I shot a lot of video with my go pro camera in 2704x2028 which I believe is a 4:3 aspect ratio. I created my project, added all my transitions, music etc and then realised when I went to render it was 4:3 when I wanted 16:9 720p video.

Since I shot the video higher than 720p resolution can I somehow convert/crop/transform my video to 16:9 720p without redoing my entire project from scratch?

My project is set to 1280x960 119.88fps. Do I change my project settings?
Do I re-scale during rendering?
Do I change my project settings and apply a zoom effect to all my clips?

I'm a bit lost.

I realise that switching from a 4:3 aspect ratio to 16:9 aspect ratio means some clipping will occur but I think that's preferable to having black bars on my rendered video especially because my playback device lacks zoom/scaling.

I'm a kdenlive and video editing newbie so any help would be greatly appreciated.

Thanks,
Brad

I figured out how to do it. For posterity's sake:

I changed the project settings to: HD 720p 29.97 fps

Note doing this may mess up your effects and cause you to have to adjust your project clips. (I ended up removing all my wipes and adding them back in for example)

You'll be prompted to backup your project (at least I was)

Now you need to add a "Position and Zoom" effect to each one of your clips.

I set the size to 140% (but use your own judgement) then I needed to drag the clip around to get the full video on the screen. You can also set the hard coded x and y axis using the properties dialog.

Note if you have other effects on the clip you may need to either hide the effects or in some cases remove and re-add them. This is slightly less work than re-doing the project but you will have to fuss with a lot.

I suppose this is hard lesson for me to learn for next time - to shoot in a 16:9 aspect ratio and start the project with at 16:9 aspect ratio. Thankfully I shot at a high enough resolution that I could do this.

It should go without saying but this approach only works if your final render resolution is lower than your starting resolution. So in my case I shot in 2704x2028 and my destination resolution was 1280x720.