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 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package com.sun.media.jfxmediaimpl.platform.java;

import com.sun.media.jfxmediaimpl.MetadataParserImpl;
import java.io.IOException;
import java.util.Arrays;
import com.sun.media.jfxmedia.locator.Locator;
import com.sun.media.jfxmedia.logging.Logger;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;

final class ID3MetadataParser extends MetadataParserImpl {

    private static final int ID3_VERSION_MIN = 2;
    private static final int ID3_VERSION_MAX = 4;

    private static final String CHARSET_UTF_8 = "UTF-8";
    private static final String CHARSET_ISO_8859_1 = "ISO-8859-1";
    private static final String CHARSET_UTF_16 = "UTF-16";
    private static final String CHARSET_UTF_16BE = "UTF-16BE";

    private int COMMCount = 0;
    private int TXXXCount = 0;
    private int version = 3; // Default to 3
    private boolean unsynchronized = false;

    public ID3MetadataParser(Locator locator) {
        super(locator);
    }

    protected void parse() {
        try {
            // We will need ISO-8859-1
            if (!Charset.isSupported(CHARSET_ISO_8859_1)) {
                throw new UnsupportedCharsetException(CHARSET_ISO_8859_1);
            }

            //
            // An ID3v2 tag can be detected with the following pattern:
            //
            // byte   0    1    2   3  4  5  6  7  8  9
            // value 0x49 0x44 0x33 yy yy xx zz zz zz zz
            //
            // Where yy is less than 0xFF, xx is the 'flags' byte and zz is
            // less than 0x80. We also require the version, byte 3,
            // to be exactly 3 to indicate ID3v2.3.0, period.
            //
            // http://id3.org/id3v2.3.0#head-697d09c50ed7fa96fb66c6b0a9d93585e2652b0b
            //

            byte[] buf = getBytes(10);
            version = (int)(buf[3] & 0xFF);
            if (buf[0] == 0x49 && buf[1] == 0x44 && buf[2] == 0x33 &&
                    (version >= ID3_VERSION_MIN && version <= ID3_VERSION_MAX)) {
                int flags = buf[5] & 0xFF;
                if ((flags & 0x80) == 0x80) {
                    unsynchronized = true;
                }

                int tagSize = 0;
                for (int i = 6, shift = 21; i < 10; i++) {
                    tagSize += (buf[i] & 0x7f) << shift;
                    shift -= 7;
                }

                startRawMetadata(tagSize + 10);
                stuffRawMetadata(buf, 0, 10); // put the header back in the raw metadata blob
                readRawMetadata(tagSize);
                setParseRawMetadata(true);
                skipBytes(10); // reposition to past the ID3 header

                while (getStreamPosition() < tagSize) { // size
                    int frameSize;
                    byte[] idBytes;

                    if (2 == version) {
                        // v2 has a six byte header
                        idBytes = getBytes(3);
                        frameSize = getU24();
                    } else {
                        idBytes = getBytes(4);
                        frameSize = getFrameSize();
                        skipBytes(2);
                    }

                    if (0 == idBytes[0]) {
                        // terminate on zero padding, NULL characters not allowed in frame ID
                        if (Logger.canLog(Logger.DEBUG)) {
                            Logger.logMsg(Logger.DEBUG, "ID3MetadataParser", "parse",
                                "ID3 parser: zero padding detected at "
                                    +getStreamPosition()+", terminating");
                        }
                        break;
                    }

                    String frameID = new String(idBytes, Charset.forName(CHARSET_ISO_8859_1));

                    if (Logger.canLog(Logger.DEBUG)) {
                        Logger.logMsg(Logger.DEBUG, "ID3MetadataParser", "parse",
                                getStreamPosition()+"\\"+tagSize
                                +": frame ID "+frameID+", size "+frameSize);
                    }
                    if (frameID.equals("APIC") || frameID.equals("PIC")) {
                        byte[] data = getBytes(frameSize);
                        if (unsynchronized) {
                            data = unsynchronizeBuffer(data);
                        }

                        byte[] image = frameID.equals("PIC") ? getImageFromPIC(data) : getImageFromAPIC(data);

