var (
		regeneratedSize int
		compressedSize  int
		streams         int
	)
	switch (hdr >> 2) & 3 {
	case 0, 1:
		if off+1 >= len(data) {
			return 0, nil, r.makeEOFError(off)
		}
		regeneratedSize = (int(hdr) >> 4) | ((int(data[off]) & 0x3f) << 4)
		compressedSize = (int(data[off]) >> 6) | (int(data[off+1]) << 2)
		off += 2
		if ((hdr >> 2) & 3) == 0 {