Disappearing disk space with Quicktime

Hello,

I've been working with videos in Quicktime and noticed that my free disk space seems to be disappearing afterwards. Just now I converted a mov file to an avi file. The resulting file was too big so I deleted it. Now, however, I have 3GB less disk space than I did before the conversion. It's not the first time that I've noticed this, and I'm beginning to run fairly low on spare disk space, while not actually doing much that I would expect to take up that much.

Does Quicktime have a cache or something that I'm missing? Obviously I've removed the unwanted converted file from my MBP, but something is still taking up that space and I can't figure out what it is.

Thanks in advance,

Adam

 

Anyone? Help would be much appreciated.

 

Yes, the file is deleted and the trash emptied. Some of my disk space has slowly started to reappear (I had about 21GB, then 17GB when I converted the file. After deleting the file I had 18GB, now it's crept up to 20GB, with only a small amount of that being due to removing other files). It seems quite erratic.