Whilst NTSC and PAL do use different colour, frame rate and resolution, this does not seem to be true of FF7.
15 fps is more cartoon frame rate. Movie original is 24 fps, PAL 25 fps, NTSC 29.97 fps
Resolution of PAL is 720 (or 768) X 576 and NTSC is 720 X 480
[the only advantage of NTSC over PAL is frame rate. The colour and resolution of PAL is better]
It appears as if FF7 video does not use any defined spec at all ( 15fps @ 320 X 224), it certainly isn't PAL or NTSC. And I think you have worked out the problem. The psx videos are longer. I will watch out for that, well spotted
I am baffled by the resolution of the FF7 video's....half of 640*480 is 320 * 240 yet it uses 320*224.....