예제 #1
0
void
MP4::Tag::updateOffsets(long delta, long offset)
{
  MP4::Atom *moov = d->atoms->find("moov");
  if(moov) {
    MP4::AtomList stco = moov->findall("stco", true);
    for(MP4::AtomList::ConstIterator it = stco.begin(); it != stco.end(); ++it) {
      MP4::Atom *atom = *it;
      if(atom->offset > offset) {
        atom->offset += delta;
      }
      d->file->seek(atom->offset + 12);
      ByteVector data = d->file->readBlock(atom->length - 12);
      unsigned int count = data.toUInt();
      d->file->seek(atom->offset + 16);
      unsigned int pos = 4;
      while(count--) {
        long o = static_cast<long>(data.toUInt(pos));
        if(o > offset) {
          o += delta;
        }
        d->file->writeBlock(ByteVector::fromUInt(o));
        pos += 4;
      }
    }

    MP4::AtomList co64 = moov->findall("co64", true);
    for(MP4::AtomList::ConstIterator it = co64.begin(); it != co64.end(); ++it) {
      MP4::Atom *atom = *it;
      if(atom->offset > offset) {
        atom->offset += delta;
      }
      d->file->seek(atom->offset + 12);
      ByteVector data = d->file->readBlock(atom->length - 12);
      unsigned int count = data.toUInt();
      d->file->seek(atom->offset + 16);
      unsigned int pos = 4;
      while(count--) {
        long long o = data.toLongLong(pos);
        if(o > offset) {
          o += delta;
        }
        d->file->writeBlock(ByteVector::fromLongLong(o));
        pos += 8;
      }
    }
  }

  MP4::Atom *moof = d->atoms->find("moof");
  if(moof) {
    MP4::AtomList tfhd = moof->findall("tfhd", true);
    for(MP4::AtomList::ConstIterator it = tfhd.begin(); it != tfhd.end(); ++it) {
      MP4::Atom *atom = *it;
      if(atom->offset > offset) {
        atom->offset += delta;
      }
      d->file->seek(atom->offset + 9);
      ByteVector data = d->file->readBlock(atom->length - 9);
      const unsigned int flags = data.toUInt(0, 3, true);
      if(flags & 1) {
        long long o = data.toLongLong(7U);
        if(o > offset) {
          o += delta;
        }
        d->file->seek(atom->offset + 16);
        d->file->writeBlock(ByteVector::fromLongLong(o));
      }
    }
  }
}
예제 #2
0
void
MP4::Properties::read(File *file, Atoms *atoms)
{
  MP4::Atom *moov = atoms->find("moov");
  if(!moov) {
    debug("MP4: Atom 'moov' not found");
    return;
  }

  MP4::Atom *trak = 0;
  ByteVector data;

  const MP4::AtomList trakList = moov->findall("trak");
  for(MP4::AtomList::ConstIterator it = trakList.begin(); it != trakList.end(); ++it) {
    trak = *it;
    MP4::Atom *hdlr = trak->find("mdia", "hdlr");
    if(!hdlr) {
      debug("MP4: Atom 'trak.mdia.hdlr' not found");
      return;
    }
    file->seek(hdlr->offset);
    data = file->readBlock(hdlr->length);
    if(data.containsAt("soun", 16)) {
      break;
    }
    trak = 0;
  }
  if(!trak) {
    debug("MP4: No audio tracks");
    return;
  }

  MP4::Atom *mdhd = trak->find("mdia", "mdhd");
  if(!mdhd) {
    debug("MP4: Atom 'trak.mdia.mdhd' not found");
    return;
  }

  file->seek(mdhd->offset);
  data = file->readBlock(mdhd->length);

  const unsigned int version = data[8];
  long long unit;
  long long length;
  if(version == 1) {
    if(data.size() < 36 + 8) {
      debug("MP4: Atom 'trak.mdia.mdhd' is smaller than expected");
      return;
    }
    unit   = data.toUInt(28U);
    length = data.toLongLong(32U);
  }
  else {
    if(data.size() < 24 + 8) {
      debug("MP4: Atom 'trak.mdia.mdhd' is smaller than expected");
      return;
    }
    unit   = data.toUInt(20U);
    length = data.toUInt(24U);
  }
  if(unit > 0 && length > 0)
    d->length = static_cast<int>(length * 1000.0 / unit + 0.5);

  MP4::Atom *atom = trak->find("mdia", "minf", "stbl", "stsd");
  if(!atom) {
    return;
  }

  file->seek(atom->offset);
  data = file->readBlock(atom->length);
  if(data.containsAt("mp4a", 20)) {
    d->codec         = AAC;
    d->channels      = data.toShort(40U);
    d->bitsPerSample = data.toShort(42U);
    d->sampleRate    = data.toUInt(46U);
    if(data.containsAt("esds", 56) && data[64] == 0x03) {
      unsigned int pos = 65;
      if(data.containsAt("\x80\x80\x80", pos)) {
        pos += 3;
      }
      pos += 4;
      if(data[pos] == 0x04) {
        pos += 1;
        if(data.containsAt("\x80\x80\x80", pos)) {
          pos += 3;
        }
        pos += 10;
        d->bitrate = static_cast<int>((data.toUInt(pos) + 500) / 1000.0 + 0.5);
      }
    }
  }
  else if(data.containsAt("alac", 20)) {
    if(atom->length == 88 && data.containsAt("alac", 56)) {
      d->codec         = ALAC;
      d->bitsPerSample = data.at(69);
      d->channels      = data.at(73);
      d->bitrate       = static_cast<int>(data.toUInt(80U) / 1000.0 + 0.5);
      d->sampleRate    = data.toUInt(84U);
    }
  }

  MP4::Atom *drms = atom->find("drms");
  if(drms) {
    d->encrypted = true;
  }
}