                        if (image != null) {
                            addMetadataItem("image", image);
                        }
                    } else if (frameID.startsWith("T") && !frameID.equals("TXXX")) {
                        String encoding = getEncoding();
                        byte[] data = getBytes(frameSize - 1);
                        if (unsynchronized) {
                            data = unsynchronizeBuffer(data);
                        }
                        String value = new String(data, encoding);
                        String[] tag = getTagFromFrameID(frameID);
                        if (tag != null) {
                            for (int i = 0; i < tag.length; i++) {
                                Object tagValue = convertValue(tag[i], value);
                                if (tagValue != null) {
                                    addMetadataItem(tag[i], tagValue);
                                }
                            }
                        }
                    } else if (frameID.equals("COMM") || frameID.equals("COM")) {
                        String encoding = getEncoding();
                        // Get language
                        byte[] data = getBytes(3);
                        if (unsynchronized) {
                            data = unsynchronizeBuffer(data);
                        }
                        String language = new String(data, Charset.forName(CHARSET_ISO_8859_1));
                        // Get content description and comment
                        data = getBytes(frameSize - 4);
                        if (unsynchronized) {
                            data = unsynchronizeBuffer(data);
                        }
                        String value = new String(data, encoding);
                        if (value != null) {
                            int index = value.indexOf(0x00);
                            String content = "";
                            String comment;
                            if (index == 0) {
                                if (isTwoByteEncoding(encoding)) {
                                    comment = value.substring(2);
                                } else {
                                    comment = value.substring(1);
                                }
                            } else {
                                content = value.substring(0, index);
                                if (isTwoByteEncoding(encoding)) {
                                    comment = value.substring(index + 2);
                                } else {
                                    comment = value.substring(index + 1);
                                }
                            }
                            String[] tag = getTagFromFrameID(frameID);
                            if (tag != null) {
                                for (int i = 0; i < tag.length; i++) {
                                    addMetadataItem(tag[i] + "-" + COMMCount, content + "[" + language + "]=" + comment);
                                    COMMCount++;
                                }
                            }
                        }
                    } else if (frameID.equals("TXX") || frameID.equals("TXXX")) {
                        String encoding = getEncoding();
                        byte[] data = getBytes(frameSize-1);
                        if (unsynchronized) {
                            data = unsynchronizeBuffer(data);
                        }
                        String value = new String(data, encoding);
                        if (null != value){
                            int index = value.indexOf(0x00);
                            String description = (index != 0) ? value.substring(0, index) : "";
                            String text = isTwoByteEncoding(encoding) ? value.substring(index+2) : value.substring(index+1);

                            String[] tag = getTagFromFrameID(frameID);
                            if (tag != null) {
                                for (int i = 0; i < tag.length; i++) {
                                    if (description.equals("")) {
                                        addMetadataItem(tag[i] + "-" + TXXXCount, text);
                                    } else {
                                        addMetadataItem(tag[i] + "-" + TXXXCount, description + "=" + text);
                                    }
                                    TXXXCount++;
                                }
                            }
                        }
                    } else {
                        // Unknown or unsupported frame.
                        skipBytes(frameSize);
                    }
                }
            }
        } catch (Exception ex) {
            // Ignore all exceptions as it is preferable to play audio.
            // fail gracefully, probably just hit the end of the buffer
            if (Logger.canLog(Logger.WARNING)) {
                Logger.logMsg(Logger.WARNING, "ID3MetadataParser", "parse",
                        "Exception while processing ID3v2 metadata: "+ex);
            }
        } finally {
            if (null != rawMetaBlob) {
                setParseRawMetadata(false);
                addRawMetadata(RAW_ID3_METADATA_NAME);
                disposeRawMetadata();
            }
            done();
        }
    }

    private int getFrameSize() throws IOException {
        if (version == 4) {
            byte[] buf = getBytes(4);
            int size = 0;
            for (int i = 0, shift = 21; i < 4; i++) {
                size += (buf[i] & 0x7f) << shift;
                shift -= 7;
            }
            return size;
        } else {
            return getInteger();
        }
    }

    private String getEncoding() throws IOException {
        byte encodingType = getNextByte();
        if (encodingType == 0x00) {
            return CHARSET_ISO_8859_1;
        } else if (encodingType == 0x01) {
            return CHARSET_UTF_16;
        } else if (encodingType == 0x02) {
            return CHARSET_UTF_16BE;
        } else if (encodingType == 0x03) {
            return CHARSET_UTF_8;
        } else {
            throw new IllegalArgumentException();
        }
    }

    private boolean isTwoByteEncoding(String encoding) {
        if (encoding.equals(CHARSET_ISO_8859_1) || encoding.equals(CHARSET_UTF_8)) {
            return false;
        } else if (encoding.equals(CHARSET_UTF_16) || encoding.equals(CHARSET_UTF_16BE)) {
            return true;
        } else {
            throw new IllegalArgumentException();
        }
    }

