wavheader.java

编辑视频文件

            output.append("\n================ rdata chunk ===================");
            output.append("\n08-11 Letters                 : ").append(wID);
            output.append("\n=============== format chunk ================");
            output.append("\n12-15 Letters                 : ").append(fID);
            output.append("\n16-19 Length of rest of chunk : ").append(fLen);
            output.append("\n20-21 WAV Format Tag          : ").append(wFormatTag);
            output.append("\n22-23 Number of channels      : ").append(nChannels);
            output.append("\n24-27 Sample frequency        : ").append(nSamplesPerSec);
            output.append("\n28-31 nAvgBytesPerSec         : ").append(nAvgBytesPerSec);
            output.append("\n32-33 nBlockAlign             : ").append(nBlockAlign);

            for (int i = 0; i < formatSpecific.length; i++) {
                output.append("\n").append((34 + (i * 2)) + "-" +
                    (35 + (i * 2)));
                output.append(" Format specific data    : ").append(formatSpecific[i]);
            }

            output.append("\n================ data chunk =================");
            output.append("\n" + (20 + fLen) + "-" + (23 + fLen)).append(" Letters                 : ");
            output.append(dID).append("\n" + (24 + fLen) + "-" + (27 + fLen));
            output.append(" Length of following data: ")
                  .append(dLen + "\n" + (28 + fLen) + "-" + (28 + fLen + dLen))
                  .append(" (data)");

            if (cuePoints.length > 0) {
                output.append("\n================= cue Chunk =================");

                for (int i = 0; i < cuePoints.length; i++) {
                    output.append("\nCue point " + i + ":\n" + cuePoints[i]);
                }
            }

            if (cueSections.length > 0) {
                output.append("\n==================list chunk ================");
                output.append("\n============ labeled text chunk ===========");

                for (int i = 0; i < cueSections.length; i++) {
                    output.append("\nCue section " + i + ":\n" +
                        cueSections[i]);
                }
            }

            output.append(getInfo());
        } catch (NullPointerException e) {
            e.printStackTrace();

            return "";
        }

        return output.toString();
    }

    private static WAVCuePoint[] getCuePoints(RandomAccessFile soundFile)
        throws IOException {
        byte[] b = new byte[4];
        soundFile.read(b); //cueChunkDataSize
        soundFile.read(b);

        int numCuePoints = getInt(b);
        WAVCuePoint[] cuePoints = new WAVCuePoint[numCuePoints];
        int ID;
        int position;
        String dataChunkID;
        int chunkStart;
        int blockStart;
        int sampleOffset;

        for (int i = 0; i < cuePoints.length; i++) {
            soundFile.read(b);
            ID = getInt(b);
            soundFile.read(b);
            position = getInt(b);
            soundFile.read(b);
            dataChunkID = getString(b);
            soundFile.read(b);
            chunkStart = getInt(b);
            soundFile.read(b);
            blockStart = getInt(b);
            soundFile.read(b);
            sampleOffset = getInt(b);

            if ("data".equals(dataChunkID)) {
                cuePoints[i] = new WAVCuePoint(ID, position, chunkStart,
                        blockStart, sampleOffset);
            } else {
                System.out.println("Warning: Reading of cue points failed!");
                System.out.println(
                    "Cannot handle Cue Point with Data Chunk ID '" +
                    dataChunkID + "'");

                return new WAVCuePoint[0];
            }
        }

        return cuePoints;
    }

    private static WAVCueSection getCueSection(RandomAccessFile soundFile,
        WAVCuePoint[] cuePoints) throws IOException {
        byte[] b = new byte[4];
        byte[] s = new byte[2];
        byte[] t;
        WAVCueSection cueSection = null;

        int cuePointID;
        int sampleLength;
        String purposeID;
        short country;
        short language;
        short dialect;
        short codePage;
        String label;

        long seek = soundFile.getFilePointer();
        soundFile.read(b);

        int chunkDataSize = getInt(b);

        soundFile.read(b);
        cuePointID = getInt(b);

        soundFile.read(b);
        sampleLength = getInt(b);

        soundFile.read(b);
        purposeID = getString(b);

        soundFile.read(s);
        country = getShort(s);

        soundFile.read(s);
        language = getShort(s);

        soundFile.read(s);
        dialect = getShort(s);

        soundFile.read(s);
        codePage = getShort(s);

        if ((chunkDataSize - 20 - 1) >= 0) {
            t = new byte[chunkDataSize - 20 - 1];

