Miscellaneous Technical Information

MPEG Video Codec

The AVI (Audio Video Interleave) format is a wrapper file. It will be recognised by most computer operating systems. The video and audio content within such files can conform to a variety of different codecs, some of which may not be recognised by some computer operating systems. The movies here use the MPEG-4 codec; there is no audio content. The movie can be played in both Linux and Windows using the VLC media player.

URL of Specific Sub-Sections

By mousing over the sub-sections in the menu on the left, one can see the filename and anchor label within that file. For example, under “NZ EQ Forecast”, subsection “Latest Forecasts” the link is shown as .../sslib/forecast.php#latest. If one were to use this as the URL, the page would appear, but the menu on the left will not appear.

The better way is to use the URL: .../sslib/?forecast?latest. This will also display the menu. The top of the page would be .../sslib/?forecast?.

Explanation: The SSLib website uses frames, and hence it is easy to attach the same main menu to all displayed pages within the website. A disadvantage is that the URL to individual pages is not so transparent; all pages appear to have the same .../sslib/ URL. We overcome the problem of more specific client requests to the web-server by processing the request with PHP. By appending ?filename?anchor, where the filename is without the suffix (.html or .php), the web-server interprets this to mean that the file in the main frame window should be filename.html#anchor (or filename.php#anchor, respectively), i.e. scrolled down to anchor, rather than home.html.