Tag Archives: editing

iMovie 101

A few weeks ago a friend showed me some footage from his GoPro HD HERO which had been attached to the front mudguard of his motorbike when he was following me on my Moto Guzzi. I have been thinking about buying the same camera so I thought I would try editing it on my Mac and uploading to YouTube – you can view the result below. The process was not too difficult but there were a few pitfalls which I will go on to describe.

The file I got was a 2.09 GB 960p MPEG-4 movie at 29.97 frames per second. The camera can also shoot 1080p, 720p and WVGA, all of which are 16:9 aspect ratio, whereas 960p is 1280 x 960 pixels which is 4:3 aspect ratio. More on resolutions later. All I wanted to do was isolate a clip, mute the audio, and add a suitable soundtrack. There may have been other ways to achieve that but I decided to buy the latest iMovie from the Mac App Store and learn to use it. When I first started up iMovie there was a message saying “iMovie needs to generate thumbnails for the videos in your iPhoto Library” (I already had the latest iPhoto and there were a number of short videos in my iPhoto library that had been imported from my Canon Digital Ixus 400). Once the thumbnails had been generated I was able to see these old videos in the iMovie Event Library but the video I wanted was in a separate file so I had to import it using File -> Import -> Movies… where I created a new event for it. I wasn’t sure whether to “Optimise video” but in this instance I chose not to.

The next step was to create a project using File -> New Project… where I set the aspect ratio to 4:3 and the frame rate to 30 fps. I then selected the clip I wanted from the thumbnails of the event and dragged it into the new project. Muting the audio was as easy as selecting Clip -> Mute Clip. I had already decided on what I wanted to replace it with – a track called “Son of a Bush” by Public Enemy from my iTunes library.

It wasn’t obvious how to add audio but I found it under Help -> iMovie Help -> Get Started -> Enhance your project -> Add background music from your iTunes library. Following the instructions I opened the “Music and Sound Effects” browser, searched for the track and then dragged it to the project window. The instructions were quite specific about dragging the song not onto a clip but to dark grey area to the right of the last clip, which puts it in the so called “background music well” of the project. So that is what I did and it worked – sort of. The problem is I didn’t want the track to start immediately and it was important to get the audio accurately synced to the video, which I could not seem to do. I found the answer in this YouTube video from macmost. All I had to do was ignore what I had read and drag the song onto the clip itself rather than the background well. I was then able to move it around until it lined up the way I wanted. At that point I was basically done so I selected File -> Finalize Project.

So now all I had to do was upload it to YouTube, which you can do directly with the Share -> YouTube… menu. The trouble is, “Size to publish” was set to “Large” (720 x 540) pixels and the higher resolution options (1280 x 720 and 1920 x 1080) were greyed out. I accepted this anyway but it would have been nice to upload at a higher resolution since the original footage was 1280 x 960 pixels. I did find a partial workaround in this post on the Vimeo forums. Using File -> Project Properties… I changed the aspect ratio from standard to widescreen, opened the “Cropping, Ken Burns and Rotation” window, selected the “Fit” option and then finalized the project again. Now when I opened the Share -> YouTube… menu the size was still set to “Large” but now “Large” was 960 x 540 pixels as opposed to 720 x 540 (which just means that there is a blank bit on either side). Also the 1280 x 720 option was no longer greyed out so I could have uploaded at this higher resolution but I chose to leave things as they were. Ideally the camera would have been set to shoot 1080p and I guess I would then have been able to upload to YouTube directly at 1080p – useful to know if I do get one myself.