            // minus cuePoint & language bytes minus string end char
            soundFile.read(t);
            label = getString(t);
        } else {
            label = "";
        }

        for (int i = 0; i < cuePoints.length; i++) {
            if (cuePoints[i].getID() == cuePointID) {
                cueSection = new WAVCueSection(cuePoints[i], sampleLength,
                        purposeID, country, language, dialect, codePage, label);

                break;
            }
        }

        seek += (chunkDataSize + 4);
        seek += (seek % 2); //add 1 if uneven
        soundFile.seek(seek);

        return cueSection;
    }

    private static String getInfo(RandomAccessFile soundFile)
        throws IOException {
        String info = "";
        byte[] b = new byte[4];
        soundFile.read(b);

        int chunkDataSize = getInt(b);

        if (chunkDataSize > 0) {
            byte[] t = new byte[chunkDataSize];
            soundFile.read(t);
            info = getString(t);
        }

        soundFile.seek(soundFile.getFilePointer() +
            (soundFile.getFilePointer() % 2));

        return info;
    }

    private static int getInt(byte[] bytes) {
        return getInt(bytes[0], bytes[1], bytes[2], bytes[3]);
    }

    private static int getInt(byte b1, byte b2, byte b3, byte b4) {
        return (b1 & 0xff) | ((b2 & 0xff) << 8) | ((b3 & 0xff) << 16) |
        ((b4 & 0xff) << 24);
    }

    private static short getShort(byte[] s) {
        return getShort(s[0], s[1]);
    }

    private static short getShort(byte b1, byte b2) {
        return (short) ((b1 & 0xff) | ((b2 & 0xff) << 8));
    }

    private static String getString(byte[] bytes) {
        return getString(bytes, bytes.length);
    }

    private static String getString(byte[] bytes, int nrOfBytes) {
        char[] asChar = new char[nrOfBytes];

        for (int i = 0; i < nrOfBytes; i++) {
            asChar[i] = (bytes[i] > 32) ? (char) bytes[i] : ' ';
        }

        return new String(asChar);
    }

    private void readAssociatedDataList(RandomAccessFile soundFile) {
        ArrayList cueSectionList = new ArrayList();
        byte[] b = new byte[4];

        try {
            while (soundFile.getFilePointer() < soundFile.length()) {
                soundFile.read(b);

                if ("ltxt".equals(getString(b))) {
                    WAVCueSection cueSection = getCueSection(soundFile,
                            cuePoints);

                    if (cueSection != null) {
                        cueSectionList.add(cueSection);
                    }
                } else if ("labl".equals(getString(b))) {
                    readCuePointLabels(soundFile, cuePoints);
                } else if ("note".equals(getString(b))) {
                    readCuePointNotes(soundFile, cuePoints);
                } else {
                    break;
                }
            }

            cueSections = (WAVCueSection[]) cueSectionList.toArray(new WAVCueSection[0]);
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
    }

    private static void readCuePointLabels(RandomAccessFile soundFile,
        WAVCuePoint[] cuePoints) throws IOException {
        byte[] b = new byte[4];
        byte[] t;
        String label;
        long seek = soundFile.getFilePointer();
        soundFile.read(b);

        int chunkDataSize = getInt(b);
        soundFile.read(b);

        int cuePointID = getInt(b);

        if ((chunkDataSize - 4 - 1) >= 0) {
            t = new byte[chunkDataSize - 4 - 1];

            // minus cuePoint bytes minus string end byte (&x00)
            soundFile.read(t);
            label = getString(t);

            for (int i = 0; i < cuePoints.length; i++) {
                if (cuePoints[i].getID() == cuePointID) {
                    cuePoints[i].setLabel(label);

                    break;
                }
            }
        }

        seek += (chunkDataSize + 4);
        seek += (seek % 2); //add 1 if uneven
        soundFile.seek(seek);
    }

    private static void readCuePointNotes(RandomAccessFile soundFile,
        WAVCuePoint[] cuePoints) throws IOException {
        byte[] b = new byte[4];
        byte[] t;
        String label;
        long seek = soundFile.getFilePointer();
        soundFile.read(b);

        int chunkDataSize = getInt(b);
        soundFile.read(b);

        int cuePointID = getInt(b);

        if ((chunkDataSize - 4 - 1) >= 0) {
            t = new byte[chunkDataSize - 4 - 1];

            // minus cuePoint bytes minus string end byte (&x00)
            soundFile.read(t);
            label = getString(t);

            for (int i = 0; i < cuePoints.length; i++) {
                if (cuePoints[i].getID() == cuePointID) {
                    cuePoints[i].setNote(label);

                    break;
                }
            }
        }

        seek += (chunkDataSize + 4);
        seek += (seek % 2); //add 1 if uneven
        soundFile.seek(seek);
    }

    private void readCues(RandomAccessFile soundFile) {
        byte[] b = new byte[4];

        try {
            soundFile.seek(28 + fLen + dLen);

            int listChunkSize = 0;

            while (soundFile.getFilePointer() < soundFile.length()) {
                soundFile.read(b);

                if ("list".equals(getString(b).toLowerCase())) {
                    soundFile.read(b);
                    listChunkSize = getInt(b);
                }

                if ("cue ".equals(getString(b))) {
                    cuePoints = getCuePoints(soundFile);

                    continue;
                } else if ("adtl".equals(getString(b))) {
                    readAssociatedDataList(soundFile);

                    continue;
                } else if ("info".equals(getString(b).toLowerCase())) {
                    long endOfChunk = (soundFile.getFilePointer() +
                        listChunkSize) - 4;

                    while (soundFile.getFilePointer() < endOfChunk) {
                        soundFile.read(b);
                        infos.put(getString(b), getInfo(soundFile));
                    }
                }
            }
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
    }
}