Higher – Intraframe Vs Interframe

Intraframe compression applies to compressing individual frames.

Interframe compression applies the compression to many frames and stores only what changes between each frame.

We also talked today about bitrate, this is the amount of data in a single second of data. This is normally measured in bps (bits per second).

Higher – Javascript mouse events

The code bellow uses mouse events to run a javascript function.

On line 15  the onmouseover and onmouseout events are used to call the function on line 6.

Line 7 targets the swap id and uses the argument passed to replace the image source.


<!doctype html>
<html>
<head>

<script type="text/javascript">
function changeImage(img_src) {
document.getElementById("swap").src = img_src;

}
</script>

</head>
<body>
<h1>roll over</h1>
<img id="swap" src="redButton.jpg" onmouseover='changeImage("blueButton.jpg")' onmouseout='changeImage("redButton.jpg")'>

</body>
</html>

Higher – Database Learning Points

We have now finished Databases. Here is what you should know.

From Scholar

  • How to describe the structure of a database in terms of tables, records and fields.

  • The advantages of using relational databases.

  • The purpose of primary, surrogate, foreign and compound keys.

  • The differences between one-to-one, one-to-many and many-to-many relationships.

  • The purpose and uses of tables, forms and reports.

  • What is meant by a relationship in a database.

  • How to perform complex operations, such as performing a query, creating a form, creating a report.

  • A calculated field is one which is created using a query which calculates a result from one or more existing fields.