Highly recommended: I was faced with the issue of a small semi-covert camera I put on my bicycle which records at 480/30p – but I live (as do all of us in Europe and some of Asia) where the SD video standard is 576/25p (PAL) which is what I usually edit all my videos in. A mixed frame rate (though it will work on our modern equipment) is a nuisance as it will either slow down your video editing software and just hacking the header of the AVI file to change fps to 25 puts the audio out of sync and the duration/relative speed of the video is all wrong as well..
A lot of software copes easy enough with the resize (though aspect ratio might be slightly off, I haven’t the head for maths or time to work out how to sort this to keep aspect ratio as it will involve expanding then cropping the US video frame (don’t mind losing a few lines on the edges of the picture, this is for entertainment not security evidence quality) – but if the software just dumps each 5th frame then the video will look like shit.
if you have bought a DVD from the “you want DVD?” man which started off as a 30p (NTSC) copy you will have seen this, the video looks jumpy like old silent movie where they had to turn the camera by hand.
To add to this the camera is not correct 30p (or 29.997fps) anyway. its defined rate is (30.997 WTF?) but varies frame rate as it interpolates (mixes) frames when the light level changes as part of the auto exposure. So even Americans and others are going to have issues with using it!
This also happens with many small video cameras or still cameras with 30fps recording. Why on earth these are sold in 25fps countries without a simple setting to change it annoys me as it is not simply a matter of “outdated nationalism” but means extra work and confusion especially for younger people who want to make short films, and do not know what correct frame rate to use – plus unless you look at television with your room in darkness and/or have a very expensive set with frame rate conversion/doubling, if the content frame rate is different to the mains frequency of the lights in the room (especially modern kinds made to save electricity) it can even result in unpleasantess like headaches (which is also why people sometimes get paranoid that “TV is making them ill/controlling their minds”). Even stranger, my Blackberry made in the USA records video at 24-25fps.
I’m fairly certain a traditional movie is still shot and edited at 24fps…
Nowadays I only use my idiot-lantern to play out videos I have made myself or other interesting stuff, but I always make sure it is 576/25p or 576/25i and same type of AVI file as my DV-camera
So here is some open source software which does a really good job of converting frame rates – it can blend (rather than just drop) the extra frame – and even for those in 30fps countries it should be able to do things the other way..
Avidemux.org
