If you need a free way to encode and convert your videos then Avidemux is a simple but effective application.
Avidemux is a free video editor designed for simple cutting, filtering and encoding. Its very flexible, supporting AVI, DVD compatible MPEG files, MP4 and ASF files using a variety of codecs. This means there is no messing around converting it to DV format before you can edit it in a third party editing application. Tasks can be automated using projects, job queues and powerful scripting capabilities.
Avidemux is completely open source and works across platforms, so it's ideal for those that are working on both Macs and PCs. However, the look and feel of Avidemux could do with some work. It looks like some kind of Windows 95 throwback app but don't judge the book by its cover. Avidemux is very powerful and although it's not particularly intuitive at first, with trial and error you can quickly learn the editing basics.
Note that although it claims to handle MPEG clips I was confronted with an 'H.264' error which meant it has to operate in 'Safe' mode and led to the loss of several frames.
It's far from perfect, but Avidemux is a handy tool for anyone that wants to perform basic editing for free and doesn't want to have to convert to another format first.
Download Avidemux 2.6.3 in Softonic