in this toString() method are only correct whe just fmt and data header are present!!!
        try {
            output.append("\n00-03 Letters                 : ").append(riff);
            output.append("\n04-07 Length of rdata chunk   : ").append(rLen);