[doveman2]

Both PAL and NTSC have non-square pixels (http://en.wikipedia.org/wiki/Pixel_aspect_ratio)
For a 4:3 display PAL=1.09, NTSC=0.9
For a 16:9 display PAL=1.45, NTSC=1.21

The latest commit should handle those cases correctly.
Note: there is no way of the Pi knowing a composite display is 16:9, so it assumes it is 4:3, and you can override it with sdtv_aspect=3 in config.txt (http://elinux.org/RPi_config.txt).

Ah I see, thanks. I just assumed that composite PAL and NTSC must have been working OK already and this fix was something more exotic I hadn't noticed the problem but I've not done a lot of testing (on the 14" 4:3 CRT TV I have here) so I'll test it properly on a larger 16:9 TV when I get a chance.