    /* Supported tags:
     *  PIC / APIC -> image
     *  TP2 / TPE2 -> ALBUMARTIST_TAG_NAME
     *  TAL / TALB -> ALBUM_TAG_NAME
     *  TP1 / TPE1 -> ARTIST_TAG_NAME
     *  COM / COMM -> COMMENT_TAG_NAME
     *  TCM / TCOM -> COMPOSER_TAG_NAME
     *  TLE / TLEN -> DURATION_TAG_NAME
     *  TCO / TCON -> GENRE_TAG_NAME
     *  TT2 / TIT2 -> TITLE_TAG_NAME
     *  TRK / TRCK -> TRACKNUMBER_TAG_NAME, TRACKCOUNT_TAG_NAME
     *  TPA / TPOS -> DISCNUMBER_TAG_NAME DISCCOUNT_TAG_NAME
     *  TYE / TYER / TDRC -> YEAR_TAG_NAME
     *  TXX / TXXX -> TEXT_TAG_NAME
     */

    private String[] getTagFromFrameID(String frameID) {
        if (frameID.equals("TPE2") || frameID.equals("TP2")) {
            return new String[]{MetadataParserImpl.ALBUMARTIST_TAG_NAME};
        } else if (frameID.equals("TALB") || frameID.equals("TAL")) {
            return new String[]{MetadataParserImpl.ALBUM_TAG_NAME};
        } else if (frameID.equals("TPE1") || frameID.equals("TP1")) {
            return new String[]{MetadataParserImpl.ARTIST_TAG_NAME};
        } else if (frameID.equals("COMM") || frameID.equals("COM")) {
            return new String[]{MetadataParserImpl.COMMENT_TAG_NAME};
        } else if (frameID.equals("TCOM") || frameID.equals("TCM")) {
            return new String[]{MetadataParserImpl.COMPOSER_TAG_NAME};
        } else if (frameID.equals("TLEN") || frameID.equals("TLE")) {
            return new String[]{MetadataParserImpl.DURATION_TAG_NAME};
        } else if (frameID.equals("TCON") || frameID.equals("TCO")) {
            return new String[]{MetadataParserImpl.GENRE_TAG_NAME};
        } else if (frameID.equals("TIT2") || frameID.equals("TT2")) {
            return new String[]{MetadataParserImpl.TITLE_TAG_NAME};
        } else if (frameID.equals("TRCK") || frameID.equals("TRK")) {
            return new String[]{MetadataParserImpl.TRACKNUMBER_TAG_NAME, MetadataParserImpl.TRACKCOUNT_TAG_NAME};
        } else if (frameID.equals("TPOS") || frameID.equals("TPA")) {
            return new String[]{MetadataParserImpl.DISCNUMBER_TAG_NAME, MetadataParserImpl.DISCCOUNT_TAG_NAME};
        } else if (frameID.equals("TYER") || frameID.equals("TDRC")) {
            return new String[]{MetadataParserImpl.YEAR_TAG_NAME};
        } else if (frameID.equals("TXX") || frameID.equals("TXXX")) {
            return new String[]{MetadataParserImpl.TEXT_TAG_NAME};
        }

        return null;
    }

    private byte[] getImageFromPIC(byte[] data) {
        /*
         * Attached picture   "PIC"
         * Frame size         $xx xx xx
         *     (data byte array starts here)
         * Text encoding      $xx
         * Image format       $xx xx xx  (PNG/JPG)
         * Picture type       $xx
         * Description        <textstring> $00 (00)
         * Picture data       <binary data>
         */
        // find end of description string
        int imgOffset = 5;
        while (0 != data[imgOffset] && imgOffset < data.length) {
            imgOffset++;
        }
        if (imgOffset == data.length) {
            // only description? maybe it's a URI
            return null;
        }

