How to Convert an AVI to MP4 Using iMovieby Nicole Vulcan
Using the Quicktime conversion options provided in iMovie, it's quite simple to import a movie in one format and then convert it to another format, including turning an .avi file to a .mp4 -- also called a MPEG-4 video file. Even if you don't have any experience working with the video editing program, you should be able to accomplish this task with little hassle. Depending on the length of your video, the longest part of the process will likely be waiting for the file to save as a Quicktime file.
Open iMovie and start a new project by clicking "File" and "New Project." When prompted, give the project a name and direct it to save in the folder of your choosing. Your video will now appear in the Preview pane of iMovie.
Click on the video you just imported and drag it down to the Timeline. If you want to make any edits to the video such as adding transitions, music or other effects, use the Effects tabs under the Video Player to add them to the Timeline now.
Click "Share" from the top menu of iMovie, then click "Export using Quicktime." A popup menu will appear; click "Export," then choose "Movie to MPEG-4." Give the file a name in the "Save As" window, making sure to leave the .mp4 extension on the end of the file name. Choose the folder you would like your video saved to, and then click "Save."
Exit iMovie and open the folder where you saved your new .mp4, to ensure the file is there and saved in the proper format.