RAW video aspect ratio fix for 60D sensor

[larrycafe]

the raw video in 60D with MLV_REC works great

I am shooting in canon 720P mode, so that it is outputting 1728 X 694 (sensor is 5184 X 3456), which is 1/3 of 5184 and 1/5 of 3456.

meaning that stretching 694 lines (by 1.6666X) to 1156 lines gives a perfect 3:2 ratio.

if I want 1728 as a 16:9 ratio, the correct number of lines needed is 1728 / 16 X 9 / 1.666 = 584 lines

right now the aspect ratio is assumed 1.4X in MLV_REC, it might works for other sensor, but not right for 60D. I cannot fit exactly 584 lines in my record, I should either leaving a thin black lines on top and at the bottom of my video, or capture more lines, which will reduce the number of frame it can capture.

please fix it to 1.666X for 60D sensor, thanks