        String type = new String(data, 1, 3, Charset.forName(CHARSET_ISO_8859_1));
        if (Logger.canLog(Logger.DEBUG)) {
            Logger.logMsg(Logger.DEBUG, "ID3MetadataParser", "getImageFromPIC",
                    "PIC type: "+type);
        }

        if (type.equalsIgnoreCase("PNG") || type.equalsIgnoreCase("JPG")) {
            // image data follows description
            return Arrays.copyOfRange(data, imgOffset+1, data.length);
        }
        if (Logger.canLog(Logger.WARNING)) {
            Logger.logMsg(Logger.WARNING, "ID3MetadataParser", "getImageFromPIC",
                    "Unsupported picture type found \""+type+"\"");
        }
        return null;
    }

    private byte[] getImageFromAPIC(byte[] data) {
        boolean isImageJPEG = false;
        boolean isImagePNG = false;

        // Look for string "image/".
        int maxIndex = data.length - 10;
        int offset = 0;
        for (int j = 0; j < maxIndex; j++) {
            if (data[j] == 'i'
                    && data[j + 1] == 'm'
                    && data[j + 2] == 'a'
                    && data[j + 3] == 'g'
                    && data[j + 4] == 'e'
                    && data[j + 5] == '/') {
                // Found "image/"; offset by its length.
                j += 6;

                // Look for "jpeg".
                if (data[j] == 'j'
                        && data[j + 1] == 'p'
                        && data[j + 2] == 'e'
                        && data[j + 3] == 'g') {
                    // MIME type "image/jpeg" found; save offset.
                    isImageJPEG = true;
                    offset = j + 4;
                    break;
                } // Look for "png".
                else if (data[j] == 'p'
                        && data[j + 1] == 'n'
                        && data[j + 2] == 'g') {
                    // MIME type "image/png" found; save offset.
                    isImagePNG = true;
                    offset = j + 3;
                    break;
                }
            }
        } // for j

        if (isImageJPEG) {
            // Look for JPEG signature.
            boolean isSignatureFound = false;
            int upperBound = data.length - 1;

            for (int j = offset; j < upperBound; j++) {
                // JPEG start of image (SOI) marker is 0xff 0xd8
                if (-1 == data[j] && -40 == data[j + 1]) {
                    // JPEG SOI found.
                    isSignatureFound = true;
                    offset = j;
                    break; // JPEG image
                }
            }

            if (isSignatureFound) {
                // Save JPEG data stream starting at SOI.
                return Arrays.copyOfRange(data, offset, data.length);
            }
        } // isImageJPEG

        if (isImagePNG) {
            // Look for PNG signature.
            boolean isSignatureFound = false;
            int upperBound = data.length - 7;

            for (int j = offset; j < upperBound; j++) {
                // PNG decimal signature {137 80 78 71 13 10 26 10}.
                if (-119 == data[j]
                        && 80 == data[j + 1]
                        && 78 == data[j + 2]
                        && 71 == data[j + 3]
                        && 13 == data[j + 4]
                        && 10 == data[j + 5]
                        && 26 == data[j + 6]
                        && 10 == data[j + 7]) // increment by 1
                {
                    // PNG signature found.
                    isSignatureFound = true;
                    offset = j;
                    break; // PNG image
                }
            }

            if (isSignatureFound) {
                // Save PNG data stream starting at signature.
                return Arrays.copyOfRange(data, offset, data.length);
            }
        } // isImagePNG
        return null;
    }

    private byte[] unsynchronizeBuffer(byte[] data) {
        byte[] udata = new byte[data.length];
        int udatalen = 0;

        for (int i = 0; i < data.length; i++) {
            if (((data[i] & 0xFF) == 0xFF && data[i + 1] == 0x00 && data[i + 2] == 0x00)
                    || ((data[i] & 0xFF) == 0xFF && data[i + 1] == 0x00 && (data[i + 2] & 0xE0) == 0xE0)) {
                udata[udatalen] = data[i];
                udatalen++;
                udata[udatalen] = data[i + 2];
                udatalen++;
                i += 2;
            } else {
                udata[udatalen] = data[i];
                udatalen++;
            }
        }

        return Arrays.copyOf(udata, udatalen);
    }
}
