gistfile1.txt

void MPEG::XingHeader::parse(const ByteVector &data)
{
  // Check to see if a valid Xing header is available.

  if(!data.startsWith("Xing") && !data.startsWith("Info"))
    return;

  // If the XingHeader doesn't contain the number of frames and the total stream
  // info it's invalid.

  d->valid = true;

  unsigned int qualityOffset = 8;

  if(data[7] & 0x01)
      qualityOffset += 4;
  else
      d->valid = false;

  if(data[7] & 0x02)
      qualityOffset += 4;
  else
      d->valid = false;

  if(data[7] & 0x04)
      qualityOffset += 100;

  if (d->valid) {
      d->frames = data.toUInt(8U);
      d->size   = data.toUInt(12U);
  }

  if(data[7] & 0x08) {
      d->hasQuality = true;
      d->quality = data.toUInt(qualityOffset);
  }
}