Video Gallery

Videos - Techy Background Info

Updated 24 Aug

For reasons I have been unable to understand or correct, the web server being used for this site will NOT work with the .f4v files I have created. These same files HAVE been loaded onto 2 other web servers (UK2.net & Easynet) where they DO work fine.
For this reason I have removed all the f4v videos from the site, and will use only flv in future. The advantage of the newer f4v format is its better compression = smaller file size, see table below.
Currently the videos on the site are 1 or 2 sizes:

Pixel size	Flash format	File size
448 x 252 px	flv (= original)	1x
768 x 432 px	flv (= original)	2.5x
768 x 432 px	f4v (= newer)	1x

Pixel Dimensions
These seemingly odd sizes are not accidental. Standard UK PAL TV & DVD's (and therefore video cameras & editing software) all work at 1024 x 576 (square) pixels. Wide screen CRT televisions and some early flat-screens used the anamorphic widescreen technique from cinema, using 720 rectangular "pixels" x 576 pixels/lines.
Better conversion to smaller sizes is obtained at clean sub-multiples of this 1024 x 576 picture. 768x432 is 3/4 of a full sized picture , the software thus makes a 3x3 area for every 4x4 from the original. Although modern software is amazingly good at recreating new pixels, I prefer to make the task as easy as possible & stick with the "standard" sub sizes.

Progressive Download
Adobe Progressive Download Flash videos work by having a small .swf file (59 kb here) which sources video from the much (x1000 +) larger video files listed above. Thus the video can start playing almost immediately and continue uninterrupted providing the download is faster than the play rate.
(without the development of Progressive Download the whole file would need to download BEFORE play could start). Note the operation of the rectangular bar below the video, the bar itself will show a darker colour, the extent of this indicates the amount of the video file downloaded (if you pause the play note the download continues). The up arrow beneath the bar indicates the viewing point, ie it moves along as you watch the movie (also can pick with mouse & move = rewind / FF)

RT50