The basic idea behind iMovie, which is built into all Macs running 10.4+, is that the user records their own sound and movies by using a microphone or video camera hooked up to the computer through USB, Firewire, or otherwise. Then they import these clips in the respective applications (iMovie for movie clips and GarageBand for music clips), edit them together with transitions and effects applied to each clip, add titles and/or narration where desired, export the finished product as QuickTime files on their hard drive or burn it directly on a CD or DVD, and then upload it to a file-sharing website for their friends and family to enjoy.
Please note that this is a simplified version of the process without all of the details included. Also note that The GarageBand icon will be used as a reference icon throughout this article.
iMovie or GarageBand
In order to use iMovie or GarageBand, one must have an iPod (any generation) or an iPhone running iOS 3+. This grants them access to iMovie for iPhone and GarageBand for iOS, both of which are native applications on said devices. Although they can be purchased from iTunes as stand-alone applications, they are free if you have either device mentioned above. Another feature available on any Mac running 10.4+ or PC running Windows 7+, the iLife suite of applications (iPhoto, iMovie and GarageBand), can be used as a free alternative to these applications.
The first step would be to run either iMovie or GarageBand on their respective devices. Once they have started up successfully, users must go into the app’s preferences and change some settings:
Source: https://www.garagebandforwindows.info/blog/garageband-online/
Video Camera
For both apps it is necessary to set the “Video Camera” option as “On.” This setting allows you to start importing video footage from your device’s camera/video camera so it may be imported into the program for editing. If this option is not turned on, no videos will appear under ‘Media Browser’ in order for them to be recollected and edited.
Media Browser
Under the “Media Browser” tab, users will have to change the “Designated File Type:” option to “Movie.” This will allow for their videos to be visible in their ‘Media Browser’ section. Without changing this setting, no file types other than ringtones will appear.
Recording Pause
To record the video footage properly, it is necessary for users of either app to select the recording pause option (under the “Input Source” sub-menu). Selecting this option allows GarageBand and iMovie to import pauses within recordings made by an application such as Skype or FaceTime. When recordings are paused, timecode is saved rather than video; editing that information into a project may be easily achieved using these timecodes.
Recording Frame Rate
Both GarageBand and iMovie users will notice that when they begin to record, the frame rate of their video is considerably slowed down when compared to the frame rate when not recording. This is due to the fact that in order for both programs to recognize pauses in a recording, it becomes necessary for them to ‘prepare’ recordings with this slowed-down frame rate. Otherwise, importing files into either application would be near impossible without encountering excessive audio/video sync issues during playback or editing processes.