I want to know if there are any video clips which help with showing how to transfer a MP4 clip and changing pitch of voices of person being interviewed. Operating system Windows 8.1
Welcome to the Magix Sound Forge users community @gail-b.
Sound Forge AS (Audio Studio) includes the "élastique Pro" time stretch and pitch shift plug-in. I am not aware of any specific Magix tutorials on pitch shift.. Search. You can download the SF AS-15 trial version and try it out. Otherwise it is relatively simple and straight forward. btw, to work with AVC /AAC <.mp4) files in Sound Forge, you need to have the QuickTime codec installed (if you do not have it already).
Not sure what you mean by "automatically". SF can process all, or any part of the file you select with pitch shift.
If you do not want to re-encode the picture (inherent quality loss), 'save as' the pitch shifted audio as an MP4/AAC 'audio only' file and 'mux' in the processed audio, which leaves the picture data untouched. I usually use MeGUI for muxing-in processed audio to an MP4 (AVC) video file. 'AvidMux' and 'MP4 Box' are other muxing utilities.