HLSFixPMT.java

package org.jcodec.codecs.mpeg12;
import org.jcodec.common.Assert;
import org.jcodec.common.io.NIOUtils;
import org.jcodec.containers.mps.MTSUtils;

import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.lang.System;
import java.nio.ByteBuffer;
import java.util.zip.CRC32;

/**
 * This class is part of JCodec ( www.jcodec.org ) This software is distributed
 * under FreeBSD License
 * 
 * @author The JCodec project
 * 
 */
public class HLSFixPMT {

    public void fix(File file) throws IOException {
        RandomAccessFile ra = null;

        try {
            ra = new RandomAccessFile(file, "rw");
            byte[] tsPkt = new byte[188];

            while (ra.read(tsPkt) == 188) {

                Assert.assertEquals(0x47, tsPkt[0] & 0xff);
                int guidFlags = ((tsPkt[1] & 0xff) << 8) | (tsPkt[2] & 0xff);
                int guid = (int) guidFlags & 0x1fff;
                int payloadStart = (guidFlags >> 14) & 0x1;
                int b0 = tsPkt[3] & 0xff;
                int counter = b0 & 0xf;
                int payloadOff = 0;
                if ((b0 & 0x20) != 0) {
                    payloadOff = (tsPkt[4 + payloadOff] & 0xff) + 1;
                }
                if (payloadStart == 1) {
                    payloadOff += (tsPkt[4 + payloadOff] & 0xff) + 1;
                }

                if (guid == 0) {
                    if (payloadStart == 0)
                        throw new RuntimeException("PAT spans multiple TS packets, not supported!!!!!!");
                    ByteBuffer bb = ByteBuffer.wrap(tsPkt, 4 + payloadOff, 184 - payloadOff);
                    fixPAT(bb);
                    ra.seek(ra.getFilePointer() - 188);
                    ra.write(tsPkt);
                }
            }
        } finally {
            if (ra != null)
                ra.close();
        }
    }

    public static void fixPAT(ByteBuffer data) {
        ByteBuffer table = data.duplicate();
        MTSUtils.parseSection(data);
        ByteBuffer newPmt = data.duplicate();

        while (data.remaining() > 4) {
            short num = data.getShort();
            short pid = data.getShort();
            if (num != 0) {
                newPmt.putShort(num);
                newPmt.putShort(pid);
            }
        }
        if (newPmt.position() != data.position()) {
            // rewrite Section len
            ByteBuffer section = table.duplicate();
            section.get();
            int sectionLen = newPmt.position() - table.position() + 1;
            section.putShort((short) ((sectionLen & 0xfff) | 0xB000));
            // Redo crc32
            CRC32 crc32 = new CRC32();
            table.limit(newPmt.position());
            crc32.update(NIOUtils.toArray(table));
            newPmt.putInt((int) crc32.getValue());
            // fill with 0xff
            while (newPmt.hasRemaining())
                newPmt.put((byte) 0xff);
        }
    }

    public static void main1(String[] args) throws IOException {
        if (args.length < 1)
            exit("Please specify package location");

        File hlsPkg = new File(args[0]);

        if (!hlsPkg.isDirectory())
            exit("Not an HLS package, expected a folder");

        File[] listFiles = hlsPkg.listFiles(new FilenameFilter() {
            public boolean accept(File dir, String name) {
                return name.endsWith(".ts");
            }
        });
        HLSFixPMT fix = new HLSFixPMT();
        for (int i = 0; i < listFiles.length; i++) {
            File file = listFiles[i];
            System.err.println("Processing: " + file.getName());
            fix.fix(file);
        }
    }

    private static void exit(String message) {
        System.err.println("Syntax: hls_fixpmt <hls package location>");
        System.err.println(message);
        System.exit(-1);
    }
}