[Confrontation Unit 8] Sorting Footage, Converting Framerates & A Quick lesson On Frame Interpolation

While sorting through the footage I wanted to make sure the files were compatible with the editing software that I use. I realised that I was having one of the same issues that I encountered while editing the Sci-Fi Weekender documentary. This issue is that the audio slips out of sync with the video in an unpredictable way. This was caused by the varying frame rate of the original video files, which confuses the editing software, causing syncing issues.

I managed to fix this using a software called Handbrake, which allows the user to import video files and export them with a number of changes. One of these optional changes includes capping the frame rate / making it constant. It does this by finding the lowest frame rate that the original file dips to, and converting the rest of the video to that frame rate. As a result, it means that the exported videos can have a very low frame rate, as it is impossible to increase the frame rate without using a technique called frame interpolation, in which a program detects two frames, and estimates what the frame in-between them would look like. This is repeated until (for example) 30fps becomes 60fps. This however can cause some visual issues such as distortion, as the middle frame isn't always correct.

Here's an example of what frame interpolation can do:



As you can see, for the most part the film is devoid of any visual distortion, but there are still moments where the estimated frame is incorrect.

I ran a test and I was correct: it was the varying frame rate causing the syncing issues.

After all videos were converted, I then sorted through the footage, deleting all video clips I definitely wouldn't be using, e.g. me accidently filming, filming nothing happening at all.